Plateau of adiposity in Australian children diagnosed with Type 1 diabetes: a 20-year study

AimsTo examine temporal trends in anthropometry in children with Type 1 diabetes from Sydney, Australia. MethodsWe conducted a retrospective study in a total of 1975 children with Type 1 diabetes, aged <16years, between 1990 and 2009. Trends in height, weight and BMI standard deviation score after initial stabilization were examined by age group (<5years, 5 to <10years, 10 to 16years) and time period of diagnosis (T1: 1990-1994, T2: 1995-1999; T3: 2000-2004 and T4: 2005-2009). Factors associated with BMI standard deviation score (time period, age group, gender and socio-economic status) were examined using multivariable linear regression. ResultsThe mean BMI standard deviation score (sd) increased between T1 and T2 (0.541.14 vs 0.811.14, P=0.002), but remained steady thereafter (T3: 0.851.11, T4: 0.871.09; T2 to T4: P=0.40). Similarly, the prevalence of overweight and obesity increased from T1 to T2 (26 to 35%, P=0.01), but was unchanged thereafter (T3: 34%, T4: 34%; T2 to T4: P=0.90). On multivariable regression analysis, a higher BMI standard deviation score was associated with younger age (5years vs <5years, =-0.40, 95% CI -0.51 to -0.28, P<0.001), later time period (T2 to T4 vs T1, =0.30, 95% CI 0.16-0.45, P<0.001) and male gender (=0.25, 95% CI 0.15-0.34, P<0.001). ConclusionThe prevalence of overweight and obesity has remained unchanged in children at diagnosis of Type 1 diabetes over 15years. These findings suggest that higher adiposity alone cannot account for the continued rising incidence of Type 1 diabetes in recent years. What's new? In contrast to other studies examining the accelerator hypothesis, the present 20-year study of 1975 children with newly diagnosed Type 1 diabetes shows evidence of a plateau having been reached in adiposity since 1995. While the incidence of Type 1 diabetes continues to rise, these findings indicate that the accelerator hypothesis alone can no longer account for the development of Type 1 diabetes in our study population. Nevertheless, rates of overweight and obesity in children with Type 1 diabetes remain alarmingly high compared with the general population, emphasizing that intervention studies aimed at reducing childhood obesity and insulin resistance are essential.