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Brachial artery flow-mediated dilatation and increasing blood pressure during exercise in normotensive adults
156
Luque
ARTERY FLOW-MEDIATED DILATATION AND Ff-9] BRACHIAL INCREASING BLOOD PRESSURE DURING EXERCISE IN NORMOTENSIVE ADULTS M.RM.E Luque, R.M.A. Coching, V.E Combate Jr., H.N. Ong-Garcia, ER. Collado, H.B. Calleja. St. Luke" s Heart Institute, Quezon City,
Philippines Background: Endothelial dysfunction has been implicated in the pathogenesis of coronary artery disease, diabetes, smoking and hypertension. Studies have shown exercise blood pressure to be predictive of future hypertension and its attendant complications. It would be logical then to assume abnormal flow-mediated dilation in normotensives with increasing blood pressure during exercise. Methods: This is a cross-sectional study. Normotensives without known cardiovascular risk factors or drug intake were included, undergoing both endothelial function and treadmill exercise tests. Demographic: clinical and laboratory data were collected and statistically analyzed using Pearson' s correlation. Results: The study population consisted of 70 normotensive patients. There were 37 males (53%) and 33 females (47%). Mean age was 43.81±8.97 years. All had adequate stress tests. There was no significant association between flow-mediated dilatation and resting heart rate, systolic and diastolic blood pressures; peak heart rate and systolic blood pressure; delta systolic and diastolic blood pressure; and MET-adjusted delta systolic and diastolic blood pressures. However, r change for peak diastolic blood pressure was 0.24 with p<0.05. Conclusion: Only peak diastolic blood pressure significantly correlated with flow-mediated dilatation of the brachial artery. This may indicate that endothelial dysfunction and hypertensive diastolic blood pressure response to exercise are closely linked and occur early in the natural history of hypertension compared to changes in systolic blood pressure. ~'~
LOW PARAOXONASE ACTIVITY IS A RISK FACTOR F O R CORONARY HEART DISEASE IN A PROSPECTIVE STUDY
B. Mackness 1, P. Durrington1, P. McElduff2, M. Mackness 1. 1Manchester
Royal Infirmary," 2University of Manchester, UK Background: Human serum paraoxonase (PONt) retards the oxidation of low density lipoprotein (LDL) and could therefore protect against the development of coronary heart disease (CHD). Therefore, we have investigated serum PONt activity as a risk factor for CHD in a prospective study. Materials and Methods: PONt activity towards paraoxon was measured in 1353 men from the Caerphilly and Speedwell prospective study who were followed for up to 8 years. Results: 163 had a CHD event defined as angina (Rose questionnaire), fatal and non-fatal myocardial infarction and the appearance of major or moderate Q waves on a resting ECG. Men in the lowest quintile of PONt activity had a relative risk of developing CHD of t.7 compared to men in the highest quintile of PONt activity (P-0.03t when adjusted for all other CHD risk factors except HI)L). This association became non-significant when HDL was included in the adjustment (P-0.t2). Conclusion: Low PONt activity is a risk factor for CHD in the Caerphilly and Speedwell Prospective Study. PONt is physically located on HDL and is likely to explain part of its apparent protective effect against CHD. [42-1] PREDISPOSING FACTORS IN 100 PATIENTS W I T H SILENT MYOCARDIAL INFARCTION M.L Mahmoudi, M. Gharouni, S. Moradmand, N. Rezaei, M. Mahmoudi, S. Dargahi. Tehran University of Medical Sciences, Tehran, Iran Background and Objectives: Myocardial Infarction (MI), sequelae of Coronary Artery Disease (CAD), can be sometimes asymptomatic, called Silent Myocardial Infarction (SMI). In this study, we intend to determine the predisposing factors in such patients. Methods: We included those patients with electrocardiogram changes, consistent with MI, who had not any symptoms of ischemia or a previous history of CAD, consulted to pre-operative work up of eye surgery during the year 2000. Results: We analyzed tOO patients with the diagnosis of SMI (59males). Among our patients, 99% were above 50 years of age. Their mean age at the time of study was 69.7 years. Seventy eight percent of patients were illiterate. In 41 of them body mass index was above the normal limits (overweight and obese). Their past medical history revealed that 46 patients had hypertension,
38 patients had hyperlipidemia, and 26 cases had diabetes mellitus. Also, a positive family history of CAD was seen in 52% of the patients. The rate of cigarette smokers and opium addicts, among our patients, was 33 and 13 percents, respectively. Analysis of electrocardiogram changes, showed that 43 patients had inferior MI, 24 had anteroseptal, and 17 of them suffered from anterior MI. Conclusions: Almost all of our patients with SMI lied in old age group. Diabetes mellitus, hypertension, overweight, and hyperlipidemia were the most important predisposing factors, found in such patients; Thus, taking into account these elements and control of them would dramatically reduce the prevalence of morbidity and mortality of patients with SMI. ~-~
PLASMA Lp(a) LEVELS AND URINARY 8-ISOPROSTANE/PROSTAGLANDIN F2 ALPHA CONCENTRATIONS IN TRAINING ATHLETES
K. Makino 1, A. Katayama 1, I. Watanabe 2. J Gifu College of Medical
Technology, Seki," 2Asahi University, Gifu, Japan Lp(a) is an independent risk factor for atherosclerosis. Urinary 8-isoprostane/ prostaglandin F2 alpha (8-iso-PGF 2 alpha) is a product of free radical catalyzed peroxidation of arachidonic acid and considered to be a sensitive marker of oxidative stress in vivo. The purpose of this study is to investigate the effect of physical training on plasma Lp(a) levels and on oxidative stress by assessment of urinary 8-iso-PGF 2 alpha concentrations. Methods: 30 running athletes were studied. Plasma Lp(a) and urinary 8-iso-PGF 2 alpha concentrations were determined by EIA. (Results) Serum levels of TC,TG,ApoB,LDL-C and LDL-C/HDL-C ratio were significantly decreased and those of HDL-C and HDL-C/TC ratio were significantly increased in athletes. Principal component analysis demonstrated that Lp(a) was entirely independent of other factors, such as TC,TG,ApoB,HDL-C,LDL-C,LDL-C/HDL-C ratio and LDL-C/TC ratio. There was no significant difference in plasma Lp(a) concentrations between running athletes and control subjects(tJ.9±t6.4 mg/dl, 14.7±14.4 mg/dl). Urinary 8-iso-PGF 2 alpha concentrations were significantly increased in athletes. Conclusions: Plasma Lp(a) concentrations did not appear to be significantly altered by hard exercise. Physical training may be associated with increased oxidative stress, suggesting that Lp(a) will be more atherogenic in training athletes. ~ - 3 ] COMBINED EFFECT OF CHONDROITIN SULFATEMODIFIED SUPEROXIDE DISMUTASE AND CATALASE IN ANTITHROMBOTIC PROTECTION OF VASCULAR WALL A.V. Maksimenko, V.L. Golubykh, E.G. Tischenko. Russian Cardiology Research Center, Institute of Experimental Cardiology, Moscow, Russia Keeping of vascular endothelium against the damage caused by free oxygen radicals is an important factor of antiatherosclerotic protection. With this in mind we studied the antithrombotic activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) chemically conjugated to the vascular wall glycosaminoglycan chondroitin sulfate (CHS). The following compounds were prepared: covalent conjugated SOD-CHS and CAT-CHS, bienzyme covalent conjugate SOD-CHS-CAT, native SOD and CAT, and free CHS. They were tested for antithrombotic activity in a rat model of arterial thrombosis. The rats were given a preventive intravenous bolus administration of the studied compounds (or control), after which aqueous solution of ferrous chloride was applied onto arterial wall. The occlusion time and thrombus mass were determined after t-h blood flow monitoring. The SOD-CHS and CAT-CHS conjugates produced significantly stronger antithrombotic effects than their components injected individually or as a mixture, which emphasizes the importance of covalent conjugation of antioxidant enzymes to CHS. The SOD-CHS conjugate markedly reduced the thrombus mass, while CAT-CHS predominantly preserved blood flow. A single-bolus injection of combination between SOD-CHS and CAT-CHS had a significantly lower antithrombotic effect compared with that of the SOD-CHS-CAT conjugate. This could be explained by different surface distribution of the conjugates in the circulation. Small effective dose of SOD-CHS-CAT conjugate implies prospectiveness of its further biomedical investigation. These findings suggest that the modified antioxidant enzymes can be used in pharmacological and surgical manipulations. The bienzyme conjugate SOD-CHS-CAT could be prospective for intravascular therapeutic injection. The SOD-CHS/CAT-CHS mixture could be useful for surface modification of vascular prostheses and bypasses during surgical revascularization.
73rd EAS Congress
Luque
ARTERY FLOW-MEDIATED DILATATION AND Ff-9] BRACHIAL INCREASING BLOOD PRESSURE DURING EXERCISE IN NORMOTENSIVE ADULTS M.RM.E Luque, R.M.A. Coching, V.E Combate Jr., H.N. Ong-Garcia, ER. Collado, H.B. Calleja. St. Luke" s Heart Institute, Quezon City,
Philippines Background: Endothelial dysfunction has been implicated in the pathogenesis of coronary artery disease, diabetes, smoking and hypertension. Studies have shown exercise blood pressure to be predictive of future hypertension and its attendant complications. It would be logical then to assume abnormal flow-mediated dilation in normotensives with increasing blood pressure during exercise. Methods: This is a cross-sectional study. Normotensives without known cardiovascular risk factors or drug intake were included, undergoing both endothelial function and treadmill exercise tests. Demographic: clinical and laboratory data were collected and statistically analyzed using Pearson' s correlation. Results: The study population consisted of 70 normotensive patients. There were 37 males (53%) and 33 females (47%). Mean age was 43.81±8.97 years. All had adequate stress tests. There was no significant association between flow-mediated dilatation and resting heart rate, systolic and diastolic blood pressures; peak heart rate and systolic blood pressure; delta systolic and diastolic blood pressure; and MET-adjusted delta systolic and diastolic blood pressures. However, r change for peak diastolic blood pressure was 0.24 with p<0.05. Conclusion: Only peak diastolic blood pressure significantly correlated with flow-mediated dilatation of the brachial artery. This may indicate that endothelial dysfunction and hypertensive diastolic blood pressure response to exercise are closely linked and occur early in the natural history of hypertension compared to changes in systolic blood pressure. ~'~
LOW PARAOXONASE ACTIVITY IS A RISK FACTOR F O R CORONARY HEART DISEASE IN A PROSPECTIVE STUDY
B. Mackness 1, P. Durrington1, P. McElduff2, M. Mackness 1. 1Manchester
Royal Infirmary," 2University of Manchester, UK Background: Human serum paraoxonase (PONt) retards the oxidation of low density lipoprotein (LDL) and could therefore protect against the development of coronary heart disease (CHD). Therefore, we have investigated serum PONt activity as a risk factor for CHD in a prospective study. Materials and Methods: PONt activity towards paraoxon was measured in 1353 men from the Caerphilly and Speedwell prospective study who were followed for up to 8 years. Results: 163 had a CHD event defined as angina (Rose questionnaire), fatal and non-fatal myocardial infarction and the appearance of major or moderate Q waves on a resting ECG. Men in the lowest quintile of PONt activity had a relative risk of developing CHD of t.7 compared to men in the highest quintile of PONt activity (P-0.03t when adjusted for all other CHD risk factors except HI)L). This association became non-significant when HDL was included in the adjustment (P-0.t2). Conclusion: Low PONt activity is a risk factor for CHD in the Caerphilly and Speedwell Prospective Study. PONt is physically located on HDL and is likely to explain part of its apparent protective effect against CHD. [42-1] PREDISPOSING FACTORS IN 100 PATIENTS W I T H SILENT MYOCARDIAL INFARCTION M.L Mahmoudi, M. Gharouni, S. Moradmand, N. Rezaei, M. Mahmoudi, S. Dargahi. Tehran University of Medical Sciences, Tehran, Iran Background and Objectives: Myocardial Infarction (MI), sequelae of Coronary Artery Disease (CAD), can be sometimes asymptomatic, called Silent Myocardial Infarction (SMI). In this study, we intend to determine the predisposing factors in such patients. Methods: We included those patients with electrocardiogram changes, consistent with MI, who had not any symptoms of ischemia or a previous history of CAD, consulted to pre-operative work up of eye surgery during the year 2000. Results: We analyzed tOO patients with the diagnosis of SMI (59males). Among our patients, 99% were above 50 years of age. Their mean age at the time of study was 69.7 years. Seventy eight percent of patients were illiterate. In 41 of them body mass index was above the normal limits (overweight and obese). Their past medical history revealed that 46 patients had hypertension,
38 patients had hyperlipidemia, and 26 cases had diabetes mellitus. Also, a positive family history of CAD was seen in 52% of the patients. The rate of cigarette smokers and opium addicts, among our patients, was 33 and 13 percents, respectively. Analysis of electrocardiogram changes, showed that 43 patients had inferior MI, 24 had anteroseptal, and 17 of them suffered from anterior MI. Conclusions: Almost all of our patients with SMI lied in old age group. Diabetes mellitus, hypertension, overweight, and hyperlipidemia were the most important predisposing factors, found in such patients; Thus, taking into account these elements and control of them would dramatically reduce the prevalence of morbidity and mortality of patients with SMI. ~-~
PLASMA Lp(a) LEVELS AND URINARY 8-ISOPROSTANE/PROSTAGLANDIN F2 ALPHA CONCENTRATIONS IN TRAINING ATHLETES
K. Makino 1, A. Katayama 1, I. Watanabe 2. J Gifu College of Medical
Technology, Seki," 2Asahi University, Gifu, Japan Lp(a) is an independent risk factor for atherosclerosis. Urinary 8-isoprostane/ prostaglandin F2 alpha (8-iso-PGF 2 alpha) is a product of free radical catalyzed peroxidation of arachidonic acid and considered to be a sensitive marker of oxidative stress in vivo. The purpose of this study is to investigate the effect of physical training on plasma Lp(a) levels and on oxidative stress by assessment of urinary 8-iso-PGF 2 alpha concentrations. Methods: 30 running athletes were studied. Plasma Lp(a) and urinary 8-iso-PGF 2 alpha concentrations were determined by EIA. (Results) Serum levels of TC,TG,ApoB,LDL-C and LDL-C/HDL-C ratio were significantly decreased and those of HDL-C and HDL-C/TC ratio were significantly increased in athletes. Principal component analysis demonstrated that Lp(a) was entirely independent of other factors, such as TC,TG,ApoB,HDL-C,LDL-C,LDL-C/HDL-C ratio and LDL-C/TC ratio. There was no significant difference in plasma Lp(a) concentrations between running athletes and control subjects(tJ.9±t6.4 mg/dl, 14.7±14.4 mg/dl). Urinary 8-iso-PGF 2 alpha concentrations were significantly increased in athletes. Conclusions: Plasma Lp(a) concentrations did not appear to be significantly altered by hard exercise. Physical training may be associated with increased oxidative stress, suggesting that Lp(a) will be more atherogenic in training athletes. ~ - 3 ] COMBINED EFFECT OF CHONDROITIN SULFATEMODIFIED SUPEROXIDE DISMUTASE AND CATALASE IN ANTITHROMBOTIC PROTECTION OF VASCULAR WALL A.V. Maksimenko, V.L. Golubykh, E.G. Tischenko. Russian Cardiology Research Center, Institute of Experimental Cardiology, Moscow, Russia Keeping of vascular endothelium against the damage caused by free oxygen radicals is an important factor of antiatherosclerotic protection. With this in mind we studied the antithrombotic activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) chemically conjugated to the vascular wall glycosaminoglycan chondroitin sulfate (CHS). The following compounds were prepared: covalent conjugated SOD-CHS and CAT-CHS, bienzyme covalent conjugate SOD-CHS-CAT, native SOD and CAT, and free CHS. They were tested for antithrombotic activity in a rat model of arterial thrombosis. The rats were given a preventive intravenous bolus administration of the studied compounds (or control), after which aqueous solution of ferrous chloride was applied onto arterial wall. The occlusion time and thrombus mass were determined after t-h blood flow monitoring. The SOD-CHS and CAT-CHS conjugates produced significantly stronger antithrombotic effects than their components injected individually or as a mixture, which emphasizes the importance of covalent conjugation of antioxidant enzymes to CHS. The SOD-CHS conjugate markedly reduced the thrombus mass, while CAT-CHS predominantly preserved blood flow. A single-bolus injection of combination between SOD-CHS and CAT-CHS had a significantly lower antithrombotic effect compared with that of the SOD-CHS-CAT conjugate. This could be explained by different surface distribution of the conjugates in the circulation. Small effective dose of SOD-CHS-CAT conjugate implies prospectiveness of its further biomedical investigation. These findings suggest that the modified antioxidant enzymes can be used in pharmacological and surgical manipulations. The bienzyme conjugate SOD-CHS-CAT could be prospective for intravascular therapeutic injection. The SOD-CHS/CAT-CHS mixture could be useful for surface modification of vascular prostheses and bypasses during surgical revascularization.
73rd EAS Congress