Creatine fails to augment the benefits from resistance training in patients with HIV infection: a randomized, double-blind, placebo-controlled study

Abstract

Background: Progressive resistance exercise training (PRT) improves physical functioning in patients with HIV infection. Creatine supplementation can augment the benefits derived from training in athletes and improve muscle function in patients with muscle wasting. The objective of this study was to determine whether creatine supplementation augments the effects of PRT on muscle strength, energetics, and body composition in HIV-infected patients.

Methodology/principal findings: This is a randomized, double blind, placebo-controlled, clinical research center-based, outpatient study in San Francisco. 40 HIV-positive men (20 creatine, 20 placebo) enrolled in a 14-week study. Subjects were randomly assigned to receive creatine monohydrate or placebo for 14 weeks. Treatment began with a loading dose of 20 g/day or an equivalent number of placebo capsules for 5 days, followed by maintenance dosing of 4.8 g/day or placebo. Beginning at week 2 and continuing to week 14, all subjects underwent thrice-weekly supervised resistance exercise while continuing on the assigned study medication (with repeated 6-week cycles of loading and maintenance). The main outcome measurements included muscle strength (one repetition maximum), energetics ((31)P magnetic resonance spectroscopy), composition and size (magnetic resonance imaging), as well as total body composition (dual-energy X-ray absorptiometry). Thirty-three subjects completed the study (17 creatine, 16 placebo). Strength increased in all 8 muscle groups studied following PRT, but this increase was not augmented by creatine supplementation (average increase 44 vs. 42%, difference 2%, 95% CI -9.5% to 13.9%) in creatine and placebo, respectively). There were no differences between groups in changes in muscle energetics. Thigh muscle cross-sectional area increased following resistance exercise, with no additive effect of creatine. Lean body mass (LBM) increased to a significantly greater extent with creatine. CONCLUSIONS / SIGNIFICANCE: Resistance exercise improved muscle size, strength and function in HIV-infected men. While creatine supplementation produced a greater increase in LBM, it did not augment the robust increase in strength derived from PRT.

Trial registration: ClinicalTrials.gov NCT00484627.

Figure 1. CONSORT Diagram showing the disposition of subjects randomized to receive creatine monohydrate or an equivalent number of placebo capsules for 14 weeks.

Figure 2. Muscle strength before and after 14 weeks of study.

Large rectangles represent the average values, while smaller rectangles individual data before and after creatine supplementation. Similarly, large circles represent the average values, while smaller circles individual data before and after placebo supplementation. Data are the sum of strength (1 RM) in 8 muscle groups in subjects randomized to receive creatine monohydrate or placebo. Strength increased significantly within each treatment group (P<0.01), but there was no significant difference between groups in the magnitude of the increase (average increase 44 and 42% (difference 2%, 95% CI −9.5% to 13.9%) in creatine and placebo, respectively, P = 0.58).