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 Americans 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, such as 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 Americans newly diagnosed with OSA and discern peripheral blood analytes linked to symptoms while accounting for co-occurring hypertension.

Methods: Adult African Americans 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 three months after diagnosis.

Discussion: Findings indicate that hypertension is linked to increased fatigue upon diagnosis of OSA in this sample of African Americans. Fatigue in persons with hypertension improved after treatment. 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 those with OSA regardless of hypertension status.