Objective: Our objective was to examine the effect of a lifestyle diet and exercise intervention on cardiorespiratory fitness (CRF) and to examine predictors of change in CRF.
Design: People living with HIV (PLHIV) are at increased risk for cardiovascular disease. CRF is a better predictor of cardiovascular disease-related mortality than established risk factors yet very little is known about CRF in PLHIV.
Methods: One-hundred and seven virally suppressed PLHIV were randomized to a group-based intervention to improve lifestyle behaviors or a control condition. All PLHIV maximal cardiorespiratory stress test to determine VO2 peak, VO2 at anaerobic threshold, and ventilatory efficiency/VCO2, at baseline and 6 months later. Participants wore an accelerometer to measure physical activity, completed waist-hip circumference measures, and had a fasting lipid profile, IL-6, and high sensitivity C-reactive protein analyzed. Generalized estimating equations were used to examine the effect of the intervention on CRF and predictors of change in CRF.
Results: Participants were approximately 53 years old, 65% male (n = 70), and 86% African-American (n = 93). There was no effect of the intervention on markers of CRF over time (P > 0.05). After controlling for age, sex, waist-hip-ratio, the inflammatory biomarker IL-6 was inversely associated with a decline in both VO2 peak (P = 0.03) and VO2 at anaerobic threshold (P = 0.03). In addition, participants who walked an additional 10 000 steps per day had a 2.69 ml/kg per min higher VO2 peak (P = 0.02).
Conclusion: Despite HIV viral suppression, PLHIV had remarkably poor CRF and inflammation was associated with a clinically adverse CRF profile. However, increased physical activity was associated with improved CRF.