Dursun Dursunoglu

Neck circumference as a measure of central obesity: Associations with metabolic syndrome and obstructive sleep apnea syndrome beyond waist circumference

BACKGROUND & AIMS To investigate the relationship of neck circumference (NC) to metabolic syndrome (MetS) and obstructive sleep apnea syndrome (OSAS) and whether it adds information to that provided by waist circumference. METHODS Cross-sectional analysis of a population sample of 1,912 men and women, aged 55.1 +/- 12 years, representative of Turkish adults. MetS was identified based on modified criteria of the ATP-III, OSAS when habitual snoring and episodes of apnea were combined with another relevant symptom. RESULTS NC measured 36.7 (+/- 3.5) cm in the total sample. It was significantly correlated with numerous risk factors, above all body mass index and waist girth (r > or = 0.6), homeostatic model-assessed insulin resistance, blood pressure and, inversely, with smoking status and sex hormone-binding globulin. Sex- and age-adjusted NC was associated significantly with MetS, at a 2-3-fold increased likelihood for 1 standard deviation (SD) increment. After further adjustment for waist circumference and smoking status, a significant residual odds ratio (OR, 1.13 [95% CI 1.08; 1.19]) persisted, corresponding to ORs of 1.53 and 1.27 in males and females, respectively, for 1 SD increment. Even when adjusted for all MetS components, a residual OR (1.08 [95% CI 1.000; 1.17]) remained. Sex- and age-adjusted NC was associated significantly also with OSAS in genders combined, independent of waist girth, yielding an added OR of 1.3 for 1 SD increment. CONCLUSIONS NC contributes to MetS likelihood beyond waist circumference and the MetS components. Regarding association with OSAS, NC is of greater value than WC among Turkish men, not women.

Heart rate variability in patients with rheumatoid arthritis

Heart rate variability (HRV) is a useful tool for the detection of sympathetic-parasympathetic balance in the autonomic nervous system. Autonomic nervous system involvement in patients with rheumatoid arthritis (RA) has rarely been studied and has shown conflicting results. Our purpose was to determine if HRV showed changes in patients with RA in comparison with the normal population. Short-term analysis of HRV was performed for time-domain frequency in 42 patients with RA and 44 matched controls. In this analysis, patients displayed lower standard deviation of the mean than healthy subjects (P<0.0001). Patients tended to display higher pNN50 and root-mean-square of successive difference values than did healthy subjects, but these differences were not statistically significant (P>0.05). In frequency domain analysis, the spectral measures of HRV showed reduced high-frequency (HF) values and an higher low-frequency (LF) values; as a result, the ratio between low and high frequencies (LF/HF), representative of sympathovagal modulation, was significantly increased (P=0.001, P=0.012, and P=0.003, respectively). Our data suggest an increase in sympathetic control of the heart rate in patients with RA. This increased sympathetic activity could play a key role in the development of ventricular tachyarrhythmias in RA and may be related to the higher incidence of sudden death in this disorder.

Time and frequency domain analyses of heart rate variability in patients with epilepsy.

Heart rate variability (HRV) is a useful tool for the detection of sympathetic-parasympathetic balance of autonomic nervous system in patients at risk of sudden death (SD). SD is more common in patients with epilepsy and the exact mechanisms of SD are unknown. Autonomic nervous system involvement in patients with epilepsy has rarely been studied and has shown conflicting results. Our purpose was to determine if HRV showed any changes in patients with epilepsy in comparison with normal population. A short period analysis of HRV was performed for both the frequency and time domain in 43 epilepsy patients who had generalized tonic-clonic seizures (GTCS) and who were not taking any medications and also in 43 age and sex matched controls. In the time domain analysis, patients displayed higher SDNN (standard deviation of all R-R intervals), SDANN (standard deviation of mean NN intervals in 5 min recordings) and HRV triangular index than did healthy subjects (p < 0.0001). Patients tended to display higher pNN50 (number of R-R intervals differed by > 50 ms from adjacent interval divided by the total number of all R-R intervals) and RMSSD (root-mean-square of successive differences) values than did healthy subjects, but the differences were not statistically significant (p > 0.05). In the frequency domain analysis, the spectral measures of HRV showed a reduction of high frequency (HF) values (is a marker of parasympathetic activity) and an increase of low frequency (LF) values (is a measure of sympathetic activity); as a result, the ratio between low and high frequencies (LF/HF) was significantly increased (p < 0.0001, p < 0.0001 and p < 0.001, respectively). Our data suggests an increase in the sympathetic control of the heart rate in epilepsy patients who have GTCS. This increased sympathetic activity could play a key role in the development of ventricular tachyarrhythmias in patients with epilepsy and may be related to the higher incidence of sudden death in this disorder as compared to controls.

Bilateral Diagonal Earlobe Crease and Coronary Artery Disease: A Significant Association

Background: The association between the presence of diagonal earlobe crease (ELC) and coronary artery disease (CAD) still remains controversial. Objective: The aim of this study was to evaluate the association between bilateral ELC and CAD. Methods: 415 patients were examined for the presence or absence of bilateral ELC, angiographic evidence of CAD and coronary risk factors. The patients were divided into 2 groups according to angiographic evidence of CAD. Results: Bilateral ELC was significantly and positively correlated with CAD, hypertension, age, male gender, cigarette smoking and family history of CAD. The ELC was an independent variable for CAD. The observed sensitivity, specificity, positive predictive value and negative predictive value of the bilateral ELC for the diagnosis of CAD were in the following order: 51.3, 84.8, 89.4 and 41.2%. Conclusion: The presence of bilateral ELC was significantly associated with CAD and coronary risk factors. The bilateral ELC was an important dermatological indicator of CAD, and it might be a useful diagnostic tool in the clinical examination of patients.

Impact of Obstructive Sleep Apnea on Right Ventricular Global Function: Sleep Apnea and Myocardial Performance Index

Background: Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstructions during sleep, and it might cause cardiovascular complications such as heart failure, arrhythmias, myocardial infarction, systemic and pulmonary hypertension. Objectives: To determine right ventricular diameters and myocardial performance index (MPI) reflecting ventricular global function in uncomplicated OSA patients. Methods: 49 subjects without hypertension, diabetes mellitus, or any cardiac or pulmonary disease referred for evaluation of OSA had overnight polysomnography and complete echocardiographic assessment. According to the apnea-hypopnea index (AHI), subjects were divided into three groups: group 1: control subjects (AHI <5, n = 20), group 2: patients with mild OSA (AHI: 5–14, n = 11), and group 3: moderate-severe OSA (AHI ≧15, n = 18). Right ventricular free wall diameter was measured by M mode, and right ventricular MPI was calculated as (isovolumic contraction time + isovolumic relaxation time)/pulmonary ejection time. Results: There were no differences of age, body mass index, heart rates, systolic and diastolic blood pressures among the groups (p > 0.05). Right ventricular end-diastolic and end-systolic diameters were not statistically different between the groups, and were within normal limits. Also, right ventricular free wall diameter was not significantly different between the groups of control, mild OSA and moderate-severe OSA (6.7 ± 0.9, 6.9 ± 1.0, 7.1 ± 1.1 mm, p > 0.05). Right ventricular diastolic dysfunction was shown only in group 3 patients. Right ventricular MPI was statistically higher in group 3 (0.62 ± 0.18) than in group 2 patients (0.50 ± 0.10), and group 1 patients (0.48 ± 0.08, p < 0.001). Conclusions: It wassuggested that patients with moderate-severe OSA had a right ventricular global dysfunction, in addition to the presence of a diastolic dysfunction.

Effects of CPAP on right ventricular myocardial performance index in obstructive sleep apnea patients without hypertension

ObjectivesObstructive sleep apnoea (OSA) might cause right ventricular dysfunction and pulmonary hypertension. We aimed to determine the effects of nasal continuous positive airway pressure (CPAP) therapy on right ventricular myocardial performance index (MPI) in OSA patients without hypertension.Methods49 subjects without hypertension, diabetes mellitus, any cardiac and pulmonary disease had overnight polysomnography and echocardiography. In 18 moderate-severe OSA (apnea-hypopnea index ≥ 15) patients, right ventricular free wall diameter (RVFWD) was measured by M-mode, and right ventricular MPI was calculated as (isovolumic contraction time+ isovolumic relaxation time) / pulmonary ejection time using Doppler at baseline and after 6 months CPAP therapy.ResultsMean age was 46.5 ± 4.9 year. Patients had high body mass index (BMI: 30.6 ± 4,0 kg/m2), but there was no change in either BMI or blood pressures after 6 months. Right ventricular end-diastolic and end-systolic diameters were in normal limits at baseline, and did not change after CPAP usage. Baseline RVFWD (7.1 ± 2.1 mm) significantly decreased after CPAP therapy (6.2 ± 1.7 mm, p < 0.001). 15 of patients (83%) had right ventricular diastolic dysfunction at baseline, and it was completely improved in 11 of them (73%) by CPAP usage. Right ventricular global dysfunction was shown in 11 patients (61%) with a high MPI (62.2 ± 9.3%) at baseline; and MPI was significantly decreased after CPAP therapy (47.3 ± 8.4%, p < 0.0001), and it was completely corrected in 4 of them (36%).ConclusionCPAP therapy significantly decreases RVFWD and improves right ventricular diastolic and global functions (MPI) in OSA patients without hypertension.

Lifestyle and Metabolic Determinants of Incident Hypertension, With Special Reference to Cigarette Smoking : A Longitudinal Population-Based Study

BACKGROUND Lifestyle and metabolic determinants of incident hypertension in a population with a high prevalence of metabolic syndrome (MetS) need to be further assessed. METHODS A representative sample of middle-aged and elderly Turkish adults was prospectively evaluated over a mean 7.4 years, after exclusion of prevalent hypertension and major renal dysfunction. RESULTS In 2,427 men and women, aged 45.8 +/- 11.7 years, Kaplan-Meier analysis showed in combined genders mean time to incident hypertension to be 7.23 years in never, 7.78 years in current smokers (P < 0.001). Age and female sex were major determinants of subsequent hypertension after adjustment for physical activity grade, family income bracket, smoking status, usage of alcohol and of hormone replacement or birth control pill. Relative risk (RR) for incident hypertension of current vs. never smoking was reduced in women (P = 0.058) and both genders combined (P = 0.054). Former smokers uniformly exhibited significantly higher risk for the development of hypertension than both never (P = 0.054) and current (P < 0.001) smokers, whereby abdominally obese individuals were at increased risk. In further multivariable models, circulating C-reactive protein (CRP) and fasting insulin emerged as modest independent determinants and waist girth, modulated by current smoking, as a major determinant of subsequent hypertension. CONCLUSIONS Age, female sex, and waist circumference are major and serum insulin and CRP modest determinants of incident hypertension in middle-aged Turkish adults in whom current cigarette smoking plays a protective role at borderline significance, largely by modulating waist girth. Former smokers with abdominal obesity are under higher risk of subsequent hypertension than current smokers.

Relatively high coronary death and event rates in Turkish women: Relation to three major risk factors in five-year follow-up of cohort

The study describes rates of coronary heart disease death and nonfatal coronary events over five years in a cohort of random sample population and relates them to levels of three major risk factors. It is based on a longitudinal follow-up of survey conducted initially in 1990 in all geographic regions of Turkey. Two-thirds of the original cohort aged 20 years or over 2259 adults comprising 1146 women was followed up by physical examination and an ECG recording at rest. New coronary events were defined to include myocardial infarction and stable angina with or without associated myocardial ischemia developed during the follow-up period. Overall annual death rate was nine per 1000 adults. Coronary deaths numbered 55 (of which 26 were women) representing 4.1 per year and were found high in women. New coronary events were registered in 37 men and 32 women (annual rates 7.2 and 5.8 per 1000, respectively). Among male participants aged initially 40 years or over, high systolic blood pressure (> or = 130 mmHg) at baseline significantly predicted coronary death (age-adjusted risk ratio (RR) 3.3) while high cholesterol concentrations (> or = 5.2 mmol l-1) predicted new coronary events alone (RR almost 2). In women systolic pressure again strongly predicted coronary death (age-adjusted RR 3.9), whereas abnormal cholesterol levels discriminated for coronary death and new coronary events (RR around 2.3 for each). High diastolic pressure (> or = 85 mmHg) was of predictive value for the combined outcome of coronary death and events in women (RR 1.9) but not in men. Multivariate analysis by logistic regression identified systolic blood pressure in men as significant independent predictor of coronary death, while total cholesterol concentration in both genders and systolic blood pressure in men were independent predictors of the combined outcome of coronary death or nonfatal coronary events. It was concluded that known major risk factors act in similar magnitudes commensurate with the specific risk increments also in populations with essentially low cholesterol levels. The relatively high coronary morbidity and mortality in Turkish women approaching that in men may be accounted for by an inherent greater risk burden.

Relation of insulin resistance and left ventricular function and structure in non-diabetic patients with essential hypertension

Objective — Both left ventricular hypertrophy and insulin resistance (IR) have often been demonstrated in patients with essential hypertension (EH). Insulin may exert a direct growth-promoting effect on cardiomyocytes.The purpose of this study was to examine the relationship between left ventricular structure, function and IR in patients with EH. Methods — We enrolled 73 patients (21 men, mean age 51.7 ± 9.2 years) with untreated hypertension (BP > 140 and/or 90 mm Hg, fasting glycaemia < 110 mg/dl) and 64 healthy subjects without diabetes mellitus and hypertension (21 men, mean age 48.9 ± 10.6 years) constituted the control group. In all subjects, transthoracic echocardiography was performed and blood samples were taken. Homeostasis model assessment (HOMA) was calculated by the formula: HOMA-index = fasting blood glucose (mg/dl) * immunoreactive insulin (mU/ml) /405 for the assessment of IR. Hypertensive patients were divided in two groups by mean HOMA index values. Each subject was examined for LV end-diastolic diameter, septal and posterior wall thickness, LV mass index (LVMI), fractional shortening (FS), mitral inflow velocity pattern, atrial filling fraction (AFF), left ventricular outflow velocity pattern and the total ejection isovolume index (TEI index). Results — The HOMA index (p < 0.001), LVMI (p < 0.001), AFF (p < 0.0001), peak A velocity (p < 0.028), septal (p < 0.0001) and posterior (p < 0.0001) wall thickness were significantly higher and FS (p < 0.001), E/A ratio (p < 0.0001) were significantly lower in hypertensive patients than healthy controls. LVMI (p < 0.01) and septal wall thickness (p < 0.001) were significantly higher in those hypertensive patients with a higher HOMA index.The HOMA-index was univariately related to the TEI index (r = 0.27, p = 0.01) and septal wall thickness (IVS) (r = 0.29, p = 0.01) by Pearson correlation analysis in hypertensive patients. LVMI, FS and mitral inflow velocity pattern were not related to the HOMA index. The TEI index (R2 = 0.20, p = 0.0001) and IVS (R2 = 0.12, p = 0.002) were significantly related to the HOMA-index as an independent variable by stepwise regression analysis Conclusions — These results demonstrated that hypertensive patients had both abnormal cardiac structure and function and higher IR index. In our study group, the effect of hypertension on cardiac structure and function was correlated with IR. Our results suggested that IR might be an important factor causing left ventricular dysfunction and wall thickness in non-diabetic patients with EH.

Spectral and Time-Domain Analyses of Heart-Rate Variability During Head-Upright Tilt-Table Testing in Children with Neurally Mediated Syncope

Neurocardiac syncope (NS) is a common cause of syncope in children. The mechanism, though related to abnormalities in autonomic function, has not been fully elucidated, particularly in pediatric patients. This study assessed the heart-rate variability (HRV) response to head-upright tilt-table test (HUT) in children with NS and normal volunteers. Spectral and time-domain analysis of HRV was used to assess changes in autonomic function in 27 children (9 male, mean age 12.3 ± 1.6 years) with a history of at least one episode of syncope and positive passive HUT and 27 age-matched normal volunteers with negative passive HUT before and during postural tilt and to attempt to relate such changes to specific types of hemodynamic response to tilt. Frequency-domain measurements of the high-(HF) and low-(LF) frequency bands and the ratio LF/HF were derived from Holter recordings and computed by fast Fourier analysis for 5-min intervals. Time-domain measurements of the SDNN, SDNNI, SDANN, RMSSD, and triangular index were derived from 24-h Holter recordings. There were no significant differences between clinical characteristics, time-domain, and basal frequency domain parameters of the groups. Mean values of LF and LF/HF ratio was increased and HF was decreased significantly in response to tilt in both patient and control groups. Mean values of LF and LF/HF ratio were higher and HF was lower compared to controls immediately after tilt. LF and LF/HF ratio showed a statistically significant decrease and a significant increase in HF during syncope in patients. The three subgroups of patients had similar patterns of changes in autonomic activity. The results of this study show that although the basal autonomic function was similar to that of the control group, patients with NS have a different pattern of response to the HUT. In our study, patients with NS demonstrated an exaggerated response to the HUT. This exaggerated response may be the factor that activates the pathological reflexes of NS. The pathological mechanism leading to NS appears to be independent of the specific type of hemodynamic response to HUT.