A systematic review 1 including 10 controlled studies (of which 4 were randomised) with a total of 330 subjects was abstracted in DARE. Using the fixed effects model, bootstrap analysis showed statistically significant changes in lumbar spine bone mineral density. Changes in lumbar spine density, corrected for sample size, ranged from -2.41% to 8.12%, sample mean +2.83%, 95% CI 1.15 to 4.50%. This increase was caused primarily by the loss of lumbar bone mineral density in the non-exercise group.
Comment: Publication bias was observed in the funnel plot with an absence of studies with small sizes.
Another systematic review 2 by the same author abstracted in DAREincluded 11 RCTs with a total of 719 subjects. The overall treatment effect change for all groups was 0.27 (95% CI 0.16 to 0.37). There was significant heterogeneity in the results.
A third systematic review 3 abstracted in DAREincluded 21 RCTs with a total of 1,703 women. Evaluations of exercise vs no exercise, or exercise vs alternative exercise appear to suggest that exercise may confer some benefit in relation to increasing/maintaining bone density when compared to no exercise. However, some trials (4 out of 15) did not demonstrate this effect. The overall trend appears to suggest that the addition of oestrogen, oestrogen/progesterone, or calcium supplements to exercise may result in more favourable outcomes compared with exercise alone.
A fourth systematic review 4 including 2 RCTs and 4 controlled non-randomised studies with a total of 230 subjects was abstracted in DARE. Across all designs and categories, changes in bone density at the hip yielded an average effect size of 0.43 (95% CI 0.04 to 0.81), There was an overall change of approximately 2.42% (exercise = 2.13, non-exercise = -0.29) in bone density at the hip.
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