Effects of different exercise intensity on bone mineral density in adults: a comparative systematic review and meta-analysis

PURPOSE

The primary objective of the present systematic review and meta-analysis was to determine the effect of differing exercise intensity on (areal) bone mineral density (BMD) at lumbar spine and hip in adults by a comparative meta-analysis.

METHODS

A systematic review of the literature according to the PRISMA statement included: (a) exercise trials, (b) with ≥two study arms that compared different exercise intensities, (c) intervention ≥6 months, (d) BMD assessments at lumbar spine (LS) or hip. Five electronic databases were scanned without language restrictions up to July 2021. The present analysis of exercise intensity was conducted as a mixed-effect meta-analysis and applied "type of exercise" and "study duration" as moderator in subgroup analyses. Outcome measures were standardized mean differences (SMD) for BMD changes at the LS, and hip.

RESULTS

Eleven exercise studies with 26 study arms were included. Although the effect of high-intensity exercise was more pronounced on LS-BMD (SMD: 0.19, 95%-CI: 0.61 to -0.23) and hip-ROI (0.17, 0.38 to -0.04), we did not observe significant differences between the groups (LS-BMD: p=0.373 and hip-BMD: p=0.109). We observed a substantial level of heterogeneity between the trials for LS- but not for hip-BMD. Applying "type of exercise" and "study duration" as moderators did not significantly modify the differences between low and high exercise intensity on BMD at LS or hip.

CONCLUSION

There is insufficient evidence for a superior effect of high-intensity exercise on areal BMD at lumbar spine and hip in people aged 50 years and older. Varying exercise intensity with periods of lower exercise intensity intermitted by higher intensity might be a promising option to address the issue of exercise intensities in intervention studies.

[Health education and health training with osteoarthritis]

Osteoarthrosis is one of the most prevalent diseases in orthopedics. Its impact for the individual patient as well as for the socio-economic system is enormous. An increasing loss of function and pain progress of disease leads to chronic handicap, which severely restricts freedom of a self-determined life and reduces quality of life. Besides conservative and later surgical treatment, health-inducing offers to patients with arthrosis deformans have gained more importance in the process of coping with the illness similar to other chronic diseases. Health education and exercise are supposed to help patients gain more theoretical and practical knowledge of the disease and foster a more positive attitude in order to improve self management. The effect of patient educating programs with respect to self-help activities and socio-economic savings (return to work, days of hospital treatment) could be verified during recent years in many cases of chronic disease, such as rheumatic disease, diabetes and asthma through prospective multicenter studies. Whether special health training in osteoarthrosis leads to similar effects is subject of current studies.