Diagnoses of type 1 and type 2 diabetes in youths present a substantial clinical and public health burden. The prevalence of these diseases increased in the 2001–2009 period, but data on recent incidence trends are lacking. We ascertained cases of type 1 and type 2 diabetes mellitus at five study centers in the United States. Denominators (4.9 million youths annually) were obtained from the U.S. Census or health-plan member counts. After the calculation of annual incidence rates for the 2002–2012 period, we analyzed trends using generalized autoregressive moving-average models with 2-year moving averages. A total of 11,245 youths with type 1 diabetes (0 to 19 years of age) and 2846 with type 2 diabetes (10 to 19 years of age) were identified. Overall unadjusted estimated incidence rates of type 1 diabetes increased by 1.4% annually (from 19.5 cases per 100,000 youths per year in 2002–2003 to 21.7 cases per 100,000 youths per year in 2011–2012, P=0.03). In adjusted pairwise comparisons, the annual rate of increase was greater among Hispanics than among non-Hispanic whites (4.2% vs. 1.2%, P<0.001). Overall unadjusted incidence rates of type 2 diabetes increased by 7.1% annually (from 9.0 cases per 100,000 youths per year in 2002–2003 to 12.5 cases per 100,000 youths per year in 2011–2012, P<0.001 for trend across race or ethnic group, sex, and age subgroups). Adjusted pairwise comparisons showed that the relative annual increase in the incidence of type 2 diabetes among non-Hispanic whites (0.6%) was lower than that among non-Hispanic blacks, Asians or Pacific Islanders, and Native Americans (P<0.05 for all comparisons) and that the annual rate of increase among Hispanics differed significantly from that among Native Americans (3.1% vs. 8.9%, P=0.01). After adjustment for age, sex, and race or ethnic group, the relative annual increase in the incidence of type 1 diabetes was 1.8% (P<0.001) and that of type 2 diabetes was 4.8% (P<0.001). The incidences of both type 1 and type 2 diabetes among youths increased significantly in the 2002–2012 period, particularly among youths of minority racial and ethnic groups. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and the Centers for Disease Control and Prevention.)

Information on recent trends in the prevalence of type 1 and type 2 diabetes in the United States is limited. Imperatore et al¹ reported that the predicted increase in the number of youth living with type 1 and type 2 diabetes by the year 2050 would be primarily among youth of minority race/ethnic groups. Worldwide, from 1990 to 2008, the incidence of type 1 diabetes has been increasing by 2.8% to 4.0% per year,² similar to that observed in the United States³ for both non-Hispanic white (hereafter called white) and Hispanic youth. However, a recent report from Finland, with the world’s highest incidence, suggested a possible leveling off of the increase from 2005-2011.⁴ Due to the very low mortality among youth with type 1 diabetes in the United States,⁵ an increase in the incidence of type 1 diabetes will likely result in an increase in prevalence.

Youth-onset type 1 and type 2 diabetes are serious chronic health conditions. Individuals with youth-onset diabetes are at risk for early complications, comorbidities, and excess mortality, particularly those who develop type 2 diabetes and those from racial and ethnic minority groups.^1,2 The SEARCH for Diabetes in Youth Study reported increases in the prevalence of type 1 diabetes and type 2 diabetes from 2001 to 2009³ and estimated that there were 187 246 US youths 19 years or younger with diabetes in 2009.⁴ In an article published in 2020, data from the SEARCH study demonstrated increases in the incidence of type 1 and type 2 diabetes in the US from 2002 through 2015.⁵ Although non-Hispanic White (hereafter referred to as White) youths (aged 19 years or younger) have the highest type 1 diabetes incidence, larger relative percent increases in incidence were observed among non-Hispanic Black (hereafter referred to as Black) and Hispanic youths from 2002 through 2015 and among Asian or Pacific Islander youths from 2011 through 2015 compared with White youths. American Indian and Black youths aged 10 to 19 years had the highest type 2 diabetes incidence. Significant increases in type 2 diabetes incidence were observed among American Indian, Asian or Pacific Islander, Black, and Hispanic youths.⁵

The increased prevalence of type 2 diabetes among children and adolescents has been relatively recent in most populations,^1-3 beginning in the early to mid-1990s. Additionally, a long-term increase in type 1 diabetes has been observed both worldwide⁴ and in the United States.³ These recent epidemiologic trends in type 1 and type 2 diabetes diagnosed in young individuals raise the question of whether the pattern of complications differs by diabetes type at similar ages and diabetes duration. Recent studies have reported higher prevalence of some^5-7 but not all⁸ complications in children and adolescents with type 2 diabetes compared with those with type 1. Reasons for discrepancies across previous studies include population differences, relatively small sample sizes, variable length of duration of diabetes at outcome assessment, variable ages, and reliance on routine clinical or administrative records to document outcomes. Preliminary findings have suggested that there is a higher prevalence of selected complications and risk factors among adolescents and young adults with type 2 diabetes compared with type 1.⁹

Importance The sequelae of gestational diabetes (GD) by contemporary criteria that diagnose approximately twice as many women as previously used criteria are unclear. Objective To examine associations of GD with maternal glucose metabolism and childhood adiposity 10 to 14 years’ postpartum. Design, Setting, and Participants The Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study established associations of glucose levels during pregnancy with perinatal outcomes and the follow-up study evaluated the long-term outcomes (4697 mothers and 4832 children; study visits occurred between February 13, 2013, and December 13, 2016). Exposures Gestational diabetes was defined post hoc using criteria from the International Association of Diabetes and Pregnancy Study Groups consisting of 1 or more of the following 75-g oral glucose tolerance test results (fasting plasma glucose ≥92 mg/dL; 1-hour plasma glucose level ≥180 mg/dL; 2-hour plasma glucose level ≥153 mg/dL). Main Outcomes and Measures Primary maternal outcome: a disorder of glucose metabolism (composite of type 2 diabetes or prediabetes). Primary outcome for children: being overweight or obese; secondary outcomes: obesity, body fat percentage, waist circumference, and sum of skinfolds (>85th percentile for latter 3 outcomes). Results The analytic cohort included 4697 mothers (mean [SD] age, 41.7 [5.7] years) and 4832 children (mean [SD] age, 11.4 [1.2] years; 51.0% male). The median duration of follow-up was 11.4 years. The criteria for GD were met by 14.3% (672/4697) of mothers overall and by 14.1% (683/4832) of mothers of participating children. Among mothers with GD, 52.2% (346/663) developed a disorder of glucose metabolism vs 20.1% (791/3946) of mothers without GD (odds ratio [OR], 3.44 [95% CI, 2.85 to 4.14]; risk difference [RD], 25.7% [95% CI, 21.7% to 29.7%]). Among children of mothers with GD, 39.5% (269/681) were overweight or obese and 19.1% (130/681) were obese vs 28.6% (1172/4094) and 9.9% (405/4094), respectively, for children of mothers without GD. Adjusted for maternal body mass index during pregnancy, the OR was 1.21 (95% CI, 1.00 to 1.46) for children who were overweight or obese and the RD was 3.7% (95% CI, −0.16% to 7.5%); the OR was 1.58 (95% CI, 1.24 to 2.01) for children who were obese and the RD was 5.0% (95% CI, 2.0% to 8.0%); the OR was 1.35 (95% CI, 1.08 to 1.68) for body fat percentage and the RD was 4.2% (95% CI, 0.9% to 7.4%); the OR was 1.34 (95% CI, 1.08 to 1.67) for waist circumference and the RD was 4.1% (95% CI, 0.8% to 7.3%); and the OR was 1.57 (95% CI, 1.27 to 1.95) for sum of skinfolds and the RD was 6.5% (95% CI, 3.1% to 9.9%). Conclusions and Relevance Among women with GD identified by contemporary criteria compared with those without it, GD was significantly associated with a higher maternal risk for a disorder of glucose metabolism during long-term follow-up after pregnancy. Among children of mothers with GD vs those without it, the difference in childhood overweight or obesity defined by body mass index cutoffs was not statistically significant; however, additional measures of childhood adiposity may be relevant in interpreting the study findings.