Differential effects of strength training and testosterone treatment on soluble CD36 in aging men: Possible relation to changes in body composition

Abstract

Purpose. We measured soluble CD36 (sCD36) and body composition to determine the effects of testosterone treatment (TT) and/or strength training (ST) on cardiovascular risk in men with low normal testosterone levels. Methods. Double-blinded, placebo-controlled study in 54 men aged 60–78 years with bioavailable testosterone < 7.3 nmol/L and waist > 94 cm randomized to TT (gel, 50–100 mg/day, n = 20), placebo (n = 18) or ST (n = 16) for 6 months. Moreover, the ST group was randomized to TT (ST + TT, n = 7) or placebo (ST + placebo, n = 9) after 3 months. Outcomes. sCD36, total and regional fat mass were established by Dual X-ray absorptiometry and magnetic resonance imaging. Data are presented as median (quartiles). Kruskal-Wallis and Mann-Whitney tests were performed on delta values at 0, 3 and 6 months. Results. ST + placebo decreased sCD36 levels by 21% [from 0.80 (0.68–1.22) to 0.63 (0.51–0.73) rel. units] vs. TT and vs. placebo (p < 0.05). ST + placebo did not change bioavailable testosterone and lean body mass. Fat mass measures significantly improved during ST + placebo, ST + TT, and TT vs. placebo. During ST + placebo, delta sCD36 was associated with delta total fat mass (r = 0.81) and delta central fat mass (r = 0.84). Conclusions. Compared to testosterone treatment, six months of strength training reduced sCD36 levels suggesting decreased cardiovascular risk, possibly due to a reduction in central fat mass.

Key Words::

• Relative hypogonadism
• magnetic resonance imaging (MRI)
• DXA-scan
• body fat distribution
• abdominal fat
• biochemical marker

Acknowledgements and funding

We thank the Novo Nordisk Foundation and the Institute of Clinical Research–University of Southern Denmark. Ipsen Scandinavia provided Testim^® and placebo but was otherwise not involved in the study planning or interpretation of results. Lone Larsen is thanked for skilful technical assistance.

Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.