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.
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.
| Original language | English |
|---|---|
| Article number | e20181067 |
| Pages (from-to) | 1-10 |
| Number of pages | 10 |
| Journal | Pediatrics |
| Volume | 142 |
| Issue number | 5 |
| Early online date | 22 Oct 2018 |
| DOIs | |
| Publication status | Published - Nov 2018 |
Bibliographical note
We thank Emma Morely of STEPS Charity Worldwide (www.steps-charity.org.uk), the patient charity that helped direct the research agenda and will assist in the dissemination of results. We also thank the Information Services Division (ISD) of NHS Scotland for the provision of data from ISD Scotland, particularly Andrew Duffy, the research coordinator within National Services Scotland.FUNDING: Dr Perry is funded by a UK National Institute for Health Research Clinician Scientist Award (grant NIHR/CS/2014/14/012). This article presents independent research funded by the National Institute for Health Research (NIHR). The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health.
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- Accepted Manuscript
This is the author's manuscript of a paper accepted for publication Pediatrics.