Abstract
PURPOSE: Prevalence of osteoporosis reported as high as 50% in thalassemia major patients. We compared bone density (BMD) of our patients with results of bone densitometry of participants of a national study, to find if BMD diagnosis is ethnicity sensitive or not. METHODS: In 177 adult beta thalassemia major patients and 490 normal subjects of 20-39 y/o range, dual-energy X-ray absorptiometry of the spine and femur performed. Normal subjects participated in Iranian Multi-center Osteoporosis Study (IMOS). Mean and standard deviation of normal ones achieved and Z-score of patients re-calculated based on normal Iranians. As BMD of normal participants and patients performed by devices of different brands, analyses done based on calculated standard BMD of all participants. RESULTS: BMD of patients was significantly lower than normal participants (P value <0.001). Frequency of Z-score ≤-2 found in 52% and 56% of patients in femur and spine regions, respectively. New Z-score of patients according to Iranian normal populations calculated. Frequency of this new Z-score ≤-2 found in 16% and 72% of patients in femur and spine regions, respectively. CONCLUSIONS: We think in secondary osteoporosis, may be other cut-off points, especially according to BMD of normal population of that geographical region are needed.