A clinical trial (NCT01114360) found that African American individuals with severe sleep apnea and other adverse sleep patterns are more likely to have high blood glucose levels than those without those patterns. The findings appear in the April 29 online edition of the Journal of the American Heart Association.
The findings suggest that better sleep habits may lead to better blood glucose control, help prevent type 2 diabetes, and improve diabetes management in African Americans, who are at higher risk for type 2 diabetes than other groups.
For the study, researchers evaluated sleep patterns while also measuring blood glucose markers among 789 African American men and women in the Jackson Heart Study (NCT00005485), the largest study of cardiovascular disease in African Americans.
The participants averaged the age of 63 years. Of the participants, 74% were women, 25% had type 2 diabetes, 20% were taking diabetes medication, and 57% had obstructive sleep apnea but were not receiving treatment for the condition.
Participants completed at-home sleep apnea tests and used a wrist actigraph watch—a tool that measures wakefulness and sleep—for 7 days. The tests calculated sleep duration, sleep efficiency, night-to-night variability in sleep duration, and sleep fragmentation (multiple disruptions during sleep). The researchers took several measures of glucose metabolism, including fasting blood glucose concentration, HbA1c levels, and insulin resistance.
The study focused on 4 main groups: regular sleepers (no sleep apnea) and those with mild, moderate, and severe sleep apnea. The study found that those with severe sleep apnea had 14% higher fasting blood glucose levels than those without the condition. Severe sleep apnea was also associated with higher HbA1c levels.
The researchers found that participants who had other types of disturbed sleep, such as sleep fragmentation and sleep duration variability, were also more likely to have increased blood glucose levels.
The study also found that the connection between sleep apnea and high blood glucose levels is greater among black men than black women. African American men with severe sleep apnea had 10% higher fasting blood glucose levels than African American women with the same condition.
“The study underscores the importance of developing interventions to promote regular sleep schedules, particularly in those with diabetes,” said Yuichiro Yano, MD, PhD, Department of Family Medicine and Community Health, Duke University. “It also reaffirms the need to improve the screening and diagnosis of sleep apnea, both in African-Americans and other groups.”
Michael S. Cartwright, MD, MS, and Hwajin Lee, MD
Michelle L. Dougherty, MD, FAES, FAAN
Vanessa Baute Penry, MD; Rachana Gandhi Mehta, MD; and Fatemeh Sadeghifar, BS