Behavioral and Functional Adaptation to Chronic Stress in Older Adults

Background The wear and tear from chronic stress exposure has been linked to premature aging through allostatic load; however, it is unclear how chronic stress exposure affects physical functioning and physical activity in older adults. Objectives The study aims were to examine the behavioral and functional adaptation to chronic stress in older adults and its mediational pathways. Methods Data from the Health and Retirement Study 2016 and 2020 (N = 3075, mean age 66 years) were analyzed. Chronic and perceived stress exposure was quantified using Troxel’s Chronic Stressors Scale and Cohen’s Perceived Stress Scale. Physical activity was quantified using self-reported questionnaires, including light, moderate, and vigorous physical activity. Physical functioning was operated as a latent construct with four perceived physical limitations (i.e., difficulty in movement, hand strength, shortness of breath, and balance). The cross-sectional data were analyzed using latent regression analysis. The longitudinal data were analyzed using serial mediation based on MacKinnon’s bias-corrected bootstrap confidence intervals. Results Cross-sectionally, psychological stress, as a latent construct indicated by stress exposure and stress perception, explained more variances in perceived physical limitation than physical activity. Longitudinally, perceived stress and physical activity mediated the relationship between chronic stress exposure and perceived physical limitation with significant indirect effects. Furthermore, perceived physical limitation suppressed the effect of chronic stress exposure on physical activity levels. The effects of mediation and suppression remained significant after the adjustment for age, gender, years of education, race, number of comorbidities, working status, and marital status. Discussion The promotion of physical activity and physical functioning in older adults might not achieve the optimal outcome if the program design overlooks the target population’s chronic stress process and functional limitations.

Longitudinal Fatigue Symptoms and Inflammatory Markers in African American Adults With Hypertension and Obstructive Sleep Apnea

Background There is a dearth of research inclusive of African American adults living with obstructive sleep apnea (OSA) despite differences in symptom presentations compared to non-Hispanic White patient populations. Less is known regarding the potential effect of comorbidities, including hypertension, on commonly reported symptoms, such as fatigue, and their association with inflammatory biomarkers. Objective This longitudinal pilot study aimed to characterize fatigue symptom presentations among African American adults newly diagnosed with OSA and discern peripheral blood analytes linked to symptoms while accounting for co-occurring hypertension. Methods African American adults newly diagnosed with OSA with and without co-occurring hypertension were approached by study staff and recruited following their diagnostic visit with sleep medicine clinicians at two health systems and followed over 6 months after commencing continuous positive airway pressure treatment. Patient-Reported Outcomes Measurement Information System Fatigue surveys and plasma were collected every 3 months from 29 participants. Mixed-effects models examined changes in fatigue symptom presentations over time while accounting for plasma-based analytes and hypertension status. Results Despite higher fatigue symptom severity upon diagnosis, participants with co-occurring hypertension reported greater improvements in fatigue scores after commencing continuous positive airway pressure treatment for up to 6 months than those without hypertension. Inverse correlations were observed between fatigue scores, C-reactive protein, matrix metalloproteinase-8, and osteoprotegerin analyte levels among participants with/without hypertension. Across all participants, changes in interleukin-6 were associated with changes in fatigue scores in the first 3 months after diagnosis. Discussion Findings indicate that hypertension is linked to increased fatigue upon diagnosis of OSA in this sample of African American adults. Fatigue in persons with hypertension improved after treatment in this sample. These hypothesis-generating findings can inform future interventional studies aimed at improving fatigue among persons with OSA while leveraging markers linked to fatigue symptom severity as potential objective markers of improvements. Further research on the role of inflammatory markers, such as IL-6, on fatigue symptom presentations is warranted in persons with OSA.