Childhood Obesity and Slipped Capital Femoral Epiphysis.

UNLABELLED: : media-1vid110.1542/5828355774001PEDS-VA_2018-1067Video Abstract

BACKGROUND

Slipped capital femoral epiphysis (SCFE) is believed to be associated with childhood obesity, although the strength of the association is unknown.

METHODS

We performed a cohort study using routine data from health screening examinations at primary school entry (5-6 years old) in Scotland, linked to a nationwide hospital admissions database. A subgroup had a further screening examination at primary school exit (11-12 years old).

RESULTS

BMI was available for 597 017 children at 5 to 6 years old in school and 39 468 at 11 to 12 years old. There were 4.26 million child-years at risk for SCFE. Among children with obesity at 5 to 6 years old, 75% remained obese at 11 to 12 years old. There was a strong biological gradient between childhood BMI at 5 to 6 years old and SCFE, with the risk of disease increasing by a factor of 1.7 (95% confidence interval [CI] 1.5-1.9) for each integer increase in BMI z score. The risk of SCFE was almost negligible among children with the lowest BMI. Those with severe obesity at 5 to 6 years old had 5.9 times greater risk of SCFE (95% CI 3.9-9.0) compared with those with a normal BMI; those with severe obesity at 11 to 12 years had 17.0 times the risk of SCFE (95% CI 5.9-49.0).

CONCLUSIONS

High childhood BMI is strongly associated with SCFE. The magnitude of the association, temporal relationship, and dose response added to the plausible mechanism offer the strongest evidence available to support a causal association.