Relationship between hepcidin levels and periodic limb movement disorder in patients with obstructive sleep apnea syndrome

Abstract

Purpose: This study was aimed to assess potential correlations between periodic leg movement (PLM) index, hepcidin levels, and iron status in patients with obstructive sleep apnea syndrome (OSAS).

Methods: Forty-four newly diagnosed OSAS patients and 49 non-apneic controls were enrolled in this study. All patients underwent polysomnographic evaluation. The hepcidin, iron, ferritin, total iron binding capacity, and C-reactive protein levels were measured.

Results: The mean age was 47.4 ± 7.2 years (18-68) in the OSAS group and 44.9 ± 11.1 years (23-65) in the control group. There were no differences in age, gender, and smoking between OSAS patients and controls. Mean apnea-hypopnea index (AHI) was 25.1 events/h. Mean serum hepcidin levels were significantly higher in OSAS subjects (725.9 ng/ml) than in control subjects (646.0 ng/ml) (p < 0.001). Serum iron levels were significantly lower in the OSAS and PLM disorder groups than in control subjects (p < 0.001). Serum hepcidin levels were significantly correlated with AHI (r = 0.453) and PLM index (r = 0.114). Serum iron levels were significantly negatively correlated with AHI (r = -0.169) and PLM index (r = -0.180).

Conclusions: In our study, the level of hepcidin was increased in patients with OSAS. Our study indicates that levels of hepcidin correlate with the AHI and PLM index severity of OSAS.