Further evidence supports a much lower prevalence of radiographic osteoporotic vertebral fracture in Hong Kong Chinese women than in Italian Caucasian women

A comparison of radiographic degeneration features of older Chinese women and older Italian Caucasian women with a focus on thoracic spine

BACKGROUND

Compared with Caucasians, East Asians have a lower incident of back pain, lower prevalence and severity of osteoporotic vertebral fracture and lumbar spine degeneration.

AIM

This study compares radiographic spine degeneration features of older Chinese women (as an example of East Asians) and older Italian women (as an example of Caucasians) with a focus on the thoracic spine.

METHODS

From two population-based epidemiological studies conducted in Hong Kong, China and Rome, Italy, 297 pairs (mean age: 73.6 years) age-matched older community women's lateral spine radiographs were sampled. Existence (or absence) of seven degeneration features were assessed including: (1) hyper-kyphosis, (2) disc space narrowing (T3/T4 ~ T11/T12), (3) osteoarthritic (OA) wedging (T4 ~ T12), (4) generalised osteophyte formation (T4 ~ T12); (5) acquired short vertebrae (T4 ~ T12), (6) Schmorl node (T4 - L5), (7) disc calcification (T4-L5).

RESULTS

Italian women were more likely to have hyper-kyphosis (53.4% vs 25.6%), disc space narrowing (34.4% vs. 17.2%), OA wedging (6.4% vs. 0.67%), Schmorl node (19.5% vs. 4.4%, all P < 0.001). However, there was no statistically significant difference in osteophyte formation (7.7% vs. 9.4%, P > 0.1) and acquired short vertebrae (8.0% vs. 10.4%, P > 0.1). Disc calcification was uncommon among both Chinese and Italians.

DISCUSSION AND CONCLUSION

For the first time, this study documented a lower prevalence of a number of thoracic spine degeneration features among Chinese. This study further affirms the concept of a generally healthier spine in older Chinese relative to older Caucasians. The observed differences may reflect a foundational background influence of genetic predisposition that represents an important line of future research.

Lower Prevalence and Severity of Degenerative Changes in the Lumbar Spine in Elderly Hong Kong Chinese Compared With Age-Matched Italian Caucasian Women

STUDY DESIGN

Cross-sectional observational study.

OBJECTIVE

The aim was to compare the prevalence and severity of radiographic lumbar spine degeneration between elderly Hong Kong Chinese and elderly Italian Caucasian women.

SUMMARY OF BACKGROUND DATA

Rates of symptomatic low back pain and osteoporotic vertebral fracture have been shown to be lower in Asian and Chinese populations compared with Caucasians, but ethnic differences in spinal degeneration are less established.

METHODS

Lumbar spine lateral radiographs of 566 age-matched (mean: 73.6 yr; range: 65-87 yr) female subjects from two population-based epidemiological studies from Hong Kong (n=283) and Rome, Italy (n=283) were reviewed. Grading of degeneration categories: disk height loss (none, <30%, 30%-60%, >60%), osteophyte formation (not present, minimal, small, large), endplate sclerosis (none, mild, moderate, severe), and antero/retrolisthesis (none, <25%, 25%-50%, >50%) was performed for vertebral levels from L1/2 to L5/S1 (five levels). Each category was assigned a score (0, 1, 2, 3) at individual vertebral level according to severity. The total degeneration score was obtained by adding scores for all categories across the vertebral levels.

RESULTS

Italian subjects [total score (mean±SD): 7.0±5.5] had a higher severity of overall degenerative changes compared with Hong Kong subjects (5.7±4.4), P <0.01. Italian subjects had higher scores for individual findings of disk height loss (Italian, 3.6±2.8 vs. Hong Kong 2.5±2.1, P <0.01); antero/retrolisthesis (Italian 0.3±0.7 vs. Hong Kong 0.2±0.4, P =0.01); and endplate sclerosis (Italian 1.0±1.2 vs. Hong Kong 0.6±1.0, P <0.01). At each individual level from L1/2 to L5/S1, total degeneration scores were higher in Italian than Hong Kong subjects ( P <0.01-0.04).

CONCLUSION

Degenerative changes in the lumbar spine are less prevalent and less severe in elderly Hong Kong Chinese women than in age-matched Italian Caucasian women. The observed differences may reflect a foundational background influence of genetic predisposition that requires further studies.

Conversion of osteoporotic vertebral fracture severity score to osteoporosis T-score equivalent status: a framework and a comparative study of Hong Kong Chinese and Rome Caucasian older women

We explored how the severity of radiological osteoporotic vertebral fracture (OVF) can be converted to the equivalent T-score values.

INTRODUCTION

To perform a study to define what portion of older community women with what severity of radiographic OVF correspond to what low T-score status.

METHODS

There were age-matched 301 Italian community women and 301 Chinese community women (sub-group A, age, 73.6 ± 6.1 years). In addition, Chinese sub-groups B and C included 110 community women (age, 68.9 ± 5.5 years) and 101 community women (age: 82.2 ± 4.3 years), respectively. For each vertebra in women, a score of 0, - 0.5, - 1, - 1.5, - 2, - 2.5, and - 3 was assigned for no OVF or OVF of < 20%, ≥ 20 ~ 25%, ≥ 25% ~ 1/3, ≥ 1/3 ~ 40%, ≥ 40%-2/3, and ≥ 2/3 vertebral height loss, respectively, OVFss was defined as the summed score of vertebrae T4 to L5. OVFss and T-scores were ranked from the smallest to the largest values.

RESULTS

For the Chinese total group (sub-groups A, B, and C together), OVFss = - 1 corresponded to lowest T-score (lowest T-score of lumbar spine, femoral neck, and total hip) of - 3.4 ~ - 3.2. OVFss ≤ - 1.5 corresponded to femoral neck T-score ≤ - 2.5. OVFss = -1.5 corresponded to a mean femoral neck T-score of - 3.0, - 2.6, and - 2.4, among Chinese sub-groups B, A, and C subjects, respectively. For Italians, all cases with OVFss ≤ - 1 had lowest T-score ≤ - 2.5. For cases with femoral neck T-score = - 2.5, 41.7% had OVFss = - 1.5, and 58.3% had OVFss = - 1.

CONCLUSION

For older women, statistically OVFss ≤ - 1 suggests this subject is osteoporotic according to lowest T-score. If using femoral neck T-score, OVFss ≤ - 1.5 qualifies osteoporosis diagnosis.