Characteristics of sleep-wake cycle and sleep duration in Japanese type 2 diabetes patients with visceral fat accumulation.

Sleep pattern has been shown to be associated with type 2 diabetes mellitus. Here, we investigated the difference in bedtime, waking time and estimated sleep duration in type 2 diabetes mellitus patients with or without visceral fat accumulation, using a questionnaire on sleep patterns. The study participants were 59 Japanese type 2 diabetes mellitus patients (men/women 34/25, age 64.5 +/- 12.1 years). Visceral fat accumulation was defined as estimated visceral fat area 100 cm(2). The patients with visceral fat accumulation (n = 40) showed significantly later bedtime (23.51 +/- 01.27 h in the [+] group vs 22.49 +/- 01.23 h in the [-] group) and shorter estimated sleep duration (6.6 +/- 1.4 h in the [+] group vs 7.9 +/- 1.0 h in the [-] group) on weekdays, compared with those without (n = 19). Later bedtime and shorter estimated sleep duration existed in the type 2 diabetes mellitus patients with visceral fat accumulation, compared with those without.