Aerobic fitness, phase angle, and bioelectrical impedance vector analysis in adolescents living with HIV: a cross-sectional study.

Objective: To analyze the association between phase angle (PhA) and bioelectrical impedance vector analysis (BIVA) with aerobic fitness in HIV+ adolescents.

Methods: Aerobic fitness was assessed using the modified Canadian Aerobic Fitness Test, PhA, and BIVA by bioelectrical impedance analysis. Multivariable linear regression was performed to test the association between peak oxygen consumption (peak VO2) and PhA. BIVA ellipses were evaluated considering a reference population of Spanish adolescents.

Results: Forty-seven HIV-infected adolescents (10-18 years old) were included; 25 (53%) were females. Mean peak VO2 and PhA were 48.9 standard deviation (±) 7.0 ml.kg-1.min-1 and 4.6±1.4 degrees, respectively. Multivariable analysis revealed a significant positive association between peak VO2 and PhA (βstd=0.349; p=0.025). Peak VO2 adjusted for covariates explained 49% of PhA variation. BIVA ellipses indicated lower classifications for body cell mass (BCM) and fatfree mass (FFM) in HIV+ adolescents (vs reference population) (p<0.001). HIV+ females (vs HIV+ males) showed a higher classification for dehydration and a lower classification for BCM (p=0.007). No relevant differences were found between the subgroups based on aerobic fitness (p=0.735).

Conclusions: A significant association exists between peak VO2 and PhA in HIV+ adolescents. Alterations in hydration and lower classifications for BCM and FFM were observed in this population.