A secular increase in BMD in Chinese women

Development and validation of the Chinese osteoporosis screening algorithm (COSA) in identification of people with high risk of osteoporosis

Objectives

To enhance the public awareness and facilitate diagnosis of osteoporosis, we aim to develop a new Chinese Osteoporosis Screening Algorithm (COSA) to identify people at high risk of osteoporosis.

Methods

A total of 4747 postmenopausal women and men aged ≥ 50 from the Hong Kong Osteoporosis Study were randomly split into a development (N = 2373) and an internal validation cohort (N = 2374). An external validation cohort comprising 1876 community-dwelling subjects was used to evaluate the positive predictive value (PPV).

Results

Among 11 predictors included, age, sex, weight, and history of fracture were significantly associated with osteoporosis after correction for multiple testing. Age- and sex-stratified models were developed due to the presence of significant sex and age interactions. The area under the curve of the COSA in the internal validation cohort was 0.761 (95% CI, 0.711-0.811), 0.822 (95% CI, 0.792-0.851), and 0.946 (95% CI, 0.908-0.984) for women aged < 65, women aged ≥ 65, and men, respectively. The COSA demonstrated improved reclassification performance when compared to Osteoporosis Self-Assessment Tool for Asians. In the external validation cohort, the PPV of COSA was 40.6%, 59.4%, and 19.4% for women aged < 65, women aged ≥ 65, and men, respectively. In addition, COSA > 0 was associated with an increased 10-year risk of hip fracture in women ≥ 65 (OR, 4.65; 95% CI, 2.24-9.65) and men (OR, 11.51; 95% CI, 4.16-31.81).

Conclusions

We have developed and validated a new osteoporosis screening algorithm, COSA, specific for Hong Kong Chinese.

Secular changes in bone mineral density of adult Japanese women from 1995 to 2013

Introduction:

Secular changes in hip fracture incidence have been reported in the last few decades in Japan, but whether long-term bone mineral density (BMD) is also changing is unclear. This study aimed to determine whether BMD of Japanese women has changed over time.

Methods:

Subjects were 10,649 adult women who underwent BMD measurement in a health check-up population in Niigata, Japan, between 1995 and 2013. BMD of the distal, non-dominant forearm was measured by dual-energy X-ray absorptiometry. Demographic information and BMI were also obtained. Secular trends were determined by linear regression analysis.

Results:

BMD of subjects in their 40’s decreased significantly in the age-adjusted model (P for trend=0.0162), but not in the age- and BMI-adjusted model (P for trend=0.2171). BMD of subjects in their 50’s decreased marginally in the age-adjusted model (P for trend=0.0535), but not in the age- and BMI-adjusted model (P for trend=0.6601). BMDs of subjects in their 30’s and 60’s did not significantly change, while BMIs of subjects in their 40’s-60’s decreased significantly.

Conclusions:

A secular decrease in BMD, partly attributed to decreases in BMI, was observed in middle-aged Japanese women from 1995 to 2013. Measures to help maintain suitable BMI will be necessary to prevent a decrease in BMD among women.

Osteoporosis in East Asia: Current issues in assessment and management

The greatest burden of hip fractures around the world is expected to occur in East Asia, especially China. However, there is a relative paucity of information on the epidemiology and burden of fractures in East Asia. Osteoporosis is greatly under-diagnosed and under-treated, even among the highest-risk subjects who have already suffered fractures. The accessibility to bone densitometry, the awareness of the disease by professionals and the public, and the use and reimbursement of drugs are some of the areas which need improvement especially. Cost-effective analysis on screening strategy and intervention thresholds based on local epidemiology data and economic status are available only in Japan. In addition, clinical risk factor models for the assessment of fracture probability may be ethnic specific. Further research is needed to develop a cost-effective risk assessment strategy to identify high-risk individuals for screening and treatment based on local data. Moreover, inadequate calcium and vitamin D intake is still an issue faced by this region.

Vitamin D status and bone mineral density in the Chinese population: a review

Low vitamin D status is associated with low bone mass which, in turn, is an important predictor of fracture. However, data on this relationship in non-Caucasian populations are scarce. This review shows such an association in the Chinese population in five of the 11 included studies.

INTRODUCTION

In the elderly population, the serum 25-hydroxyvitamin D [25(OH)D] concentration is often inadequate. This may cause a lower bone mineral density (BMD), which is an important predictor of fracture. It is estimated that by 2050 more than half of all hip fractures worldwide will occur in Asia. However, data on the relationship between vitamin D status and BMD in a non-Caucasian population are scarce. Therefore, this study reviews the literature on the relationship between serum 25(OH)D and BMD in the Chinese population.

METHODS

A search was made in PubMed, EMBASE, Web of Science and Cochrane Library (up to December 2014) to identify relevant studies using the terms vitamin D status, bone mineral density, and Chinese.

RESULTS

Of the 293 studies identified, 11 fulfilled the inclusion and exclusion criteria and were analyzed. Mean serum 25(OH)D concentrations ranged from 29-82 nmol/L. In 5 of the 11 studies, an association was found between vitamin D status and BMD in the Chinese population.

CONCLUSION

The evidence for a relationship between the serum 25(OH)D concentration and BMD in the middle-aged and elderly Chinese population living in Asia appears to be limited and inconsistent.

Multi-level femoral morphology and mechanical properties of rats of different ages

A macro-micro-nano-multi-level study was conducted to explore age-related structural and mechanical properties of bone, as well as the effects of aging on bone properties. A total of 70 male Wistar rats were used, ranging in the ages of 1, 3, 5, 7, 9, 11, 14, 15, 16, and 17 months (n = 7/age group). After micro-computed tomography (CT) scanning, longitudinal cortical bone specimens with a length of 5mm were cut along the femoral shaft axis from left femur shafts for mechanical testing, and the cross-sectional areas were measured. The macro-mechanical properties obtained in mechanical testing and microarchitecture parameters measured by micro-CT were significantly correlated with the animal age (r(2) = 0.96, p < 0.001). Scanning electron microscopy was used for detecting the microarchitecture features of the fractured surfaces, which exhibited age-related plate-fibrous-mixed fibrous-plate texture, resulting in changes in macro-mechanical properties (r(2) > 0.90, p < 0.001). The mineral phase of the left femoral shaft and head was analyzed by atomic force microscopy. Longitudinal and transverse trabecular bone tissues, as well as longitudinal cortical bone tissue, were used for nanoindentation test, and the chemical composition was evaluated by quantitative chemical analyses. The correlations between mineral content and bone material properties (i.e., elastic properties of the bone tissue and size and roughness of bone mineral grains) were highly significant (r > 0.95, p < 0.001). Multi-level femur morphology, mechanical property, and mineral content were significantly correlated with the animal age. The correlations between bone mineral content and bone material morphological and mechanical properties may partly explain the increase in bone fragility with aging, which will provide a theoretical basis for the investigation of age-related bone properties in clinics.

Geographic and ethnic disparities in osteoporotic fractures

Osteoporotic fractures are a major worldwide epidemic. Here, we review global variability, ethnic differences and secular changes in osteoporotic fractures. Worldwide, age-standardized incidence rates of hip fracture vary >200-fold in women and >140-fold in men when comparing the country in which incidence rates are the highest with that in which they are the lowest. Median age-standardized rates are highest in North America and Europe, followed by Asia, Middle East, Oceania, Latin America and Africa. Globally, rates of hip fracture are greater in women than in men, with an average ratio of ∼2:1. The incidence of radiographic vertebral fractures is much higher than that of hip fractures, whereas the incidence rates of clinical vertebral fractures mirror hip fracture rates in most countries. Methodological challenges of defining and ascertaining vertebral fractures limit the interpretation of these data. Secular declines in hip fracture rates have been reported in populations from North America, Europe and Oceania. These declines are especially notable in women, suggesting that reproductive factors might contribute to this reduction. By contrast, hip fracture rates are increasing in parts of Asia and Latin America. Global indicators of health, education and socioeconomic status are positively correlated with fracture rates suggesting that lifestyles in developed countries might contribute to hip fracture. Improvements in fracture assessment, in particular for nonhip fractures, and identification of factors that contribute to this variability might substantially influence our understanding of osteoporotic fracture aetiology and provide new avenues for prevention.

Temporal trends in the incidence of osteoporotic fractures

Osteoporotic fractures are associated with excess mortality and decreased functional capacity and quality of life. Age-standardized incidence rates of fragility fractures, particularly of the hip and forearm, have been noted to be decreasing in the last decade across many countries with the notable exception of Asia. The causes for the observed changes in fracture risk have not been fully identified but are likely the result of multiple factors, including birth cohort and period effects, increasing obesity, and greater use of anti-osteoporosis medications. Changing rates of fragility fractures would be expected to have an important impact on the burden of osteoporosis.

2013 International Society for Clinical Densitometry Position Development Conference: Task Force on Normative Databases

Following the standard protocol for development of Official Positions for the International Society for Clinical Densitometry, the Expert Panel heard the report and recommendations from the Task Force on Normative Databases; using the RAND methodology, agreement was reached on the following statements: 1. Manufacturers should continue to use their own databases for the lumbar spine as the reference standard for T-scores. 2. Manufacturers should continue to use National Health and Nutrition Examination Survey III data as the reference standard for femoral neck and total hip T-scores. 3. If local reference data are available, they should be used to calculate only Z-scores but not T-scores. 4. A uniform Caucasian (non-race adjusted) female reference database should be used to calculate T-scores for men of all ethnic groups.