Prevalence and risk factors of radiographic vertebral fracture in postmenopausal Vietnamese women.

ABSTRACT

BACKGROUND: Vertebral fracture is associated with an increased risk of atraumatic fracture and mortality. The prevalence of vertebral fractures among postmenopausal Caucasian women has been reported to range between 15% and 35%. Because there is no estimate of the magnitude of the problem in Vietnam, we undertook this study to estimate the prevalence and risk factors of vertebral fracture in Vietnam. METHODS: Radiographs were taken from 209 postmenopausal women aged between 50 and 85 years (average 62) who were randomly sampled from various districts in Ho Chi Minh City. The presence of vertebral fracture was assessed by the Genant's semi-quantitative method with two independent readers. Bone mineral density (BMD) at the lumbar spine (LS), femoral neck (FN) and whole body was measured by DXA (Hologic QDR4500). Anthropometric and clinical data were obtained by a standardized questionnaire. RESULTS: Among the 209 women, 48 were found to have at least one radiographic vertebral fracture, which yielded a prevalence of 23% (95%CI 18-29%). Although fracture occurred in all vertebrae, most (83%) occurred at the L1-L5. Most fractures occurred at one vertebra, and only 12% occurred at multiple vertebrae. The prevalence increased with age such that it reached 39% among those aged 70+ years. There was no significant association between vertebral fracture and back pain, fall history, and dietary calcium intake. In simple log-binomial regression analysis, higher risk of vertebral fracture was associated with advancing age (prevalence ratio [PR] per 10 years 1.40; 1.16-2.05) and lower lumbar spine BMD (PR per SD 1.51; 1.18-1.92). In multivariable analysis, the two factors remained independently associated with fracture risk, with the area under the receiver operating characteristic curve being 0.66. CONCLUSIONS: These data suggest that approximately one out of 4 postmenopausal women in Vietnam have a radiographic vertebral fracture, and this prevalence is as common as in Caucasian populations. The number of women needed to screen to identify one vertebral fracture is about 4 to 5, which seems to be cost-effective.