Prevalent vertebral fractures in black women and white women

Abstract

Vertebral fractures are the most common osteoporotic fracture. Hip and clinical fractures are less common in black women, but there is little information on vertebral fractures. We studied 7860 white and 472 black women >or=65 yr of age enrolled in the Study of Osteoporotic Fractures. Prevalent vertebral fractures were identified from lateral spine radiographs using vertebral morphometry and defined if any vertebral height ratio was >3 SD below race-specific means for each vertebral level. Information on risk factors was obtained by questionnaire or examination. Lumbar spine, total hip, and femoral neck BMD and BMC were measured by DXA. The prevalence of vertebral fractures was 10.6% in black and 19.1% in white women. In age-adjusted logistic regression models, a 1 SD decrease in femoral neck BMD was associated with 47% increased odds of fracture in black women (OR = 1.47; 95% CI, 1.12-1.94) and 80% increased odds in white women (OR = 1.80; 95% CI, 1.68-1.94; interaction p = 0.14). The overall lower odds of fracture among black women compared with white women was independent of femoral neck BMD and other risk factors (OR = 0.51; 95% CI, 0.37-0.72). However, the prevalence of vertebral fractures increased with increasing number of risk factors in both groups. The prevalence of vertebral fractures is lower in black compared with white women but increases with age, low BMD, and number of risk factors.

Figures

FIG. 1

Mean normative vertebral height ratios for white and black women by vertebral level: (A) Ha/Hp; (B) Hm/Hp; (C) Hp/Hp−; (D) Hp/Hp+; (E) Ha/Ha−; and (F) Ha/Ha+.

FIG. 2

Prevalence (%) of vertebral fractures by tertiles of femoral neck BMD, BMC, and BMAD in white women and black women.

FIG. 3

Prevalence (%) of vertebral fractures by age and the number of risk factors in white women and black women. The number of black women in each age group was as follows: n = 10; 70–74, n = 146; 75–79, n = 168; and 80+, n = 120. The number of white women in each age group was as follows: <70, n = 3382; 70–74, n = 2401; 75–79, n = 1169; and 80+, n = 632. For continuous variables, the risk factor was considered present for women in the lowest tertile. Risk factors included low femoral neck BMD (<0.60 g/cm2), using arms to stand, height (≤156.7 cm), health status (fair or worse), calcium supplement use, estrogen use, COPD, diabetes, and positive fracture history.