A new study from the National University of Singapore suggests that cutting sleep short during the workweek may disrupt the body’s ability to process glucose, even if people sleep longer on the weekends. The findings, published in SLEEP, add to growing evidence that regular, adequate sleep plays a key role in metabolic health and type 2 diabetes risk.
The study took place in a sleep lab with 48 healthy adults ages 21 to 35. After two nights of full rest, participants were assigned to one of three weekday sleep patterns: a consistent six hours of sleep per night, a variable pattern ranging from four to eight hours or a full eight hours. Everyone received eight hours of sleep on weekend nights. Glucose tolerance was measured using an oral glucose tolerance test at baseline and after each weeknight sleep period.
The results were clear. Participants sleeping only six hours during the week showed signs of insulin resistance. Their bodies produced more insulin in an attempt to manage blood sugar, yet glucose levels stayed higher than when they were well rested.
The group with fluctuating weekday sleep had even greater increases in blood glucose. Unlike the stable short sleep group, they did not show a noticeable insulin response, which the researchers say may signal early strain on the pancreas. The control group, which slept eight hours every night, showed no changes in glucose tolerance across the study.
“Many people believe weekend sleep can ‘reset’ the body, but our findings show that weekend catch-up sleep may not be able to prevent increases in blood glucose levels induced by subsequent sleep curtailment on weekdays,” said study lead June Chi-Yan Lo.
The researchers note that both the amount and regularity of weekday sleep shaped metabolic responses. Stable short sleep raised insulin resistance, while irregular short sleep appeared to affect the body’s ability to produce insulin. The team says consistent sleep should be considered alongside diet and physical activity when addressing type 2 diabetes risk.
Funding for this study was provided by the National University of Singapore.