Risk factors for osteoporosis in urban Iranian postmenopausal women (A center based study)

Osteoporosis is recognized as a major healthcare problem in elders. Data on prevalence and risk factors of osteoporosis in developing countries is sparse. In this study we aim to define the risk factors of osteoporosis in a selected group of postmenopausal women in Tehran. This is a case-control, interview based study that was conducted in a popular public hospital (Shariati) in Tehran during period 2002-2003. The sample sizes included 272 post menopausal women (136 case and 136 controls in the same age group). The case group were identified as osteoporotic patients based on WHO definition in spine and/or total femoral region interest using DEXA method and Lunar DPX machine. A self made questionnaire was used for data collection. It included some information on demographic, obstetrical and menstrual factors, medical and drug history, nutritional status, physical activity and life style. Risk factors for osteoporosis were calculated by adjusted odds ratios using multiple logistic regressions. The significant (P<0.05) risk factors in present study population with their Odds Ratios (in parenthesis) were as follow: BMI<25 (4.2), duration of menopause > 5 years (2.4), Parity >3, lactation >3 years, steroid therapy (3.6), Bone and joint disorders (2.34) teeth problems (2.30), education < 12 schooling yrs (2.6) and red meat consumption ≥ 4 times/w (2.1).Regular consumption of milk ≥ 3/w (0.4), cheese ≥ 30g/d (0.5), chicken (0.4), fish (0.3) and honey (0.42) appeared to be significant protective factors. Calcium supplementation (0.3), regular walking (0.4) and sunshine exposure (0.4) also reduced the risk significantly. Osteoporosis, in this study, appears to be associated with several risk factors. The association of environmental factors like diet, exercise and sunshine exposure with osteoporosis indicates need of more studies in this area and also the direction for elders, health strategies for osteoporosis prevention in Iran.