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 health. Disturbances of sleep may arise from and contribute to the disease process in chronically ill patients with type 1 diabetes. RESEARCH DESIGN AND METHODS - Using standard polysomnography and repetitive blood sampling, neuroendocrine sleep architecture was assessed under well-controlled nonhypoglycemic conditions in 14 type 1 diabetic patients and 14 healthy control subjects matched for age, sex, and BMI. RESULTS - As expected, plasma glucose (P = 0.02) and serum insulin (P < 0.001) levels were constantly higher in type 1 diabetic patients than in healthy subjects throughout the night. Beside these characteristic alterations of glucose metabolism, type 1 diabetic patients displayed higher blood levels of growth hormone (P = 0.001) and epinephrine (P = 0.02) during the entire night and higher levels of ACTH (P = 0.01) as well as a tendency toward higher cortisol levels (P = 0.072) during the first night-half, compared with healthy control subjects. Patients spent slightly less time in slow wave sleep (P = 0.09) during the first night-half (where this sleep stage predominates), and overall exhibited an increased proportion of stage 2 sleep (P = 0.01). Correspondingly, assessment of mood and symptoms after sleep revealed that subjective sleep was less restorative in type 1 diabetic patients than in healthy subjects. CONCLUSIONS - Our data indicate distinct alterations in the neuroendocrine sleep architecture of patients with type 1 diabetes, which add to the generally adverse impact of the disease on the patients' health.