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

Quantitative CT lumbar spine BMD cutpoint value for classifying osteoporosis among older Chinese men can be the same as that of older Chinese women, both much lower than the value for Caucasians

For older Caucasian women and men, the QCT (quantitative CT) lumbar spine (LS) bone mineral density (BMD) threshold for classifying osteoporosis is 80 mg/ml. It was recently proposed that, for older East Asian women, the QCT LS BMD value equivalent to the Caucasian women's threshold of 80 mg/mL is about 45∼50 mg/ml. For a data of 328 cases of Chinese men (age: 73.6 ± 4.4 years) who had QCT LS BMD and DXA LS BMD at the same time and with the DXA BMD value of ≤ 0.613 g/cm2 to classify osteoporosis, the corresponding QCT LS BMD threshold is 53 mg/ml. Osteoporotic-like vertebral fracture sum score (OLVFss) ≤ -2.5 has been proposed to diagnose osteoporosis. For 316 cases of Chinese men (age:73.7±4.5 years), OLVFss ≤ -2.5 defines an osteoporosis prevalence of 4.4%; to achieve this osteoporosis prevalence, the corresponding QCT LS BMD value is < 47.5 mg/ml. In the China Action on Spine and Hip Status study, a Genant grades 2/3 radiographic 'osteoporotic vertebral fracture' prevalence was 2.84% for Chinese men (total n = 1267, age: 62.77 ± 9.20 years); to achieve this osteoporosis prevalence, the corresponding BMD value was < 42.5 mg/ml. In a study of 357 Beijing older men, according to the clinical fragility fracture prevalence and femoral neck DXA T-score, the QCT LS BMD value to classify osteoporosis was between 39.45 mg/ml and 51.38 mg/ml. For older Chinese men (≥ 50 years), we recommend the cutpoint for the QCT LS BMD definition of osteoporosis to be 45∼50 mg/ml which is the same as the value for Chinese women.

Radiological diagnosis of prevalent osteoporotic vertebral fracture on radiographs: an interim consensus from a group of experts of the ESSR osteoporosis and metabolism subcommittee

When a low-energy trauma induces an acute vertebral fracture (VF) with clinical symptoms, a definitive diagnosis of osteoporotic vertebral fracture (OVF) can be made. Beyond that, a "gold" radiographic standard to distinguish osteoporotic from non-osteoporotic VFs does not exist. Fracture-shaped vertebral deformity (FSVD) is defined as a deformity radiographically indistinguishable from vertebral fracture according to the best of the reading radiologist's knowledge. FSVD is not uncommon among young populations with normal bone strength. FSVD among an older population is called osteoporotic-like vertebral fracture (OLVF) when the FSVD is likely to be associated with compromised bone strength. In more severe grade deformities or when a vertebra is collapsed, OVF diagnosis can be made with a relatively high degree of certainty by experienced readers. In "milder" cases, OVF is often diagnosed based on a high probability rather than an absolute diagnosis. After excluding known mimickers, singular vertebral wedging in older women is statistically most likely an OLVF. For older women, three non-adjacent minimal grade OLVF (< 20% height loss), one minimal grade OLVF and one mild OLVF (20-25% height loss), or one OLVF with ≥ 25% height loss, meet the diagnosis of osteoporosis. For older men, a single OLVF with < 40% height loss may be insufficient to suggest the subject is osteoporotic. Common OLVF differential diagnoses include X-ray projection artifacts and scoliosis, acquired and developmental short vertebrae, osteoarthritic wedging, oncological deformities, deformity due to high-energy trauma VF, lateral hyperosteogeny of a vertebral body, Cupid's bow, and expansive endplate, among others.

Radiographic Diagnosis of Osteoporotic Vertebral Fracture in Older Women and Men Based on Statistical Probability

A radiographic gold standard to distinguish osteoporotic vertebral fractures (VFs) from nonosteoporotic VFs does not exist. Radiographic fracture-shaped vertebral deformity (FSVD) is common among young populations with normal bone strength. FSVD in an older population is called osteoporotic-like vertebral fracture (OLVF) when the FSVD is likely associated with compromised bone strength. For more severe grade deformities or when a vertebra is collapsed, experienced readers can make an osteoporotic VF diagnosis with a high degree of certainty. In milder cases, radiographic osteoporotic VF is often diagnosed based on a high probability rather than an absolute diagnosis. For older women, three nonadjacent minimal grade OLVFs (< 20% height loss), one minimal grade OLVF and one mild OLVF (≥ 20∼25% height loss), or one OLVF with ≥ 25% height loss meets the diagnosis of osteoporosis. For older men, a single OLVF with ≥ 33 to 40% height loss is insufficient to suggest the patient has osteoporosis.

Quantitative CT lumbar spine BMD cutpoint value for classifying osteoporosis among older East Asian women should be lower than the value for Caucasians

For Caucasian women, the QCT (quantitative CT) lumbar spine (LS) bone mineral density (BMD) cutpoint value for classifying osteoporosis is 80 mg/ml. At the age of approximate 78 years, US Caucasian women QCT LS BMD population mean is 80 mg/ml, while that of Chinese women and Japanese women is around 50 mg/ml. Correlation analyses show, for Chinese women and Japanese women, QCT LS BMD of 45 mg/ml corresponds to the dual-energy X-ray absorptiometry cutpoint value for classifying osteoporosis. For Chinese and Japanese women, if QCT LS BMD 80 mg/ml is used as the threshold to classify osteoporosis, then the specificity of classifying subjects with vertebral fragility fracture into the osteoporotic group is low, whereas threshold of 45 mg/ml approximately achieve a similar separation for women with and without vertebral fragility fracture as the reports for Caucasian women. Moreover, by using 80mg/ml as the cutpoint value, LS QCT leads to excessively high prevalence of osteoporosis for Chinese women, with the discordance between hip dual-energy X-ray absorptiometry and LS QCT measures far exceeding expectation. Considering the different bone properties and the much lower prevalence of fragility fractures in the East Asian women compared with Caucasians, we argue that the QCT cutpoint value for classifying osteoporosis among older East Asian women will be close to and no more than 50 mg/ml LS BMD. We suggest that it is also imperative the QCT osteoporosis classification criterion for East Asian male LS, and male and female hips be re-examined.

Revision of the 1994 World Health Organization T-score definition of osteoporosis for use in older East Asian women and men to reconcile it with their lifetime risk of fragility fracture

The 1994 WHO criterion of a T-score ≤ -2.5 for densitometric osteoporosis was chosen because it results in a prevalence commensurate with the observed lifetime risk of fragility fractures in Caucasian women aged ≥ 50 years. Due to the much lower risk of fragility fracture among East Asians, the application of the conventional WHO criterion to East Asians leads to an over inflated prevalence of osteoporosis, particularly for spine osteoporosis. According to statistical modeling and when a local BMD reference is used, we tentatively recommend the cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.7 for Hong Kong Chinese women. Using radiographic osteoporotic vertebral fracture as a surrogate clinical endpoint, we empirically demonstrated that a femoral neck T-score of -2.77 for Chinese women was equivalent to -2.60 for Italian women, a spine T-score of -3.75 for Chinese women was equivalent to -2.44 for Italian women, and for Chinese men a femoral neck T-score of -2.77 corresponded to spine T-score of -3.37. For older Chinese men, we tentatively recommend the cutpoint values for T-score of femoral neck, total hip, and spine to be approximately -2.7, -2.6, and -3.2. With the BMD reference published by IKi et al. applied, T-score of femoral neck, total hip, and spine of -2.75, -3.0, and -3.9 for Japanese women will be more in line with the WHO osteoporosis definition. The revised definition of osteoporosis cutpoint T-scores for East Asians will allow a more meaningful international comparison of disease burden.