Early adiposity rebound in childhood and risk of Type 2 diabetes in adult life.

Type 2 diabetes is associated with a small body size at birth and a high BMI in adult life. The aim of our study was to assess the associations between Type 2 diabetes and birth size, infant growth and age at adiposity rebound. We carried out a longitudinal study of 8760 subjects born in Helsinki during 1934 to 1944. On average, they had 18 measurements of height and weight between birth and 12 years of age. In western countries BMI usually decreases after the age of 2 years and rises again at around 6 years--the so-called adiposity rebound. We defined age at adiposity rebound by the age of lowest BMI between one and 12 years. We identified people with Type 2 diabetes using a national register. A total of 290 individuals developed Type 2 diabetes in adult life. The cumulative incidence of Type 2 diabetes decreased progressively from 8.6% in persons whose adiposity rebound occurred before the age of 5 years to 1.8% in those in whom it occurred after 7 years ( p<0.001). Early adiposity rebound was preceded by low weight gain between birth and 1 year ( p<0.001). Large differences in the incidence of Type 2 diabetes are associated with growth rates in utero, weight gain in infancy and age at adiposity rebound.