Exercise Intervention for Osteoporosis Prevention in Postmenopausal Women: A Systematic Review
Mishaal Al Khaldi
Senior Physical therapist, King Fahad Specialist Hospital, Dammam, Eastern Province, Saudi Arabia
The aim of this review was to assess the effectiveness of different types of exercise on BMD in post-menopausal women, including weight bearing exercise, non-weight bearing exercise, a combination of weight bearing and non-weight bearing as well as vibration. Further, aims were to identify evidence about optimal exercise frequency and the effects of adding nutritional supplements, especially calcium and/ or vitamin D, to the intervention.
Weight bearing exercise appeared to have good effects on the BMD in post-menopausal women with longer intervention time and maybe calcium/vitamin D supplements however, some studies were not conclusive. Most of the non-weight bearing exercise studies used additive medication and supplements e.g. calcium, vitamin D, HRT, but the results were not significantly in favour to these types of exercises.
However, longer studies showed more notable effects than shorter studies, which suggests that non-weight bearing exercises over a longer duration may have beneficial effects on BMD.
Combination exercise trials showed no significant effects on BMD, but some good effects were noted when the exercises were combined with HRT. The majority of studies had low quality assessment scores, which may have influenced the results. Some sources of risk of possible risk bias and errors were found in most of the trials especially in the non-weight bearing studies like small sample sizes, large dropout rates and low compliance which should be avoided in the future research.
In terms of frequency, most studies performed exercise 3 times/ week which showed good effects on BMD. The longer the term of the treatment duration, the more benefits on BMD were noted. The most effective frequency of each type of exercise was difficult to determine due to the large variety of the exercises and participant compliance. Furthermore, some frequencies of the exercises were changed during the trials, so future research should aim to test exercise with a variety of frequencies.
Adding calcium seemed to be beneficial when accompanied with exercises, especially weight bearing or combination exercises, while calcium alone appeared to have no effectiveness on the BMD. However, in many of those studies, all groups received calcium supplements, allowing no clear conclusion about the effect of calcium and exercise in comparison to no supplementation or exercise.
Summarizing the results of this review, weight bearing exercise might be the recommended exercise type for maintaining or improving BMD in post-menopausal women especially when combined with nutritional supplements. However, further research should confirm validity of the results with larger sample sizes and improve study quality for both non-weight bearing and a combination of weight bearing and non-weight bearing exercise types which showed controversial results on BMD in this review. Whole body vibration combined with exercise seems to give good results on BMD, but further research is recommended to distinguish effects of WBV plus exercise against exercise alone.
Overall, however, due to a considerable amount of heterogeneity and a lack of distinction between the effects in combined interventions, the results of this review are not conclusive enough to allow for a recommendation regarding the effectiveness of a specific intervention in this population. In order to provide a solid evidence base for practice recommendations in the treatment and prevention of osteoporosis, further high quality research is necessary.