The Endothelial Nitric Oxide Synthase (NOS3-786T>C) Genetic Polymorphism in Chronic Heart Failure: Effects of Mutant -786C allele on Long-term Mortality.

BACKGROUND: Nitric oxide plays an important role in the regulation of basal vascular tone and cardiac myocyte function. We investigated the NOS3-786T>C polymorphism in chronic heart failure (CHF) and its effects on long-term mortality. METHODS: Ninety-one patients with CHF who were referred to the Department of Cardiology of Siyami Ersek Cardiovascular and Thoracic Surgery Center for cardiopulmonary exercise testing between April 2001 and January 2004 and 30 controls were enrolled in this study. Patient were followed prospectively for a period of 1 to 12 years. RESULTS: Patients and controls were divided into three groups: TT, TC and CC, according to their NOS3-786T>C polymorphism. We noted that there was no significant difference in the genotype distribution between patients and controls. There was also no significant difference in endothelial nitric oxide synthase (eNOS) gene polymorphism between ischemic HF and nonischemic HF. During the follow-up period, 61 (67%) deaths occurred. The nonsurvivor group had lower left ventricular ejection fraction (LVEF) (p = 0.01), reduced peak oxygen consumption (p = 0.04) and were of older age (p = 0.001). Age, LVEF, peak oxygen consumption and genotype were found to be predictors of mortality (p < 0.05). Additionally, mortality was significantly increased in -786CC genotype patients compared to TT genotype patients (hazard ratio = 2.2; p = 0.03). By multivariate analysis, age and eNOS genotype were determined to be significant independent predictors of death. Additionally, Kaplan-Meier analysis confirmed that homozygote -786C genotype was associated with an increased risk of death (χ2 = 4.6, p = 0.03). CONCLUSIONS: Our findings showed that the NOS3-786T>C polymorphism was associated with an increased risk of mortality in patients with CHF.

Serum paraoxonase 1 activity in women with metabolic syndrome.

BACKGROUND: Metabolic syndrome (MetS) is a leading risk factor for coronary artery disease (CAD) in women. Reduced paraoxonase 1 (PON1) activity may play a role in the pathogenesis of atherosclerosis through increased susceptibility to lipid peroxidation in patients with MetS. AIM: To examine whether there is a relationship between serum PON1 activity and MetS in women. METHOD: The study group consisted of 54 women with MetS. The NCEP ATP III guidelines were used to define MetS. The control group consisted of 65 women without MetS and CAD. All patients from the MetS group underwent coronary angiography. RESULTS: The PON1 activity and salt-stimulated PON1 activity were not significantly altered in women with MetS when compared to controls (p = 0.902, p = 0.877, respectively). There was no significant difference in PON1 activity (p = 0.159), and salt-stimulated PON1 activity (p = 0.139) between diabetics and non-diabetics. In the MetS group, patients with CAD (n = 16) had significantly reduced PON1 activity and salt-stimulated PON1 activity compared to MetS patients without CAD (p = 0.008 and p = 0.004, respectively). CONCLUSIONS: Serum PON1 activity is significantly reduced in women with CAD and MetS. MetS per se does not alter serum PON1 activities.

The impact of CYP2C9 and VKORC1 genetic polymorphism and patient characteristics upon warfarin dose requirements in an adult Turkish population.

In this study, we investigated the contribution of vitamin K epoxide reductase (VKORC1) and cytochrome P450 2C9 (CYP2C9) genotypes, age, and body surface area (BSA) on warfarin dose requirements and in an adult Turkish population. Blood samples were collected from 100 Turkish patients with stable warfarin dose requirements and an international normalized ratio (INR) of the prothrombin time within the therapeutic range. Genetic analyses for CYP2C9 genotypes (*2 and *3 alleles) and VKORC1 -1639 G>A polymorphism were performed and venous INR determined. The mean warfarin daily dose requirement was higher in CYP2C9 homozygous wild-type patients, compared to those with the variant *3 allele (P < 0.05), similar to those with the variant *2 allele (P > 0.05) and highest in patients with the VKORC1 -1639 GG genotype compared to those with the GA genotype and the AA genotype (P < 0.01). The time to therapeutic INR was longer in CYP2C9 homozygous wild-type patients compared with those with the variant *2 and *3 alleles (P < 0.01), and longer in patients with the VKORC1 (position -1639) GG genotype compared with those with the GA genotype and the AA genotype (P < 0.01). The multivariate regression model including the variables of age (R (2) = 4.4%), BSA (R (2) = 27.4%), CYP2C9 (R (2) = 8.1%), and VKORC1 genotype (R (2) = 34.1%) produced the best model for estimating warfarin dose (R (2) = 60.4%). VKORC1 genotype and CYP2C9 polymorphism affect daily dose requirements and time to therapeutic INR in Turkish patients receiving warfarin for anticoagulation.

Effects of drug-eluting stents on systemic inflammatory response in patients with unstable angina pectoris undergoing percutaneous coronary intervention.

Inflammatory markers are elevated in acute coronary syndromes, and are also known to play a crucial role in the pathogenesis of neointimal proliferation and stent restenosis. Drug-eluting stents (DESs) have been shown to decrease stent restenosis in different studies. In this study, we aimed to investigate the effect of treatment with DESs on systemic inflammatory response in patients with unstable angina pectoris who underwent percutaneous coronary intervention (PCI). We compared plasma high-sensitivity C-reactive protein (hsCRP), human tumor necrosis factor alpha (Hu TNF-alpha), and interleukin 6 (IL-6) levels after DES (dexamethasone-eluting stent [DEXES], and sirolimuseluting stent [SES]) implantation with levels after bare metal stent (BMS) implantation. We performed PCI with a single stent in 90 patients (62 men; 59 +/- 9 years of age; n = 30 in the BMS group, n = 30 in the DEXES group, n = 30 in the SES group) who had acute coronary syndrome. Plasma hsCRP, Hu TNF-alpha, and IL-6 levels were determined before intervention and at 24 h, 48 h, and 1 week after PCI. The results were as follows. Plasma hsCRP levels at 48 h (11.19 +/- 4.54, 6.43 +/- 1.63 vs 6.23 +/- 2.69 mg/l, P = 0.001) after stent implantation were significantly higher in the BMS group than in the DES group; this effect persisted for 7 days (P = 0.001). Plasma Hu TNF-alpha levels at each time point were higher in the SES group than in the BMS and DEXES groups (P < 0.05). The time course of Hu TNF-alpha values was similar in all groups. Although IL-6 levels at baseline and at 24 and 48 h showed no statistically significant difference between the study groups, postprocedural values at 7 days were slightly statistically significant in the SES group (P = 0.045). Drug-eluting stents showed significantly lower plasma hsCRP levels after PCI compared with BMSs. This may reflect the potent effects of DESs on acute inflammatory reactions induced by PCI.

Endothelial nitric oxide synthase gene (T-786C) polymorphism in patients with slow coronary flow.

OBJECTIVES: In this study, we aimed to investigate the relationship between T-786C polymorphism of the endothelial nitric oxide synthase (eNOS) gene and slow coronary flow (SCF). STUDY DESIGN: A total of 56 patients with SCF but otherwise normal coronary arteries (mean age 48+/-9 years) and 37 controls with normal coronary angiograms (mean age 50+/-12 years) were enrolled in the study. Screening for the eNOS T-786C polymorphism was performed by restriction fragment length polymorphism methodology. RESULTS: In normal coronary artery and SCF groups, TT genotype frequency was 23 (62.2%) versus 22 (39.3%), TC heterozygote genotype frequency was 11 (29.7%) versus 30 (53.6%), and CC homozygote genotype frequency was 3 (8.1%) versus 4 (7.1%), respectively (P=0.07). In dominant model statistical analysis, total CC and CT genotype frequency in control and study groups was found to be 14 (37.3%) versus 34 (60.7%), respectively (P=0.025). A positive correlation was found between the mean thrombolysis in myocardial infarction frame count and C allele in patients with SCF (r=0.21, P=0.043). CONCLUSION: We concluded that the T-786C polymorphism of eNOS gene might be a risk factor for the SCF.

Tissue Doppler imaging adds incremental value in predicting exercise capacity in patients with congestive heart failure.

Left ventricular (LV) systolic and diastolic parameters derived from Doppler echocardiography have been used widely to predict functional capacity but diastolic filling is affected by various factors. Tissue Doppler imaging (TDI) that records systolic and diastolic velocities within the myocardium and at the corners of the mitral annulus, has been shown to provide additional information about regional and global LV function. The goal of this study was to examine whether TDI-derived parameters add incremental value to other standard Doppler echocardiographic measurements in predicting exercise capacity. The study enrolled 59 consecutive patients with stable congestive heart failure (CHF). The etiology of heart failure was coronary artery disease in 42 patients and dilated cardiomyopathy in 17. Twenty-three age-matched healthy subjects were recruited as controls. Conventional echocardiographs and TDI were obtained. Early (Ea) and late (Aa) diastolic and systolic (Sa) mitral annulus velocities, the Ea/Aa and E/Ea ratios, were measured by pulsed wave TDI placed at the septal side of the mitral annulus and results were compared with results of cardiopulmonary exercise testing. Systolic and early diastolic velocities of mitral annulus were decreased and the E/Ea ratio was increased in the restrictive group as compared to controls (P = 0.02, P = 0.03, P < 0.001, respectively) but there was no significant difference in late diastolic velocity and the Ea/Aa ratio between the restrictive group and controls. The average peak VO2 of the patients were 14.9 +/- 4.9 ml/min per kg. Achieved peak VO2 of the patients with E/Ea ratio 7.5 (P < 0.001). Interestingly, the patients with the nonrestrictive pattern and E/Ea ratio >7.5 had reduced exercise capacity, as did the group with restrictive LV filling patterns (12.8 +/- 3.3 vs 12.9 +/- 4.0 ml/min per kg, P = 0.9). Similarly, there was no significant difference in the mean exercise capacity between the patients with a nonrestrictive pattern vs restrictive pattern with E/Ea ratio 7.5 was used, 21 out of 24 patients in the reduced exercise capacity group were identified with 16 false positives in the preserved exercise capacity group (P = 0.001). Mitral annular systolic and diastolic velocities of TDI were associated with cardiopulmonary exercise capacity in patients with LV systolic dysfunction. Index of the E/Ea ratio was found to be the most powerful predictor of peak oxygen uptake.

The role of paraoxonase (PON) enzyme in the extent and severity of the coronary artery disease in type-2 diabetic patients.

Increased coronary artery disease (CAD) risk is well established in diabetes mellitus (DM). Paraoxonase (PON) enzyme is known to have protective effects on lipid peroxidation. This study aimed to investigate the changes in PON activity levels with duration of DM as well as the role of PON activity in progression of CAD. Eighty-four consecutive diabetic patients (mean age 58 years, 46 men) who underwent coronary angiography for diagnostic purposes were examined. Before the angiography, fasting venous blood samples were taken for PON enzyme activity, thiobarbituric acid reactive substances (TBARS), and routine biochemical parameters. Severity and extent of coronary atherosclerosis were scored numerically using the Gensini scoring system. The population was divided into three groups according to Gensini score: Group 1, mild CAD; Group 2, moderate CAD; Group 3, severe CAD. Group 1 had higher PON levels and shorter DM duration than those of Group 3. Gensini score was significantly correlated with, PON activity (r = -0.361) and apo-AI (r = -0.375). TBARS (r = -0.290) and the duration of DM (r = -0.336) also showed a significant correlation with PON activity levels. Also, multivariate linear regression and Pearson correlation analyses showed that PON activity (P = 0.04), apo-AI levels (P = 0.01), and the duration of DM (P = 0.003) were significantly associated with Gensini score. Paraoxonase activity decreases parallel to DM duration. The lack of protective effect of PON enzyme on lipid peroxidation may be a factor in acceleration of CAD in DM.

Exercise-induced increase in lipid peroxidation in patients with chronic heart failure: relation to exercise intolerance.

BACKGROUND: Little is known about the relationship between exercise intolerance and lipid peroxidation in chronic heart failure (CHF) patients. This study was designed to investigate the relationship between exercise-induced plasma malondialdehyde (MDA) changes in CHF patients and to determine whether there is any association between plasma MDA levels and exercise capacity assessed by cardiopulmonary exercise testing. METHODS: Cardiopulmonary exercise testing was applied to 31 CHF patients (16 ischemic, 15 idiopathic) and controls. Rest and peak exercise blood samples were analyzed for MDA. RESULTS: Patients with CHF had elevation of plasma MDA levels during exercise compared with controls (p < 0.001 vs. p = 0.588). MDA change remained significant both in ischemic and idiopathic cardiomyopathy groups (p < 0.05 and p < 0.01, respectively). Delta MDA (peak exercise MDA - rest MDA) showed significant inverse correlation with peak oxygen consumption in patients with CHF. CONCLUSION: Lipid peroxidation is increased in patients with CHF during exercise regardless of etiology, and this increase is inversely related to oxygen consumption.

Plasma homocysteine concentration in patients with poor or good coronary collaterals.

BACKGROUND: Elevated plasma homocysteine (Hcy) concentrations are associated with an increased risk of vascular disease. Hcy is known to inhibit endothelial cell proliferation in vitro. The purpose of the present study was to investigate the role of plasma Hcy concentrations on development of collateral circulation in single-vessel chronic total occlusion. METHODS AND RESULTS: Collateral status was determined by Rentrop's classification. Of 817 patients, 56 cases of pure single-vessel chronic total occlusion were studied. Plasma Hcy concentrations in patients with single-vessel total coronary occlusion were higher compared with controls (17.3 +/-12.6 micromol/L vs 10.9+/-4.9 micromol/L, p=0.015). There was no significant difference in plasma Hcy concentrations of the good and poor collateral groups (17.2+/-13.7 micromol/L vs 15.3+/-9.3 micromol/L, p=0.834). Plasma Hcy concentrations in individual Rentrop subclasses 0, 1, 2 and 3 were as follows: 15.9 +/-9.1, 16.3+/-12.4, 17.1+/-14.1 and 20.1+/-13.5 micromol/L (p=0.893). There was a positive linear correlation between Rentrop subclass and angina pectoris duration (r=0.41, p=0.003). Angina pectoris duration was the only independent variable affecting the development of coronary collaterals in the present study (odds ratio [confidence interval]: 1.85 [1.12-2.91], p=0.014). CONCLUSION: Patients with single-vessel chronic total occlusion had higher plasma Hcy concentrations than controls, but similar Hcy concentrations when compared according to the presence of poor or good coronary collaterals. There is a lack of association between plasma Hcy concentration and coronary collateral status in the current study.

The relationship between endothelial nitric oxide synthase gene polymorphism (T-786 C) and coronary artery disease in the Turkish population.

Previous studies revealed that there were various mutations on endothelial nitric oxide synthase (eNOS) gene and these mutations might be a risk factor for coronary artery disease (CAD), myocardial infarction (MI), and hypertension (HT). In this study, we aimed to investigate the relationship between eNOS gene polymorphism (T-786 C) and coronary artery disease in the Turkish population. Two hundred and eleven unrelated individuals (152 male, 59 female, mean age 59 years, range 27-85) whose angiographic examinations were performed in our hospital were enrolled into the study; 159 of these had angiographically determined coronary artery lesions (>or=50% stenosis at least in one vessel). Fifty-two individuals were free of coronary artery disease on their coronary angiography. The Gensini scoring system was used to determine the severity of the CAD. The polymerase chain reaction (PCR) method was used for genotyping the individuals. To determine the independent risk factors for coronary artery disease, multivariate logistic regression analysis was used. The variant distribution of the T-786 C polymorphism was as follows. For all individuals: TT 94 (44.5%), TC 88 (41.7%), CC 29 (13.8%); in CAD patients: TT 63 (39.6%), TC 73 (45.9%), CC 23 (14.5%); and in normal individuals: TT 31 (59.6%), TC 15 (28.8%), CC 6 (11.5%). There was a statistically significant difference in the variant distribution between CAD and normal individuals (P<0.05). On the other hand, when we compared the frequency of the at-least-one-C-allele carriers (CC+TC, dominant model) and TT homozygous, those with at least one C allele were more prevalent in CAD patients. The results were as follows. In coronary artery disease patients: CC+TC 96 (60.4%), TT 63 (39.6%); in normals: TC+CC 21 (40.4%), TT 31 (59.6%) (P<0.01). When we compared the allele distribution (T vs C, additive model) between CAD patients and normal controls, the results were as follows: T 0.625 vs 0.740, C 0.375 vs 0.260; there was also a statistically significant association between CAD and C allele (P<0.05). When we compared the means of the Gensini scores between each genotype of the T-786 C mutation, there was a statistically significant difference. The results were TT (48.6+/-37.3, median 43.0), TC (55.4+/-41.2, median 41.0), CC (77+/-43.6, median 80.0) (P<0.05). Multivariate logistic regression analysis revealed that C-dominant (CC+TC) individuals had 2.9-fold more likelihood to suffer from CAD (odds ratio: 2.902; confidence interval: 1.272-6.622) (P<0.05). We conclude that the T-786 C polymorphism of eNOS gene might be a risk factor for coronary artery disease in the Turkish population.

Single high-dose bolus tirofiban with high-loading-dose clopidogrel in primary coronary angioplasty.

Glycoprotein IIb/IIIa inhibitor therapy during primary percutaneous coronary intervention (PCI) decreases the incidence of major adverse cardiac events. These effects directly result from the level of platelet inhibition. It was shown that standard dosing of tirofiban is insufficient for optimal platelet inhibition. We sought to determine the efficacy and safety of single high-dose bolus (HDB) tirofiban with high-dose clopidogrel loading in primary PCI in acute ST elevation myocardial infarction. A total of 100 patients (mean age 55.2 +/- 9.9 years, male/female = 86/14) undergoing primary PCI, pretreated with clopidogrel (450 mg) and aspirin (325 mg), were consecutively randomized into two groups. Group I (n = 50) received a standard dose bolus of tirofiban (10 microg/kg/3 min) with 24-h infusion at a rate of 0.15 microg/kg/min. Group II received single HDB tirofiban (25 microg/kg/3 min). The assessed angiographic, clinical, and echocardiographic endpoints were: initial and final Thrombolysis in Myocardial Infarction (TIMI) grade flow (TGF), corrected TIMI frame count (CTFC), ST-segment resolution (STR) at 90 min, in-hospital bleeding complications, echocardiographic left ventricular ejection fraction (LVEF), death, reinfarction, and repeat target vessel revascularization at 1 month. Platelet function inhibition was measured using PFA-100 (Behring-Dade, Liederbach, Germany) with a test cartridge unit containing a membrane coated with 2 microg of equine Type I collagen and 50 microg adenosine diphosphate before, and 10 min, 2, 4, 6, 12, and 24 h after the bolus of the tirofiban in the first 10 cases of each group. There were no significant differences in baseline characteristics between groups. Initial TGF III was more frequent (24% vs 8%, P = 0.029) and the value of CTFC was lower (75 +/- 34 vs 89 +/- 25, P = 0.03) in group II. Postprocedural TGF, CTFC, STR, bleeding complications, and LVEF at 1 month were not different between the two groups. There was a higher rate of reinfarction in group II (8%) compared with group I (2%), but this difference was not statistically significant (P > 0.05). The results of platelet function analyses showed that group II patients had significantly prolonged platelet function assay closure times (299 +/- 6 s) compared with group patients (236 +/- 97 s) at 10 min after the bolus dose (P = 0.04). However, after the first dose between 2 and 24 h, PFA closure times were significantly prolonged in patients with tirofiban infusion. High-dose bolus of tirofiban seems to be safe and more effective than conventional dose at the periprocedural time, whereas continuous infusion of tirofiban may be necessary in the first 24 h before stable and safe antiplatelet status is reached with clopidogrel. However, safety and efficacy of HDB tirofiban and high-loading-dose clopidogrel together with tirofiban infusion requires further studies with a larger population.

Exercise intensity and its effects on thyroid hormones.

BACKGROUND: Physical activity influences energy metabolism in human subjects by increasing activity-induced energy expenditure and resting metabolic rate for several hours after exercise. Effects of exercise on circulating thyroid hormone values remain controversial. We have investigated the effect of acute aerobic exercise on thyroid hormone values. MATERIALS/METHODS: The effect of different intensity levels of acute aerobic exercise on thyroid hormones was investigated in 60 male well-trained athletes by performing bicycle ergometer at 45% (low intensity), 70% (moderate intensity), and 90% (high intensity). These intensities were selected according to their maximum heart rate (MHR). At each intensity level, heart rate, blood lactic acid, serum total thyroxine (T4), free thyroxine (fT4), total triiodothyronine (T3), free triiodothyronine (fT3) and thyroid stimulating hormone (TSH) values were measured. RESULTS: The results of this study show that exercise performed at the anaerobic threshold (70% of maximum heart rate, lactate level 4.59 +/- 1.75 mmol/l) caused the most prominent changes in the amount of any hormone values. While the rate of T4, fT4, and TSH continued to rise at 90% of maximum heart rate, the rate of T3 and fT3 started to fall. CONCLUSIONS: Maximal aerobic exercise greatly affects the level of circulating thyroid hormones.

Influence of angiotensin converting enzyme insertion/deletion polymorphism on long-term total graft occlusion after coronary artery bypass surgery.

BACKGROUND: The renin-angiotensin system has a very important role in coronary thrombosis and restenosis. Plasma angiotensin converting enzyme (ACE) activity is associated with an insertion/deletion polymorphism in the gene coding for ACE. It is known that there is a strong correlation between ACE DD and atherosclerosis. However, little has been documented about its role in venous graft failure. The objective of this study was to investigate the relationships among the ACE gen polymorphism and long-term vein graft occlusion. METHODS: The study population consisted of 87 consecutive white patients with symptomatic coronary artery disease in the previous month, who had had aorto-coronary bypass surgery (ACBS) more than 5 years back and who underwent coronary angiography for diagnostic purposes. On the same day of angiography, 10 mL whole blood was taken for ACE gene insertion/deletion (I/D) polymorphism. RESULTS: Mean age of the patients was 64.4 +/- 8.6 years, and 71 (82%) of the patients were men. The average ACBS time was 7.9 +/- 1.9 years. The ACE genotype was II in 15 patients (17.2%), ID in 47 patients (54.0%), and DD in 25 patients (28.7%). Thus, D allele frequency was .82. There was no significant difference between the cases with regard to age, body mass index, blood pressure status, plasma glucose level, plasma lipid profile, smoking status, average of ACBS time or family history of coronary heart disease. In ACE II group 5 patients had total venous graft occlusion, in ACE ID group 27 patients had total occlusion and in ACE DD group 20 patients had at least one graft total occlusion. The frequency of the venous graft occlusion about total venous grafts is 36% in the ACE II group, 49% in the ACE ID group, and 80% in the ACE DD group (P = .01). CONCLUSION: The ACE I/D gene polymorphism is associated with long-term survival of venous conduit. The ACE DD genotype or D allele influences the angiographic outcome of patients post-ACBS. These data suggest that routine determination of the ACE genotype may help identify patients who are at higher risk of venous graft failure after ACBS.

Long-term combined therapy with losartan and an angiotensin-converting enzyme inhibitor improves functional capacity in patients with left ventricular dysfunction.

OBJECTIVE: The efficacy of angiotensin-converting enzyme (ACE) inhibitors in the treatment of heart failure (HF) is well documented. However, ACE inhibitors may provide incomplete blockade of the renin-angiotensin-aldosterone system due to the alternative pathways for the production of angiotensin II (Ang II). The aim of this study was to evaluate the efficacy of combined therapy of an ACE inhibitor and the Ang II receptor blocker losartan in patients with HF by using cardiopulmonary exercise testing (CPET) on a treadmill. METHODS AND RESULTS: Seventeen patients (ejection fraction < or = 40%) were included in the study group. At the start of the study, all participants were on chronic ACE inhibitors therapy. Fifty mg losartan was added to the treatment and CPET was performed before and 6-8 months after starting losartan therapy. Sixteen patients with HF were included in the control group. CPET was performed once at the beginning and repeated 6-8 months later without any change in the treatment protocol. The change in CPET values (walk-time (WT), peakVO2, anaerobic threshold (AT), minute ventilation (VE), VE/VO2, peak heart rate (HR),VO2/HR) was investigated. In the losartan-treated group a significant increase was noted in WT (393 +/- 157 vs. 507 +/- 155 sec, p < 0.01); peak VO2 (1205 +/- 240 vs. 1330 +/- 253 ml/min, p < 0.05); and AT (794 +/- 131 vs. 895 +/- 177 ml/min, p < 0.05). In the control group exercise parameters did not change significantly. The change from baseline to follow-up between the two groups is statistically significant for WT and peak VO2 (114 +/- 94 vs. -58 +/- 134 sec, p < 0.0 1 and 125 +/-183 vs. -116 +/- 221 ml/min, p <0.01). CONCLUSIONS: Addition of losartan to the ACE inhibitor therapy in patients with HF improves functional capacity in the long run.

Effects of exercise on visual evoked potentials.

The aim of this study was to investigate the effects of acute or habitual exercise on visual evoked potentials (VEP). The study group consisted of 9 female and 7 male volleyball players and the control group contained 9 female and 7 male students who were not involved in any sportive activity. The N75, P100, and N145 latency and amplitudes were measured before and after exercise. Intragroup comparison was made to evaluate the acute effects and intergroup comparison for the chronic effects of exercise. Significant differences were noted between athletes and the sedentary subjects in terms of pre-exercise left-N145 latencies and amplitudes and left -P100 amplitudes. Right-eye N145 latencies of inactive female subjects obtained before and after exercise were also statistically different. The results suggest that acute and habitual exercise affects the VEP responses independent from the body temperature and other physiological parameters. Small sized pre-exercise P100 amplitudes in the athletes can be attributed to the effect of rapid visual-activity-demanding sports on the central nervous system. Visual evoked potentials maybe used as neurophysiological criteria in defining the performance of an athlete.

The effect of exercise on salivary IgA levels and the incidence of upper respiratory tract infections in postmenopausal women.

OBJECTIVES: To examine the patterns of upper respiratory tract infections (URTI) in postmenopausal Turkish women and the relationship of moderate aerobic exercise with secretion of salivary IgA and episodes of URTI. MATERIALS AND METHODS: Ninety healthy, sedentary women at ages 45 to 65 years volunteered to participate in a 12-week prospective study. They were randomized to three groups equal in number: indoor exercise, outdoor exercise, and no exercise. The exercising women were supervised during 30 min indoor treadmill walk or outdoor track walking sessions during 5 days/week at 60% of their calculated maximal heart rate. During a 12-week exercise program, episodes suggestive of URTI were recorded. Non-exercising women were followed with weekly telephone calls. The salivary IgA levels were measured in all the subjects before and at the end of the study. RESULTS: There were significant differences between the exercising and non-exercising women with respect to the number of URTI episodes and the length of URTI symptomatology per episode in favor of exercise. No significant difference was found between the indoor and outdoor exercising groups. The salivary IgA levels showed no significant differences between the three groups and within each group. CONCLUSION: Moderate intensity aerobic exercise is associated with fewer episodes of URTI and fewer days of URTI symptomatology per episode in healthy postmenopausal Turkish women, but this does not seem to be related to salivary IgA concentrations.

Angiotensin-converting enzyme gene polymorphism, left ventricular remodeling, and exercise capacity in strength-trained athletes.

The mechanisms that regulate the development of human physiological cardiac hypertrophy remain poorly understood. The renin-angiotensin system, which is modulated by genetic polymorphism, plays an important role in the regulation of vascular tone and myocardial hypertrophy. Although a few studies have analyzed the association of angiotensin-converting enzyme (ACE) polymorphism and left ventricular (LV) hypertrophy in isotonic exercise-trained subjects who developed eccentric cardiac hypertrophy, there has been no research done in power athletes who developed concentric cardiac hypertrophy. We have hypothesized that ACE genotypic modulation characteristics may affect LV mass in power athletes. This study included 29 elite Caucasian wrestlers (mean age, 22.6 years) and 51 age-matched sedentary subjects. According to the absence or presence of the insertion segment in the polymerase chain reaction (PCR) product, the subjects were classified as homozygous deletion-deletion (DD), insertion-insertion (II), or heterozygous insertion-deletion (ID). The association of LV hypertrophy with ACE gene insertion/deletion (I/D) polymorphism was analyzed. Left ventricular mass and index were determined by echocardiography. Angiotensin-converting enzyme genotyping was performed on peripheral leukocytes using the polymerase chain reaction technique. The study and control group subjects were similar in height and weight. Left ventricular hypertrophy in the athletes was more apparent than in the controls. Angiotensin-converting enzyme genotype II frequency was 17.2% (5) in the athletes, 17.6% (9) in the controls; ID frequency was 51.7% (15) in the athletes, 56.8% (29) in the controls; and the DD frequency was 31% (9) in the athletes and 25.4% (13) in the controls. Left ventricular mass and mass index were found to be higher in genotype DD (126.2 +/- 2.9g/m2) than genotype II (85.5 +/- 4.0g/m2) or genotype ID (110.1 +/- 2.3g/m2) in the athletes (P < 0.001). Furthermore, maximal oxygen consumption in genotype DD was found to be higher than in II and ID. An association was found between ACE gene I/D polymorphism and LV hypertrophy in strength-trained athletes.