Bone mineral density in the normal Iranian population: a comparison with American reference data

SUMMARY: In order to establish the normative curves for BMD in Iranian individuals, we measured BMDs at the lumbar spine and femoral regions of 760 women and 632 men using dual-energy X-ray absorptiometry. This study provides a baseline normative for Iranian individuals. BMD values of Iranian subjects were generally lower than those of the American population. INTRODUCTION: In order to establish the normative curves for BMD in Iranian individuals, we measured BMDs at the lumbar spine and femoral regions. The BMDs at the lumbar spine and femoral neck regions of 760 women and 632 men, which were selected by multi-stage random sampling, were measured using dual-energy X-ray absorptiometry (DXA). RESULTS: The peak bone mass in the males and females at the lumbar spine was reached around the age of 28.5±1.5 and 30±2 and at the neck of the femur was reached around the age of 24±1.5 and 33±2. About 16.4% and 3% of men aged 50 and older were osteoporotic according to American reference data, respectively, but using Iranian normative data for L2-L4 and the neck of the femur, the corresponding values were only 13.4% and 2.1%. Using American reference data, the respective values in women aged 50 and older for the same regions were 44.4% and 12%, whereas according to the Iranian normative data, the corresponding rates were 41.1% and 10.4%. CONCLUSIONS: This study provides a baseline normative for Iranian individuals. Due to the differences in ethnicity, diet, lifestyle, and small body size, BMD values of Iranian subjects were generally lower than those of the American population.