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Glucometabolic state in Chinese patients undergoing elective coronary angiography
diabetes research and clinical practice 91 (2011) 300–306
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Diabetes Research and Clinical Practice jou rna l hom ep ag e: w ww.e lse v ier .com/ loca te /d iab res
Glucometabolic state in Chinese patients undergoing elective coronary angiography Zhu-Zhi Wen a,1, Dong-mei Jin b,1, Ya-mei Zhang c, Jing-Feng Wang a, Deng-Feng Geng a,* a
Department of Cardiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China Department of Rehabilitation Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China c Department of Cardiology, Zhejiang Xiaoshan Hospital, No. 728, Yucai North Road, Xiaoshan District, Hangzhou 311202, China b
article info
abstract
Article history:
Aim: The aim of this study is to characterize the glucometabolic state of patients undergoing
Received 18 August 2010
elective coronary angiography (CA) in a subpopulation in China.
Received in revised form
Methods and results: This study recruited 896 patients undergoing elective CA for the
4 November 2010
evaluation of suspected coronary artery disease (CAD). Oral glucose tolerance tests (OGTTs)
Accepted 18 November 2010
performed in patients without previously known diabetes revealed that 173 (19.2%) had
Published on line 6 January 2011
newly diagnosed diabetes and 281 (31.5%) had impaired glucose regulation. The prevalence of abnormal glucose metabolism (AGM) was significant difference among three groups of CA
Keywords:
diagnosis, including normal coronary, nonsignificant stenosis and CAD. Overall, the pro-
Coronary angiography
portion of patients with type 2 diabetes increased from 22.0% at baseline to 41.2% post-OGTT
Coronary artery disease
analysis. In total, 270 (59.5%) patients with AGM would have remained undetected if OGTTs
Diabetes mellitus
had not been performed. Patients with CAD, hypertension, dyslipidemia, obesity and high C-
Abnormal glucose metabolism
reactive protein levels were at high risk of AGM.
Oral glucose tolerance test
Conclusions: AGM is common and underestimated by FPG testing alone in patients undergoing elective CA. OGTTs should be routinely performed to assess the glucometabolic state of patients undergoing elective CA, especially in patients with high risks of AGM. Detecting the state of AGM in CA individuals may provide strategies to reduce the progression of AGM and associated complications. # 2010 Elsevier Ireland Ltd. All rights reserved.
1.
Introduction
Cardiovascular disease (CVD) is the major cause of morbidity and mortality for individuals with diabetes and the largest contributor to the direct and indirect costs of diabetes mellitus (DM) [1–3]. Researches revealed that not only previously known DM (pre-DM) but also newly diagnosed DM (newDM) or impaired glucose regulation (IGR), including impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), are risk factors for cardiovascular events and strongly associated
with poor prognosis of CVD [1,4–7]. Results from above studies indicated that individuals with any category of abnormal glucose metabolism (AGM) have an increased risk of cardiovascular events and mortality, implying that hyperglycaemia is a continuous risk factor for CVD. Unfortunately, because of the ageing population and an increasing prevalence of overweight and sedentary lifestyles, AGM has been increasing at a rapid speed all over the world. Data from International Diabetes Foundation [8] showed that the number of diabetic patients in the age group 20–79, is expected to increase to some
* Corresponding author at: Department of Cardiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 West Yanjiang Road, Guangzhou 510120, China. Tel.: +86 20 81332361; fax: +86 20 81332361. E-mail addresses: [email protected], [email protected] (D.-F. Geng). 1 These authors contributed equally to this work. 0168-8227/$ – see front matter # 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.diabres.2010.11.027
diabetes research and clinical practice 91 (2011) 300–306
439 million by 2030, and the number of IGT in the some population will increase from 344 million in 2010 to 472 million by 2030. Patients undergoing elective CA may be at high risk of CVD events, for a vast majority of them may suffer from heart diseases, especially suffer from CAD. Both Euro Heart Survey and China Heart Survey demonstrated that AGM was common in CAD [9,10]. Several studies even revealed that AGM was prevalent in CA patients [4,11–15], and associated with more multi-vessel and diffuse coronary artery stenosis documented by CA [4,12–14,16–18]. But little evidence has been given to indicate the glucometabolic state of elective CA patients without previously angiographic history or myocardial infarction in China. The main objectives of this study were to assess the prevalence of AGM in adult patients undergoing elective CA a Chinese sub-population and to provide further evidence to implement screening and therapies directed to reduce the incidence and associated complications of DM in elective CA patients.
2.
Materials and methods
2.1.
Study population and data collection
We consecutively enrolled 912 Chinese patients at Department of Cardiology of Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University between July 2008 and May 2010. All patients admitted to hospital cardiovascular wards were to undergo their first elective CA routinely to evaluate suspected CAD. Individuals were assessed, investigated and treated according to the usual institutional practice. Patients with type 1 DM and previous CA history, with acute or old myocardial infarction diagnosed by CA or not were excluded from the study. Meanwhile, those with congestive heart failure, severe hepatic dysfunction and renal insufficiency, current infectious disease and corticosteroid therapy, which might impact the glucose level, were also excluded from the study. Data collection included demographic data, medical history, treatment and diagnosis for CAD and glucometabolic abnormalities. Body measurements, lipid levels, creatinine levels, Creactive protein levels and smoking status were also recorded. The study complies with the Declaration of Helsinki. The study protocol was approved by the Ethics Committee of Sun Yat-sen Memorial Hospital of Sun Yat-sen University. All participants were given informed consent to undergo CA and informed consent to take oral glucose tolerance tests (OGTTs) and allowed their medical records to be studied by anonymous means.
2.2.
Measurement of glucometabolic state
Individuals who had a history of DM and/or already been treated with oral hypoglycemic drugs or insulin were defined as previously known DM (pre-DM). All patients without preDM, oral administration of 82.5 g glucose monohydrate (equivalent to 75 g glucose anhydrate) in 250–300 ml water was performed on the morning after the admission. For those who had a potential infectious disease or other diseased states
301
that might influence blood glucose levels, the OGTT was performed or retaken when patients were in steady state before discharge. Venous plasma glucose concentrations were measured according to hospital routines. Classification of glucometabolic state was based on 0 min and 2 h values in the OGTT, and the diagnostic history of DM according to the World Health Organization criterion in 1998 and American Diabetes Association criterion in 2007: normal glucose tolerance (NGT) was defined as a fasting plasma glucose concentration < 5.6 mmol/L and a 2-h plasma glucose concentration < 7.8 mmol/L; impaired fasting glucose (IFG) was defined as fasting plasma glucose between 5.6 mmol/L and 6.9 mmol/L, and a 2-h plasma glucose concentration < 7.8 mmmol/L; impaired glucose tolerance (IGT) was defined as a 2-h plasma glucose concentration between 7.8 mmol/L and 11.0 mmol/L, and a fasting glucose concentration < 7.0 mmol/ L; DM was defined as a fasting plasma glucose concentration 7.0 mmol/L and/or a 2-h glucose concentration 11.1 mmmol/L, or current anti-diabetes therapy. In the study, impaired glucose regulation (IGR) refers to the two prediabetic conditions, IFG and IGT, and AGM refers to DM and IGR. Patients diagnosed as DM were further divided into newly diagnosed DM (new-DM) and previously known DM (pre-DM).
2.3. Coronary angiography and evaluation criteria for coronary artery stenosis Selective CA was performed with Judkins technique in all patients. Coronary angiograms were evaluated by two experienced interventional cardiologists, who were unclear of the patients’ glucometabolic status. According to the angiographic results, the patients were divided into three groups: patients who did not have any visible stenosis in any major vessel along with their important branches were divided into the normal coronary group; those who had at least one visible stenosis in any major vessel, but the largest stenosis less than 50%, were divided into the nonsignificant stenosis group; patients who had at least one stenosis 50% in the any major vessel were divided into CAD group. Coronary artery stenosis with lumen narrowing 50% was considered significant. According to the number of significant stenotic vessels, CAD patients were further classified as 1-vessel, 2vessel, and 3-vessel group.
2.4. Diagnosis of hypertension, dyslipidemia and other factors Hypertension was defined as systolic blood pressure 140 mmHg and/or diastolic blood pressure 90 mmHg on at least 2 different occasions, or by a previous diagnosis of hypertension with current antihypertensive medication use according to the criterion of the Chinese Hypertension League. Dyslipidemia was defined by the Chinese Cholesterol Education Program and the Chinese Guideline of Prevention and Treatment of Dyslipidemia in adults as follows: total cholesterol (TC) 5.18 mmol/L (200 mg/dL); high-density lipoprotein cholesterol (HDL-C) < 1.04 mmol/L (40 mg/dL); low-density lipoprotein cholesterol (LDL-C) 3.37 mmol/L (140 mg/dL); triglycerides (TG) 1.70 mmol/L (150 mg/dL); or undergoing current lipidlowering treatment. The high ratio of apoB/apoA1 (the ratio of
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plasma apolipoprotein B levels to apolipoprotein A1 levels) was defined >0.9 in men and >0.8 in women. Smoking status was divided into never smoking, former smoking and current smoking. Body mass index (BMI) was calculated as the body weight (kg) divided by the square of the height (m2). Obesity was defined as a BMI > 28.0 kg/m2. High creatinine was defined by serum creatinine concentration > 133 mmol/L (1.5 mg/dL). High high-sensitivity C-reactive protein (hs-CRP) was defined by the serum hs-CRP concentration > 3 mg/L.
2.5.
Statistical analysis
Continuous variables were presented as median (lower, upper quartiles), and were compared by the Kruskal–Wallis test and Mann–Whitney U test. Categorical variables were presented as number and proportion (n, %), differences in study variables were tested for statistical significance with thex2 test. A twotailed P-value < 0.05 was considered significant, and an adjusted P value was used in subgroups for comparison. All statistical analyses were performed with the software package SPSS 16.0 for Windows.
3.
Result
3.1. Demographic and clinical characteristics in patients undergoing CA The study recruited 912 patients undergoing elective CA at entry. A group of 16 patients were excluded owing to incomplete study data. Analysis was carried out for 896 patients, of whom 486 (54.2%) had CAD, 146 (16.3%) had nonsignificant stenosis and 264 (29.5%) had normal coronary arteries. Overall, 54.0% of the patients enrolled were male and significant high in CAD patients (Table 1.). The average age was
62 years and CAD patients’ average age was older than other two groups of patients (P < 0.001). Total prevalence of hypertension and percentage of smoking in CAD patients were significant higher than that in patients with normal coronary arteries and patients with nonsignificant stenosis. There were significant differences among three groups of patients in average levels of body mass index, OGTT 2-h plasma glucose and fasting plasma glucose (all P < 0.05). CAD patients had significant higher average levels in triglyceride, high-sensitivity C-reactive protein, serum creatinine, and uric acid, and a significant lower average level in HDL cholesterol (all P < 0.05), while no differences were found among three groups in average total cholesterol and LDL-cholesterol values.
3.2.
Glucometabolic state
In the study population, 197 (22.0%) patients with previously known DM did not undergo an OGTT. All patients with previously diagnosed DM were receiving antidiabetic therapy. The median (lower–upper quartile) FPG level in this patient group was 6.6 mmol/L (5.6–7.8 mmol/L). OGTTs were performed to the remaining 699 participants to assess their glucometabolic state (OGTT cohort). On the basis of 0 min and/ or 2 h values of OGTT, a further 173 (19.2%) patients in the OGTT cohort were newly diagnosed type 2 diabetes. The overall proportion of patients diagnosed with diabetes therefore increased from 22.0% (n = 197) at baseline to 41.2% (n = 370) following the OGTT analysis. IGR was detected in 281 (31.5%) patients, including 2.8% IFG patients and 28.7% IGT patients. Overall, there was a significant difference in glucometabolic classification (NGT, IFG, IGT, new-DM, preDM) among the three groups of angiography diagnosis (P < 0.001), and differences were also found between subgroups of the three groups of angiography diagnosis (Fig. 1.). In the OGTT cohort, the prevalence of AGM was significantly different among the groups of angiography diagnosis by
Table 1 – Clinical characteristics of the study population with different angiographic profiles. Group Number (n) Male (%) Age (year) BMI (kg/m2) Hypertension (%) Smoking current/former/never (n) Triglyceride (mmol/L) Total cholesterol (mmol/L) HDL cholesterol (mmol/L) LDL cholesterol (mmol/L) Apolipoprotein A1 (g/L) Apolipoprotein B (g/L) High-sensitivity C-reactive protein (mg/L) Creatinine (mmol/L) Uric acid (U/L) Fasting plasma glucose (mmol/L) OGTT 2-h plasma glucose (mmol/L)c
Normal coronary
Nonsignificant stenosis
CAD
264 47.3 57 (50,63) 23.7 (21.4,26.1) 50.4 59/18/187 1.47 (1.08,2.06) 5.00 (4.14,5.60) 1.22 (1.03,1.45) 3.08 (2.39,3.61) 1.13 (1.00,1.28) 0.80 (0.65,0.93) 1.60 (0.80,3.78) 96 (86,107) 348 (290,409) 5.0 (4.6,5.7) 7.6 (6.4,10.0)
146 45.2 60 (55,69)a 24.2 (23.0,26.9) 61.0 22/11/113 1.62 (1.13,2.48) 4.87 (4.17,5.68) 1.16 (0.99,1.40) 3.00 (2.45,3.53) 1.12 (0.97,1.24) 0.78 (0.67,0.96) 1.99 (1.10,4.78) 94 (85,106) 374 (312,432) 5.2 (4.8,5.8) 8.5 (6.5,10.2)
486 60.3a,b 64 (57,72)a,b 23.8 (22.1,26.0) 70.2a 152/38/296b 1.74 (1.24,2.45)a 4.92 (4.20,5.72) 1.12 (0.94,1.34)a 3.05 (2.36,3.63) 1.11 (0.98,1.24) 0.82 (0.68,0.98) 2.46 (1.17,6.59)a 100 (89,116)a,b 372 (308,442)a 5.3 (4.8,6.3)a 9.7 (7.1,11.6)a,b
Data are presented as median (lower, upper quartiles) or n (%). P value based on Kruskal–Wallis test or x2 test for trend. P < 0.0167 vs. normal. b P < 0.0167 vs. CAS. c Only for patients without diagnosed DM. a
P value <0.001 <0.001 0.048 <0.001 0.001 0.001 0.938 <0.001 0.841 0.217 0.076 <0.001 <0.001 0.002 0.003 <0.001
diabetes research and clinical practice 91 (2011) 300–306
[()TD$FIG]
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Fig. 1 – Prevalence of AGM in elective coronary angiography patients. There are significant differences of overall compared among groups (P < 0.001) and subgroups.
OGTT analysis, but this difference disappeared among them when solely based on OGTT 0 min values. The glucometabolic state of the OGTT cohort diagnosed using both 0 min and 2 h plasma glucose values was compared with that diagnosed using only the 0 min value. The proportion of patients with AGM was substantially higher in the analysis that included both plasma glucose values (Fig. 2). Without the post-challenge data provided by the OGTTs, 270 (59.5%) patients with AGM would remain undiagnosed in time, of which 137 (79.2%) are new-DM patients and 133 (47.3%) are isolated IGT patients. For CAD patients, there was no significant difference in glucometabolic state (NGT, IGR, new-DM) among patients with 1-vessel, 2-vessel and 3-vessel stenosis (x2 = 3.754, P = 0.440) in the OGTT cohort. Overall, no significant difference in glucometabolic state (NGT, IGR, new-DM, pre-DM) was found among patients with 1-vessel, 2-vessel and 3-vessel stenosis (x2 = 12.420, P = 0.053).
3.3.
Other predictors for abnormal glucose metabolism
Patients with previously known diabetes in the study were receiving antidiabetic therapy. Herein, other factors were analyzed to help screen high risk patients with AGM in the
[()TD$FIG]
Fig. 2 – Comparison of glucometabolic state determined by OGTT (OGTT 0 min and 2 h values) and FPG test (OGTT 0 min values only) in patients without previously diagnosed DM.
OGTT cohort. Patients with components of metabolic syndrome (hypertension, obesity, high triglyceride, low HDL cholesterol) were at high risk of AGM, even after adjustment for age and sex. In additional, high hs-CRP and high ratio of apoB/apoA1 were at high risk for AGM, whereas high creatinine was not after adjustment for sex and age (Table 2.).
4.
Discussion
A high prevalence of AGM is obtained from our 896 elective CA patients who without previous CA history or myocardial infarction determined by CA or not. CA patients documented with CAD are at high risk of AGM, even after adjustment for age and sex. The prevalence of AGM in CAD patients is similar to that of the study [11], and may be higher than that in other studies [14,19–21]. Patients with CAD documented by CA have the prevalences of AGM, type 2 diabetes and IGR were 81.5%, 50.8% and 30.7%, respectively. In contrast, the prevalences of AGM, type 2 diabetes and IGR in the China Heart Survey were 76.9%, 52.9% and 24.0%, respectively [10]. Different subjects recruited and study designed may explain this slight difference. The study population without previously diagnosed DM, if attention was only paid to the fasting plasma glucose, 270 (59.5%) patients with AGM would not be diagnosed in time, of which 137 (79.2%) are new-DM patients and 133 (47.3%) are isolated IGT patients. Our patients mainly manifested postprandial hyperglycemia accompanied by normal fasting glucose concentrations is a key feature of glucose abnormalities in the study, which agrees with that of the China Heart Survey [10] and other studies [9,14]. Our study and others [9,10,14] show that the prevalence of isolated IFG is the lowest among classifications of glucometabolic state in patients with CAD, and most patients with IFG diagnosed by FPG may coexist IGT or turn into DM post-OGTT analysis. These studies also show that the prevalence of isolated IFG in Asian populations is lower than that in Caucasian populations, which may partly result from the difference of the degree of insulin resistance and impaired insulin secretion between ethnic groups [22,23]. Therefore an OGTT is suggested by these
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Table 2 – Risk factors of AGM for elective CA patients without diagnosed diabetes mellitus (n = 699). NGT n = 245 Coronary artery disease (n, %) Hypertension (n, %) Current smoking (n, %) Obesity (n, %) High total cholesterol (n, %) High triglyceride (n, %) Low HDL cholesterol (n, %) High LDL cholesterol (n, %) High ratio of apoB/apoA1 High hs-CRP (n, %) High creatinine (n, %)
89 120 54 24 96 84 57 81 51 57 9
(36.3) (49.0) (22.0) (9.8) (39.2) (34.3) (23.3) (30.1) (20.1) (23.3) (3.7)
AGM n = 454 251 285 128 67 191 228 156 164 154 199 26
(55.3) (62.8) (28.2) (14.8) (42.1) (50.2) (34.4) (36.1) (31.9) (43.8) (5.7)
P values
Odds ratios
<0.001 0.001 0.460 0.035 0.267 <0.001 0.009 0.300 <0.001 <0.001 0.378
2.031 1.774 1.173 1.721 1.200 2.005 1.620 1.192 2.090 2.609 0.703
95% confidence intervals 1.456–2.833 1.276–2.467 0.769–1.788 1.039–2.849 0.870–1.656 1.118–2.777 1.128–2.327 0.855–1.660 1.443–3.027 1.834–3.712 0.321–1.539
Data are presented as n (%). P-values are for glucometabolic trend and are from age- and sex-adjusted analyses.
studies as a routine examination in all patients with diagnostic or suspected CAD. Previous studies revealed that IFG was associated with coronary lesions, and oral glucose challenge was not superior to fasting glucose in predicting this increased cardiovascular risk [12,17]. Horimoto et al. demonstrated no association between IGT and coronary atherosclerosis in their study [24]. However, more studies proved that OGTT 2-h plasma glucose rather than fasting hyperglycaemia, had a strong and significant association with coronary atherosclerosis and coronary stenosis, and might be a better predictor for the severity of coronary atherosclerosis and cardiovascular events, even after adjustment for other well-established risk factors [14,20,25,26]. The present study shows that incidence of AGM is found significantly different only after postchallenge data provided by the OGTTs in the OGTT cohort, implying that OGTT 2-h plasma glucose rather than fasting hyperglycaemia may be related with the presence of coronary artery disease and severity of coronary atherosclerosis. Though no difference was found in glucometabolic state in CAD patients with different number of stenosic vessels, the prevalence of AGM worsened from patients with normal coronary arteries to patients with nonsignificant stenosis, then to patients with CAD both in total and in the OGTT cohort. Previous researches demonstrated that the progressing deterioration of AGM state was strongly associated with the presence and severity of coronary atherosclerosis [12,20] and might also be associated with disturbed coronary microcirculation [27]. In order to reduce cardiovascular events and damage to target organs, attention should be paid not only to diagnostic DM patients, but also on large number of IGR patients and occult DM patients [28]. However, a vast majority of patients with AGM have not been diagnosed, because most of them have normal fasting plasma glucose (FPG) or are in the long asymptomatic preclinical phase, and sometimes attention is paid only to their FPG levels and an OGTT is not performed for them [8,29,30]. Taubert et al. [12] reported that half of the DM patients scheduled for coronary angiography were previously unrecognized and half of the newly diagnosed DM patients were detectable only by use of glucose challenge. High blood pressure, obesity, high triglyceride, and low HDL cholesterol are well-established risk factors of CVD. The present study prove that patients with hypertension, obesity, high triglyceride, or low HDL cholesterol at baseline are
associated with an increased risk of AGM, even after adjustment for age and sex, which has been powered by sufficient evidences [10,31–33]. In individuals with metabolic syndrome (MS), generally defined as a cluster of risk factors, including hyperglycaemia, obesity, high blood pressure, and unhealthy cholesterol levels, even without diabetes, risks of CAD and CVD mortality remained elevated [34]. MS itself is a more strongly predictor for CAD, CVD, and total mortality than its individual components [34]. Therefore, DM or IGR coexists with MS or its individual components except high blood sugar, may contribute to a substantially elevated risk of CAD and CVD. In additional, the present study reveals the high prevalence of AGM is associated with the ratio of apoB/apoA1 which rather than LDL cholesterol may be a superior risk marker for cardiovascular disease [35]. The baseline plasma concentration of C-reactive protein which is a well-established risk of CAD and CVD [36], may be significantly higher in patients with AGM than that in patients with NGT, even after adjustment for age, sex, and BMI [37,38]. Likewise, compared with its counterpart, CA patients with high plasma levels of hs-CRP at baseline have a higher risk of AGM in the present study. There is insufficient evidence to determine the benefit of screening for diabetes in general populations, but screening for diabetes in adults with other risk factors of CVD is recommended and do benefit from the screening [2,31]. Detecting and early treating the large number of IGR patients and occult DM patients by lifestyle changes or diet modifications or medications, can halt them progress into overt DM patients, protect target organs damages, reduce cardiovascular events, and obtain a better prognosis [28,32,39,40], but whether treatment for prediabetes alters final health outcomes is still devoid of sufficient evidence to power for those outcomes. The outcome of an OGTT is indeed a reliable measure of the glucometabolic state, even for patients with acute myocardial infarction before hospital discharge [41]. CA patients who have CAD, essential hypertension or problems with lipid levels should ask their doctors to test them for AGM by OGTTs.
5.
Study limitations
Although our study includes a relatively larger sample, it is inevitable to have some limitations. First, the present study
diabetes research and clinical practice 91 (2011) 300–306
excluded patients with a previous CA history, with new or old myocardial infarction, or with a history of PCI or CABG, so its findings may not apply to these excluded subjects representing more severe cases. Results of our CAD patients may be not suitable for patients with non-CA diagnosed CAD. Second, most of the patients come from Guangzhou and its neighboring areas, so their glucose metabolic state may not completely be in coincidence with population of other places. Finally, bias of the prevalence of AGM may exist, owing to some excluded CA patients’ refusal to taking an OGTTs during study period and different uses of antihypertensive drugs in included population which may impact the level of plasma glucose.
6.
Conclusion
The present study reveals a high prevalence of abnormal glucometabolism in elective CA patients without a previous CA history or myocardial infarction. AGM is significantly associated with the presence of coronary stenosis documented by CA. Most AGM patients would remain undetected if attention is only paid to the fasting plasma glucose. Patients with CAD, hypertension, components of metabolic syndrome, high hs-CRP level and high ratio of apoB/apoA1 are at substantially elevated risk for AGM. The OGTT is a reliable tool to detect all categories of AGM and should be warranted as a routine method for elective CA patients in order to CVD prevention. Furthermore, some prospective researches with a larger population in multi-center are required to provide adequate evidence whether early AGM control as a result of screening provides an incremental benefit for CVD clinical outcomes compared with initiating treatment after clinical diagnosis.
Acknowledgements We appreciate our nurses for their help to us and all their dedicated assistance to patients. Also, we are grateful to our colleagues, in particular, Dr. Xin-mei Zhang for their help to collect study data. We also thank other colleagues in the Department of Cardiology for their support and help in the process of the study.
Conflict of interest There are no conflicts of interest.
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Contents lists available at ScienceDirect
Diabetes Research and Clinical Practice jou rna l hom ep ag e: w ww.e lse v ier .com/ loca te /d iab res
Glucometabolic state in Chinese patients undergoing elective coronary angiography Zhu-Zhi Wen a,1, Dong-mei Jin b,1, Ya-mei Zhang c, Jing-Feng Wang a, Deng-Feng Geng a,* a
Department of Cardiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China Department of Rehabilitation Medicine, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, China c Department of Cardiology, Zhejiang Xiaoshan Hospital, No. 728, Yucai North Road, Xiaoshan District, Hangzhou 311202, China b
article info
abstract
Article history:
Aim: The aim of this study is to characterize the glucometabolic state of patients undergoing
Received 18 August 2010
elective coronary angiography (CA) in a subpopulation in China.
Received in revised form
Methods and results: This study recruited 896 patients undergoing elective CA for the
4 November 2010
evaluation of suspected coronary artery disease (CAD). Oral glucose tolerance tests (OGTTs)
Accepted 18 November 2010
performed in patients without previously known diabetes revealed that 173 (19.2%) had
Published on line 6 January 2011
newly diagnosed diabetes and 281 (31.5%) had impaired glucose regulation. The prevalence of abnormal glucose metabolism (AGM) was significant difference among three groups of CA
Keywords:
diagnosis, including normal coronary, nonsignificant stenosis and CAD. Overall, the pro-
Coronary angiography
portion of patients with type 2 diabetes increased from 22.0% at baseline to 41.2% post-OGTT
Coronary artery disease
analysis. In total, 270 (59.5%) patients with AGM would have remained undetected if OGTTs
Diabetes mellitus
had not been performed. Patients with CAD, hypertension, dyslipidemia, obesity and high C-
Abnormal glucose metabolism
reactive protein levels were at high risk of AGM.
Oral glucose tolerance test
Conclusions: AGM is common and underestimated by FPG testing alone in patients undergoing elective CA. OGTTs should be routinely performed to assess the glucometabolic state of patients undergoing elective CA, especially in patients with high risks of AGM. Detecting the state of AGM in CA individuals may provide strategies to reduce the progression of AGM and associated complications. # 2010 Elsevier Ireland Ltd. All rights reserved.
1.
Introduction
Cardiovascular disease (CVD) is the major cause of morbidity and mortality for individuals with diabetes and the largest contributor to the direct and indirect costs of diabetes mellitus (DM) [1–3]. Researches revealed that not only previously known DM (pre-DM) but also newly diagnosed DM (newDM) or impaired glucose regulation (IGR), including impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), are risk factors for cardiovascular events and strongly associated
with poor prognosis of CVD [1,4–7]. Results from above studies indicated that individuals with any category of abnormal glucose metabolism (AGM) have an increased risk of cardiovascular events and mortality, implying that hyperglycaemia is a continuous risk factor for CVD. Unfortunately, because of the ageing population and an increasing prevalence of overweight and sedentary lifestyles, AGM has been increasing at a rapid speed all over the world. Data from International Diabetes Foundation [8] showed that the number of diabetic patients in the age group 20–79, is expected to increase to some
* Corresponding author at: Department of Cardiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 West Yanjiang Road, Guangzhou 510120, China. Tel.: +86 20 81332361; fax: +86 20 81332361. E-mail addresses: [email protected], [email protected] (D.-F. Geng). 1 These authors contributed equally to this work. 0168-8227/$ – see front matter # 2010 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.diabres.2010.11.027
diabetes research and clinical practice 91 (2011) 300–306
439 million by 2030, and the number of IGT in the some population will increase from 344 million in 2010 to 472 million by 2030. Patients undergoing elective CA may be at high risk of CVD events, for a vast majority of them may suffer from heart diseases, especially suffer from CAD. Both Euro Heart Survey and China Heart Survey demonstrated that AGM was common in CAD [9,10]. Several studies even revealed that AGM was prevalent in CA patients [4,11–15], and associated with more multi-vessel and diffuse coronary artery stenosis documented by CA [4,12–14,16–18]. But little evidence has been given to indicate the glucometabolic state of elective CA patients without previously angiographic history or myocardial infarction in China. The main objectives of this study were to assess the prevalence of AGM in adult patients undergoing elective CA a Chinese sub-population and to provide further evidence to implement screening and therapies directed to reduce the incidence and associated complications of DM in elective CA patients.
2.
Materials and methods
2.1.
Study population and data collection
We consecutively enrolled 912 Chinese patients at Department of Cardiology of Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University between July 2008 and May 2010. All patients admitted to hospital cardiovascular wards were to undergo their first elective CA routinely to evaluate suspected CAD. Individuals were assessed, investigated and treated according to the usual institutional practice. Patients with type 1 DM and previous CA history, with acute or old myocardial infarction diagnosed by CA or not were excluded from the study. Meanwhile, those with congestive heart failure, severe hepatic dysfunction and renal insufficiency, current infectious disease and corticosteroid therapy, which might impact the glucose level, were also excluded from the study. Data collection included demographic data, medical history, treatment and diagnosis for CAD and glucometabolic abnormalities. Body measurements, lipid levels, creatinine levels, Creactive protein levels and smoking status were also recorded. The study complies with the Declaration of Helsinki. The study protocol was approved by the Ethics Committee of Sun Yat-sen Memorial Hospital of Sun Yat-sen University. All participants were given informed consent to undergo CA and informed consent to take oral glucose tolerance tests (OGTTs) and allowed their medical records to be studied by anonymous means.
2.2.
Measurement of glucometabolic state
Individuals who had a history of DM and/or already been treated with oral hypoglycemic drugs or insulin were defined as previously known DM (pre-DM). All patients without preDM, oral administration of 82.5 g glucose monohydrate (equivalent to 75 g glucose anhydrate) in 250–300 ml water was performed on the morning after the admission. For those who had a potential infectious disease or other diseased states
301
that might influence blood glucose levels, the OGTT was performed or retaken when patients were in steady state before discharge. Venous plasma glucose concentrations were measured according to hospital routines. Classification of glucometabolic state was based on 0 min and 2 h values in the OGTT, and the diagnostic history of DM according to the World Health Organization criterion in 1998 and American Diabetes Association criterion in 2007: normal glucose tolerance (NGT) was defined as a fasting plasma glucose concentration < 5.6 mmol/L and a 2-h plasma glucose concentration < 7.8 mmol/L; impaired fasting glucose (IFG) was defined as fasting plasma glucose between 5.6 mmol/L and 6.9 mmol/L, and a 2-h plasma glucose concentration < 7.8 mmmol/L; impaired glucose tolerance (IGT) was defined as a 2-h plasma glucose concentration between 7.8 mmol/L and 11.0 mmol/L, and a fasting glucose concentration < 7.0 mmol/ L; DM was defined as a fasting plasma glucose concentration 7.0 mmol/L and/or a 2-h glucose concentration 11.1 mmmol/L, or current anti-diabetes therapy. In the study, impaired glucose regulation (IGR) refers to the two prediabetic conditions, IFG and IGT, and AGM refers to DM and IGR. Patients diagnosed as DM were further divided into newly diagnosed DM (new-DM) and previously known DM (pre-DM).
2.3. Coronary angiography and evaluation criteria for coronary artery stenosis Selective CA was performed with Judkins technique in all patients. Coronary angiograms were evaluated by two experienced interventional cardiologists, who were unclear of the patients’ glucometabolic status. According to the angiographic results, the patients were divided into three groups: patients who did not have any visible stenosis in any major vessel along with their important branches were divided into the normal coronary group; those who had at least one visible stenosis in any major vessel, but the largest stenosis less than 50%, were divided into the nonsignificant stenosis group; patients who had at least one stenosis 50% in the any major vessel were divided into CAD group. Coronary artery stenosis with lumen narrowing 50% was considered significant. According to the number of significant stenotic vessels, CAD patients were further classified as 1-vessel, 2vessel, and 3-vessel group.
2.4. Diagnosis of hypertension, dyslipidemia and other factors Hypertension was defined as systolic blood pressure 140 mmHg and/or diastolic blood pressure 90 mmHg on at least 2 different occasions, or by a previous diagnosis of hypertension with current antihypertensive medication use according to the criterion of the Chinese Hypertension League. Dyslipidemia was defined by the Chinese Cholesterol Education Program and the Chinese Guideline of Prevention and Treatment of Dyslipidemia in adults as follows: total cholesterol (TC) 5.18 mmol/L (200 mg/dL); high-density lipoprotein cholesterol (HDL-C) < 1.04 mmol/L (40 mg/dL); low-density lipoprotein cholesterol (LDL-C) 3.37 mmol/L (140 mg/dL); triglycerides (TG) 1.70 mmol/L (150 mg/dL); or undergoing current lipidlowering treatment. The high ratio of apoB/apoA1 (the ratio of
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plasma apolipoprotein B levels to apolipoprotein A1 levels) was defined >0.9 in men and >0.8 in women. Smoking status was divided into never smoking, former smoking and current smoking. Body mass index (BMI) was calculated as the body weight (kg) divided by the square of the height (m2). Obesity was defined as a BMI > 28.0 kg/m2. High creatinine was defined by serum creatinine concentration > 133 mmol/L (1.5 mg/dL). High high-sensitivity C-reactive protein (hs-CRP) was defined by the serum hs-CRP concentration > 3 mg/L.
2.5.
Statistical analysis
Continuous variables were presented as median (lower, upper quartiles), and were compared by the Kruskal–Wallis test and Mann–Whitney U test. Categorical variables were presented as number and proportion (n, %), differences in study variables were tested for statistical significance with thex2 test. A twotailed P-value < 0.05 was considered significant, and an adjusted P value was used in subgroups for comparison. All statistical analyses were performed with the software package SPSS 16.0 for Windows.
3.
Result
3.1. Demographic and clinical characteristics in patients undergoing CA The study recruited 912 patients undergoing elective CA at entry. A group of 16 patients were excluded owing to incomplete study data. Analysis was carried out for 896 patients, of whom 486 (54.2%) had CAD, 146 (16.3%) had nonsignificant stenosis and 264 (29.5%) had normal coronary arteries. Overall, 54.0% of the patients enrolled were male and significant high in CAD patients (Table 1.). The average age was
62 years and CAD patients’ average age was older than other two groups of patients (P < 0.001). Total prevalence of hypertension and percentage of smoking in CAD patients were significant higher than that in patients with normal coronary arteries and patients with nonsignificant stenosis. There were significant differences among three groups of patients in average levels of body mass index, OGTT 2-h plasma glucose and fasting plasma glucose (all P < 0.05). CAD patients had significant higher average levels in triglyceride, high-sensitivity C-reactive protein, serum creatinine, and uric acid, and a significant lower average level in HDL cholesterol (all P < 0.05), while no differences were found among three groups in average total cholesterol and LDL-cholesterol values.
3.2.
Glucometabolic state
In the study population, 197 (22.0%) patients with previously known DM did not undergo an OGTT. All patients with previously diagnosed DM were receiving antidiabetic therapy. The median (lower–upper quartile) FPG level in this patient group was 6.6 mmol/L (5.6–7.8 mmol/L). OGTTs were performed to the remaining 699 participants to assess their glucometabolic state (OGTT cohort). On the basis of 0 min and/ or 2 h values of OGTT, a further 173 (19.2%) patients in the OGTT cohort were newly diagnosed type 2 diabetes. The overall proportion of patients diagnosed with diabetes therefore increased from 22.0% (n = 197) at baseline to 41.2% (n = 370) following the OGTT analysis. IGR was detected in 281 (31.5%) patients, including 2.8% IFG patients and 28.7% IGT patients. Overall, there was a significant difference in glucometabolic classification (NGT, IFG, IGT, new-DM, preDM) among the three groups of angiography diagnosis (P < 0.001), and differences were also found between subgroups of the three groups of angiography diagnosis (Fig. 1.). In the OGTT cohort, the prevalence of AGM was significantly different among the groups of angiography diagnosis by
Table 1 – Clinical characteristics of the study population with different angiographic profiles. Group Number (n) Male (%) Age (year) BMI (kg/m2) Hypertension (%) Smoking current/former/never (n) Triglyceride (mmol/L) Total cholesterol (mmol/L) HDL cholesterol (mmol/L) LDL cholesterol (mmol/L) Apolipoprotein A1 (g/L) Apolipoprotein B (g/L) High-sensitivity C-reactive protein (mg/L) Creatinine (mmol/L) Uric acid (U/L) Fasting plasma glucose (mmol/L) OGTT 2-h plasma glucose (mmol/L)c
Normal coronary
Nonsignificant stenosis
CAD
264 47.3 57 (50,63) 23.7 (21.4,26.1) 50.4 59/18/187 1.47 (1.08,2.06) 5.00 (4.14,5.60) 1.22 (1.03,1.45) 3.08 (2.39,3.61) 1.13 (1.00,1.28) 0.80 (0.65,0.93) 1.60 (0.80,3.78) 96 (86,107) 348 (290,409) 5.0 (4.6,5.7) 7.6 (6.4,10.0)
146 45.2 60 (55,69)a 24.2 (23.0,26.9) 61.0 22/11/113 1.62 (1.13,2.48) 4.87 (4.17,5.68) 1.16 (0.99,1.40) 3.00 (2.45,3.53) 1.12 (0.97,1.24) 0.78 (0.67,0.96) 1.99 (1.10,4.78) 94 (85,106) 374 (312,432) 5.2 (4.8,5.8) 8.5 (6.5,10.2)
486 60.3a,b 64 (57,72)a,b 23.8 (22.1,26.0) 70.2a 152/38/296b 1.74 (1.24,2.45)a 4.92 (4.20,5.72) 1.12 (0.94,1.34)a 3.05 (2.36,3.63) 1.11 (0.98,1.24) 0.82 (0.68,0.98) 2.46 (1.17,6.59)a 100 (89,116)a,b 372 (308,442)a 5.3 (4.8,6.3)a 9.7 (7.1,11.6)a,b
Data are presented as median (lower, upper quartiles) or n (%). P value based on Kruskal–Wallis test or x2 test for trend. P < 0.0167 vs. normal. b P < 0.0167 vs. CAS. c Only for patients without diagnosed DM. a
P value <0.001 <0.001 0.048 <0.001 0.001 0.001 0.938 <0.001 0.841 0.217 0.076 <0.001 <0.001 0.002 0.003 <0.001
diabetes research and clinical practice 91 (2011) 300–306
[()TD$FIG]
303
Fig. 1 – Prevalence of AGM in elective coronary angiography patients. There are significant differences of overall compared among groups (P < 0.001) and subgroups.
OGTT analysis, but this difference disappeared among them when solely based on OGTT 0 min values. The glucometabolic state of the OGTT cohort diagnosed using both 0 min and 2 h plasma glucose values was compared with that diagnosed using only the 0 min value. The proportion of patients with AGM was substantially higher in the analysis that included both plasma glucose values (Fig. 2). Without the post-challenge data provided by the OGTTs, 270 (59.5%) patients with AGM would remain undiagnosed in time, of which 137 (79.2%) are new-DM patients and 133 (47.3%) are isolated IGT patients. For CAD patients, there was no significant difference in glucometabolic state (NGT, IGR, new-DM) among patients with 1-vessel, 2-vessel and 3-vessel stenosis (x2 = 3.754, P = 0.440) in the OGTT cohort. Overall, no significant difference in glucometabolic state (NGT, IGR, new-DM, pre-DM) was found among patients with 1-vessel, 2-vessel and 3-vessel stenosis (x2 = 12.420, P = 0.053).
3.3.
Other predictors for abnormal glucose metabolism
Patients with previously known diabetes in the study were receiving antidiabetic therapy. Herein, other factors were analyzed to help screen high risk patients with AGM in the
[()TD$FIG]
Fig. 2 – Comparison of glucometabolic state determined by OGTT (OGTT 0 min and 2 h values) and FPG test (OGTT 0 min values only) in patients without previously diagnosed DM.
OGTT cohort. Patients with components of metabolic syndrome (hypertension, obesity, high triglyceride, low HDL cholesterol) were at high risk of AGM, even after adjustment for age and sex. In additional, high hs-CRP and high ratio of apoB/apoA1 were at high risk for AGM, whereas high creatinine was not after adjustment for sex and age (Table 2.).
4.
Discussion
A high prevalence of AGM is obtained from our 896 elective CA patients who without previous CA history or myocardial infarction determined by CA or not. CA patients documented with CAD are at high risk of AGM, even after adjustment for age and sex. The prevalence of AGM in CAD patients is similar to that of the study [11], and may be higher than that in other studies [14,19–21]. Patients with CAD documented by CA have the prevalences of AGM, type 2 diabetes and IGR were 81.5%, 50.8% and 30.7%, respectively. In contrast, the prevalences of AGM, type 2 diabetes and IGR in the China Heart Survey were 76.9%, 52.9% and 24.0%, respectively [10]. Different subjects recruited and study designed may explain this slight difference. The study population without previously diagnosed DM, if attention was only paid to the fasting plasma glucose, 270 (59.5%) patients with AGM would not be diagnosed in time, of which 137 (79.2%) are new-DM patients and 133 (47.3%) are isolated IGT patients. Our patients mainly manifested postprandial hyperglycemia accompanied by normal fasting glucose concentrations is a key feature of glucose abnormalities in the study, which agrees with that of the China Heart Survey [10] and other studies [9,14]. Our study and others [9,10,14] show that the prevalence of isolated IFG is the lowest among classifications of glucometabolic state in patients with CAD, and most patients with IFG diagnosed by FPG may coexist IGT or turn into DM post-OGTT analysis. These studies also show that the prevalence of isolated IFG in Asian populations is lower than that in Caucasian populations, which may partly result from the difference of the degree of insulin resistance and impaired insulin secretion between ethnic groups [22,23]. Therefore an OGTT is suggested by these
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Table 2 – Risk factors of AGM for elective CA patients without diagnosed diabetes mellitus (n = 699). NGT n = 245 Coronary artery disease (n, %) Hypertension (n, %) Current smoking (n, %) Obesity (n, %) High total cholesterol (n, %) High triglyceride (n, %) Low HDL cholesterol (n, %) High LDL cholesterol (n, %) High ratio of apoB/apoA1 High hs-CRP (n, %) High creatinine (n, %)
89 120 54 24 96 84 57 81 51 57 9
(36.3) (49.0) (22.0) (9.8) (39.2) (34.3) (23.3) (30.1) (20.1) (23.3) (3.7)
AGM n = 454 251 285 128 67 191 228 156 164 154 199 26
(55.3) (62.8) (28.2) (14.8) (42.1) (50.2) (34.4) (36.1) (31.9) (43.8) (5.7)
P values
Odds ratios
<0.001 0.001 0.460 0.035 0.267 <0.001 0.009 0.300 <0.001 <0.001 0.378
2.031 1.774 1.173 1.721 1.200 2.005 1.620 1.192 2.090 2.609 0.703
95% confidence intervals 1.456–2.833 1.276–2.467 0.769–1.788 1.039–2.849 0.870–1.656 1.118–2.777 1.128–2.327 0.855–1.660 1.443–3.027 1.834–3.712 0.321–1.539
Data are presented as n (%). P-values are for glucometabolic trend and are from age- and sex-adjusted analyses.
studies as a routine examination in all patients with diagnostic or suspected CAD. Previous studies revealed that IFG was associated with coronary lesions, and oral glucose challenge was not superior to fasting glucose in predicting this increased cardiovascular risk [12,17]. Horimoto et al. demonstrated no association between IGT and coronary atherosclerosis in their study [24]. However, more studies proved that OGTT 2-h plasma glucose rather than fasting hyperglycaemia, had a strong and significant association with coronary atherosclerosis and coronary stenosis, and might be a better predictor for the severity of coronary atherosclerosis and cardiovascular events, even after adjustment for other well-established risk factors [14,20,25,26]. The present study shows that incidence of AGM is found significantly different only after postchallenge data provided by the OGTTs in the OGTT cohort, implying that OGTT 2-h plasma glucose rather than fasting hyperglycaemia may be related with the presence of coronary artery disease and severity of coronary atherosclerosis. Though no difference was found in glucometabolic state in CAD patients with different number of stenosic vessels, the prevalence of AGM worsened from patients with normal coronary arteries to patients with nonsignificant stenosis, then to patients with CAD both in total and in the OGTT cohort. Previous researches demonstrated that the progressing deterioration of AGM state was strongly associated with the presence and severity of coronary atherosclerosis [12,20] and might also be associated with disturbed coronary microcirculation [27]. In order to reduce cardiovascular events and damage to target organs, attention should be paid not only to diagnostic DM patients, but also on large number of IGR patients and occult DM patients [28]. However, a vast majority of patients with AGM have not been diagnosed, because most of them have normal fasting plasma glucose (FPG) or are in the long asymptomatic preclinical phase, and sometimes attention is paid only to their FPG levels and an OGTT is not performed for them [8,29,30]. Taubert et al. [12] reported that half of the DM patients scheduled for coronary angiography were previously unrecognized and half of the newly diagnosed DM patients were detectable only by use of glucose challenge. High blood pressure, obesity, high triglyceride, and low HDL cholesterol are well-established risk factors of CVD. The present study prove that patients with hypertension, obesity, high triglyceride, or low HDL cholesterol at baseline are
associated with an increased risk of AGM, even after adjustment for age and sex, which has been powered by sufficient evidences [10,31–33]. In individuals with metabolic syndrome (MS), generally defined as a cluster of risk factors, including hyperglycaemia, obesity, high blood pressure, and unhealthy cholesterol levels, even without diabetes, risks of CAD and CVD mortality remained elevated [34]. MS itself is a more strongly predictor for CAD, CVD, and total mortality than its individual components [34]. Therefore, DM or IGR coexists with MS or its individual components except high blood sugar, may contribute to a substantially elevated risk of CAD and CVD. In additional, the present study reveals the high prevalence of AGM is associated with the ratio of apoB/apoA1 which rather than LDL cholesterol may be a superior risk marker for cardiovascular disease [35]. The baseline plasma concentration of C-reactive protein which is a well-established risk of CAD and CVD [36], may be significantly higher in patients with AGM than that in patients with NGT, even after adjustment for age, sex, and BMI [37,38]. Likewise, compared with its counterpart, CA patients with high plasma levels of hs-CRP at baseline have a higher risk of AGM in the present study. There is insufficient evidence to determine the benefit of screening for diabetes in general populations, but screening for diabetes in adults with other risk factors of CVD is recommended and do benefit from the screening [2,31]. Detecting and early treating the large number of IGR patients and occult DM patients by lifestyle changes or diet modifications or medications, can halt them progress into overt DM patients, protect target organs damages, reduce cardiovascular events, and obtain a better prognosis [28,32,39,40], but whether treatment for prediabetes alters final health outcomes is still devoid of sufficient evidence to power for those outcomes. The outcome of an OGTT is indeed a reliable measure of the glucometabolic state, even for patients with acute myocardial infarction before hospital discharge [41]. CA patients who have CAD, essential hypertension or problems with lipid levels should ask their doctors to test them for AGM by OGTTs.
5.
Study limitations
Although our study includes a relatively larger sample, it is inevitable to have some limitations. First, the present study
diabetes research and clinical practice 91 (2011) 300–306
excluded patients with a previous CA history, with new or old myocardial infarction, or with a history of PCI or CABG, so its findings may not apply to these excluded subjects representing more severe cases. Results of our CAD patients may be not suitable for patients with non-CA diagnosed CAD. Second, most of the patients come from Guangzhou and its neighboring areas, so their glucose metabolic state may not completely be in coincidence with population of other places. Finally, bias of the prevalence of AGM may exist, owing to some excluded CA patients’ refusal to taking an OGTTs during study period and different uses of antihypertensive drugs in included population which may impact the level of plasma glucose.
6.
Conclusion
The present study reveals a high prevalence of abnormal glucometabolism in elective CA patients without a previous CA history or myocardial infarction. AGM is significantly associated with the presence of coronary stenosis documented by CA. Most AGM patients would remain undetected if attention is only paid to the fasting plasma glucose. Patients with CAD, hypertension, components of metabolic syndrome, high hs-CRP level and high ratio of apoB/apoA1 are at substantially elevated risk for AGM. The OGTT is a reliable tool to detect all categories of AGM and should be warranted as a routine method for elective CA patients in order to CVD prevention. Furthermore, some prospective researches with a larger population in multi-center are required to provide adequate evidence whether early AGM control as a result of screening provides an incremental benefit for CVD clinical outcomes compared with initiating treatment after clinical diagnosis.
Acknowledgements We appreciate our nurses for their help to us and all their dedicated assistance to patients. Also, we are grateful to our colleagues, in particular, Dr. Xin-mei Zhang for their help to collect study data. We also thank other colleagues in the Department of Cardiology for their support and help in the process of the study.
Conflict of interest There are no conflicts of interest.
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