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Updated: Sep 1, 2025

Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity
Published on: March 7, 2019
Patterns of objectively measured physical activity differ between men living with and without HIV
Lacey H Etzkorn1, Fangyu Liu1, Jacek K Urbanek2
1Johns Hopkins Bloomberg School of Public Health.
Objective:
To use accelerometers to quantify differences in physical activity (PA) by HIV serostatus and HIV viral load (VL) in the Multicenter AIDS Cohort Study (MACS).
Methods:
MACS participants living with (PLWH, n = 631) and without (PWOH, n = 578) HIV wore an ambulatory electrocardiogram monitor containing an accelerometer for 1-14 days. PA was summarized as cumulative mean absolute deviation (MAD) during the 10 most active consecutive hours (M10), cumulative MAD during the six least active consecutive hours (L6), and daily time recumbent (DTR). PA summaries were compared by HIV serostatus and by detectability of VL (>20 vs. ≤20 copies/ml) using linear mixed models adjusted for sociodemographics, weight, height, substance use, physical function, and clinical factors.
Results:
In sociodemographic-adjusted models, PLWH with a detectable VL had higher L6 (β = 0.58 mg, P = 0.027) and spent more time recumbent (β = 53 min/day, P = 0.003) than PWOH. PLWH had lower M10 than PWOH (undetectable VL β = -1.62 mg, P = 0.027; detectable VL β = -1.93 mg, P = 0.12). A joint test indicated differences in average PA measurements by HIV serostatus and VL (P = 0.001). However, differences by HIV serostatus in M10 and DTR were attenuated and no longer significant after adjustment for renal function, serum lipids, and depressive symptoms.
Conclusions:
Physical activity measures differed significantly by HIV serostatus and VL. Higher L6 among PLWH with detectable VL may indicate reduced amount or quality of sleep compared to PLWH without detectable VL and PWOH. Lower M10 among PLWH indicates lower amounts of physical activity compared to PWOH.
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