Table 2 Key results of the five included RCTs
Study identification | Physiological outcomes (assessments, units) | Adherence to PRT intervention | Key results |
|---|---|---|---|
Alberga et al. 2012 Canada [99] | Body weight (kg); BMI (kg/m2); DEXA (total lean mass (kg) and percent body fat (%)) | Not reported | Percent body fat increased in the control group versus PRT group (p = 0.005); total lean mass was maintained in the PRT group versus a loss in the control group (p = 0.005) |
Nilsen et al. 2015, 2016 | Body composition via DEXA (lean body mass: total, trunk, lower extremities, upper extremities, appendicular; fat mass: total and trunk in kg, and percent body fat (%)); body mass (kg); BMI (kg/m2); BMD (total body, total lumbar, total hip, trochanter, femoral neck); skeletal muscle biopsy (total muscle CSA, type I and II muscle CSA, μm2; number of myonuclei, nuclei/fiber; myonuclear domain, cytoplasm:nuclei; number of satellite cells; androgen receptors, myostatin, mitochondrial proteins (i.e. citrate synthase, cytochrome c oxidase subunit IV (COXIV), HSP60); indicators of muscle cellular stress (HSP70, alpha B-crystallin, HSP27, free ubiquitin, and total ubiquitinated proteins) | 84% and 88% upper and lower body exercises completed, respectively | Lower extremity (p = 0.01), upper extremity (p = 0.05) and appendicular (p = 0.001) lean body mass significantly increased in PRT versus control. No change in BMD outcomes. Significant increase in total muscle fiber CSA in PRT versus control (p = 0.04) showing a larger effect in type II (p = 0.03) than type I fibers (p = 0.11). Significant increase in number of myonuclei per type I fibers (+ 17%, p = 0.01) but not type II fibers in PRT versus control. Significant reduction in myonuclear domain in type I fibers but not type II fibers in PRT versus control (p = 0.05). No change androgen receptor or myostatin content, or any mitochondrial protein or indicator of muscle cellular stress. Post hoc: within-group analysis revealed that HSP70 was reduced in the PRT group and a trend towards a reduction in citrate synthase in the control group |
Segal et al., 2003 Canada [101] | Body weight (kg); BMI (kg/m2); waist circumference (cm), sum of four skinfolds (mm) | 79% | No change in body weight, BMI, waist circumference or subcutaneous skinfolds |
Taafe et al. 2017 Australia [102] | PSA (ng/ml), total testosterone (ng/dl) | 69% | No significant change in PSA or testosterone |
Winters-Stone et al. 2014, 2015 | BMD of proximal femur (total hip, greater trochanter, and femoral neck) and lumbar spine (L1-L4) via DEXA; bone turnover via serum osteocalcin (ng/mL) and urinary deoxypyrodinoline (nmol/L); Body composition via DEXA (total lean mass, total fat mass, and trunk fat mass in kg; percent body fat (%)); insulin (mclU/ml); IGF-1 (ng/ml); SHBG (nmol/ml); total testosterone (ng/dl); body weight (kg) | 84% and 43% for supervised and home-based sessions, respectively | PRT had a significant effect on preservation of BMD (− 0.4%) at the L4 vertebrae compared with losses (− 3.1%) in the placebo control group (p = 0.03). Adjusting for patients who completed the study (i.e. follow-up assessments) the PRT program significantly reduced total fat mass (p = 0.02) with a trend towards reduced body fat percentage (p = 0.06) and trunk fat mass (p = 0.07) versus control; and deoxypyrodinoline decreased in the control group versus the PRT group (p = 0.03). Reduction of total fat mass (p = 0.04) and trunk fat mass (p = 0.03) associated with reductions in fasting insulin |