Premium
Resistance Training and Testosterone Replacement Induced Changes in Body Composition, Free Testosterone, IGF‐1, and IGFBP‐3 in the Frail Elderly
Author(s) -
Lambert Charles P,
Bopp Melinda M,
Johnson Larry E,
Sullivan Dennis H
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a396-d
Subject(s) - anabolism , testosterone (patch) , medicine , endocrinology , sex hormone binding globulin , hormone , insulin resistance , androgen , insulin
The purpose of this study was to examine the effects of two resistance exercise intensities and testosterone replacement on changes in hormone/growth factors and their relationship to body composition changes in the frail elderly. The study design was 2 X 2 X 2 with Drug (100 mg/wk of testosterone; T or no‐testosterone), Resistance Exercise (Low Intensity and High‐Intensity) and Time (Pre and Post intervention). Sixty‐one men with a mean age of 77.8 (6.1) and a total testosterone of < 480 ng/dL participated. Serum was analyzed for insulin like growth factor‐1 (IGF‐1), IGF binding protein 3 (IGFBP‐3), sex hormone binding globulin (SHBG), and total testosterone. Leg strength and mid‐thigh cross‐sectional muscle area were measured pre‐ and post‐intervention. A significant association was observed between the % change in IGF‐1/IGFBP‐3 and the % change in thigh cross‐sectional muscle area (%MCSA; r=0.28, p<0.05). A significant drug effect was observed for the % change in IGFBP‐3 with those on T having a significant decrease compared to no T. Total T at post was related to the % MSCA (r=0.32, p<0.05) and to the % change in leg strength (r=0.35, p<0.05). The associations between the % change in serum IGF‐I/IGFBP‐3 and % MCSA and between total T at post and both % MCSA and % change in leg strength are important as there are few markers in blood which indicate a change in muscle anabolism.