A pilot study of moderate physical activity in HIV-infected persons receiving anti-HIV drugs : benefits on soluble and cell markers of inflammation

Introduction HIV infection and combined antiretroviral therapy (cART) are associated with chronic immune activation, which can contribute to the development of metabolic problems and chronic diseases, e.g., cardiovascular diseases, type-2 diabetes. In the general population moderate physical activity has shown to reduce both inflammation and burden of chronic diseases. Aim of this study was to evaluate the effects of brisk walking, as moderate aerobic exercise, on physical fitness, metabolic measures and soluble and cell inflammatory markers among HIV-infected treated subjects. Methods A pilot study was designed including HIV-infected, cART-treated, sedentary subjects with metabolic problems, in a 12-week protocol consisting of 3 outdoor sessions/week of 60 min brisk walking at 65-75% of HRmax with (“walk-strength” group) or without (“walk” group) 30 min circuit training at 65% of 1-ripetition maximum (RM). Measures at baseline (BL) and at week 12 (W12) included distance walked at 6 minute walking test (6MWT) and 1-RM Test; morphometric measures; fasting lipid and glucose blood profile; plasma level of d-dimer, high-sensitivity CRP (hsCRP), interleukin-6 (IL-6), interleukin-18 (IL-18), soluble CD14 (sCD14), myostatin, and CD38 and HLA-DR expression on CD4+ and CD8+ cells. Differences between groups were tested by the Mann-Whitney test and W12 changes from BL by the Wilcoxon-signed rank test. Results are expressed as median values. Results Forty-nine subjects were enrolled and 35 completed the 12-week program: 14 in the ’walk-strength’ group and 21 in the ’walk” group. Median adherence was 67%. At W12, significant improvements from BL were observed of both aerobic and strength performance, with a 14% improvement of distance walked during 6MWT, of BMI, waist and hip circumference, and total and LDL cholesterol, without differences between training groups. Significant reductions were observed of plasma levels of d-dimer (from 272 to 181 ng/mL, p=0.0002), hCRP (from 2.02 to 1.14 μg/mL, p=0.001), IL-6 (from 4.63 to 4.47 pg/mL, p=0.021), IL-18 (from 354 to 304 pg/mL, p=0.010) and myostatin (from 20.9 to 13.5 pg/mL, p=0.006), and of frequency of CD8+CD38+ (from 10.19 to 10.23%, p=0.010), CD8+HLA-DR+ (from 4.34 to 1.79%, p=0.001) and CD4+HLA-DR+ cells (from 10.87 to 6.85%, p=0.024). Conclusions A 12-week protocol of brisk walking was associated with a significant reduction of immune activation in HIV- treated subjects with metabolic disorders. Moderate physical activity can be proposed as a strategy to control long-term consequences of treated HIV infection.