The aim of this study was to elucidate body composition, anthropometric indices, and hydration status in obstructive sleep apnea (OSA) patients, taking into account different disease stages, gender, and the possibility of the presence of cachexia. There were 98 OSA patients and 23 control subjects enrolled into the study. All study participants underwent polysomnography examination. Body mass index (BMI), fat mass index (FMI), fat free mass, muscle mass, body cell mass, total body water, and extracellular and intracellular water were evaluated. The neck, abdominal, and waist circumference was measured. We found that overweight and obesity were present in 96% of patients. Cachexia was present in one OSA individual with comorbidities. Apnea-hypopnea index correlated with the neck and waist circumference, and with BMI in OSA patients. All muscle indices and water contents above outlined were significantly higher in severe OSA compared with control subjects. BMI, FMI, neck circumference, and extracellular water were greater in a subset of severe OSA compared with a moderate OSA stage. The female OSA patients had a higher FMI than that present in males at a comparable BMI. We conclude that the most body composition indices differed significantly between severe OSA patients and control subjects. A higher FMI in females at a comparable BMI could be due to a discordance between BMI and FMI. Cachexia occurs rarely in OSA and seems to coexist with comorbidities.
Keywords: Apnea-hypopnea index; Body composition; Body water content; Cachexia; Hydration; Nutritional status; Obesity; Obstructive sleep apnea.