Walking and leisure-time activity and risks of hip fracture in postmenopausal women.
Feskanich D et al. JAMA 2002 Nov 13; 288 (18):2300.
The authors investigated the relation between walking, leisure-time activity and risk of hip fractures in postmenopausal women.
They followed 61,2000 postmenopausal women in the Nurse’s Health Study (US) for 12 years. The age of the participants was between 40 and 77 years.
415 women with hip fractures were identified over 1986-1998 period. After adjusting for different variables they calculated that the risk of hip fracture was lowered by 6% for each increase of 3 metabolic equivalent (MET)-hours per week of activity (equivalent of 1hour/week of walking at an average pace). Women with 24 MET hours/week had a 55% lower risk of hip fracture compared with sedentary women with less than 3 MET hours/week.
Women who did not do any other exercises but walked at least 4 hours per week had a 41% lower risk of hip fractures compared with those who walked less than 1 hour per week.
Long-term outcomes of exercise: follow-up of a randomized trial in older women with osteopenia.
Korpelainen R. et al. Arch Intern Med 2010 Sep 27; 170(17):1548.
Authors followed 160 women (aged 70-73) with osteopenia for 7 years. It was a randomized controlled exercise trial. They measured femoral neck bone mineral density, postural sway and leg strength. They also look into the frequency of hospital treated fractures and functional ability measures.
They found a significant difference between groups in favour of exercise (postural sway, walking speed and Frenchay activity score). The bone mineral density decreased similarly in both groups. There were no hip fractures in exercise group and 5 hip fractures in control group.
Authors concluded that mainly home-based exercises followed by voluntary home training seem to have a long-term effect on balance and gait and may even protect high-risk elderly women from hip fractures.
“Weight bearing exercise training and lumbar bone mineral content in postmenopausal women”. Dalsky et al. Ann Intern Med. 1988; 108(6):824
Design: controlled short term (9 months) and long term (22 months) exercise training and detraining (13 months).
35 healthy sedentary postmenopausal women taking 1500 mg/day of calcium did weight bearing exercise (walking, jogging, stair climbing) at 70 to 90% of maximal oxygen uptake capacity for 50-60 min, 3 times weekly.
Bone mineral density increased 5.2% above baseline after short term training with no change in the control group. After 22 months of exercise, bone mineral density was 6.1% above baseline. After 13 months of decreased activity, bone mass was 1.1% above baseline in the detraining group.
It was concluded that weight bearing exercise led to significant increase above the baseline in the bone mineral content. With reduced exercise, bone mass decreased to the baseline levels.
