TY - JOUR
T1 - Exercise effects on bone mineral density
T2 - Relationships to changes in fitness and fatness
AU - Stewart, Kerry J.
AU - Bacher, Anita C.
AU - Hees, Paul S.
AU - Tayback, Matthew
AU - Ouyang, Pamela
AU - De Beur, Suzanne Jan
N1 - Funding Information:
We are grateful to Debbie Hill for her expert assistance with data management, and Stephanie Bosley and Katherine Turner for their invaluable assistance with data acquisition and analysis. We also thank the Johns Hopkins Bayview General Clinical Research Center nursing staff for their support with many of the clinical tasks required by the study. This study was supported by a grant from the Heart, Lung, and Blood Institute, National Institutes of Health (R01HL59164, KJS), and by the Johns Hopkins Bayview General Clinical Research Center (M01-RR-02719), from the National Center for Research Resources, National Institutes of Health. The funding organizations were not involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
Funding Information:
This study was supported by a grant from the Heart, Lung, and Blood Institute, National Institutes of Health (R01HL59164, KJS), and by the Johns Hopkins Bayview General Clinical Research Center (M01-RR-02719), from the National Center for Research Resources, National Institutes of Health. The funding organizations were not involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.
PY - 2005/6
Y1 - 2005/6
N2 - Background: Weight loss typically reduces bone mineral density (BMD). Exercise may preserve or increase BMD even while reducing fatness. We examined the relationships among exercise-induced changes in fitness and fatness with BMD. Design: Randomized controlled trial conducted between July 1999 and November 2003. Participants: Men and women (n =115) aged 55 to 75 years. Intervention: Six months of exercise training. Main Outcome Measures: Fitness measured as peak oxygen uptake and muscle strength, body composition by anthropometry, dual-energy x-ray absorptiometry, and magnetic resonance imaging. Results: A total of 51 men and 53 women completed the trial. Exercise increased aerobic and strength fitness and lean body mass, and reduced general and abdominal obesity. BMD did not change among men in either group. Among women exercisers, there were reductions in total skeleton BMD (p =0.02) and greater trochanter BMD (p =0.02). By bivariate correlation, among women, increased femoral neck BMD was associated with increased aerobic fitness (p =0.01) and with reduced body weight (p =0.02) and BMI (p =0.02). In the final regression model, 13% of the change in femoral neck BMD was explained by the change in aerobic fitness (p <0.01). Among the men, increased total hip BMD and femoral shaft BMD were associated with increased lean mass and lower-body strength. In the final regression models, the change in lean mass explained 9% of the variance in total hip BMD (p =0.04). The change in lean mass explained 20% of the change in femoral shaft BMD (p <0.01), and the change in lower-body strength explained an additional 6% (p <0.04). Conclusions: When examined by group assignment, 6 months of exercise had no effect on BMD among men, and reduced BMD among women. When examined by change in fitness and fatness, women who had the greatest increases in aerobic capacity and men who had the greatest increases in strength and lean mass were more likely to increase their BMD. Exercise-induced reductions in fatness did not lead to bone loss.
AB - Background: Weight loss typically reduces bone mineral density (BMD). Exercise may preserve or increase BMD even while reducing fatness. We examined the relationships among exercise-induced changes in fitness and fatness with BMD. Design: Randomized controlled trial conducted between July 1999 and November 2003. Participants: Men and women (n =115) aged 55 to 75 years. Intervention: Six months of exercise training. Main Outcome Measures: Fitness measured as peak oxygen uptake and muscle strength, body composition by anthropometry, dual-energy x-ray absorptiometry, and magnetic resonance imaging. Results: A total of 51 men and 53 women completed the trial. Exercise increased aerobic and strength fitness and lean body mass, and reduced general and abdominal obesity. BMD did not change among men in either group. Among women exercisers, there were reductions in total skeleton BMD (p =0.02) and greater trochanter BMD (p =0.02). By bivariate correlation, among women, increased femoral neck BMD was associated with increased aerobic fitness (p =0.01) and with reduced body weight (p =0.02) and BMI (p =0.02). In the final regression model, 13% of the change in femoral neck BMD was explained by the change in aerobic fitness (p <0.01). Among the men, increased total hip BMD and femoral shaft BMD were associated with increased lean mass and lower-body strength. In the final regression models, the change in lean mass explained 9% of the variance in total hip BMD (p =0.04). The change in lean mass explained 20% of the change in femoral shaft BMD (p <0.01), and the change in lower-body strength explained an additional 6% (p <0.04). Conclusions: When examined by group assignment, 6 months of exercise had no effect on BMD among men, and reduced BMD among women. When examined by change in fitness and fatness, women who had the greatest increases in aerobic capacity and men who had the greatest increases in strength and lean mass were more likely to increase their BMD. Exercise-induced reductions in fatness did not lead to bone loss.
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U2 - 10.1016/j.amepre.2005.02.003
DO - 10.1016/j.amepre.2005.02.003
M3 - Article
C2 - 15894149
AN - SCOPUS:19344364521
SN - 0749-3797
VL - 28
SP - 453
EP - 460
JO - American journal of preventive medicine
JF - American journal of preventive medicine
IS - 5
ER -