There is little known about the association between obesity and temporal trends in the incidence of diabetes in children and young adults.
We examined the recent incidence of type 1 diabetes (T1D) and type 2 diabetes (T2D) in relation to high body mass index (BMI) in English children and young adults.
Cohort and nested case-control.
375 general practices that contribute to the UK Clinical Practice Research Datalink (CPRD).
369,362 participants aged 2-15 years old at BMI measurements in CPRD between 1994 and 2013.
Main outcome measures:
Incident T1D and T2D.
There were 654 incident cases of T2D and 1318 T1D cases. The incidence of T2D per 100,000 persons per year increased from 6.4 in 1994-8 to 33.2 in 2009-13; that for T1D increased from 38.2 to 52.1 per 100,000 over the same period. The incidence of T2D increased in both overweight (85th-95th percentile for age- and sex-specific BMI; P=0.01) and obese (≥95th percentile; P<0.01) individuals from 1994 to 2013. Obese individuals, who constituted 47.1% of T2D cases, had a markedly higher risk of incident T2D (odds ratio, 3.75[95%CI, 3.07-4.57]) with an incidence rate ratio of 4.33 (95%CI, 3.68-5.08), compared with normal BMI category. There was no positive linear association between obesity (higher BMI) and incident T1D.
Increasing obesity is contributing to the rising incidence of T2D, but not T1D, among UK children and young adults, with a four-fold greater risk of developing T2D in those who are obese.