Asian-Caucasian difference in fracture rates reported
MedWire News: Chinese and Japanese people have lower incidence of hip fractures but a similar or higher rate of vertebral fractures compared with Caucasians, research shows.
"The present study further confirmed that, although the risk of hip fractures in Asians was low, Asian men do have a vertebral fracture risk similar to Caucasian men, and Asian women have an even higher clinical vertebral fracture risk than Caucasian women," comment Cora Bow (The University of Hong Kong, China) and colleagues.
The researchers note that information on clinical vertebral fracture risk in Asians is lacking. The World Health Organization fracture risk assessment algorithms (FRAX) estimate osteoporotic fracture risk based on the assumption that the ratio of hip-to-vertebral fracture is the same in Asian populations as in Swedish populations.
"Our study demonstrated the variations of the spine-to-hip fracture ratios between ethnic groups; thus, a fracture prediction model that assumes a universal spine-to-hip fracture ratio may be biased," write Bow and co-authors in the journal Osteoporosis International.
The team followed-up 4112 Southern Chinese people (56% women) aged 50 years and older, who were participating in the Hong Kong Osteoporosis Study, for a mean period of 4 years. They compared the clinical vertebral and hip fracture rates during the follow-up period with those of previously published results from Sweden and Japan.
In the Hong Kong cohort, vertebral and hip fracture incidence increased exponentially with increasing age in both genders. For example, the incidence of vertebral and hip fractures increased from 219 and 16 cases per 100,000 person-years, respectively, in women aged 50-54 years, to 564 and 103 cases per 100,000 person-years in women aged 65-69 years, and 2689 and 1377 cases per 100,000 person-years in women aged 85 years and older.
While the incidence of hip fractures also rose exponentially with age in Caucasian men and women - albeit at a greater rate than both Asian populations - the rise was almost linear for vertebral fractures.
This means that although the hip fracture rates for Asian (Hong Kong Chinese and Japanese) men and women is less than half of that in Caucasians, the vertebral-to-hip fracture ratio is actually higher.
Bow et al conclude: "Estimation of the absolute fracture risk for Asians may need to be readjusted for the higher clinical vertebral fracture rate."
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2011
By Laura Dean