Risk factors for osteoporosis and associated fractures.

Established risk factors for osteoporosis and associated fractures are increasing age, female sex, white race, removal of the ovaries at an early age, prolonged immobility, and prolonged use of corticosteroids. Obesity and use of estrogen replacement therapy are protective. Factors that probably or possibly increase risk in postmenopausal white women include a low calcium intake, cigarette smoking, and, at least for hip fractures, use of long half-life psychotrophic drugs and heavy alcohol consumption. Factors probably or possibly associated with a decreased risk include ingestion of vitamin D and its metabolites, fluoride levels of 2 ppm or more in drinking water, moderate physical activity, pregnancies and breast feeding, use of thiazide diuretics, and progestogens. Some evidence suggests that calcium intake and physical activity at young ages may be important determinants of peak bone mass. Few studies have been undertaken in males and blacks, although at least some risk factors in males may be similar to those in females. Preventive efforts may be aimed at increasing peak bone mass at young ages, preventing bone loss in postmenopausal women, and preventing fractures and their adverse consequences in older people with osteoporosis.