Association of Physical Activity and Calcium Intake with the Maintenance of Bone Mass in Premenopausal Women

Abstract

Altogether 92 initially 25- to 30-year-old women of 132 original subjects participated in this 4-year follow-up study, which evaluated the influence of physical activity and calcium intake on the bone mineral content (BMC) of premenopausal women. The subjects were originally selected for a cross-sectional study according to their level of physical activity (high PA+ and low PA-) and calcium intake (high Ca+ and low Ca-), and the original groups were maintained in this follow-up study. The mean loss of BMC (95% CI) in the pooled data was 1.5% (0.7% to 2.4%) at the femoral neck, 0.6% (-0.8% to 1.9%) at the trochanter and 6.0% (4.5% to 7.4%) at the distal radius during the 4-year follow-up. According to repeated measures analyses of covariance neither physical activity nor physical fitness at baseline was associated with the rate of bone loss from the proximal femur. High calcium intake and the maintenance of body weight were both associated with a lower rate of bone loss from the proximal femur and distal radius. In addition, a long duration of breast feeding was associated with a higher rate of bone loss from the distal radius.

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

“…There are, of course, a few contrary studies that suggest lactation predicts lower BMD (261,336,352,472,559,686,770,946,971,973) or increases the risk of fracture (97,525,559,699). Smoking may cause breastfeeding to have a negative effect on BMD that is not seen in nonsmokers who breastfed (448).…”

Exercise and Bone Mass in Adults

“…However, the findings of studies performed in young adults have not consistently produced these findings. Standard resistance-training protocols enhance muscle mass, [128][129][130][131] and in several cases bone mass, [114,132] in young women. Friedlander et al [114] reported significant increases after a 2-year programme of aerobics and weight-training in lumbar spine, intertrochanteric and calcaneal BMD.…”

Effects of risedronate in a rat model of osteopenia due to orchidectomy and disuse: Densitometric, histomorphometric and microtomographic studies

“…(15)(16)(17) The mechanisms governing the fat and lean masses and their relationships to the decrease in bone mass with age and gender are still unclear. (18) Muscular activity is well known to exert positive effects on bone mass (19,20) and hormones released by adipocytes (leptin and adiponectin)…”