- Email: [email protected]
The effect of acute café latte ingestion on fasting serum lipid levels in healthy individuals
Journal of Clinical Lipidology (2013) 7, 165–168
The effect of acute cafe latte ingestion on fasting serum lipid levels in healthy individuals Atanaz Zargar, PharmD, BCPS, Clint Auttapibarn, BS, Sung Hee Hong, BS, Tyler J. Larson, BS, Katelyn H. Hayworth, BS, Matthew K. Ito, PharmD, FCCP, FNLA* Oregon State University/Oregon Health & Science University College of Pharmacy, 3303 SW Bond Avenue, Portland, OR 97239, USA KEYWORDS: Coffee; Cafe latte; Cholesterol; Lipid panel; Fasting; Gluscose; LDL cholesterol
BACKGROUND: Many patients drink cafe latte as part of their habitual morning routine to start their day and may be unable to skip this step before drawing a fasting blood sample for cholesterol testing. However, it is unknown what the acute effects of consuming a cafe latte are on fasting serum lipids just before blood sampling. OBJECTIVE: This was a prospective, open-label study with the primary objective of evaluating the acute effect of a 12-oz cafe latte (2% milk) on calculated low-density lipoprotein cholesterol (LDL-C) and secondary objectives of triglyceride, total cholesterol, high-density lipoprotein cholesterol (HDLC), non-HDL-C, and fasting blood glucose (FBG). METHODS: A 10-hour fasting lipid profile was obtained before and 30 minutes after subjects consumed the cafe latte. RESULTS: Forty-nine adult participants (34 females; age [mean 6 SD] 32.2 6 13.2 years) were studied. No significant changes in total cholesterol, LDL-C, or non-HDL-C were observed after coffee consumption. Triglyceride significantly decreased from a median of 76.0 to 75.0 mg/dL (P 5 .002). HDL-C and FBG increased from a mean of 54.4 6 12.7 to 56.4 6 14.5 mg/dL (P 5 .015) and 87.2 6 7.0 to 97.3 6 12.9 mg/dL (P , .001), respectively. CONCLUSION: Consumption of 12 oz. of cafe latte within one hour of blood draw did not result in a significant change in LDL-C or non-HDL-C in young, nonobese healthy individuals. However, FBG levels increased by almost 12%. Ó 2013 National Lipid Association. All rights reserved.
The National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP III) guideline recommends that a fasting lipid panel be obtained in all adults aged 20 years or older, once every 5 years to assess coronary heart disease (CHD) risk and more routinely to help guide lipidlowering therapy.1 The use of the Friedewald equation allows one to calculate low-density lipoprotein cholesterol * Corresponding author. E-mail address: [email protected] Submitted July 20, 2012. Accepted for publication November 26, 2012.
(LDL-C) without the use of ultracentrifugation. This method, however, requires the accurate measurement of total cholesterol (TC), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) without inclusion of chylomicron particles.2 The calculation is based on the assumptions that the ratio of TG to cholesterol in verylow-density lipoprotein (VLDL) particles is 5 to 1 and that chylomicrons are not present. When TG levels increase, the TG content in VLDL increases, and this ratio is disrupted. Therefore, the Friedewald equation is not recommended for specimens with TG levels .400 mg/dL. Patients are thus required to fast for an extended period before
1933-2874/$ - see front matter Ó 2013 National Lipid Association. All rights reserved. http://dx.doi.org/10.1016/j.jacl.2012.11.001
166 the test,2,3 that is, a minimum fasting time of 9 hours,4 to ensure chylomicrons are not present. A number of patients, while abstaining from food, may still consume their morning cup of coffee before coming in for a morning fasting lipid panel. A meta-analysis of randomized controlled clinical trials revealed that the regular consumption of multiple cups of unfiltered coffee, but not filtered coffee, increased the serum levels of both TC and LDL-C.5 Furthermore, it has been recognized that a component of unfiltered coffee, cafestol, increased plasma TG concentrations by increasing the production of VLDL apolipoprotein B.6 In another randomized controlled trial investigators demonstrated that abstention from filtered coffee resulted in a decrease in TC.7 However, a previous study has indicated that acute ingestion of a single 6-oz cup of black coffee or a coffee with nondairy creamer with one sugar does not have a clinically significant effect on the fasting plasma lipid profile.8 It is still unknown, however, whether acute consumption of unfiltered specialty coffee drinks such as a cafe latte, which contains milk and espresso, will affect LDL-C or TG significantly, thereby altering the calculated LDL-C. Therefore, we cannot be sure whether the lipoprotein profiles of patients consuming these drinks are accurate and whether we can make treatment adjustments or decisions based on those readings. This leads to increased laboratory and clinic visit costs as patients are instructed to repeat laboratory draws and are rescheduled for clinic visits. The purpose of this study was to evaluate the effect of a single 12-oz cafe latte (2% milk) on fasting LDL-C levels.
Methods Design This was a prospective, open-label, single center study designed to evaluate the effect of a 12-oz cafe latte with regards to the fasting lipid panel. The primary end point was the change in calculated LDL-C. Secondary end points included changes in TG, TC, HDL-C, non-HDL-C, and fasting blood glucose (FBG).
Study participants Study participants were recruited through recruitment fliers posted in approved public areas and clinics at the Oregon Health & Science University (OHSU). The study protocol, consent form, and recruitment fliers were approved by OHSU and Oregon State University institutional review board. Participants were required to be between the ages of 18 and 75 years, capable of fasting for at least 10 hours, and sign the informed consent form before entering the study. Participants were excluded from the study if they had a contraindication to cafe latte consumption, including pregnancy, stage II hypertension ($160 mmHg systolic and $100 mmHg diastolic), and lactose intolerance, or could
Journal of Clinical Lipidology, Vol 7, No 2, April 2013 not finish a cafe latte within the allotted amount of time of 30 minutes. Subjects known to have baseline serum TG .400 mg/dL or laboratory values that exceeded the range of detection of the Cholestech LDX Analyzer (Alere Inc, Waltham, MA) were excluded based on manufacture settings.9 All information regarding medical conditions, medications, age, height, weight, and fasting state were obtained and recorded directly from the patient prior to the procedure. Medical history and medications were not adjudicated because the participant’s medical records were not available. All participants were evaluated and tested at the Center for Health and Healing at OHSU by one of the investigators between 7:00 am and 11:00 am after an overnight fast.
Lipid analysis Each participant was asked to fast for a minimum of 10 hours (no food or drinks other than water and medication) the night before their scheduled visit. A capillary blood sample (40 mL) was obtained at baseline and 30 minutes after the participant consumed a 12-oz cafe latte. Each cafe latte was prepared in a standardized manner by employees of the Daily cafe within the Center for Health and Healing and was made with 3 oz of espresso (two shots) and 10 oz of 2% milk. The espresso beans were Hair Bender (Stumptown Coffee Roaster, Portland, OR) and the milk was supplied by Sunshine Dairy Foods (Portland, OR). Participants were asked to consume the cafe latte within 30 minutes. Capillary blood samples were obtained using Cholestech LDX capillary tubes (Alere 52193; Alere, Inc) from one of the center fingers and the blood sample was immediately inserted into the test cassette well and inserted into the Cholestech LDX Analyzer. Cholestech LDX Analyzers were calibrated each morning before use with the Optic Check Cassette (CTH-10-228; Alere, Inc). Test cassettes analyzed TC, HDL-C, TG, and blood glucose (Alere 10-991; Alere, Inc). LDL-C was calculated using the Friedewald equation and non-HDL-C was calculated by subtracting HDL-C from TC. The Cholestech LDX System is a clinical laboratory improvement amendment-waived test and certified by the Cholesterol Reference Method Laboratory Network. The coefficients of variation (CVs) for TC, LDL-C, TG, HDLC, non-HDL-C, and FBG were calculated by the use of the two control solutions (level 1 and level 2) purchased from Cholestech. The CV using the level 1 solution were 1.02%, 1.09%, 1.42%, 1.97%, 0.83%, and 4.64%, respectively. The CV using the level 2 solution were 0.85%, 2.63%, 1.53%, 6.84%, 2.25%, and 2.29%, respectively. The expected range for TC, HDL-C, TG, and FBG were 133–187 mg/dL, 27–42 mg/dL, 110–161 mg/dL, and 114–168 mg/dL, respectively, for the level 1 solution and 195–274 mg/dL, 51–81 mg/dL, 211–311 mg/dL, and 247–363 mg/dL, respectively, for the level 2 solution. Any patients with a reported TG levels ,45 mg/dL (lower level of detection), their TG level was fixed at 45 mg/dL.
Zargar et al Table 1
Acute cafe latte ingestion on fasting serum lipid levels
Baseline patient characteristics
Characteristics Age, years, mean 6 SD Sex, n (%) Female Male Weight, lbs, mean 6 SD Height, inches, mean 6 SD Body mass index, kg/m2, mean 6 SD CHD risk factors, n (%) 0 1 2 Coronary risk equivalent Concomitant medications, n (%) None Birth control pills NSAIDs Thyroid replacement Antihistamines Antidepressants Statins
32.2 6 13.2 34 (69) 15 (31) 150.4 6 30.8 66.7 6 3.3 23.7 6 4.2 38 11 0 0
(78) (22) (0) (0)
21 11 5 4 4 3 1
(43) (22) (10) (8) (8) (6) (2)
criteria. Three participants were lost to follow-up, and a second capillary blood sample could not be obtained for one participant; therefore, a total of 49 participants (34 females and 15 males) completed the study. Baseline characteristics are shown in Table 1. A majority of the study participants were young healthy university students or employees affiliated with OHSU and Oregon State University. Overall, the study participants were at low risk for CHD according to NCEP ATP III (78% and 22% for zero or 1 CHD risk factor, respectively). Baseline and post cafe latte lipid parameters are listed in Table 2. There was no statistically significant change in either TC (P 5 .054), LDL-C (P 5 .761), or non-HDL-C (P 5 .61) observed after consumption of a cafe latte. Serum TG statistically significantly decreased from median of 76.0 to 75.0 mg/dL (P 5 .002). The percent change in HDL-C, and FBG were increased by 3.8% and 11.8%, respectively, and these values was all statistically significant. The mean time between the first and second capillary blood draw was 61.0 6 20.4 minutes.
Discussion
CHD, coronary heart disease; NSAID, nonsteroidal anti-inflammatory drugs; SD, standard deviation.
Statistical analysis A sample size of 49 subjects was determined using 80% power to detect a mean difference of 10 mg/dL in LDL-C, assuming a SD of differences of 25.0 mg/dL and a two-tailed level of significance set at .05. A paired Student’s t-test was used to compare mean lipid levels before and after the cafe latte for normally distributed data. The Wilcoxon signed rank test was used to compare non-normally distributed data. All statistical analysis was performed with the SigmaPlot for Windows Version 11.0; Systate Software, Inc, San Jose, CA) and a P-value of less than .05 was considered statistically significant. All values are reported as mean 6 SD and median.
Results A total of 53 participants were recruited between April 2012 and May 2012 according to the inclusion and exclusion Table 2
167
This is the first study to our knowledge that has evaluated the acute effect of a cafe latte on the fasting lipid panel. The results of this study provide important information to help patients who may face a challenge of not being able to abstain from their habitual morning cafe latte. Currently, most clinical laboratories use the Friedewald equation to calculate LDL-C, which requires patients to fast. We observed no statistically significant difference in mean LDL-C before and after cafe latte consumption. LDL-C remains the primary target for intervention in patients without severe hypertriglyceridemia (TG $ 500 mg/dL) based on current NCEP-ATP III guidelines.1 On the basis of our results, the consumption of a cafe latte within 1 hour of a fasting lipid panel should not affect the clinicaldecision for initiating or changing LDL-lowering therapies. A previous study showed similar results with regards to LDL-C after the consumption of black coffee and coffee with nondiary creamer and sugar.8 In addition, we also observed no significant change in non-HDL-C, which is defined as a secondary target in patients with TG . 200 mg/dL.1
Changes in lipid parameters and glucose levels
Lipid parameters and glucose, mg/dL
Pre-latte mean 6 SD (median)
Post-latte mean 6 SD (median)
Total cholesterol LDL-C HDL-C TG Non-HDL-C Fasting blood glucose
171.2 6 28.8 96.7 6 22.1 54.4 6 12.7 101.3 6 75.2 116.9 6 28.9 87.2 6 7.0
173.1 98.2 56.4 93.2 116.4 97.3
(169.0) (96.5) (51.0) (76.0) (113.0) (89.0)
6 6 6 6 6 6
30.7 24.4 14.5 74.2 31.1 12.9
(169.0) (96.8) (54.0) (75.0) (110.0) (98.0)
% Change mean 6 SD 1.03 1.8 3.8 26.1 20.78 11.8
6 6 6 6 6 6
3.8* 8.3* 10.5* 20.3† 6.2* 13.4*
HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; SD, standard deviation, TG, triglycerides. *Normality test (Shapiro-Wilk) passed, Paired t-test used. †Normality test (Shapiro-Wilk) failed, Wilcoxon signed rank test used.
P-value .054 .761 .015 .002 .61 ,.001
168 The LDL and HDL particles have a half-life of 3 and 5 days, respectively.10 Most of the blood cholesterol is carried by these two lipoproteins; therefore, the blood cholesterol concentration does not fluctuate minute to minute or meal to meal and it takes days for any changes to appear. Therefore, the increase that we observed in subjects’ HDL-C after they consumed a cafe latte is most likely explained by assay variability. Our reported CVs for all lipid parameters fell within those recommended by the NCEP11 except for greater levels of HDL-C tested using the level 2 control solutions (see Methods). The median baseline HDL-C was 51 mg/dL. Thus, by definition, half the patients had HDL-C values greater than 51 mg/dL, and our calculated CV was 6.8% for a median HDL-C of 51 mg/dL versus only 2.0% for a median HDL-C of 29 mg/dL. The time between pre- and post-lipid levels averaged 61.0 minutes. Our cafe latte contained 10 oz of 2% milk, which contains approximately 6.25 g of fat.12 Generally after consumption of a fat-containing meal, serum TG increased within 10-30 minutes, known as the ‘‘early peak,’’ which is before the absorption of this meal. The rise is attributable to the release of storage pool TG in the enterocytes from the previous meal and is stimulated by the subsequent meal.13 The true primary peak of TG does not occur for up to 3-4 hours after the meal.14 Although the TG change may not be clinically significant in our study, it was statistically significant. The decrease in TG level could be explained by the additional fasting time and continued hydrolysis of TG within VLDL by lipases.15,16 The reduction in TG is less likely to be caused by excessive laboratory variability since our CV for TG met those recommended by NCEP.11 As expected, FBG levels increased between the baseline and follow-up period. Blood glucose levels increased by almost 12%. We would not recommend patients to drink cafe latte before obtaining blood glucose levels if FBG levels are to be obtained.
Limitations The use of Cholestech LDX Analyzer for measurement of serum lipids may produce slightly greater variability in regard to greater concentrations of HDL-C levels. Thus, we are unable to definitively rule out the acute effects of cafe latte consumption on HDL-C. However, both LDL-C and non-HDL-C were unchanged and these lipid parameters remain our primary and secondary targets for intervention. The results of this study only apply to consumption of a 12-oz cafe latte made with 2% milk with no additive sugars or syrup flavorings. In addition, we did not study the patients for any extended period of time after the consumed the cafe latte. Thus, TG levels could increase after a longer period of time postconsumption. We studied relatively healthy nonobese individuals. The effects of a cafe latte on fasting serum lipids could be markedly different in patients prone to postprandial lipemia, such as in obese individuals. Further studies in this population are needed. Finally, we did not ask each participant the exact time of their last meal; however, before the start of the procedure, each participant was asked if they were fasting for a
Journal of Clinical Lipidology, Vol 7, No 2, April 2013 minimum of 10 hours. The further reduction in TG observed in our study could have been influenced by individuals who may have been fasting for a shorter time interval.
Conclusion Consumption of 12-oz cafe latte made with 2% milk within 1 hour of fasting lipid profile did not significantly affect LDL-C and non-HDL-C levels in relatively healthy patients. However, FBG levels did increase.
References 1. National Cholesterol Education Program. Third Report of the Expert Panel On Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Final Report NIH Pub. No. 02–5215. Bethesda (MD): National Heart, Lung, and Blood Institute; 2002. 2. Friedewald Wi’, Levy RI, Fredrickson DS. Estimation of the concentration of low density lipoprotein cholesterol in plasma, without use of the preparative ultracentrifuge. Clin Chem. 1972;18:499–502. 3. Wilson PWF, Zech LA, Gregg RE, et al. Estimation of VLDLcholesterol in hyperlipidemia. Clin Chim Acta. 1985;151:285–291. 4. National Cholesterol Education Program Recommendations on lipoprotein measurement from the Working Group on Lipoprotein Measurement. NIH Pub. No. 95-3044: National Heart, Lung, and Blood Institute, 1995; p186. 5. Jee SH, He J, Appel LJ, Whelton PK, Suh I, Klag MJ. Coffee consumption and serum lipids: a meta-analysis of randomized controlled clinical trials. Am J Epidemiol. 2001;153:353–362. 6. de Roos B, Caslake MJ, Stalenhoef AF, et al. The coffee diterpene cafestol increases plasma triacylglycerol by increasing the production of large VLDL apolipoprotein B in healthy normolipidemic subjects. Am J Clin Nutr. 2001;73:45–52. 7. Christensen B, Mosdol A, Rettersol L, Landaas S, Thelle DS. Abstention from filtered coffee reduces the concentrations of plasma homocysteine and serum cholesterol—a randomized controlled trial. Am J Clin Nutr. 2001;74:302–307. 8. Cheung RJ, Gupta EK, Ito MK. Acute coffee ingestion does not affect LDL cholesterol level. Ann Pharmacother. 2005;38:1209–1213. 9. Cholestech LDXÒ Lipid Profile package insert. Cholestech Corporation. San Diego, CA. 2010. Available at: www.alere.com/EN_US/products/ alere-lipid-profile-glu-cassettes-poc-test/index.html. Accessed January 2012. 10. Dayspring T. Postprandial vs Fasting Lipids. Available on www. lipidcenter.com/pdf/Postprandial_and_Fasting_Lipids.pdf. Accessed June 12, 2012. 11. National Cholesterol Education Program Working Group on Lipoprotein Measurement. Recommendations on Lipoprotein Measurement NIH publication no.65-3044. Washington, DC: U.S. Department of Health and Human Services; 1995. 12. Sunshine Dairy Foods Milks. Available at: http://www.shopwell.com/ sunshine-dairy-foods-milk-2-reduced-vitamin-a-d/milk/p/7158001567. Accessed June 6, 2012. 13. Mattes RD. Oral fat exposure increases the first phase triacylglycerol concentration due to release of store lipid in humans. J Nutr. 2002; 132:3656–3662. 14. Robertson MD, Henderson RA, Vist GE, Rumsey RD. Extended effects of evening meal carbohydrate-to-fat ratio on fasting and postprandial substrate metabolism. Am J Clin Nutr. 2002;75:505–510. 15. Mirrila EA, Rarinem MR, Rehunen S, Harkonen M. Lipoprotein lipase activity in adipose tissue and skeletal muscle of runners: relation to serum lipoproteins. Metabolism. 1978;67:1661–1671. 16. Linder C, Chernicr SS, Fleck TR, Scow RO. Lipoprotein lipase and uptake of chylomicron triglyceride by skeletal muscle of rats. Am J Physiol. 1976;231:860–864.
The effect of acute cafe latte ingestion on fasting serum lipid levels in healthy individuals Atanaz Zargar, PharmD, BCPS, Clint Auttapibarn, BS, Sung Hee Hong, BS, Tyler J. Larson, BS, Katelyn H. Hayworth, BS, Matthew K. Ito, PharmD, FCCP, FNLA* Oregon State University/Oregon Health & Science University College of Pharmacy, 3303 SW Bond Avenue, Portland, OR 97239, USA KEYWORDS: Coffee; Cafe latte; Cholesterol; Lipid panel; Fasting; Gluscose; LDL cholesterol
BACKGROUND: Many patients drink cafe latte as part of their habitual morning routine to start their day and may be unable to skip this step before drawing a fasting blood sample for cholesterol testing. However, it is unknown what the acute effects of consuming a cafe latte are on fasting serum lipids just before blood sampling. OBJECTIVE: This was a prospective, open-label study with the primary objective of evaluating the acute effect of a 12-oz cafe latte (2% milk) on calculated low-density lipoprotein cholesterol (LDL-C) and secondary objectives of triglyceride, total cholesterol, high-density lipoprotein cholesterol (HDLC), non-HDL-C, and fasting blood glucose (FBG). METHODS: A 10-hour fasting lipid profile was obtained before and 30 minutes after subjects consumed the cafe latte. RESULTS: Forty-nine adult participants (34 females; age [mean 6 SD] 32.2 6 13.2 years) were studied. No significant changes in total cholesterol, LDL-C, or non-HDL-C were observed after coffee consumption. Triglyceride significantly decreased from a median of 76.0 to 75.0 mg/dL (P 5 .002). HDL-C and FBG increased from a mean of 54.4 6 12.7 to 56.4 6 14.5 mg/dL (P 5 .015) and 87.2 6 7.0 to 97.3 6 12.9 mg/dL (P , .001), respectively. CONCLUSION: Consumption of 12 oz. of cafe latte within one hour of blood draw did not result in a significant change in LDL-C or non-HDL-C in young, nonobese healthy individuals. However, FBG levels increased by almost 12%. Ó 2013 National Lipid Association. All rights reserved.
The National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP III) guideline recommends that a fasting lipid panel be obtained in all adults aged 20 years or older, once every 5 years to assess coronary heart disease (CHD) risk and more routinely to help guide lipidlowering therapy.1 The use of the Friedewald equation allows one to calculate low-density lipoprotein cholesterol * Corresponding author. E-mail address: [email protected] Submitted July 20, 2012. Accepted for publication November 26, 2012.
(LDL-C) without the use of ultracentrifugation. This method, however, requires the accurate measurement of total cholesterol (TC), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) without inclusion of chylomicron particles.2 The calculation is based on the assumptions that the ratio of TG to cholesterol in verylow-density lipoprotein (VLDL) particles is 5 to 1 and that chylomicrons are not present. When TG levels increase, the TG content in VLDL increases, and this ratio is disrupted. Therefore, the Friedewald equation is not recommended for specimens with TG levels .400 mg/dL. Patients are thus required to fast for an extended period before
1933-2874/$ - see front matter Ó 2013 National Lipid Association. All rights reserved. http://dx.doi.org/10.1016/j.jacl.2012.11.001
166 the test,2,3 that is, a minimum fasting time of 9 hours,4 to ensure chylomicrons are not present. A number of patients, while abstaining from food, may still consume their morning cup of coffee before coming in for a morning fasting lipid panel. A meta-analysis of randomized controlled clinical trials revealed that the regular consumption of multiple cups of unfiltered coffee, but not filtered coffee, increased the serum levels of both TC and LDL-C.5 Furthermore, it has been recognized that a component of unfiltered coffee, cafestol, increased plasma TG concentrations by increasing the production of VLDL apolipoprotein B.6 In another randomized controlled trial investigators demonstrated that abstention from filtered coffee resulted in a decrease in TC.7 However, a previous study has indicated that acute ingestion of a single 6-oz cup of black coffee or a coffee with nondairy creamer with one sugar does not have a clinically significant effect on the fasting plasma lipid profile.8 It is still unknown, however, whether acute consumption of unfiltered specialty coffee drinks such as a cafe latte, which contains milk and espresso, will affect LDL-C or TG significantly, thereby altering the calculated LDL-C. Therefore, we cannot be sure whether the lipoprotein profiles of patients consuming these drinks are accurate and whether we can make treatment adjustments or decisions based on those readings. This leads to increased laboratory and clinic visit costs as patients are instructed to repeat laboratory draws and are rescheduled for clinic visits. The purpose of this study was to evaluate the effect of a single 12-oz cafe latte (2% milk) on fasting LDL-C levels.
Methods Design This was a prospective, open-label, single center study designed to evaluate the effect of a 12-oz cafe latte with regards to the fasting lipid panel. The primary end point was the change in calculated LDL-C. Secondary end points included changes in TG, TC, HDL-C, non-HDL-C, and fasting blood glucose (FBG).
Study participants Study participants were recruited through recruitment fliers posted in approved public areas and clinics at the Oregon Health & Science University (OHSU). The study protocol, consent form, and recruitment fliers were approved by OHSU and Oregon State University institutional review board. Participants were required to be between the ages of 18 and 75 years, capable of fasting for at least 10 hours, and sign the informed consent form before entering the study. Participants were excluded from the study if they had a contraindication to cafe latte consumption, including pregnancy, stage II hypertension ($160 mmHg systolic and $100 mmHg diastolic), and lactose intolerance, or could
Journal of Clinical Lipidology, Vol 7, No 2, April 2013 not finish a cafe latte within the allotted amount of time of 30 minutes. Subjects known to have baseline serum TG .400 mg/dL or laboratory values that exceeded the range of detection of the Cholestech LDX Analyzer (Alere Inc, Waltham, MA) were excluded based on manufacture settings.9 All information regarding medical conditions, medications, age, height, weight, and fasting state were obtained and recorded directly from the patient prior to the procedure. Medical history and medications were not adjudicated because the participant’s medical records were not available. All participants were evaluated and tested at the Center for Health and Healing at OHSU by one of the investigators between 7:00 am and 11:00 am after an overnight fast.
Lipid analysis Each participant was asked to fast for a minimum of 10 hours (no food or drinks other than water and medication) the night before their scheduled visit. A capillary blood sample (40 mL) was obtained at baseline and 30 minutes after the participant consumed a 12-oz cafe latte. Each cafe latte was prepared in a standardized manner by employees of the Daily cafe within the Center for Health and Healing and was made with 3 oz of espresso (two shots) and 10 oz of 2% milk. The espresso beans were Hair Bender (Stumptown Coffee Roaster, Portland, OR) and the milk was supplied by Sunshine Dairy Foods (Portland, OR). Participants were asked to consume the cafe latte within 30 minutes. Capillary blood samples were obtained using Cholestech LDX capillary tubes (Alere 52193; Alere, Inc) from one of the center fingers and the blood sample was immediately inserted into the test cassette well and inserted into the Cholestech LDX Analyzer. Cholestech LDX Analyzers were calibrated each morning before use with the Optic Check Cassette (CTH-10-228; Alere, Inc). Test cassettes analyzed TC, HDL-C, TG, and blood glucose (Alere 10-991; Alere, Inc). LDL-C was calculated using the Friedewald equation and non-HDL-C was calculated by subtracting HDL-C from TC. The Cholestech LDX System is a clinical laboratory improvement amendment-waived test and certified by the Cholesterol Reference Method Laboratory Network. The coefficients of variation (CVs) for TC, LDL-C, TG, HDLC, non-HDL-C, and FBG were calculated by the use of the two control solutions (level 1 and level 2) purchased from Cholestech. The CV using the level 1 solution were 1.02%, 1.09%, 1.42%, 1.97%, 0.83%, and 4.64%, respectively. The CV using the level 2 solution were 0.85%, 2.63%, 1.53%, 6.84%, 2.25%, and 2.29%, respectively. The expected range for TC, HDL-C, TG, and FBG were 133–187 mg/dL, 27–42 mg/dL, 110–161 mg/dL, and 114–168 mg/dL, respectively, for the level 1 solution and 195–274 mg/dL, 51–81 mg/dL, 211–311 mg/dL, and 247–363 mg/dL, respectively, for the level 2 solution. Any patients with a reported TG levels ,45 mg/dL (lower level of detection), their TG level was fixed at 45 mg/dL.
Zargar et al Table 1
Acute cafe latte ingestion on fasting serum lipid levels
Baseline patient characteristics
Characteristics Age, years, mean 6 SD Sex, n (%) Female Male Weight, lbs, mean 6 SD Height, inches, mean 6 SD Body mass index, kg/m2, mean 6 SD CHD risk factors, n (%) 0 1 2 Coronary risk equivalent Concomitant medications, n (%) None Birth control pills NSAIDs Thyroid replacement Antihistamines Antidepressants Statins
32.2 6 13.2 34 (69) 15 (31) 150.4 6 30.8 66.7 6 3.3 23.7 6 4.2 38 11 0 0
(78) (22) (0) (0)
21 11 5 4 4 3 1
(43) (22) (10) (8) (8) (6) (2)
criteria. Three participants were lost to follow-up, and a second capillary blood sample could not be obtained for one participant; therefore, a total of 49 participants (34 females and 15 males) completed the study. Baseline characteristics are shown in Table 1. A majority of the study participants were young healthy university students or employees affiliated with OHSU and Oregon State University. Overall, the study participants were at low risk for CHD according to NCEP ATP III (78% and 22% for zero or 1 CHD risk factor, respectively). Baseline and post cafe latte lipid parameters are listed in Table 2. There was no statistically significant change in either TC (P 5 .054), LDL-C (P 5 .761), or non-HDL-C (P 5 .61) observed after consumption of a cafe latte. Serum TG statistically significantly decreased from median of 76.0 to 75.0 mg/dL (P 5 .002). The percent change in HDL-C, and FBG were increased by 3.8% and 11.8%, respectively, and these values was all statistically significant. The mean time between the first and second capillary blood draw was 61.0 6 20.4 minutes.
Discussion
CHD, coronary heart disease; NSAID, nonsteroidal anti-inflammatory drugs; SD, standard deviation.
Statistical analysis A sample size of 49 subjects was determined using 80% power to detect a mean difference of 10 mg/dL in LDL-C, assuming a SD of differences of 25.0 mg/dL and a two-tailed level of significance set at .05. A paired Student’s t-test was used to compare mean lipid levels before and after the cafe latte for normally distributed data. The Wilcoxon signed rank test was used to compare non-normally distributed data. All statistical analysis was performed with the SigmaPlot for Windows Version 11.0; Systate Software, Inc, San Jose, CA) and a P-value of less than .05 was considered statistically significant. All values are reported as mean 6 SD and median.
Results A total of 53 participants were recruited between April 2012 and May 2012 according to the inclusion and exclusion Table 2
167
This is the first study to our knowledge that has evaluated the acute effect of a cafe latte on the fasting lipid panel. The results of this study provide important information to help patients who may face a challenge of not being able to abstain from their habitual morning cafe latte. Currently, most clinical laboratories use the Friedewald equation to calculate LDL-C, which requires patients to fast. We observed no statistically significant difference in mean LDL-C before and after cafe latte consumption. LDL-C remains the primary target for intervention in patients without severe hypertriglyceridemia (TG $ 500 mg/dL) based on current NCEP-ATP III guidelines.1 On the basis of our results, the consumption of a cafe latte within 1 hour of a fasting lipid panel should not affect the clinicaldecision for initiating or changing LDL-lowering therapies. A previous study showed similar results with regards to LDL-C after the consumption of black coffee and coffee with nondiary creamer and sugar.8 In addition, we also observed no significant change in non-HDL-C, which is defined as a secondary target in patients with TG . 200 mg/dL.1
Changes in lipid parameters and glucose levels
Lipid parameters and glucose, mg/dL
Pre-latte mean 6 SD (median)
Post-latte mean 6 SD (median)
Total cholesterol LDL-C HDL-C TG Non-HDL-C Fasting blood glucose
171.2 6 28.8 96.7 6 22.1 54.4 6 12.7 101.3 6 75.2 116.9 6 28.9 87.2 6 7.0
173.1 98.2 56.4 93.2 116.4 97.3
(169.0) (96.5) (51.0) (76.0) (113.0) (89.0)
6 6 6 6 6 6
30.7 24.4 14.5 74.2 31.1 12.9
(169.0) (96.8) (54.0) (75.0) (110.0) (98.0)
% Change mean 6 SD 1.03 1.8 3.8 26.1 20.78 11.8
6 6 6 6 6 6
3.8* 8.3* 10.5* 20.3† 6.2* 13.4*
HDL-C, high-density lipoprotein cholesterol; LDL-C, low-density lipoprotein cholesterol; SD, standard deviation, TG, triglycerides. *Normality test (Shapiro-Wilk) passed, Paired t-test used. †Normality test (Shapiro-Wilk) failed, Wilcoxon signed rank test used.
P-value .054 .761 .015 .002 .61 ,.001
168 The LDL and HDL particles have a half-life of 3 and 5 days, respectively.10 Most of the blood cholesterol is carried by these two lipoproteins; therefore, the blood cholesterol concentration does not fluctuate minute to minute or meal to meal and it takes days for any changes to appear. Therefore, the increase that we observed in subjects’ HDL-C after they consumed a cafe latte is most likely explained by assay variability. Our reported CVs for all lipid parameters fell within those recommended by the NCEP11 except for greater levels of HDL-C tested using the level 2 control solutions (see Methods). The median baseline HDL-C was 51 mg/dL. Thus, by definition, half the patients had HDL-C values greater than 51 mg/dL, and our calculated CV was 6.8% for a median HDL-C of 51 mg/dL versus only 2.0% for a median HDL-C of 29 mg/dL. The time between pre- and post-lipid levels averaged 61.0 minutes. Our cafe latte contained 10 oz of 2% milk, which contains approximately 6.25 g of fat.12 Generally after consumption of a fat-containing meal, serum TG increased within 10-30 minutes, known as the ‘‘early peak,’’ which is before the absorption of this meal. The rise is attributable to the release of storage pool TG in the enterocytes from the previous meal and is stimulated by the subsequent meal.13 The true primary peak of TG does not occur for up to 3-4 hours after the meal.14 Although the TG change may not be clinically significant in our study, it was statistically significant. The decrease in TG level could be explained by the additional fasting time and continued hydrolysis of TG within VLDL by lipases.15,16 The reduction in TG is less likely to be caused by excessive laboratory variability since our CV for TG met those recommended by NCEP.11 As expected, FBG levels increased between the baseline and follow-up period. Blood glucose levels increased by almost 12%. We would not recommend patients to drink cafe latte before obtaining blood glucose levels if FBG levels are to be obtained.
Limitations The use of Cholestech LDX Analyzer for measurement of serum lipids may produce slightly greater variability in regard to greater concentrations of HDL-C levels. Thus, we are unable to definitively rule out the acute effects of cafe latte consumption on HDL-C. However, both LDL-C and non-HDL-C were unchanged and these lipid parameters remain our primary and secondary targets for intervention. The results of this study only apply to consumption of a 12-oz cafe latte made with 2% milk with no additive sugars or syrup flavorings. In addition, we did not study the patients for any extended period of time after the consumed the cafe latte. Thus, TG levels could increase after a longer period of time postconsumption. We studied relatively healthy nonobese individuals. The effects of a cafe latte on fasting serum lipids could be markedly different in patients prone to postprandial lipemia, such as in obese individuals. Further studies in this population are needed. Finally, we did not ask each participant the exact time of their last meal; however, before the start of the procedure, each participant was asked if they were fasting for a
Journal of Clinical Lipidology, Vol 7, No 2, April 2013 minimum of 10 hours. The further reduction in TG observed in our study could have been influenced by individuals who may have been fasting for a shorter time interval.
Conclusion Consumption of 12-oz cafe latte made with 2% milk within 1 hour of fasting lipid profile did not significantly affect LDL-C and non-HDL-C levels in relatively healthy patients. However, FBG levels did increase.
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