Bone mass density (BMD) in normal Iranian population.

Abstract: Introduction: BMD varies in different countries due to different genetic and environmental factors, It is necessary to determine BMD in normal population of Iran. This study was designed by the Rheumatology Research Center to fulfill this task. It was achieved by a grant from the Deputy Ministry for Research, the Ministry of Health, Treatment and Medical Education. Materials and methods: 280 normal Iranians were selected randomly from staffs of Shariati Hospital by age decades, (age 10 to 84), 20 for each decade (140 men & 140 women). Dual Energy X-Ray Absorptiometry (DEXA) for lumbar spine (L1, L2, L3, L4, L1-L4) and femoral neck (Neck, Trochanter, Intertrochanter, Total, Ward) was done for all of them. A computerized curve for each site in both men and women were drawn. Then they were compared with the international normal standards. Results: The BMD of both lumbar spine and femoral neck in Iranians were lower compared to the International standards. In lumbar spine the mean difference was 6.5% (2-21%, CI=1) for women and 13.8% (2-36%, CI=1.45) for men. In femoral neck the mean difference was 5.4% (2-16%, CI= 0.64) for women and 4.6% (1-14%, CI=0.96)for men. However the BMD of femoral neck in men over 75 was higher (the mean difference was 3% at age 75 and 10% at age 80). This can be attributed to osteoarthrosis. Discussion: It was shown that the BMD of lumbar spine and femoral neck in Iranians are lower compared to the international standards in all age groups and in both sexes. It is more pronounced in lower ages (less than 25).This mandates more concerns about etiologic factors of low BMD in Iran.