Exercise, Calcium Supplementation May Improve BMD in Postmenopausal Women
News Author: Laurie Barclay, MD
From Medscape Medical News.
Dec. 28, 2005 — Exercise and calcium supplementation improve bone mineral density (BMD) in postmenopausal women, according to the results of a 4-year study reported in the December issue of Osteoporosis International.
"The good news is these long-term data confirmed the potent combination of improved nutrition and increased physical activity to prevent bone loss," principal investigator Timothy Lohman, PhD, from the University of Arizona in Tucson, said in a news release. "The extended use of calcium supplementation and exercise counteracted the typical loss of BMD in women at this age, in a regimen that women really can stick with. This is quite significant for younger women as well, as these exercises and calcium supplementation can help build peak BMD which may prevent health problems and osteoporosis in the future."
In the Bone, Estrogen, Strength Training (BEST) study, 167 postmenopausal, calcium-supplemented (800 mg/day) sedentary women were randomized to a progressive strength training exercise program or to a control group and were followed up for 4 years. Mean age was 56.1 ± 4.5 years, and 54% of the women were using hormone therapy (HT) at baseline. At 1 year, women in the control group were permitted to crossover to the exercise program. The final sample consisted of 23 controls, 55 crossovers, and 89 randomized exercisers.
The prescribed exercise program was 2 sets of 6 to 8 repetitions of exercises at 70% to 80% of 1 repetition maximum, 3 times weekly.
"What sets this regimen apart is the six specific exercises that help build bone in the wrist, hip and spine — three key fracture sites," says BEST Study coinvestigator Lauve Metcalfe, MS, also from the University of Arizona in Tucson. "This type of weight-bearing exercise now is proven to be beneficial and represents a shift in prior bone health recommendations. It previously was thought that any type of exercise was helpful, but now we understand that resistance and weight-bearing exercise are essential."
Dual-energy x-ray absorptiometry (DEXA) was used to measure BMD at baseline and annually thereafter. Average 4-year percentage exercise frequency (ExFreq) was 26.8% ± 20.1% for crossovers (including the first year at 0%) and 50.4% ± 26.7% for exercisers. Average 4-year total confidence interval (CI) was 1,635 ± 367 mg/day, and supplemental calcium intake was 711 ± 174 mg/day.
Adjusted multiple linear regression models revealed that ExFreq was positively and significantly related to changes in femur trochanter (FT) and neck (FN), lumbar spine (LS), and total body (TB) BMD. For women receiving HT, FT BMD increased 1.5%, and the FN and LS BMD increased 1.2% (P < .01) for each SD of percentage ExFreq (29.5% or 0.9 days per week). Women not using HT gained 1.9% and 2.3% BMD at FT and FN, respectively, for every SD of CI (P < .05).
"The significant, positive, association between BMD change and ExFreq supports the long-term usefulness of strength training exercise for the prevention of osteoporosis in postmenopausal women, especially HT users," the authors write. "The positive relationship of CI to change in BMD among postmenopausal women not using HT has clinical implications in light of recent evidence of an increased health risk associated with HT."
Study limitations include allowing controls to cross over to the exercise group of the study after the first year of intervention; potential training time discrepancies between exercisers and crossovers; questionable accuracy of self-reports of exercise; and dropout rates.
"This study supports the long-term benefits of strength training exercise and calcium intake for the prevention of osteoporosis in postmenopausal women," the authors conclude. "Combined with exercise, women may choose to continue HT or increase total calcium intake to around 1,700 mg/day to help prevent osteoporosis."
The National Institute for Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health funded the BEST Study. Mission Pharmacal Co supplied calcium citrate (Citracal) for the study.
Osteoporos Int. 2005;16:2129-2141
From Medscape Medical News.
Dec. 28, 2005 — Exercise and calcium supplementation improve bone mineral density (BMD) in postmenopausal women, according to the results of a 4-year study reported in the December issue of Osteoporosis International.
"The good news is these long-term data confirmed the potent combination of improved nutrition and increased physical activity to prevent bone loss," principal investigator Timothy Lohman, PhD, from the University of Arizona in Tucson, said in a news release. "The extended use of calcium supplementation and exercise counteracted the typical loss of BMD in women at this age, in a regimen that women really can stick with. This is quite significant for younger women as well, as these exercises and calcium supplementation can help build peak BMD which may prevent health problems and osteoporosis in the future."
In the Bone, Estrogen, Strength Training (BEST) study, 167 postmenopausal, calcium-supplemented (800 mg/day) sedentary women were randomized to a progressive strength training exercise program or to a control group and were followed up for 4 years. Mean age was 56.1 ± 4.5 years, and 54% of the women were using hormone therapy (HT) at baseline. At 1 year, women in the control group were permitted to crossover to the exercise program. The final sample consisted of 23 controls, 55 crossovers, and 89 randomized exercisers.
The prescribed exercise program was 2 sets of 6 to 8 repetitions of exercises at 70% to 80% of 1 repetition maximum, 3 times weekly.
"What sets this regimen apart is the six specific exercises that help build bone in the wrist, hip and spine — three key fracture sites," says BEST Study coinvestigator Lauve Metcalfe, MS, also from the University of Arizona in Tucson. "This type of weight-bearing exercise now is proven to be beneficial and represents a shift in prior bone health recommendations. It previously was thought that any type of exercise was helpful, but now we understand that resistance and weight-bearing exercise are essential."
Dual-energy x-ray absorptiometry (DEXA) was used to measure BMD at baseline and annually thereafter. Average 4-year percentage exercise frequency (ExFreq) was 26.8% ± 20.1% for crossovers (including the first year at 0%) and 50.4% ± 26.7% for exercisers. Average 4-year total confidence interval (CI) was 1,635 ± 367 mg/day, and supplemental calcium intake was 711 ± 174 mg/day.
Adjusted multiple linear regression models revealed that ExFreq was positively and significantly related to changes in femur trochanter (FT) and neck (FN), lumbar spine (LS), and total body (TB) BMD. For women receiving HT, FT BMD increased 1.5%, and the FN and LS BMD increased 1.2% (P < .01) for each SD of percentage ExFreq (29.5% or 0.9 days per week). Women not using HT gained 1.9% and 2.3% BMD at FT and FN, respectively, for every SD of CI (P < .05).
"The significant, positive, association between BMD change and ExFreq supports the long-term usefulness of strength training exercise for the prevention of osteoporosis in postmenopausal women, especially HT users," the authors write. "The positive relationship of CI to change in BMD among postmenopausal women not using HT has clinical implications in light of recent evidence of an increased health risk associated with HT."
Study limitations include allowing controls to cross over to the exercise group of the study after the first year of intervention; potential training time discrepancies between exercisers and crossovers; questionable accuracy of self-reports of exercise; and dropout rates.
"This study supports the long-term benefits of strength training exercise and calcium intake for the prevention of osteoporosis in postmenopausal women," the authors conclude. "Combined with exercise, women may choose to continue HT or increase total calcium intake to around 1,700 mg/day to help prevent osteoporosis."
The National Institute for Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health funded the BEST Study. Mission Pharmacal Co supplied calcium citrate (Citracal) for the study.
Osteoporos Int. 2005;16:2129-2141
posted by Ricardo Pocurull at 7:57 AM
0 Comments:
Post a Comment
<< Home