Sleep-wake cycle irregularities in type 2 diabetics

The study subjects were 106 consecutive outpatients with lifestyle-related diseases (males/females？=？56/50), who answered a questionnaire on sleep status. Subjects were divided into two groups; non-T2DM (n？=？32) and T2DM (n？=？74) subjects.T2DM subjects retired to bed on weekdays and holidays significantly later than non-T2DM subjects (23:43 versus 22:52, p？=？0.0032; 23:45 versus 22:53, p？=？0.0038, respectively), and woke up significantly later on weekdays and holidays, compared with non-T2DM subjects (06:39 versus 06:08, p？=？0.0325; 06:58 versus 06:24, p？=？0.0450, respectively). There was no significant difference in the estimated sleep duration between the two groups. Daytime sleepiness was reported significantly more commonly by T2DM subjects than non-T2DM subjects (p？=？0.0195).Sleep-wake cycle irregularities are more common in T2DM subjects than non-T2DM. Confirmation that such irregularity plays a role in the metabolic abnormalities of T2DM requires further investigation in the future.UMIN 000002998The etiology of type 2 diabetes mellitus (T2DM) includes both genetic and environmental factors. The incidence of T2DM has been increasing recently mainly due to changes in lifestyle, such as over-eating, physical inactivity, and sleep deprivation. Sleep is a highly active and dynamic process, and serves immune defense in particular, with an important role in disease resistance [1]. Several studies have reported major differences in the frequency of sleep disturbances between diabetics and non-diabetics [2,3]. Patients with T2DM sleep less than the general population [4]. The recent dramatic increase in the incidence of obesity and diabetes, and the close relationship between sleep cycles and diabetes [5], suggest detrimental deprivation of certain sleep stages [6,7]. The endogenous circadian clock, including the suprachiasmatic nucleus (SCN) in the hypothalamus and peripheral oscillators in vital organs, regulates much of our physiology and behavior across the 24-h？d