Lower osteoporotic-like vertebral fractural deformity (OLVF) prevalence and severity among older Thais and Indonesians than among older Chinese.

BACKGROUND

Chinese are known to have a lower vertebral fragility fracture risk than Caucasians. This study evaluates radiographic osteoporotic-like vertebral fractural deformity (OLVF) prevalence and severity among Chinese, Thai, Indonesian women and men.

METHODS

In an epidemiological study with community subjects, spine radiographs (T4-L5) were sampled for 195 Thai women (mean: 73.6 years), 202 Thai men (mean: 73.7 years), 236 Indonesian women (mean: 70.4 years), and 174 Indonesian men (mean: 70.2 years). Spine radiographs of age-matched subjects were also sampled for Chinese. OLVF classification included no OLVF (grade 0), and OLVFs with <20% (grade 0.5, minimal grade), ≥20-25% (grade 1, mild grade), ≥25%-1/3 (grade 1.5, moderate grade), ≥1/3-40% (grade 2, marked grade), ≥40%-2/3 (grade 2.5, severe grade), and ≥2/3 height loss (grade 3, collapsed grade). OLVF sum score (OLVFss) was calculated with each vertebra assigned a score of 0, -0.5, -1, -1.5, -2, -2.5, and -3 for no OLVF or OLVF grades 0.5-3. Osteoporosis prevalences were estimated based on OLVFss. For a woman, OLVFss ≤-1.0 and OLVFss ≤-1.5 were the thresholds to classify the case being osteoporotic according to the lowest T-score or femoral neck T-score respectively. For men, these thresholds were OLVFss ≤-2.5 and OLVFss ≤-3.0.

RESULTS

Compared with Southeast Asians, Chinese had overall higher prevalences of all-inclusive OLVF, apparent OLVF, and OLVF among Chinese were more likely to be multiple. A trend was noted that Chinese women were more likely to have severe and collapsed grades OLVFs than Southeast Asian women, while such a trend was not noted for Chinese men Southeast Asian men comparison. For men, the Chinese Southeast Asians difference was that Chinese had a higher prevalence of milder OLVFs. For the Thais Indonesians comparison, OLVFss (mean ± standard deviation) was -0.62±1.43 for Thai men, -0.47±0.98 for Indonesian men, -0.82±2.39 for Thai women, and -0.76±2.18 for Indonesian women. The lowest T-score based osteoporosis prevalence and femoral neck T-score based osteoporosis prevalence was 9.4% and 6.9% respectively for Thai men, and 6.9% and 2.9% for respectively Indonesian men; 19.5% and 14.9% respectively for Thai women, 18.9% and 14.5% respectively for Indonesian women.

CONCLUSIONS

The prevalence and severity of radiographic OLVF show a weak trend of 'Chinese > Thais > Indonesians', both for older women and for older men. The results of the current study support the notion that 'populations from a warmer climate have better spine health'.