0862 Adequate Sleep Duration Enhances Cardiovascular Benefits Of A Physical Activity Intervention In Older African Americans

Abstract

Abstract Introduction African Americans are at a greater risk for cardiovascular disease and inadequate sleep than are corresponding whites. Age-associated declines in sleep duration, cardiovascular health, and physical activity highlight the need to understand the relationship among these variables in this population. While physical activity is thought to be beneficial for promoting sleep quality, it remains unknown how habitual short sleep during a physical activity intervention influences the intervention response in this population. Methods Sedentary older African Americans (n=27; 65-85 years old; 74% female) participating in the intervention arm of a 12-week randomized controlled physical activity trial (NCT03474302) were categorized as short (n= 15) or adequate (n=12) sleepers, defined as sleeping <6 hours/night or >6 hours/night on average during the intervention. Participants wore validated activity monitors at baseline and 12 weeks, and commercially available sleep monitors were worn daily. Differences in cardiovascular outcomes at baseline and 12 weeks were assessed between sleep categories using sex-adjusted linear mixed models. Results The intervention increased accelerometer derived steps (p=0.04) with no between group differences (p=0.78). Moderate to vigorous activity (MVA) duration increased (p<0.001), but change was greater in adequate sleepers (9 minutes; p<0.05). Body weight did not significantly change (-0.71 kg; p=0.11) and changes were similar between groups (p=0.55). Total (p=0.046) and LDL cholesterol (p=0.04) decreased over time. Adequate sleepers experienced improvements in systolic blood pressure (-10 ± 4.5 mmHg; p=0.03), total cholesterol (-30 ± 11 mg/dL; p=0.01), and LDL cholesterol (-23 ± 9 mg/dL; p=0.01) from baseline while short sleepers did not (all p>0.05). Significant differences or trends between adequate and poor sleepers were observed (-10.5 mmHg; p=0.096; -30 mg/dL p=0.044; -21 mg/dL; p=0.095, respectively). Conclusion Adequate sleep during a physical activity intervention may be important to elicit cardiovascular benefits. Thus, research evaluating sleep extension complementary to increased physical activity is warranted in short sleepers. Support BrightFocus (A20175472); National Institute of General Medical Sciences of the National Institutes of Health (U54-GM104940)