The relationship between extracellular fluid and obstructive sleep apnea in non-obese patients.

Objective: To evaluate the relationship between obstructive sleep apnea syndrome (OSAS) and the fluid change in composition throughout the night.Methods: The study included 92 non-obese patients who underwent polysomnography because of suspected OSAS. Weight and body composition analyses were applied using a Tanita DC-360 multi-frequency body composition analysis device.Results: In the correlation analyses between apnea/hypopnea index (AHI) values and independent variables, a positive relationship was determined with extracellular fluid shift (r: 0.381, p = 0.009) and change in neck circumference (r: 0.226, p = 0.031), and there was a negative relationship between disease severity and an increase in the number of daily steps taken (r: 0.208, p = 0.047).Conclusion: The results of the study clearly showed that movement to the neck area of fluid accumulated in the lower extremities and an increase in extracellular fluid were related to AHI values independent of body mass index (BMI).