Androgen therapy improves muscle mass and strength but not muscle quality: results from two studies

Abstract

The relationship of strength to muscle area was used to assess change in muscle quality after anabolic interventions. Study 1: asymptomatic human immunodeficiency virus-positive men (39 ± 9 yr) were randomized to nandrolone (600 mg/wk) ± resistance training (RT). Study 2: older healthy men (72 ± 5 yr) were randomized to oxandrolone (20 mg/day) or placebo. Maximum voluntary strength was determined by the 1-repetition maximum (1-RM) method for leg press, flexion and extension, and cross-sectional area of leg muscles by MRI. From study week 0 to study week 12, muscle quality was unchanged with nandrolone, oxandrolone, or oxandrolone placebo, respectively, for total thigh muscles (1.23 ± 0.012 vs. 1.27 ± 0.29 kg/cm2; 9.0 ± 1.1 vs. 8.9 ± 1.2 N/cm2; 8.9 ± 1.2 vs. 8.9 ± 1.9 N/cm2) and hamstrings (0.41 ± 0.08 vs. 0.43 ± 0.07 kg/cm2; 0.90 ± 0.14 vs. 0.95 ± 0.016 N/cm2; 0.94 ± 0.23 vs. 0.93 ± 0.21 N/cm2). Lower-extremity 1-RM strength increased several times greater with RT+nandrolone (51–63% increases) than with nandrolone alone (4.7–16%), despite similar increases in muscle area; therefore, muscle quality increased from 1.13 ± 0.17 to 1.51 ± 0.18 kg/cm2 (+36 ± 19%; P < 0.001) for total thigh muscle, 0.37 ± 0.10 to 0.53 ± 0.08 kg/cm2 (+49 ± 39%; P < 0.001) for hamstrings, and 0.73 ± 0.19 to 1.07 ± 0.16 kg/cm2 (+55 ± 36%; P < 0.001) for quadriceps. Thus androgen therapy alone did not improve muscle quality, but the addition of RT to nandrolone produced substantive improvements.