Altered neuroendocrine sleep architecture in patients with type 1 diabetes

Objective: The modulatory influence of nocturnal sleep on neuroendocrine secretory activity is increasingly recognized as a factor critical to human's health. Disturbances of sleep may arise from and contribute to the disease process in chronically ill patients suffering from type 1 diabetes mellitus (T1DM). Research design and methods: The neuroendocrine sleep architecture was assessed under well-controlled non-hypoglycaemic conditions in 14 T1DM patients and 14 healthy controls matched for age, gender, and BMI, using standard polysomnography and repetitive blood sampling via an intravenous catheter. Results: As expected, plasma glucose (P=0.024) and serum insulin (P <0.001) levels were constantly higher in T1DM patients than in healthy subjects throughout the study night. Beside these characteristic alterations of glucose metabolism, patients with T1DM displayed higher blood levels of growth hormone (P=0.001) and epinephrine (P=0.023) during the entire night, and higher levels of ACTH (P=0.010) as well as a tendency towards higher cortisol levels (P=0.072) during the first night-half, compared with the healthy controls. The patients spent slightly less time in slow wave sleep (P=0.093) during the first night-half (where this sleep stage predominates), and overall exhibited an increased proportion of lighter stage 2 sleep (P=0.008). Correspondingly, assessment of mood and symptoms after sleep revealed that subjective sleep was less restorative in T1DM patients than in healthy subjects. Conclusions: Our data point to distinct alterations in the neuroendocrine sleep architecture of patients with T1DM which add to the generally adverse impact of the disease on the patients' health.