The prevalence of impaired glucose regulation in psychiatric patients with sleep disorders and its relationship with altered hypothalamopituitary-adrenal and hypothalamopituitary-thyroid axis activity.

BACKGROUND

Sleep restriction, an important symptom of psychiatric diseases, is associated with adverse effects on glucose regulation, but few studies have examined its association with impaired glucose regulation and altered hypothalamic activity. Our study was designed to evaluate the sleep duration, fasting glucose, tolerance glucose, and concentration of plasma insulin; to assess the function of both the hypothalamopituitary-thyroid (HPT) and hypothalamopituitary-adrenal (HPA) axis; and to investigate the relationship of altered hypothalamic function with glucose metabolism in psychiatric patients with a sleep disorders.

METHODS

From January 2010 to December 2011, 324 women (64.7%) and 177 men (35.32%) with a diagnosis of a sleep disorder participated in our cross-sectional study in the psychiatric outpatient department of the West China Hospital of Sichuan University. Results from 75-g glucose tolerance tests, insulin-releasing tests, morning (8:00 am) serum cortisol, and thyroid-stimulating hormone (TSH) (TT3, TT4, FT3, FT4) were collected, as well as body mass index and waist-hip ratio to assess the prevalence of impaired glucose regulation and function of the HPA and HPT axis. Sleep quality was assessed through self-reported questionnaires.

RESULTS

There were 301 patients previously diagnosed with an anxiety disorder (78%), and 200 patients previously diagnosed with depression and other psychiatric diseases (22%). Crude prevalence rates were 15.0% for diabetes mellitus (DM), 11.6% for impaired glucose tolerance, 15.8% for impaired fasting glucose, and 11.6% for impaired glucose regulation (impaired glucose tolerance [IGT]+impaired fasting glucose [IFG]). Total prevalence of impaired glucose regulation in patients with a sleep disorder was 48.8%. Mean cortisol level was 463.5±178.8 nmol/L, and the cortisol concentration at 8:00 am was significantly associated with a higher prevalence of impaired glucose regulation and insulin resistance. TSH values above 2.5 mU/L accounted for over 58% and were significantly associated with insulin resistance.

CONCLUSIONS

These results partially confirm that a high level of cortisol and an increased activity of the HPT axis are associated with impaired glucose regulation. Therefore, as a pathophysiologic event abnormal activity of the hypothalamic function of psychiatric patients with sleep disorders could be viewed as a potential risk factor for increasing incidence of DM.