About seven hours’ sleep a night may help lower the risk of insulin resistance, a condition that can lead to type 2 diabetes, research suggests.
A study of 10,817 adults aged 20 to 80 found that both shorter and longer sleep were linked with a higher risk of pre-diabetes, a condition where the body begins to struggle to control blood sugar.
Insulin resistance occurs when the body’s muscles and organs do not respond properly to insulin, the hormone that regulates blood sugar levels.
It is considered a key step in the development of type 2 diabetes.
Alex Miras, professor of endocrinology at Ulster University, said: “Sleep deprivation has been known for years to be associated with higher levels of body stress, meaning that the body produces excess cortisol and other molecules that have a negative effect on glucose regulation.
“More specifically, it can increase the resistance of muscles to insulin, which can increase blood glucose.”
Researchers analysed data from participants in the US National Health and Nutrition Examination Survey between 2009 and 2023.
They measured estimated glucose disposal rate, a marker of how well the body uses insulin. It is calculated using waist circumference, fasting blood glucose and blood pressure. Lower levels indicate greater insulin resistance.
Participants slept for an average of seven hours and 30 minutes per night, with just over 48 per cent reporting catching up on sleep at weekends and sometimes reaching eight hours.
After analysing the results, researchers suggested the optimal sleep duration for insulin resistance may be seven hours and 18 minutes, with both more and less sleep linked to worse outcomes.
Moderate weekend catch-up sleep also appeared beneficial. For those sleeping less than the suggested amount during the week, one to two hours of extra sleep at weekends was associated with better insulin function than no additional sleep.
However, among those already sleeping more than the weekday threshold, more than two hours of additional weekend sleep was linked with worse results.
Naveed Sattar, professor of cardiometabolic medicine at the University of Glasgow, said: “Poor sleep often leads to poorer appetite control so people tend to eat more, and less sleep means more time awake to be able to eat.”
He explained that poor sleep can directly affect hormone levels, including stress hormones, which can increase appetite and affect blood sugar levels.
The study authors wrote: “These correlational findings suggest that sleep patterns, particularly weekend recovery sleep, may be relevant for metabolic regulation in diabetes and could inform considerations for healthcare professionals in managing patient care.”
