G-16 Free Communication/Poster - Endocrinology MAY 31, 2008 7:30 AM - 11:00 AM ROOM: Hall B
Muscle Quality Following Testosterone And/or Growth Hormone Administration in Older Men: Board #63 May 31 9:30 AM - 11:00 AM
PURPOSE: We hypothesized that there would be no change in MQ with testosterone administration as strength increases would be proportional to increases in muscle mass. We determined the effect of testosterone (T) with or without recombinant human growth hormone (rhGH) administration in older men on MQ of the lower extremity (LE).
METHODS: We conducted a two-tiered, factorial, randomized, multicenter study to evaluate the effects of 16 weeks of T (5 or 10 g/day) and rhGH (0, 3, or 5 μg/ kg/d) administration in men ≥65 years of age on MQ of the LE. Maximum voluntary strength was determined by the one-repetition maximum (1-RM) method for leg press, flexion and extension and muscle volume of leg muscles were determined by MRI at baseline and week 17. MQ was determined on a relative basis by the ratio of % change in 1-RM strength / % change in muscle volume. One-way ANOVA and independent t-tests were used to determine within and between group differences in MQ. Analyses were performed masked to treatment assignment.
RESULTS: Sixty-one healthy older men (71.1±4.5 years; 83.4±12.6 kg) were evaluated. MQ was not significantly different (P>0.05 for all comparisons) between and within the 6 study groups, indicating that different dose levels of T and GH did not increase MQ (Table).
CONCLUSIONS: The wide range of differences in MQ and large variance may reflect differences in subject motivation at time of 1-RM testing or inter-current, age related processes. Regardless, improvements in MQ may not result from testosterone administration alone or in combination with rhGH when these agents are administered at physiologic doses in older men.©2008The American College of Sports Medicine