Abstract
Background. We investigated serum testosterone and insulin-like growth factor 1 (IGF-1) levels' associations with muscle fibre size and resistance training in male dialysis patients. Methods. Male patients were included in a 16-week control period followed by 16 weeks of resistance training thrice weekly. Blood samples were obtained to analyse testosterone, luteinizing hormone (LH), IGF-1, and IGF-binding protein 3. Muscle fibres' size was analysed in biopsies from m. vastus lateralis. Results. The patients' testosterone levels were within the normal range at baseline (n=20) (19.5 (8.2-52.1) nmol/L versus 17.6 (16.1-18.0), resp.) whereas LH levels were higher (13.0 (5.5-82.8) U/L versus 4.3 (3.3-4.6), P<0.001, resp.). IGF-1 and IGF-binding protein 3 levels were higher in the patients compared with reference values (203 (59-590) ng/mL versus 151 (128-276), P=0.014, and 5045 (3370-9370) ng/mL versus 3244 (3020-3983), P<0.001, resp.). All hormone levels and muscle fibre size (n=12) remained stable throughout the study. Age-adjusted IGF-1 was associated with type 1 and 2 fibre sizes (P<0.05). Conclusion. Patients' total testosterone values were normal due to markedly increased LH values, which suggest a compensated primary insufficiency of the testosterone producing Leydig cell. Even though testosterone values were normal, resistance training was not associated with muscle hypertrophy. This trial is registered with ISRCTN72099857.
| Original language | English |
|---|---|
| Article number | 121273 |
| Journal | Journal of Biomedicine and Biotechnology |
| Volume | 2014 |
| Number of pages | 7 |
| ISSN | 1110-7243 |
| DOIs | |
| Publication status | Published - 2014 |
Keywords
- Adult
- Aged
- Exercise
- Humans
- Insulin-Like Growth Factor Binding Protein 3
- Insulin-Like Growth Factor I
- Male
- Middle Aged
- Muscle Fibers, Skeletal
- Organ Size
- Renal Insufficiency, Chronic
- Testosterone