Risk factors for the development of osteoporosis in a South African population. A prospective analysis.

Despite the vast number of risk factors that apparently predispose to the development of osteoporosis (OP), they have not been accurately identified and given relative priority. In order to analyse possible risk factors prospectively in a local patient population with overt OP (histomorphometrically confirmed and characterised) and compare it with an appropriately matched non-OP control group (with normal bone mass on dual-energy X-ray absorptiometry), a detailed general history, risk factor analysis, dietary history and anthropometric data were obtained from 56 OP and 125 non-OP subjects. In females a positive family history of OP (P = 0.002), a fair complexion (P = 0.009), lower body mass (P = 0.02) and height (P = 0.03), no breast-feeding of babies (P = 0.006), a history of smoking (P = 0.001) and fat distribution around the waist (P = 0.009) were identified as risk factors. In males lack of exercise (P = 0.008), a history of smoking (P = 0.01), lower body mass (P = 0.04) and height (P = 0.04), a preference for salty food (P = 0.02) and fat distribution around the waist (P = 0.002) appeared to predispose. Dietary calcium, phosphorus, protein and caffeine intakes were similar in OP and control subjects, but alcohol consumption was clearly higher in both OP males (P = 0.001) and females (P = 0.01).