Obstructive sleep apnea syndrome and hormonal status of obese patients

• Published in: Sleep medicine 2013-12, Vol.14, p.e276-e276
• Main Authors: Strueva, N, Poluektov, M, Melnithenko, G, Saveleva, L, Katsya, G, Goncharov, N
• Format: Article
• Language: English
• Subjects: Neurology; Sleep Medicine
• ISSN: 1389-9457; 1878-5506
• DOI: 10.1016/j.sleep.2013.11.676

Introduction The aim of this research is to estimate the influence of sleep apnea on hormone metabolism of patients with obesity. Materials and methods 60 patients (36 males and 24 females, age 40 ± 11, body mass index (BMI) 40 ± 7,3 kg/m2 ) with obesity were included in this study. Exclusion criterion were severe depression, alcohol abuse, hypothyroidism, diabetes mellitus. Samples of serum insulin-like growth factor I (IGF-I), total testosterone, insulin were made after overnight fasting, at 08:00. Free cortisol levels were determined for the day and night in urine collected for 24 h. Results After night polysomnography all patients were divided in two groups comparable by age and BMI. The first group consisted from 32 patients with obstructive sleep apnea syndrome (OSAS), the second (controls)–28 patients without breath disorders during sleep. The level of basal insulin ( p < 0.05) and HOMA IR index was higher in patients with OSAS (22 ± 9.3 vs. 16 ± 9.1 μIU/ml, respectively). Statistically significant positive correlation was found between basal insulin and respiratory disturbance index (RDI) ( r = 0,37), oxygen desaturation index (ODI) ( r = 0.4), night free urine cortisol excretion (NFUC) ( r = 0,36); negative correlation with mean arterial oxygen saturation (SAT) ( r = −0.29) and minimal oxygen saturation (minSaO2) ( r = −0.45) during the night was observed. The levels of 24-h urinary and daytime urine free cortisol were not significantly different between groups. NFUC significantly increased in patients with OSAS compared with control group (125 ± 106 vs. 60 ± 26 nmol/l, p = 0,01). Statistically significant negative correlation between NFUC and SAT ( r = − 0.34), slow-wave sleep (SWS, %) ( r = −0.47) were found. The serum levels of IGF-1 were lower than those of the control group (161 ± 62 vs. 220 ± 82 ng/ml, p < 0.02). Testosterone level in men was significantly lower in OSAS group compared with control group (7.7 ± 3 vs. 14 ± 7.5 nmol/liter, ð = 0.008 ). Serum IGF-1 and testosterone levels were positively correlated with SWS percentage; testosterone levels were positively correlated with the minSaO2, SAT and negative – RDI, ODI ( p < 0.05). Conclusion Obstructive sleep apnea is accompanied by the increase in urinary cortisol during the night, high levels of basal insulin, disturbances of hepatic production of IGF-1 and dysfunction of the pituitary–gonadal axis. Our results show that sleep-related breathing disorders markedly and negatively affect