LAUSR

PURPOSE Our purpose was to examine the effects of 2 years of creatine monohydrate supplementation and exercise on bone health in postmenopausal women. METHODS 237 postmenopausal women (mean age 59y) were randomized to receive creatine (0.14 g·kg -1·day -1) or placebo during a resistance training (3d/wk) and walking (6d/wk) program for 2 years. Our primary outcome was femoral neck bone mineral density (BMD), with lumbar spine BMD, and proximal femur geometric properties as secondary outcomes. RESULTS Compared to placebo, creatine supplementation had no effect on BMD of the femoral neck (creatine: 0.725 ± 0.110 to 0.712 ± 0.100; placebo: 0.721 ± 0.102 to 0.706 ± 0.097 g/cm2), total hip (creatine: 0.879 ± 0.118 to 0.872 ± 0.114; placebo: 0.881 ± 0.111 to 0.873 ± 0.109 g/cm2), or lumbar spine (creatine: 0.932 ± 0.133 to 0.925 ± 0.131; placebo: 0.923 ± 0.145 to 0.915 ± 0.143 g/cm2). Creatine significantly maintained section modulus (1.35 ± 0.29 to 1.34 ± 0.26 vs. placebo 1.34 ± 0.25 to 1.28 ± 0.23 cm3, p = 0.0011), predictive of bone bending strength, and buckling ratio (10.8 ± 2.6 to 11.1 ± 2.2 vs. placebo 11.0 ± 2.6 to 11.6 ± 2.7; 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 meters (48.6 ± 5.6 to 47.1 ± 5.4 vs. placebo 48.3 ± 4.5 to 48.2 ± 4.9 s; p = 0.0008), but had no effect on muscular strength (i.e., 1RM) during the bench press (32.1 ± 12.7 to 42.6 ± 14.1 vs. placebo 30.6 ± 10.9 to 41.4 ± 14 kg) and hack squat (57.6 ± 21.6 to 84.4 ± 28.1 vs. placebo 56.6 ± 24.0 to 82.7 ± 25.0 kg). In sub-analysis of valid completers, creatine increased lean tissue mass compared to placebo (40.8 ± 5.7 to 43.1 ± 5.9 vs. placebo 40.4 ± 5.3 to 42.0 ± 5.2 kg; p = 0.046). CONCLUSIONS Two years of creatine supplementation and exercise in postmenopausal women had no effect on bone mineral density, yet improved some bone geometric properties at the proximal femur.