Poor Sleep Quality Is Linked to Impaired Glucose Metabolism

A recent study published in the Journal of the American Heart Association suggests that African Americans who experience sleep disturbances are more likely to develop impaired glucose metabolism. The researchers used JHS data to examine whether sleep disturbances are a risk factor for type 2 diabetes (T2D), a disease that disproportionately affects African Americans. This study suggests that improving sleep quality in African Americans with T2D might help them manage the condition better.

This study has shown that African Americans who experience sleep disturbances are more likely to develop impaired glucose metabolism. Sleep disturbances include sleep-disordered breathing (also known as sleep apnea), overnight hypoxemia (low blood oxygen levels), and sleep fragmentation (short, repetitive interruptions to sleep). The researchers used the Jackson Heart Study (JHS) data to examine if sleep disturbances are a risk factor for type 2 diabetes (T2D), a disease where the body cannot break down blood glucose (blood sugar) properly. 

The JHS participants — 789 African American men and women — who were enrolled in this study completed home-based sleep tests to find out if they had sleep disturbances. They also wore a wristwatch that measured their sleep patterns and maintained a diary to note their sleep habits. The information was used by researchers to figure out how long participants slept and whether their sleep was irregular. After overnight fasting, participants’ blood sugar was measured in a clinic visit.

Results show that participants who had sleep disturbances also had higher blood sugar. This relationship of poor sleep and high blood sugar was stronger in male participants who already had T2D, compared to non-diabetic and female participants. This was true even after accounting for the differences in the participants’ age, sex, weight, smoking habits, and history of diabetes and heart disease. Sleep deprivation also reduced the effectiveness of insulin, a hormone that regulates blood sugar, and this was seen specifically in non-diabetic participants.

T2D disproportionately affects African Americans. This study suggests that improving sleep quality in African Americans with T2D might help manage the condition better. Jointly funded by the National Heart, Lung, and Blood Institute and NIMHD, JHS is the largest study that looks at genetic and environmental risk factors for heart diseases in the African American population of the United States.