[Study of serum leptin level in patients with obstructive sleep apnea]

Abstract

Objective: To explore the change of serum leptin in patients with obstructive sleep apnea syndrome (OSAS).

Methods: Polysomnography was performed in 58 patients with OSAS and in 21 simple obese controls without differences in age and body mass index (BMI). Serum leptin level was measured by radioimmunoassay.

Results: (1) The serum leptin level in patients with OSAS was higher, in both males (6.1 +/- 1.7) microg/L and females (19.5 +/- 9.9) microgram/L, than that in the simple obese controls [male (4.5 +/- 1.7) microgram/L, female (10.5 +/- 2.4) microgram/L] (P < 0.01, P < 0.05). (2) Serum leptin levels were significantly correlated with BMI in both OSAS patients (r = 0.64, P < 0.01) and simple obese controls (r = 0.59, P < 0.01), but only in OSAS patients was the leptin level significantly correlated with apnea and hypopnea index (AHI) (r = 0.47, P < 0.01) and with neck circumference (r = 0.64, P < 0.01).

Conclusions: Serum leptin levels were higher in OSAS patients than in simple obese controls. Besides obesity and neck circumference, OSAS may also influence the leptin system, resulting in increased serum leptin level.