0475 Differences and Risk Factors Related to Hypoxic Burden in Non-Hispanic Black/African and White Older Adults

Abstract Introduction Obstructive Sleep Apnea (OSA) is as a prevalent sleep-related breathing disorder. The apnea-hypopnea index (AHI), used for the diagnosis of OSA, captures only the frequency of respiratory events and has demonstrable limitations. Measurements such as total arterial oxygen saturation 90% (T90) and Hypoxic Burden (HB) have demonstrated utility for predicting cardiometabolic diseases, and other adverse health outcomes. Additionally, OSA has been associated with differential effects across racial/ethnic categories. In this cross-sectional study, we evaluate a community-dwelling healthy cohort of non-Hispanic Black and White older adults participating in studies on sleep, memory, and aging. Methods The study included a two-day clinical visit evaluation and one-night polysomnogram (PSG). Hypoxic burden was calculated as the area between the baseline and the SpO2 trace for any episode with = 3% desaturation. Black and White older adults were relatively matched by age, gender, BMI and AHI4%. Multiple regression analyses with HB as the dependent variable and Age, Race, Sex, HTN, AHI4%, and BMI as the independent variables, and t-test was performed for group comparisons with a p-value 0.05 defined as significant. Results Of the 140 subjects, 88 (62.85%) were females, 52 (37.15%) were males, 70 (50%) were non-Hispanic Black, and 70 (50%) were non-Hispanic White. The mean age was 67 (CI=63-71) years, BMI was 25 (CI=23-32) kg/m**2, and education was 16 (CI=14-18) years. Overall, male subjects had higher HB compared to females, p.001. A significant difference in the HB was observed between blacks and whites regardless of hypertensive status, p.008 for all. Black males and females had higher HB than white males and females, respectively, p.0009 for all. Furthermore, age was negatively correlated with HB and this correlation was stronger in blacks compared to whites (r=-.43 vs. r=-.38, p.05). Conclusion Hypoxic burden is a better predictor of cardio metabolic effects, compared to the AHI. Our findings indicate a more pronounced impact, particularly among blacks, with factors such as sex, hypertension, and BMI influencing this association. Future studies should examine the effects of modifiable factors, and how these may contribute to these observed sex/racial differences. Support (if any)