A new study from Columbia University discovered that cutting sleep by 90 minutes for six weeks increases insulin resistance in women who are used to obtaining enough sleep. The effect was considerably stronger in postmenopausal women.
The recommended amount of sleep for good health is between seven and nine hours per night, yet almost one-third of Americans get less than the minimum suggested amount.
The findings are the first to indicate that a minor sleep deficit, sustained for six weeks, promotes changes in the body that increase the chance of developing diabetes in women. Previous studies that demonstrated a negative influence on insulin sensitivity comprised largely men and focused on the effects of very severe sleep restriction over a short period of time.
The new study looked at women in particular because studies suggest that poor sleep may have a greater impact on women’s cardiometabolic health than men’s. Throughout their lifespan, women face many changes in their sleep habits due to childbearing, child-rearing, and menopause.
Marie-Pierre St-Onge
Women and sleep
The new study looked at women in particular because studies suggest that poor sleep may have a greater impact on women’s cardiometabolic health than men’s.
“Throughout their lifespan, women face many changes in their sleep habits due to childbearing, child-rearing, and menopause,” says study leader Marie-Pierre St-Onge, PhD, associate professor of nutritional medicine and director of the Center of Excellence for Sleep and Circadian Research at Columbia University Vagelos College of Physicians and Surgeons.
“And more women than men have the perception they aren’t getting enough sleep.”
It is difficult to research the health consequences of persistent sleep deprivation. Some laboratory investigations have indicated that a brief period of total or partial sleep deprivation impacts glucose metabolism. However, such studies do not reflect the typical experience of being somewhat sleep-deprived, which involves surviving on around six hours of sleep for extended periods of time.
Study design
To look at the impact of mild, chronic sleep deprivation, the researchers enrolled 38 healthy women, including 11 postmenopausal women, who routinely slept at least seven hours each night.
In the study, the participants underwent two study phases in random order. In one phase, they were asked to maintain their adequate sleep; in the other, they were asked to delay their bedtime for an hour and a half, shortening their total sleep time to around six hours. Each of these phases lasted for six weeks.
Despite the difficult six-week sleep-restriction phase, all study participants were able to lower their nightly sleep time. Wearable gadgets were used to track adherence to sleep patterns.
The association between sleep length and diabetes risk can be complicated and varies from person to person. While some research has suggested that both short and extremely lengthy sleep durations may be related with an elevated risk of diabetes, evidence supporting short sleep duration has been found to be more consistent.
