Daytime napping associated with increased type 2 diabetes risk

Daytime napping for at least 1 hour is associated with a risk for developing type 2 diabetes, whereas shorter naps are not associated with increased risk, according to results from a meta-analysis presented at the 52nd European Association for the Study of Diabetes Annual Meeting.

“Daytime naps are usually brief, but can range from a few minutes to a few hours,” Tomohide Yamada, MD, PhD, of the department of diabetes and metabolic diseases at the University of Tokyo, and colleagues wrote. “We performed a meta-analysis to investigate the association between napping and the risk for metabolic disease, and to quantify the potential dose-response relation.”

Yamada and colleagues analyzed data from 307,237 Asian and Western adults from 21 studies, all adjusted for several confounders. Pooled analysis revealed that a longer nap ( 60 minutes per day) increased the risk for type 2 diabetes (RR = 1.45; 95% CI, 1.25-1.69), whereas naps of 60 minutes or less did not increase the risk (P = .07).

“A dose-response meta-analysis showed a J-shaped relation between nap time and the risk of diabetes or metabolic syndrome, with no effect of napping up to about 40 minutes per day followed by a sharp increase in the risk at longer times,” the researchers wrote.

Researchers did not observe an association between nap time and increased risk for obesity for a longer nap (RR = 1.13; 95% CI, 0.92-1.39) or for a shorter-duration nap (RR = 0.95; 95% CI, 0.88-1.02).

The researchers noted that a short nap might have the effect of improving an abnormal circadian rhythm and modifying a variety of endocrine abnormalities caused by sleep deprivation.

“Several studies have demonstrated beneficial effects of taking short naps less than 30 minutes in duration, which help to increase alertness and motor skills,” the researchers said in a press release. “Although the mechanisms by which a short nap might decrease the risk of diabetes are still unclear, such duration-dependent differences in the effects of sleep might partly explain our finding.” – by Regina Schaffer

Reference:

Yamada T, et al. Abstract#816. Presented at: 52nd EASD Annual Meeting; Sept. 12-16, 2016; Munich.

Disclosure: The researchers report no relevant financial disclosures.