Elsevier

The Journal of Pediatrics

Volume 161, Issue 6, December 2012, Pages 1035-1040.e2
The Journal of Pediatrics

Original Article
Racial Disparity in Fracture Risk between White and Nonwhite Children in the United States

https://doi.org/10.1016/j.jpeds.2012.07.054Get rights and content

Objectives

To examine risk factors for fracture in a racially diverse cohort of healthy children in the US.

Study design

A total of 1470 healthy children, aged 6-17 years, underwent yearly evaluations of height, weight, body mass index, skeletal age, sexual maturation, calcium intake, physical activity levels, and dual-energy x-ray absorptiometry (DXA) bone and fat measurements for up to 6 years. Fracture information was obtained at each annual visit, and risk factors for fracture were examined using the time-dependent Cox proportional hazards model.

Results

The overall fracture incidence was 0.034 fracture per person-year with 212 children reporting a total of 257 fractures. Being white (hazard ratio [HR] = 2.1), being male (HR = 1.8), and having skeletal age of 10-14 years (HR = 2.2) were the strongest risk factors for fracture (all P ≤ .001). Increased sports participation (HR = 1.4), lower body fat percentage (HR = 0.97), and previous fracture in white girls (HR = 2.1) were also significant risk factors (all P ≤ .04). Overall, fracture risk decreased with higher DXA z scores, except in white boys, who had increased fracture risk with higher DXA z scores (HR = 1.7, P < .001).

Conclusions

Boys and girls of European descent had double the fracture risk of children from other backgrounds, suggesting that the genetic predisposition to fractures seen in elderly adults also manifests in children.

Section snippets

Methods

The Bone Mineral Density in Childhood Study (BMDCS) is a multicenter longitudinal study examining bone accretion in a racially diverse cohort of 1554 healthy boys and girls, aged 6-17 years, recruited from July 2002 to November 2003 at 5 medical centers in the US.7 Consent and assent were obtained from parents/guardians and participants following approved institutional review board protocols. Eighty-four children who did not return for follow-up were excluded from the analysis. Thus, 1470

Results

The characteristics of the study sample are described in Table I. The 693 nonwhites included 342 blacks, 247 Hispanics, 104 Asians, and 84 identified as “other.” The mean length of follow-up was 5.0 ± 1.5 years with the majority of subjects (908/1470, 62%) completing 6 years. A total of 212 subjects reported 257 fractures; 176 subjects sustained a single fracture incident, 30 sustained 2 fracture incidents, and 6 sustained ≥3 fracture incidents. The average age at first fracture was 13.7 ± 2.9

Discussion

The results of this multicenter prospective study provide strong evidence that race/ethnicity is a major determinant of fracture risk in healthy children living in the US. We found a much higher fracture rate in non-Hispanic white children compared with children of other ancestry. These differences were independent of chronologic age, skeletal age, body mass, and degree of sexual maturation. On average, healthy boys and girls of European descent had more than twice the fracture risk of healthy

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    Supported by Eunice Kennedy Shriver National Institute of Child Health and Human Development (NO1-HD-1-3228, NO1-HD-1-3329, NO1-HD-1-3330, NO1-HD-1-3331, NO1-HD-1-3332, and NO1-HD-1-3333). The authors declare no conflicts of interest.

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