A 2-yr Randomized Controlled Trial on Creatine Supplementation during Exercise for Postmenopausal Bone Health

Abstract

Purpose Our purpose was to examine the effects of 2 yr of creatine monohydrate supplementation and exercise on bone health in postmenopausal women. Methods Two hundred and thirty-seven postmenopausal women (mean age, 59 yr) were randomized to receive creatine (0.14 g·kg-1·d-1) or placebo during a resistance training (3 d·wk-1) and walking (6 d·wk-1) program for 2 yr. Our primary outcome was the femoral neck bone mineral density (BMD), with lumbar spine BMD and proximal femur geometric properties as the secondary outcomes. Results Compared with placebo, creatine supplementation had no effect on BMD of the femoral neck (creatine: 0.725 ± 0.110 to 0.712 ± 0.100 g·cm-2; placebo: 0.721 ± 0.102 to 0.706 ± 0.097 g·cm-2), total hip (creatine: 0.879 ± 0.118 to 0.872 ± 0.114 g·cm-2; placebo: 0.881 ± 0.111 to 0.873 ± 0.109 g·cm-2), or lumbar spine (creatine: 0.932 ± 0.133 to 0.925 ± 0.131 g·cm-2; placebo: 0.923 ± 0.145 to 0.915 ± 0.143 g·cm-2). Creatine significantly maintained section modulus (1.35 ± 0.29 to 1.34 ± 0.26 vs 1.34 ± 0.25 to 1.28 ± 0.23 cm3 (placebo), P = 0.0011), predictive of bone bending strength, and buckling ratio (10.8 ± 2.6 to 11.1 ± 2.2 vs 11.0 ± 2.6 to 11.6 ± 2.7 (placebo), P = 0.011), predictive of reduced cortical bending under compressive loads, at the narrow part of the femoral neck. Creatine reduced walking time over 80 m (48.6 ± 5.6 to 47.1 ± 5.4 vs 48.3 ± 4.5 to 48.2 ± 4.9 s (placebo), P = 0.0008) but had no effect on muscular strength (i.e., one-repetition maximum) during bench press (32.1 ± 12.7 to 42.6 ± 14.1 vs 30.6 ± 10.9 to 41.4 ± 14 kg (placebo)) and hack squat (57.6 ± 21.6 to 84.4 ± 28.1 vs 56.6 ± 24.0 to 82.7 ± 25.0 kg (placebo)). In the subanalysis of valid completers, creatine increased lean tissue mass compared with placebo (40.8 ± 5.7 to 43.1 ± 5.9 vs 40.4 ± 5.3 to 42.0 ± 5.2 kg (placebo), P = 0.046). Conclusions Two years of creatine supplementation and exercise in postmenopausal women had no effect on BMD; yet, it improved some bone geometric properties at the proximal femur.