Association of epicardial fat thickness with the severity of obstructive sleep apnea in obese patients

Int J Cardiol. 2013 Sep 1;167(5):2244-9. doi: 10.1016/j.ijcard.2012.06.011. Epub 2012 Jun 20.

Abstract

Background: The correlation between obesity and severity of obstructive sleep apnea (OSA) is controversial. Although fat excess is a predisposing factor for the development of OSA, it has not been determined whether fat distribution rather than obesity per se is associated with OSA severity. Epicardial fat thickness (EFT) is an independent index of visceral adiposity and cardiometabolic risk. We investigated the relation between fat distribution and cardiometabolic risk factors, including EFT and common carotid intima-media thickness (cIMT), with the severity of OSA in obese patients.

Methods: One hundred and fifteen obese patients (56 males, 59 females) with polysomnographic evidence of OSA (≥ 5 apnea/hypopnea events per hour) of various degrees, without significant differences in grade of obesity as defined by body mass index (BMI), were evaluated. The following parameters were measured: BMI, body composition by dual energy X-ray absorptiometry, EFT, right ventricular end-diastolic diameter (RVEDD) and cIMT by ultrasound, and parameters of metabolic syndrome (waist circumference, arterial blood pressure, fasting glucose, HDL-cholesterol and triglycerides).

Results: EFT, RVEDD, cIMT and trunk/leg fat mass ratio showed a positive correlation with OSA severity in univariate analysis (r=0.536, p<0.001; r=0.480, p<0.001; r=0.345, p<0.001; r=0.330, p<0.001, respectively). However, multiple linear regression analysis showed that EFT was the most significant independent correlate of the severity of OSA (R(2)=0.376, p=0.022).

Conclusions: The present study suggests that, in obese patients, EFT may be included among the clinical parameters associating with OSA severity. The association of EFT with OSA, both cardiovascular risk factors, is independent of obesity as defined by classical measures.

Keywords: Body composition; Cardiovascular risk factor; Epicardial fat; Obesity; Obstructive sleep apnea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon / methods
  • Adipose Tissue / diagnostic imaging*
  • Adipose Tissue / physiopathology
  • Adult
  • Aged
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Middle Aged
  • Obesity / diagnostic imaging*
  • Obesity / epidemiology
  • Obesity / physiopathology
  • Pericardium / diagnostic imaging*
  • Pericardium / physiopathology
  • Polysomnography / methods
  • Risk Factors
  • Severity of Illness Index*
  • Sleep Apnea, Obstructive / diagnostic imaging*
  • Sleep Apnea, Obstructive / epidemiology
  • Sleep Apnea, Obstructive / physiopathology