(NewsNation) — Researchers have found a link between chronic insufficient sleep and increased insulin resistance in women, emphasizing the potential risk for Type 2 diabetes, according to a study funded by the National Institutes of Health.

The study, which focused exclusively on women, aimed to determine if a prolonged, mild restriction of sleep could impact blood glucose and insulin levels.

The study revealed that restricting sleep to 6.2 hours or less per night over six weeks led to a 14.8% increase in insulin resistance in pre- and postmenopausal women. Postmenopausal women experienced more severe effects, with a 20.1% increase in insulin resistance.

Additionally, premenopausal women showed an increase in fasting insulin levels, while postmenopausal women exhibited rises in both fasting insulin and fasting glucose levels.

Researchers enrolled 40 women, aged 20-75, with healthy sleep patterns but elevated risks for cardiometabolic disease due to factors such as being overweight or obese, having a family history of Type 2 diabetes, increased lipid in the blood, or cardiovascular disease. 

Participants underwent two six-week study phases in random order — one with an average of 7.5 hours per night and one with sleep restricted to 6.2 hours per night, monitoring the average sleep duration of a U.S. adult with insufficient sleep.

Participants completed an oral glucose tolerance test and an MRI scan at the beginning and end of each phase to measure glucose and insulin levels and body composition.

Researchers explored whether changes in body weight could explain the changes they saw in insulin and glucose levels. However, they found that the effects on insulin resistance were largely independent of changes in body weight. Additionally, they found that upon returning to 7-9 hours per night, the participant’s insulin and glucose levels returned to normal.