Overweight and obesity during preschool age are associated with increased risk for fracture in childhood, according to results of a Spanish population-based cohort study published in the Journal of Bone and Mineral Research.
Previous studies of childhood obesity have included a wide range of ages. Investigators aimed to determine whether elevated body mass index (BMI) during preschool age (4 years±6 months) is associated with increased risk for fracture in childhood.
Data for 466,997 children (48.6% girls) were obtained from health records from the Information System for Research in Primary Care (SIDIAP) in Catalonia, Spain. Children were grouped into BMI categories based on age- and sex-specific BMI z scores. Categories included underweight (<-2 BMI z score), normal weight (-2 to 2 BMI z score), overweight (>2 BMI z score), and obese (>3 BMI z score). Children were followed up to 15 years of age (median, 4.90 years) to assess fracture incidence in childhood.
An overweight or obese BMI was observed in 5.7% and 2.0% of children, respectively. The cumulative incidence of fracture over follow-up was 10.19% (95% CI, 9.96-10.43). The cumulative incidence was lower in girls than in boys (8.24% vs 12.05%). Upper limb fractures were the most common fracture type in both boys and girls.
The overall cumulative incidence of fracture was 9.20% in the underweight group (95% CI, 3.79-14.61), 10.06% in the normal-weight group (95% CI, 9.82-10.29), 11.28% in the overweight group (95% CI, 10.22-12.35), and 13.05% in the obese group (95% CI, 10.69-15.41). Cumulative incidence of fracture was higher in children with an obese BMI regardless of sex.
Compared with children in the normal-weight group, children with an overweight (adjusted hazard ratio [aHR], 1.12; 95% CI, 1.06-1.19) or obese BMI (aHR, 1.23; 95% CI, 1.13-1.34) were at increased risk for fracture. The strongest association was with lower limb fractures in the overweight (aHR, 1.41; 95% CI, 1.26-1.58) and obese groups (aHR, 1.72; 95% CI, 1.44-2.04).
The association between overweight or obese BMI and fracture risk was most prominent for distal fractures. Compared with normal-weight BMI categorization, an obese BMI was associated with increased risk for tibia/fibula fractures (aHR, 1.81; 95% CI, 1.38-2.37), foot fractures (aHR, 1.66; 95% CI, 1.32-2.10), and hand fractures (aHR, 1.37; 95% CI, 1.14-1.66).
The researchers noted that the proportion of children with BMIs in the overweight or obese categories were relatively small in the included population and that the generalizability of their results to other populations may be limited. In addition, the sample size of the underweight population was too small for analysis of association with fracture risk.
“This study found an association between elevated preschool BMI and increased fracture incidence in childhood,” the investigators concluded. “This work suggests that interventions to treat obesity in early childhood could have benefits for the primary or secondary prevention of fractures later in childhood, especially in the prevention of fractures within the forearm and hand or foot and ankle.”
Disclosure: Several authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of disclosures.
Lane JCE, Butler KL, Poveda-Marina JL, et al. Preschool obesity is associated with an increased risk of childhood fracture: a longitudinal cohort study of 466,997 children and up to 11 years of follow-up in Catalonia, Spain [published online April 7, 2020]. J Bone Miner Res. doi:10.1002/jbmr.3984