Adolescent Obesity and Early-onset Type 2 Diabetes

OBJECTIVE: Type 2 diabetes (T2D) is increasingly diagnosed at younger ages. We investigated the association of adolescent obesity with incident T2D at early adulthood.

RESEARCH DESIGN AND METHODS: A nationwide, population-based study of 1,462,362 adolescents (59% men; mean age 17.4 years) evaluated during 1996-2016. Data were linked to the Israeli National Diabetes Registry. Weight and height were measured at study entry. Cox proportional models were applied.

RESULTS: During 15,810,751 person-years, 2,177 people (69% men) developed T2D (mean age at diagnosis, 27 year). There was an interaction between BMI, sex and incident T2D (P_interaction=0.023). In a model adjusted for socio-demographic variables, the hazard ratios for diabetes diagnosis were 1.7 (1.4-2.0), 2.8 (2.3-3.5), 5.8 (4.9-6.9), 13.4 (11.5-15.7), and 25.8 (21.0-31.6) among men in the 50^th-74^th, 75^th-84^th, overweight, mild obesity, and severe obesity groups, respectively; and 2.2 (1.6-2.9), 3.4 (2.5-4.6), 10.6 (8.3-13.6), 21.1 (16.0-27.8), and 44.7 (32.4-61.5), respectively, in women. An inverse graded relationship was observed between baseline BMI and mean age of T2D diagnosis: 27.8 and 25.9 years among men and women with severe obesity, respectively; and 29.5 and 28.5 years among the low-normal BMI (5^th-49^th percentile; reference), respectively. The projected fractions of adult-onset T2D that were attributed to high BMI (≥85^th percentile) at adolescence were 56.9% (53.8%-59.9%) and 61.1% (56.8%–65.2%), in men and women, respectively.

CONCLUSIONS: Severe obesity significantly increases the risk for incidence of T2D in early adulthood in both sexes. The rise in adolescent severe obesity is likely to increase diabetes incidence in young adults in coming decades.