Exercise effects on bone mineral density in older adults: a meta-analysis of randomized controlled trials
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The purpose of the study was to assess the effects of exercise interventions with different impact loading characteristics on lumbar spine (LS) and femoral neck (FN) bone mineral density (BMD) in older adults. We searched electronic databases and hand searched selected journals up to February 2011 for randomized controlled trials (RCTs) investigating the effects of impact exercise interventions on LS and FN BMD in older adults. Exercise protocols were categorized according to impact loading characteristics. Weighted mean difference (WMD) meta-analyses were undertaken. Heterogeneity amongst trials and publication bias was tested. Random-effects models were applied. Trial quality assessment was also undertaken. Nineteen RCTs, including 1577 subjects, met the inclusion criteria. Twenty-two study group comparisons reported BMD data at the LS. Meta-analysis showed a significant change in BMD at this site (WMD 0.011 g/cm2, 95% CI 0.003 to 0.020; p = 0.007), although results were moderately inconsistent (I2 = 52.2%). BMD data at the FN were available from 19 study group comparisons among older adults. Results were inconsistent (I2 = 63.6%) in showing a significant positive effect of exercise on BMD at this site (WMD 0.016 g/cm2, 95% CI 0.005 to 0.027; p = 0.004). Combined loading studies of impact activity mixed with high-magnitude joint reaction force loading through resistance training were effective at LS (WMD 0.016 g/cm2, 95% CI 0.002 to 0.036; p = 0.028), and no inconsistency existed among these trials. Odd-impact protocols were also effective in increasing BMD at LS (WMD 0.039 g/cm2, 95% CI 0.002 to 0.075; p = 0.038) and FN (WMD 0.036 g/cm2, 95% CI 0.012 to 0.061; p = 0.004), although heterogeneity was evident (I2 = 87.5% and I2 = 83.5%, respectively). We found consistency among results for low-impact and resistance exercise studies on LS and FN, although non-significant BMD changes were evident amongst these types of protocols at any site and amongst the RCTs that provided a combined loading impact exercise at FN. Funnel plots showed no evidence of publication bias. Trial quality was moderate to high. The findings from our meta-analysis of RCTs support the efficacy of exercise for increasing LS and FN BMD in older adults.
KeywordsSystematic review Meta-analysis Bone density Exercise Aging
- Brooke-Wavell K, Jones PR, Hardman AE (1997) Brisk walking reduces calcaneal bone loss in post-menopausal women. Clin Sci (Lond) 92(1):75–80Google Scholar
- Cooper C, Cole ZA, Holroyd CR, Earl SC, Harvey NC, Dennison EM, Melton LJ, Cummings SR, Kanis JA (2011) Secular trends in the incidence of hip and other osteoporotic fractures. Osteoporos Int. doi:10.1007/s00198-011-1601-6
- Frost HM (1986) Intermediary organization of the skeleton. CRC, Boca RatonGoogle Scholar
- Higgins JPT, Green S (eds) (2009) Cochrane handbook for systematic reviews of interventions version 5.0.2 [updated September 2009]. The Cochrane Collaboration, 2009. Available from http://www.cochrane-handbook.org.
- Johnell O, Kanis JA, Oden A, Johansson H, De Laet C, Delmas P, Eisman JA, Fujiwara S, Kroger H, Mellstrom D, Meunier PJ, Melton LJ 3rd, O’Neill T, Pols H, Reeve J, Silman A, Tenenhouse A (2005) Predictive value of BMD for hip and other fractures. J Bone Miner Res 20(7):1185–1194. doi:10.1359/JBMR.050304 PubMedCrossRefGoogle Scholar
- Kemmler W, Von Stengel S, Engelke K, Häberle L, Kalender WA (2010) Exercise effects on bone mineral density, falls, coronary risk factors, and health care costs in older women: the randomized controlled senior fitness and prevention (SEFIP) study. Arch Intern Med 170(2):179–185PubMedCrossRefGoogle Scholar
- Marques EA, Mota J, Machado L, Sousa F, Coelho M, Moreira P, Carvalho J (2011a) Multicomponent training program with weight-bearing exercises elicits favorable bone density, muscle strength, and balance adaptations in older women. Calcif Tissue Int 88(2):117–129. doi:10.1007/s00223-010-9437-1 PubMedCrossRefGoogle Scholar
- Marques EA, Wanderley F, Machado L, Sousa F, Viana JL, Moreira-Goncalves D, Moreira P, Mota J, Carvalho J (2011b) Effects of resistance and aerobic exercise on physical function, bone mineral density. OPG and RANKL in older women. Exp Gerontol 46(7):524–532. doi:10.1016/j.exger.2011.02.005 Google Scholar
- Nelson ME, Rejeski WJ, Blair SN, Duncan PW, Judge JO, King AC, Macera CA, Castaneda-Sceppa C (2007) Physical activity and public health in older adults: recommendation from the American College of Sports Medicine and the American Heart Association. Circulation 116(9):1094–1105PubMedCrossRefGoogle Scholar
- Nichols JF, Nelson KP, Peterson KK, Sartoris DJ (1995) Bone mineral density responses to high-intensity strength training in active older women. J Aging Phys Act 3(1):26–38Google Scholar
- Wood L, Egger M, Gluud LL, Schulz KF, Juni P, Altman DG, Gluud C, Martin RM, Wood AJ, Sterne JA (2008) Empirical evidence of bias in treatment effect estimates in controlled trials with different interventions and outcomes: meta-epidemiological study. BMJ 336(7644):601–605. doi:10.1136/bmj.39465.451748.AD PubMedCrossRefGoogle Scholar