Much lower prevalence and severity of osteoporotic vertebral facture in elderly Chinese women than in age-matched Italian women: a radiographic comparison study.

Introduction: Many studies reported that East Asian's prevalence of radiographic OVF is similar to that of Caucasian. Since elderly Chinese's osteoporotic hip fracture prevalence is half (or less than half) of that of their age-match Caucasians, we hypothesize that elderly Chinese's OVF prevalence could be only half, or even less than half, of that of their agematch Caucasians. Materials: Age-matched elderly women's radiographs (T4-L5) were from two OVF population-based epidemiological studies conducted in Hong Kong (n=200) and in Rome (n=200). The study subjects had a mean age of 74.1 yrs (range: 65-87 yrs). All radiographs were double read by one reader in Hong Kong and one reader in Rome. Radiological osteoporotic vertebral deformity (ROVD) classification included no ROVD (grade 0), and ROVDs with <20%, 20~25%, ≥25%~1/3, ≥1/3~40%, ≥40%~2/3, and ≥2/3 height loss (grade 1~6). Spinal deformity index (SDI) was calculated with each vertebra assigned a score of 0, 0.5, 1, 1.5, 2, 2.5 and 3 for no ROVD or ROVDs grade 1~6. Results: 77 (38.5%) Chinese subjects and 123 Italian subjects (61.5%) had ROVD respectively (p<0.0001). ROVDs in Italian subjects tended to be more severe (total and mean SDI: 454.5 and 3.71 for Italian, and 212 and 2.72 for Chinese, p<0.05), more likely to be multiple (p<0.001), more likely to have severe and collapsed grades (p<0.001). The slope of the relationship between age vs. SDI was steeper for the Italian subjects than for the Chinese subjects, suggesting aging Italian subjects developed faster for the prevalence of ROVD and their severity. A trend suggested earlier onset of ROVD among Italian. Conclusion: Compared with elderly Italian women, elderly Chinese women have much lower prevalence of OVF. OVF in Chinese women tend to be less severe and less likely to have multiple fractures and less likely to collapse.