Parental Income Level and Risk of Developing Type 2 Diabetes in Youth

IMPORTANCE: In recent years, the global incidence of type 2 diabetes in young people has increased, especially among minoritized, Indigenous, or financially disadvantaged populations. However, few studies have examined whether poverty is associated with increased risk of youth-onset type 2 diabetes. OBJECTIVE: To examine the association of family income level with the risk of youth-onset type 2 diabetes. DESIGN, SETTING, AND PARTICIPANTS: This nationwide, population-based retrospective cohort study used data from the 2008 National Health Insurance Research Database of Taiwan, with follow-up through December 31, 2019. Participants included children and adolescents aged 0 to 19 years. Data analysis was performed from June 9, 2022, to January 16, 2023. EXPOSURES: Family income, classified as very low, low, middle, and high. MAIN OUTCOMES AND MEASURES: Cox proportional hazards models were used to estimate adjusted hazard ratios (aHRs) for the risks of youth-onset type 2 diabetes and all-cause mortality for all income groups vs the high-income group. RESULTS: The cohort included a total of 5 182 893 children and adolescents (mean [SD] age, 11.2 [5.2] years; 2 477 807 girls [48.3%]). The mean (SD) follow-up duration was 9.0 (0.3) years. The incidence rates of youth-onset type 2 diabetes were 0.52 cases per 1000 person-years for the very-low-income group, 0.40 cases per 1000 person-years for the low-income group, 0.35 cases per 1000 person-years for the middle-income group, and 0.28 cases per 1000 person-years for the high-income group. Children and adolescents from very-low-income (aHR, 1.55; 95% CI, 1.41-1.71), low-income (aHR, 1.34; 95% CI, 1.27-1.41), and middle-income (aHR, 1.27; 95% CI, 1.20-1.34) families had a significantly higher hazard of youth-onset type 2 diabetes than those from high-income families. Children and adolescents from very-low-income (aHR, 2.18; 95% CI, 1.97-2.41), low-income (aHR, 1.51; 95% CI, 1.42-1.60), and middle-income (aHR, 1.22; 95% CI, 1.14-1.31) families also had a significantly higher hazard of all-cause mortality than those from high-income families. Children and adolescents who were older, female, and obese and had dyslipidemia, gout, or psychiatric disorders had a significantly higher risk of youth-onset type 2 diabetes than children without those characteristics. CONCLUSIONS AND RELEVANCE: This population-based cohort study showed that children and adolescents from very-low-income to middle-income families had a higher hazard of youth-onset type 2 diabetes and mortality than those from high-income families. Further research to reveal the factors underlying this association may improve the accuracy of identifying individuals at greatest risk for developing type 2 diabetes in youth.