Giray Kabakci

Diastolic dysfunction and increased serum homocysteine concentrations may contribute to increased cardiovascular risk in patients with polycystic ovary syndrome

OBJECTIVE To assess cardiac flow parameters in patients with polycystic ovary syndrome (PCOS). DESIGN A prospective case-control study. SETTING University-based hospital. PATIENT(S) Thirty consecutive patients with PCOS were enrolled. Thirty women with regular menstrual cycles served as the controls. INTERVENTION(S) Systolic and diastolic function parameters were assessed by standard two-dimensional and M-mode echocardiography. Insulin sensitivity was evaluated by a standard 75-g oral glucose tolerance test and area-under-curve insulin analysis. Serum hormones, lipid profile, homocysteine, vitamin B(12), folate, fibrinogen, uric acid, and plasminogen activator inhibitor-I concentrations were measured. MAIN OUTCOME MEASURE(S) Systolic and diastolic function parameters, insulin sensitivity and serum homocysteine levels. RESULT(S) The mean serum homocysteine and uric acid concentrations were significantly higher in the PCOS group. Patients with PCOS had significant hyperinsulinemia. All systolic function parameters were comparable between the two groups. However, patients with PCOS had significantly lower peak mitral flow velocity in early diastole and significantly lower ratio between the early and late peak mitral flow velocities and also had significantly longer isovolumic relaxation time, reflecting a trend for nonrestrictive-type diastolic dysfunction. The area-under-curve insulin correlated positively with peak mitral flow velocity in late diastole (r = 0.375). The mean cholesterol/high-density lipoprotein ratio correlated negatively with mean mitral flow velocity in early diastole (E) peak (r = -0.474). The mean fasting insulin level correlated negatively with mean E/A ratio (r = -0.387). CONCLUSION(S) Diastolic dysfunction and increased serum homocysteine concentrations may contribute to increased cardiovascular disease risk in patients with PCOS.

Assessment of Endothelial Function in Alzheimer's Disease: Is Alzheimer's Disease a Vascular Disease?

OBJECTIVES: To compare endothelial function of people with Alzheimers disease (AD) with that of people without.

Effects of menstrual cycle on cardiac autonomic innervation as assessed by heart rate variability.

Objective: The aim of the study was to investigate the effects of menstrual cycle on cardiac autonomic function parameters in young healthy women by means of heart rate variability (HRV).

Melatonin levels decrease in type 2 diabetic patients with cardiac autonomic neuropathy

Abstract:  The present study has been designed to determine melatonin levels in type 2 diabetic patients and test the relationship between the autonomic nervous system and melatonin dynamics. Thirty‐six type 2 diabetic patients and 13 age‐matched healthy subjects were recruited for the study. Circadian rhythm of melatonin secretion was assessed by measuring serum melatonin concentrations between 02:00–04:00 and 16:00–18:00 hr. Melatonin dynamics were re‐evaluated with respect to autonomic nervous system in diabetic patients with autonomic neuropathy who were diagnosed by the cardiovascular reflex tests, heart rate variability (HRV), and 24‐hr blood pressure monitoring. Nocturnal melatonin levels and the nocturnal melatonin surge were low in the diabetic group (P = 0.027 and 0.008 respectively). Patients with autonomic neuropathy revealed decreased melatonin levels both at night and during day when compared with healthy controls (P < 0.001 and 0.004 respectively) while the melatonin dynamics were similar to controls in patients without autonomic neuropathy. Nocturnal melatonin level was positively correlated with nocturnal high and low frequency components of HRV (P = 0.005 and 0.011 respectively) and systolic and diastolic blood pressures at night (P = 0.002 and 0.004 respectively) in patients with autonomic neuropathy. We found a negative correlation between nocturnal melatonin levels and the degree of systolic blood pressure decrease at night (r = −0.478, P = 0.045). As a conclusion this study has shown that circadian rhythm of melatonin secretion is blunted in type 2 diabetic patients and there is a complex relationship between various components of autonomic nervous system and melatonin secretion at night. Among the patients with autonomic neuropathy those with more preserved HRV and the systolic nondippers (<10% reduction in blood pressure during the night relative to daytime values) have more pronounced melatonin surge at night.

Heart Rate Variability in Young Women with Polycystic Ovary Syndrome

Background: Limited data are available related to the effects of sex hormones on cardiac autonomic function. Few studies investigated the heart rate variability (HRV) parameters during regular menstrual cycle or in postmenopausal women using hormone replacement therapy, but the results were contradictory. The aim of the study was to compare the characteristics of the autonomic innervation of the heart in polycystic ovary syndrome (PCOS) patients with regularly cycling controls.

Advanced Age Is Associated with Endothelial Dysfunction in Healthy Elderly Subjects

Background: Aging is associated with an increased risk for atherosclerosis in which endothelial dysfunction is an early marker. Objective: The purpose of this study was to determine if endothelial function is altered with increasing age in healthy subjects. Method: The study population consisted of 30 elderly and 36 younger subjects free from major cardiovascular risk factors. Transthoracic echocardiography was performed for each subject to rule out structural heart disease. Endothelial function was evaluated by flow-mediated dilation (FMD) of the brachial artery via ultrasound. Results: Baseline characteristics of the elderly and the younger group were similar, except for age (mean age: 71.3 ± 5.8 vs. 26.5 ± 7.2). Transthoracic echocardiography was normal in all subjects. FMD of the elderly group was significantly lower than the younger group (7.9 ± 3.1 in the elderly, 10.8 ± 1.9 in the younger group, p < 0.001). A negative relationship was found between FMD and age (r = –0.528, p < 0.001). Conclusion: It can be concluded that endothelial function detected by FMD declines with increasing age in healthy human subjects. Advanced age is a predictor of impaired endothelial function.

Detection of Subclinical Cardiac Involvement in Systemic Sclerosis by Echocardiographic Strain Imaging

Background: Cardiac involvement is one of the major problems in systemic sclerosis (SSc). Subclinical cardiac involvement has a higher frequency than thought previously. In this study we investigated whether subclinical cardiac involvement can be detected by using echocardiographic strain imaging in SSc patients without pulmonary hypertension. Methods: Echocardiographic examinations were performed to 27 SSc patients and 26 healthy controls. Left ventricular strain parameters were obtained from apical views and average strain value was calculated from these measurements. Results: There were no significant differences between patients and controls regarding two‐dimensional (2D), conventional Doppler and tissue Doppler velocity measurements. Strain was reduced in 6 of 12 segments of the left ventricle (LV) and in 1 of 2 segments of the right ventricle (RV). Strain rate (SR) was reduced in 2 of 12 segments of the LV and 1 of 2 segments of the RV in SSc patients as compared to controls (P < 0.05 for all). These involvements did not match any particular coronary artery distribution. More important differences were detected by average strain and SR values of the LV between patients and controls (19.78 ± 3.00% vs 23.41 ± 2.73%, P < 0.001; 2.01 ± 0.41 vs 2.23 ± 0.27/sec, P = 0.026, respectively). Furthermore, carbon monoxide diffusion capacity (DLCO) in scleroderma patients significantly correlated with LV average strain (r = 0.59; P = 0.001). Conclusion: Evaluation of ventricular function by using echocardiographic strain imaging appears to be useful to detect subclinical cardiac involvement in SSc patients with normal standard echocardiographic and tissue Doppler velocity findings.

Relationship between Endogenous Sex Hormone Levels, Lipoproteins and Coronary Atherosclerosis in Men Undergoing Coronary Angiography

This study was carried out in order to investigate the relationship between endogenous sex steroid hormones and coronary artery disease (CAD). Three hundred and thirty-seven men undergoing coronary angiography were enrolled in the study. Total testosterone, estradiol, free testosterone levels in men with CAD (n = 213) were compared to those of men without CAD (n = 124). No significant differences were found in the serum concentrations of estradiol, total and free testosterone and serum lipid profile between the two groups. Total and free testosterone were negatively (p < 0.05 to p < 0.001) and estradiol was positively (p < 0.05) correlated with age in both groups. Total cholesterol and low-density-lipoprotein levels were positively correlated with the level of free testosterone (r = 0.221, p < 0.01; r = 0.173, p < 0.05, respectively), and high-density-lipoprotein levels were negatively correlated with total testosterone in patients with CAD (r = –0.166, p < 0.05). The results of this study do not support the role of sex steroid hormones in CAD. However, the relationship between sex steroids and serum lipids needs further clarification.

Tissue Doppler echocardiography can be a useful technique to evaluate atrial conduction time

BACKGROUND The main purpose of this study is to determine the correlation of inter- and intraatrial conduction times between the electrophysiological and tissue Doppler echocardiographic measurements, and to evaluate the appropriateness of tissue Doppler echocardiography for this measurement. METHODS One-hundred and one patients were included in the study who underwent electrophysiological study for clinical arrhythmias. Inter- and intraatrial conduction times were measured from intracardiac electrograms. Atrial conduction times were also measured by tissue Doppler echocardiography by evaluating atrial electromechanical delay between lateral mitral annulus, septal mitral annulus, and right ventricular tricuspid annulus. The correlation between electrophysiological and echocardiographic atrial conduction times were analyzed. RESULTS We found a weak correlation between the measurements of interatrial conduction times with the electrophysiological and tissue Doppler techniques (r = 0.308; p = 0.002). The correlation for intraleft atrial conduction times was moderate (r = 0.652; p 〈 0.001). There was no correlation between the measurements of intra-right atrial conduction times. CONCLUSIONS We concluded that tissue Doppler echocardiography can be used for the measurement of interatrial and intra-left atrial conduction times. Tissue Doppler echocardiography can be a suitable technique to evaluate atrial substrate.

Serum uric acid levels predict the severity and morphology of coronary atherosclerosis detected by multidetector computed tomography.

In this study, we aimed to evaluate whether serum uric acid (UA) was associated with the severity and morphology of coronary atherosclerotic plaques (CAP) shown by multidetector computed tomography (MDCT). The study population consisted of 982 patients (58% men) who underwent dual-source 64 slice MDCT for the assessment of coronary artery disease (CAD). Coronary arteries were evaluated on 16 segment basis and critical coronary plaque was described as luminal narrowing >50%, whereas plaque morphology was assessed on per segment basis. Serum UA levels were determined using commercially available assay kits. The critical atherosclerotic lesions were detected in 454/982 (46.2%) subjects by MDCT. Serum UA levels were found to be higher in patients with any coronary plaque (6.9 ± 1.5mg/dL vs. 5.1 ± 1.3mg/dL, p<0.01). Also UA level was higher in patients with critical stenosis compared to non-critical stenosis (6.1 ± 1.5mg/dL vs. 5.4 ± 1.3mg/dL, p<0.001). Subjects having primarily calcified plaques have higher UA levels compared to other plaque subtypes (5.5 ± 1.3 for non-calcified plaques, and 5.6 ± 1.2 for mixed plaques, 6.6 ± 1.6 for calcified plaques, p<0.001). This independent association was remained after multinominal regression analysis (OR: 1,987; 95% CI; 1.69-2.32; p<0.01). Our study demonstrated that serum UA level was significantly associated with the severity and the calcified morphology of CAP detected by MDCT. Further prospective clinical studies are needed to clarify the exact physiopathologic role of UA in CAD.