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

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.