Muscle Strength And Muscular Endurance Does Not Influence The Cardiopulmonary Parameters In Hiv-1 Infected Individuals

Abstract

PURPOSE: To determine the influence of muscle strength and muscular endurance on peak oxygen uptake (VO2peak), anaerobic threshold (%VO2-AT) and respiratory compensation point (%VO2-RCP) in HIV-1 infected individuals. METHODS: Sample was constituted by 41 HIV-1 infected men individuals (25–66 year-old [x: 40.75 ± 8.68 years]) of the Secondary Immunodeficiency Ambulatory from Hospital das Clínicas (Faculty of Medicine - USP). Muscle strength was established through right knee extension in an isokinetic dynamometer in which the volunteers performed 5 repetitions at the 60°·s-1, whilst muscular endurance was considered when the volunteers performed 20 repetitions at 240°·s-1. VO2peak was directly measured breath-to-breath through modifed Heck protocol during cardiopulmonary exercise testing in a metabolic equipment. %VO2-AT were evaluated by V-slope method, and the %VO2-RCP was detected by examining the minute ventilation per VCO2 plot. RESULTS: The results of muscle strength and muscular endurance were 177.63 ± 38.49 N·m-1 and 105,34 ± 23,70, respectivelly. VO2peak ranged from 20.10 to 43.40 ml·kg-1·min-1 (34.08 ± 5.81 ml·kg-1·min-1) and the results observed for %VO2-AT were 51.22 ± 7.79 % (41.00 - 79.00 %) and 69.28 ± 9.84 % (52.00 - 92.00) for %VO2-RCP There are not statistically significant association neither between VO2peak and muscle strength (r=0.09) nor VO2peak and muscular endurance (r=0.16). The association level among muscle strength and %VO2-AT (r=−0.18) or %VO2-RCP (r=0.16), as well as among muscular endurance and %VO2-AT (r=−0.07) or %VO2-RCP (r=0.06) were weak. CONCLUSION: Muscle strength as well as the muscular endurance does not influence the ventilatory threshold and peak oxygen uptake in HIV-1 infected men individuals, suggesting that there are other important variables responsible by the cardiopulmonary performance in HIV+/aids individuals.