The serum leptin level in non-obese patients with obstructive sleep apnea

Abstract

ObjectiveThis study aimed to determine the association between the severity of obstructive sleep apnea (OSA) and the serum leptin level in non-obese OSA patients. MethodsThis prospective case-control study included non-obese OSA patients that presented with sleep-related disturbances and underwent polysomnography (PSG) between April 2015 and June 2016. The serum leptin level was measured and its relationship to PSG parameters was investigated. ResultsThe study included 73 OSA patients (20 female and 53 male) with a mean age of 41.1±11.5 years and mean body-mass index (BMI) of 26.4±2.7kgm–2. The serum leptin level in 44 patients with moderate/severe OSA (AHI ≥15) was 3.4±2.6ngmL–1, versus 4.5±3.8ngmL–1 in 29 patients with snoring/mild OSA (AHI <15) (P=0.20). There were not any correlations between any of the PSG parameters and the serum leptin level, but there was a significant correlation between the leptin level and BMI (r=0.345, P<0.01). ConclusionThe serum leptin level does not differ significantly between non-obese OSA patients with moderate/severe and snoring/mild OSA. Obesity is the primary factor associated with the serum leptin level.