Muscle power in children, youth and young adults who acquired HIV perinatally.

OBJECTIVES: To compare muscle power between youth who acquired HIV perinatally and HIV unexposed uninfected (HUU) youth.

METHODS: We assessed muscle power (relative to body mass, Pmax /mass), muscle force normalized to body weight (Fmax /BW), force efficiency, jump height (Hmax ) and velocity (Vmax ) during a single two-legged jump with hands on waist on a force platform (Leonardo) in HIV+ youth (n=35, 9-21 y). Thirty-three and 22 participants returned at 12- and 24-months, respectively. We compared age- and sex-specific z-scores in the HIV+ youth to those in HUU controls (n=716, 9-21 y) adjusting for height and muscle cross-sectional area (MCSA, by pQCT).

RESULTS: At baseline, z-scores for Pmax/mass, Fmax /BW and Vmax were less than 1 standard deviation lower than HUU after adjusting for height and MCSA (p⟨0.05). Pmax /mass z-score was negatively associated with level of immunosuppression (p=0.013), but this relationship was not significant after adjusting for height and MCSA (p=0.07). Z-scores for all mechanography outcomes remained stable over time in HIV+ youth.

CONCLUSION: Small deficits in muscle power were apparent in children and youth who acquired HIV perinatally, and the trajectory of muscle power did not change over two years. Further study is needed to identify effective strategies to improve dynamic muscle function in this population.