Bone mass

Bone mass increases during childhood and adolescence and peaks between the ages of 20 and 30 years. Peak bone mass is influenced by age, sex, genetic factors, hormonal status, exercise, and calcium intake. As women in general have a lower peak bone mass than men, it is understandable why osteoporosis is predominantly seem in women.

Plain radiographs are not sensitive enough to diagnose osteoporosis. Results of bone mineral density (BMD) tests are typically reported as T scores and Z scores.
▪ The T score compares a patient's BMD with the mean value for young, healthy adults of the same sex.
▪ The Z score compares a patient's BMD with the mean value for persons of the same age and sex.
Both scores are expressed in terms of standard deviations from the mean. The World Health Organization has defined osteoporosis as a BMD of at least 2.5 standard deviations (SD) below the mean value in young normal adults (i.e. T<=-2.5).

Chronic alcoholism is another important cause of low serum phosphate level, in which case the liver enzymes will be elevated. All bisphosphonates act similarly on bone in binding permanently to mineralized bone surfaces and inhibiting osteoclastic activity. Thus, they inhibit bone resorption and less bone is degraded during the remodelling cycle. They do not stimulate bone formation.

Reference

Black DM, Cummings SR, Karpf DB, Cauley JA, Thompson DE, Nevitt MC, et al. Randomized trial of effect of alendronate on risk of fracture in women with existing vertebral fractures. Lancet 1996; 348: 1535-1541.