Associations of Midpoint of Sleep and Night Sleep Duration with Type 2 Diabetes Mellitus in Chinese Rural Population: The Henan Rural Cohort

Abstract

Background: The study aimed to explore the independent and combined associations of midpoint of sleep and night sleep duration with type 2 diabetes mellitus (T2DM) in areas with limited resources.Methods: A total of 37,276 participants (14,456 men and 22,820 women) were derived from the Henan Rural Cohort. Information on sleep were collected using the Pittsburgh Sleep Quality Index. Logistic regression models and restricted cubic splines were used to estimate the relationship of the midpoint of sleep and night sleep duration with T2DM.Results: Of the 37276 included participants, 3580 subjects suffered from T2DM. The mean midpoint of sleep among Early, Intermediate and Late groups were 1.09 ± 0.39, 1.93 ± 0.24 and 2.95 ± 0.56, respectively. Compared to Intermediate group, adjusted odd ratios (ORs) and 95% confidence interval (CI) of T2DM were 1.13 (1.04-1.22) and 1.16 (1.05-1.28) in Early group and Late group. Adjusted OR (95% CI) for T2DM compared with reference (7- h) was 1.27 (1.08-1.50) for longer (≥10 h) night sleep duration. The combination of late midpoint of sleep and night sleep duration (≥9 h) increased 39% (95% CI: 11%-75%) prevalence for T2DM. These associations were more obvious in women than men.Conclusions: Late and early midpoint of sleep and long night sleep duration were all associated with the higher odds of T2DM. Meanwhile, midpoint of sleep and night sleep duration might be jointly associated with a higher prevalence of T2DM. Sleep may be a modifiable behavior that has potential health implications for T2DM.Clinical Trail Registration: The Henan Rural Cohort Study has been registered at Chinese Clinical Trial Register (Registration number: ChiCTR-OOC-15006699). Date of registration: 2015-07-06.

Sleep variability and regularity as contributors to obesity and cardiometabolic health in adolescence

“…As mentioned previously, the circadian timing of sleep is optimal when there is a consistency in sleep onset times and wake‐up times throughout the week as well as between weekdays and weekends, as it keeps the organism entrained to the biological night. A common measure of circadian timing of sleep via actigraphy is the sleep midpoint [26], which is defined as the middle clock time (midpoint) between sleep onset and offset [50], where sleep midpoint = sleep onset time + [(sleep onset time – wake‐up time)/2 (Table 1) [51]; for example, if an individual's ad libitum sleep onset occurs at 22:00 and spontaneous wake‐up time at 6:00, the sleep midpoint would fall at 2:00. Alternatively, in scenarios in which rising time (out‐of‐bed) data, but not wake‐up time (final awakening) data, are available, the formula sleep midpoint = sleep onset time + (total sleep time)/2, may be used (Table 1) [52].…”