Objectively Measured Physical Activity in Asymptomatic Middle-Aged Men Is Associated With Routine Blood-Based Biomarkers

Abstract

Background: The use of circulating clinically routine biomarkers and volitional physical activity using wristband accelerometry in preclinical middle-aged adults may provide sensitive measures of physical function and predict sooner the onset of age- and HIV-related physical decline. Methods: Nested cross-sectional cohort study of adult men 50-65 years old with HIV infection on potent antiretroviral therapy and uninfected control participants within the Boston metropolitan area. Gait speed derived from wristband accelerometry, gait speed derived from a standardized 6-minute walk test, cellular immune biomarker levels (CD4 T cell, CD8 T cell), and serum anabolic biomarker levels (total and free testosterone, and sex-hormone-binding globulin) were measured. Results: Of the five measured biomarkers, four were significantly associated with volitional gait speed based on accelerometry, whereas only one was associated with gait speed based on the 6-minute walk test collected in a laboratory environment. Conclusion: Levels of selected immune and anabolic biomarkers were associated with volitional physical activity in middle-aged individuals. Digital and circulating biomarkers may be useful in future studies designed to identify presymptomatic individuals at increased risk for age- and HIV-associated functional decline.