Asthma in Youth and Early-Onset Type 2 Diabetes: A Nationwide Study of 1.72 Million Israeli Adolescents.

Background The prevalence of both asthma and early onset diabetes is on the rise, however the association between them remains unclear. We examined a possible association of asthma at adolescence with type 2 diabetes in young adulthood. Methods This is a nationwide, population-based study of 1,718,541 Israeli adolescents (59% males; mean age 17.3 years; range 16-19 years), examined before compulsory military service during 1992-2016, with data linked to the Israeli National Diabetes Registry. Asthma diagnosis and severity were determined by a board-certified pulmonologist and based on spirometry tests. Results Type 2 diabetes developed in 58/9,090 (0.64%), 507/97,059 (0.52%), 114/23,332 (0.49%), and 7,095/1,589,060 (0.44%) persons with moderate-to-severe, mild, inactive, and no history of asthma, respectively, during a mean follow-up >13 years. The respective odds ratios (ORs) were 1.33 (95%CI, 1.02-1.74), 1.17 (1.06-1.28), and 1.09 (0.9-1.31), considering those without asthma history as the reference, in a model adjusted for birth year, sex, BMI, and other socio-demographic variables. The association persisted when the analysis accounted for coexisting morbidities, and when persons without asthma, individually matched by age, sex, birth year, and BMI were the reference. Both mild and moderate-to-severe asthma were associated with type 2 diabetes before age 35 years: ORs 1.18 (1.05-1.34) and 1.44 (1.05-2.00), respectively. The strength of the association was accentuated over time. The effect was unchanged when adjusted for oral and inhaled glucocorticoid use. Conclusion Adolescents with active asthma have higher risk to develop type 2 diabetes. This seems related to disease severity, independent of adolescent obesity status, apparent before age 35 years, and more pronounced in recent years.