The Association between Subclinical Hypothyroidism and Epicardial Adipose Tissue Thickness

BACKGROUND AND OBJECTIVES: Subclinical hypothyroidism (SH) is considered to be a potential risk factor for cardiovascular disease. Epicardial adipose tissue (EAT) thickness is also closely related to cardiovascular disorders. The aim of this study was to evaluate whether SH is associated with higher EAT thickness. SUBJECTS AND METHODS: Fifty-one consecutive patients with SH and 51 healthy control subjects were prospectively enrolled into this trial. Thyroid hormone levels, lipid parameters, body mass index, waist and neck circumference, and EAT thickness measured by echocardiography were recorded in all subjects. RESULTS: Mean EAT thickness was increased in the SH group compared to the control group (6.7+/-1.4 mm vs. 4.7+/-1.2 mm, p<0.001). EAT thickness was shown to be correlated with thyroid stimulating hormone level (r=0.303, p=0.002). Multivariate logistic regression analysis revealed that EAT thickness was independently associated with SH {odds ratio (OR): 3.87, 95% confidence interval (CI): 1.92-7.78, p<0.001; OR: 3.80, 95% CI: 2.18-6.62, p<0.001}. CONCLUSION: Epicardial adipose tissue thickness is increased in patients with SH compared to control subjects, and this increase in EAT thickness may be associated with the potential cardiovascular adverse effects of SH.

Relationship between obstructive sleep apnea severity index and left ventricular function and volume

Obstructive sleep apnea [OSA] causes increased cardiovascular morbidity and mortality, including systemic arterial hypertension, coronary heart disease, heart rhythm and conduction disorders, heart failure and stroke. In our study, we aimed to assess left ventricular mass and myocardial performance index [MPI] in OSA patients. A cross-sectional study conducted between May 2007 and August 2009 in a tertiary hospital in Istanbul, Turkey. Forty subjects without any cardiac or pulmonary disease referred for evaluation of OSA had overnight polysomnography and echocardiography. According to the apnea-hypopnea index [AHI], subjects were classified into three groups; mild OSA [AHI: 5-14/h; n=7], moderate OSA [AHI: 15-29/h; n=13], and severe OSA [AHI: ?30/h; n=20]. The thickness of the interventricular septum [IVS] and left ventricular posterior wall [LVPW] were measured by M-mode along with left ventricular mass [LVM] and LVM index [LVMI]. The left ventricular MPI was calculated as [isovolumic contraction time + isovolumic relaxation time]/aortic ejection time by Doppler echocardiography. No differences were observed in age or body mass index among the groups, but blood pressures were higher in severe OSA compared with moderate and mild OSA. In severe OSA, the thickness of the IVS [11.6 [1.7 mm]], LVPW [10.7 [1.7 mm]], LVM [260.9 [50.5 g]], and LVMI [121.9 [21.1g/m2]] were higher than in moderate OSA [9.4 [1.3 mm]; 9.9 [1.6]; 196.4 [35.2]; 94.7 [13.2 g/m2], respectively] and mild OSA [9.8 [2.4 mm], 8.9 [2.0 mm], 187.6 [66.2 g], 95.8 [28.6 g/m2], respectively]. In severe OSA, MPI [0.8 [0.2]] was significantly higher than in mild OSA [0.5 [P<.01]] but not significantly higher than moderate OSA [0.8 [0.1]]. OSA patients have demonstrable cardiac abnormalities that worsen with the severity of apnea. The MPI may have utility in subsequent OSA studies, possibly as a surrogate outcome measure