The evaluation of body composition, adiponectin, C-reactive protein and cholesterol levels in patients with obstructive sleep apnea syndrome.

Background: Obstructive sleep apnea syndrome (OSAS) is a frequent disease, characterized by repetitive episodes of upper airway obstruction during sleep, leading to many pathological events. Adiponectin is an adipocyte-specific secreted protein that plays a role in glucose and lipid homeostasis, in addition to antiatherogenic and anti-diabetic effects. Bioelectrical impedance analysis (BIA) is a reliable, non-invasive, safe and effective technique to measure body composition.

Objectives: The aim of the study was the evaluation of body composition and adiponectin serum levels in OSAS patients and their comparison with OSAS parameters as well as with C-reactive protein (CRP) and cholesterol levels.

Material And Methods: In this study, 137 patients with OSAS and 42 persons for the control group were enrolled. In the examined group with OSAS, there were 100 males (73%) and 37 females (27%). The average age was 54.37 + 9.8 years. All subjects underwent polysomnography with Grass Aura PSG Lite and bioelectrical impedance analysis (BIA) with a single-frequency bioimpedance analyzer (Model BIA 101, AKERN-RJL, Italy). The adiponectin serum level was measured using a sandwich ELISA kit.

Results: In OSAS patients we demonstrated a higher body mass index (BMI) and percentage of extracellular water (ECW%) and lower percentage of intracellular water (ICW%) and phase angle. Moreover, severe OSAS and control comparison revealed a lower percentage of muscle mass (MM%) in severe OSAS. Positive correlations were found between the apnea-hypopnea index (AHI) and BMI, CRP and ECW%. Negative correlations were observed between AHI and ICW%, MM% and phase angle. We found neither differences in adiponectin levels between the control group and OSAS patients nor correlations between adiponectin and body composition parameters. But we showed that adiponectin levels were significantly lower in OSAS patients with diabetes than in OSAS patients without diabetes (2.64 vs. 13.46 µg/mL, p = 0.003). In OSAS patients without diabetes, we revealed many negative correlations between adiponectin levels and the body composition parameters (including phase angle, percentage of total body water - TBW%, ICW%, percentage of fat free mass - FFM% and MM%) and triglycerides. The positive relationships were between adiponectin and CRP, ECW% and percentage of fat mass (FM%).

Conclusions: Our results indicate that in OSAS patients there are many changes in body composition. The most interesting are higher BMI, TBW% and ECW% and lower BCM%, IW%, MM% and phase angle. Our results suggest that OSAS does not influence adiponectin level, but adiponectin levels are lower in patients with diabetes. Adiponectin levels correlate with many body composition parameters in OSAS patients without diabetes.