Variant level heritability estimates of type 2 diabetes in African Americans.

Type 2 diabetes (T2D) is caused by both genetic and environmental factors and is associated with an increased risk of cardiorenal complications and mortality. Though disproportionately affected by the condition, African Americans (AA) are largely underrepresented in genetic studies of T2D, and few estimates of heritability have been calculated in this race group. Using genome-wide association study (GWAS) data paired with phenotypic data from ~ 19,300 AA participants of the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, Genetics of Hypertension Associated Treatments (GenHAT) study, and the Electronic Medical Records and Genomics (eMERGE) network, we estimated narrow-sense heritability using two methods: Linkage-Disequilibrium Adjusted Kinships (LDAK) and Genome-Wide Complex Trait Analysis (GCTA). Study-level heritability estimates adjusting for age, sex, and genetic ancestry ranged from 18% to 34% across both methods. Overall, the current study narrows the expected range for T2D heritability in this race group compared to prior estimates, while providing new insight into the genetic basis of T2D in AAs for ongoing genetic discovery efforts.

The role of sex on the prevalence of cardiovascular risk factors in children and adolescents with Type 1 diabetes: The SWEET international database.

OBJECTIVE: To assess the prevalence of cardiovascular risk factors (CVRFs) in children and adolescents with type 1 diabetes (T1D) in the International SWEET registry and the possible role of clinical variables in modifying the risk of having single or multiple CVRFs. STUDY DESIGN: The study is a cross-sectional study. Cut-off points for CVRFs were fixed according to International Society for Pediatric and Adolescent Diabetes (ISPAD) guidelines and WHO parameters: LDL cholesterol (LDL-C) > 100 mg/dL; Systolic Blood Pressure (BP-SDS) > 90th percentile for sex, age, and height; BMI-SDS > 2SD for sex and age. Logistic regression models were applied to evaluate variables associated with at least 1 or 2 CVRFs among registry children and adolescents. RESULTS: 29,649 individuals with T1D (6-18 years, T1D ≥ 2 years) participating in the SWEET prospective multicenter diabetes registry were included. In the cohort, 41 % had one or more CVRFs, and 10 % had two or more CVRFs. Thirty-five percent of enrolled individuals had LDL-C > 100 mg/dL, 26 % had BMI-SDS > 2SD, and 17 % had Systolic BP-SDS > 90th percentile. Females had higher frequency than males of having 1 or 2 CVRFs (45.1 % vs 37.4 %, 11.8 % vs 7.8 %; p < 0.001). Multivariable logistic regression models showed that sex (female), HbA1c category (>7.0 %), and age (>10 years) were associated with a higher chance of having at least 1 or 2 CVRFs (p < 0.001). CONCLUSIONS: In children and adolescents with T1D, female sex, in addition to HbA1c above 7 %, and older age (>10 years) was associated with a higher risk of having at least a CVRF (LDL-C, BMI-SDS, BP) according to internationally defined cut-offs.

Clinical Prediction Models Combining Routine Clinical Measures Have High Accuracy in Identifying Youth-Onset Type 2 Diabetes Defined by Maintained Endogenous Insulin Secretion: The SEARCH for Diabetes in Youth Study.

OBJECTIVE: With high prevalence of obesity and overlapping features between diabetes subtypes, accurately classifying youth-onset diabetes can be challenging. We aimed to develop prediction models that, using characteristics available at diabetes diagnosis, can identify youth who will retain endogenous insulin secretion at levels consistent with type 2 diabetes (T2D). RESEARCH DESIGN AND METHODS: We studied 2,966 youth with diabetes in the prospective SEARCH for Diabetes in Youth study (diagnosis age ≤19 years) to develop prediction models to identify participants with fasting C-peptide ≥250 pmol/L (≥0.75 ng/mL) after >3 years' (median 74 months) diabetes duration. Models included clinical measures at the baseline visit, at a mean diabetes duration of 11 months (age, BMI, sex, waist circumference, HDL cholesterol), with and without islet autoantibodies (GADA, IA-2A) and a Type 1 Diabetes Genetic Risk Score (T1DGRS). RESULTS: Models using routine clinical measures with or without autoantibodies and T1DGRS were highly accurate in identifying participants with C-peptide ≥0.75 ng/mL (17% of participants; 2.3% and 53% of those with and without positive autoantibodies) (area under the receiver operating characteristic curve [AUCROC] 0.95-0.98). In internal validation, optimism was very low, with excellent calibration (slope 0.995-0.999). Models retained high performance for predicting retained C-peptide in older youth with obesity (AUCROC 0.88-0.96) and in subgroups defined by self-reported race/ethnicity (AUCROC 0.88-0.97), autoantibody status (AUCROC 0.87-0.96), and clinically diagnosed diabetes types (AUCROC 0.81-0.92). CONCLUSIONS: Prediction models combining routine clinical measures at diabetes diagnosis, with or without islet autoantibodies or T1DGRS, can accurately identify youth with diabetes who maintain endogenous insulin secretion in the range associated with T2D.

Clinical prediction models combining routine clinical measures identify participants with youth-onset diabetes who maintain insulin secretion in the range associated with type 2 diabetes: The SEARCH for Diabetes in Youth Study.

Objective: With the high prevalence of pediatric obesity and overlapping features between diabetes subtypes, accurately classifying youth-onset diabetes can be challenging. We aimed to develop prediction models that, using characteristics available at diabetes diagnosis, can identify youth who will retain endogenous insulin secretion at levels consistent with type 2 diabetes (T2D). Methods: We studied 2,966 youth with diabetes in the prospective SEARCH study (diagnosis age ≤19 years) to develop prediction models to identify participants with fasting c-peptide ≥250 pmol/L (≥0.75ng/ml) after >3 years (median 74 months) of diabetes duration. Models included clinical measures at baseline visit, at a mean diabetes duration of 11 months (age, BMI, sex, waist circumference, HDL-C), with and without islet autoantibodies (GADA, IA-2A) and a Type 1 Diabetes Genetic Risk Score (T1DGRS). Results: Models using routine clinical measures with or without autoantibodies and T1DGRS were highly accurate in identifying participants with c-peptide ≥0.75 ng/ml (17% of participants; 2.3% and 53% of those with and without positive autoantibodies) (area under receiver operator curve [AUCROC] 0.95-0.98). In internal validation, optimism was very low, with excellent calibration (slope=0.995-0.999). Models retained high performance for predicting retained c-peptide in older youth with obesity (AUCROC 0.88-0.96), and in subgroups defined by self-reported race/ethnicity (AUCROC 0.88-0.97), autoantibody status (AUCROC 0.87-0.96), and clinically diagnosed diabetes types (AUCROC 0.81-0.92). Conclusion: Prediction models combining routine clinical measures at diabetes diagnosis, with or without islet autoantibodies or T1DGRS, can accurately identify youth with diabetes who maintain endogenous insulin secretion in the range associated with type 2 diabetes.

Candidate biomarkers as predictors of future kidney disease and cardiovascular dysfunction in adolescents with type 2 diabetes.

AIMS: Evaluate changes in circulating biomarkers as predictors of kidney disease, and cardiac/vascular dysfunction in participants from the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) study. METHODS: Candidate biomarkers were assessed annually in 507 participants over a mean follow-up of 6.9 ± 2.4 years. Moderate albuminuria was defined as urine albumin-to-creatinine ratio ≥ 30 mg/g and hyperfiltration as eGFR ≥ 135 mL/min/1.73 m2 at two consecutive visits. Echocardiography (n = 256) and pulse wave velocity (n = 193) were evaluated twice, 5 years apart. Adjusted Cox proportional hazard models and logistic regression models were used to examine associations between biomarkers and outcomes. RESULTS: At baseline, 35.7% were male, with a mean age 13.9 years, diabetes duration 7.8 months, and HbA1c 6.0%. Higher concentrations of E-selectin and proinsulin were associated with incident moderate albuminuria and hyperfiltration. Higher concentrations of FGF-23 were associated with lower risk of hyperfiltration and negatively correlated with eGFR. No candidate biomarkers predicted a decline in cardiac or vascular function. CONCLUSIONS: Circulating biomarkers of endothelial dysfunction and markers of ß-cell dysfunction and insulin sensitivity could be used in a more personalized risk assessment of kidney disease in youth-onset type 2 diabetes. However, biomarkers studied have limited value in predicting cardiac dysfunction or vascular stiffness.

Trends in incidence of youth-onset type 1 and type 2 diabetes in the USA, 2002-18: results from the population-based SEARCH for Diabetes in Youth study.

BACKGROUND: The incidence of diabetes is increasing in children and young people. We aimed to describe the incidence of type 1 and type 2 diabetes in children and young people aged younger than 20 years over a 17-year period. METHODS: The SEARCH for Diabetes in Youth study identified children and young people aged 0-19 years with a physician diagnosis of type 1 or type 2 diabetes at five centres in the USA between 2002 and 2018. Eligible participants included non-military and non-institutionalised individuals who resided in one of the study areas at the time of diagnosis. The number of children and young people at risk of diabetes was obtained from the census or health plan member counts. Generalised autoregressive moving average models were used to examine trends, and data are presented as incidence of type 1 diabetes per 100 000 children and young people younger than 20 years and incidence of type 2 diabetes per 100 000 children and young people aged between 10 years and younger than 20 years across categories of age, sex, race or ethnicity, geographical region, and month or season of diagnosis. FINDINGS: We identified 18 169 children and young people aged 0-19 years with type 1 diabetes in 85 million person-years and 5293 children and young people aged 10-19 years with type 2 diabetes in 44 million person-years. In 2017-18, the annual incidence of type 1 diabetes was 22·2 per 100 000 and that of type 2 diabetes was 17·9 per 100 000. The model for trend captured both a linear effect and a moving-average effect, with a significant increasing (annual) linear effect for both type 1 diabetes (2·02% [95% CI 1·54-2·49]) and type 2 diabetes (5·31% [4·46-6·17]). Children and young people from racial and ethnic minority groups such as non-Hispanic Black and Hispanic children and young people had greater increases in incidence for both types of diabetes. Peak age at diagnosis was 10 years (95% CI 8-11) for type 1 diabetes and 16 years (16-17) for type 2 diabetes. Season was significant for type 1 diabetes (p=0·0062) and type 2 diabetes (p=0·0006), with a January peak in diagnoses of type 1 diabetes and an August peak in diagnoses of type 2 diabetes. INTERPRETATION: The increasing incidence of type 1 and type 2 diabetes in children and young people in the USA will result in an expanding population of young adults at risk of developing early complications of diabetes whose health-care needs will exceed those of their peers. Findings regarding age and season of diagnosis will inform focused prevention efforts. FUNDING: US Centers for Disease Control and Prevention and US National Institutes of Health.

Exploring Racial and Ethnic Differences in Arterial Stiffness Among Youth and Young Adults With Type 1 Diabetes.

Background We examined arterial stiffness in individuals with type 1 diabetes, and explored whether differences between Hispanic, non-Hispanic Black (NHB), and non-Hispanic White (NHW) individuals were attributable to modifiable clinical and social factors. Methods and Results Participants (n=1162; 22% Hispanic, 18% NHB, and 60% NHW) completed 2 to 3 research visits from ≈10 months to ≈11 years post type 1 diabetes diagnosis (mean ages of ≈9 to ≈20 years, respectively) providing data on socioeconomic factors, type 1 diabetes characteristics, cardiovascular risk factors, health behaviors, quality of clinical care, and perception of clinical care. Arterial stiffness (carotid-femoral pulse wave velocity [PWV], m/s) was measured at ≈20 years of age. We analyzed differences in PWV by race and ethnicity, then explored the individual and combined impact of the clinical and social factors on these differences. PWV did not differ between Hispanic (adjusted mean 6.18 [SE 0.12]) and NHW (6.04 [0.11]) participants after adjustment for cardiovascular risks (P=0.06) and socioeconomic factors (P=0.12), or between Hispanic and NHB participants (6.36 [0.12]) after adjustment for all factors (P=0.08). PWV was higher in NHB versus NHW participants in all models (all P<0.001). Adjustment for modifiable factors reduced the difference in PWV by 15% for Hispanic versus NHW participants; by 25% for Hispanic versus NHB; and by 21% for NHB versus NHW. Conclusions Cardiovascular and socioeconomic factors explain one-quarter of the racial and ethnic differences in PWV of young people with type 1 diabetes, but NHB individuals still experienced greater PWV. Exploration of pervasive inequities potentially driving these persistent differences is needed.

Association of Elevated Arterial Stiffness With Cardiac Target Organ Damage and Cardiac Autonomic Neuropathy in Young Adults With Diabetes: The SEARCH for Diabetes in Youth Study.

OBJECTIVE: Adults with diabetes are at risk for cardiovascular (CV) events, possibly due to increased arterial stiffness (AS) and cardiac autonomic neuropathy (CAN). We sought to determine whether 1) AS is associated with cardiac target organ damage in young adults with youth-onset diabetes, 2) whether CAN is associated with AS, as one possible etiology for increased AS in this cohort, and 3) whether these relationships differ by type of diabetes. RESEARCH DESIGN AND METHODS: Participants from the SEARCH for Diabetes in Youth Study (type 1 diabetes [T1D], n = 222; type 2 diabetes [T2D], n = 177; mean age 23 years) had clinical, echocardiographic, AS, and CAN assessed. Linear regression was performed to determine whether AS was associated with cardiac changes and CAN and whether relationships differed by diabetes type. RESULTS: AS was significantly associated with cardiac structure (left ventricular mass index, P < 0.0001), systolic function (ejection fraction, P = 0.03) and diastolic function (transmitral peak early [E]/atrial [A] wave velocities ratio, P = 0.008; early [e']/atrial [a'] waves, P = 0.02) after adjustments for CV risk factors. The association between AS and CAN was not significant when other important covariates were added. These relationships were mostly similar in both T1D and T2D. CONCLUSIONS: AS is associated with cardiac changes in young adults with diabetes. CAN-induced AS does not appear to be an etiology for cardiac abnormalities in this cohort.

Screening for Gastric Sensory Motor Abnormalities in Pediatric Patients With Type 1 Diabetes.

OBJECTIVE: To determine the frequency of gastric sensory motor symptoms in youth with type 1 diabetes. METHODS: A prospective cross-sectional study was performed to evaluate symptoms of delayed gastric emptying in participants with type 1 diabetes, aged 12 to 25 years, using the Gastroparesis Cardinal Symptom Index (GCSI) questionnaire. In addition, a 5-year (January 2015 to December 2019), a retrospective study was completed on all gastric emptying scans performed in youth at our institution. RESULTS: A total of 359 participants (mean age, 17.7 ± 3.33 years) with type 1 diabetes completed the GCSI questionnaire. Compared with nonresponders, responders were more likely to be non-Hispanic White (90% vs 86%; P =.003) and female patients (58% vs 44%; P <.0001), with a lower HbA1c (8.1 ± 1.8 vs 9.0 ± 2.1; P <.0001). At least 1 gastrointestinal symptom was reported in 270 (75%) of responders, of which nausea was the most common (71%). A GCSI score of ≥1.9 suggestive of more severe gastrointestinal symptoms was reported in 17% of responders. Participants with scores ≥1.9 were older (19.1 ± 3.0 vs 17.8 ± 3.3 years; P =.01). In the retrospective study, 778 underwent gastric emptying scan, 29 participants had type 1 diabetes and 11 (38%) showed delayed gastric emptying. CONCLUSION: Gastrointestinal symptoms related to gastric sensory motor abnormalities are seen in youth and young adults with type 1 diabetes. In particular, for those with higher GCSI scores, earlier recognition and referral may be warranted.

Youth-onset type 2 diabetes mellitus: an urgent challenge.

The incidence and prevalence of youth-onset type 2 diabetes mellitus (T2DM) and its complications are increasing worldwide. Youth-onset T2DM has been reported in all racial and ethnic groups, but Indigenous peoples and people of colour are disproportionately affected. People with youth-onset T2DM often have a more aggressive clinical course than those with adult-onset T2DM or those with type 1 diabetes mellitus. Moreover, the available treatment options for children and adolescents with T2DM are more limited than for adult patients. Intermediate complications of youth-onset T2DM, such as increased albuminuria, often develop in late childhood or early adulthood, and end-stage complications, including kidney failure, develop in mid-life. The increasing frequency, earlier onset and greater severity of childhood obesity in the past 50 years together with increasingly sedentary lifestyles and an increasing frequency of intrauterine exposure to diabetes are important drivers of the epidemic of youth-onset T2DM. The particularly high risk of the disease in historically disadvantaged populations suggests an important contribution of social and environmental factors, including limited access to high-quality health care, healthy food choices and opportunities for physical activity as well as exposure to stressors including systemic racism and environmental pollutants. Understanding the mechanisms that underlie the development and aggressive clinical course of youth-onset T2DM is key to identifying successful prevention and management strategies.

Diabetes complications and cognitive function in young adults with youth-onset type 1 or type 2 diabetes: the SEARCH for Diabetes in Youth Study.

Aims/hypotheses: People with type 1 (T1D) or type 2 diabetes (T2D) who also have diabetes complications can have pronounced cognitive deficits. It remains unknown, however, whether and how multiple diabetes complications co-occur with cognitive dysfunction, particularly in youth-onset diabetes. Methods: Using data from the SEARCH for Diabetes in Youth study cohort, a prospective longitudinal cohort, we examined clustering of complications and their underlying clinical factors with performance on cognitive tests in young adults with youth-onset T1D or T2D. Cognition was assessed via the NIH Toolbox Cognition Battery. The main cognitive variables were age-corrected scores for composite fluid cognition and associated cognitive subdomains. Diabetes complications included retinopathy, microalbuminuria, and peripheral neuropathy (PN). Lipids, systolic blood pressure (SBP), hemoglobin A1c, and other clinical factors were included in the analyses. Clustering was applied separately to each group (T1D=646; T2D=165). A three-cluster(C) solution was identified for each diabetes type. Mean values and frequencies of all factors were compared between resulting clusters. Results: The average age-corrected score for composite fluid cognition differed significantly across clusters for each group (p<0.001). People with T1D and the lowest average fluid cognition scores had the highest frequency of self-reporting at least one episode of hypoglycemia in the year preceding cognitive testing and the highest prevalence of PN. Persons with T2D and the lowest average fluid cognition scores had the highest SBP, the highest central systolic and diastolic blood pressures, and highest prevalence of PN. Conclusions/interpretations: These findings highlight shared (PN) and unique factors (hypoglycemia in T1D; SBP in T2D) that could be targeted to potentially mitigate cognitive issues in young people with youth-onset diabetes.

Household Food Insecurity and Cognition in Youth and Young Adults with Youth-Onset Diabetes.

Objective: We evaluated the association of household food insecurity (FI) with cognition in youth and young adults with type 1 diabetes (T1D) or type 2 diabetes (T2D). Design: In this cross-sectional study, age-adjusted scores for composite Fluid Cognition, and sub-domain scores for Receptive Language and Inhibitory Control and Attention, were modeled stratified by diabetes-type using linear regression, with FI in the past year as the predictor, controlling for covariates. Tests for processing speed, inhibitory control/attention, working memory, episodic memory, and cognitive flexibility were administered to measure composite Fluid Cognition score. The NIHT-CB Picture Vocabulary Test was used to assess Crystallized Cognition score and rapid identification of congruent versus noncongruent items were used to assess Inhibitory Control and Attention score. Setting: The SEARCH for Diabetes in Youth study, representative of 5 U.S. states. Participants: Included 1574 youth and young adults with T1D or T2D, mean age of 21 years, mean diabetes duration of 11 years, 51% non-Hispanic white, and 47% had higher HbA1c levels (>9% HbA1c). Results: Approximately 18% of the 1,240 participants with T1D and 31% of the 334 with T2D experienced FI. The food-insecure group with T1D had a lower composite Fluid Cognition score (ß= -2.5, 95% confidence interval (CI)= -4.8, -0.1) and a lower Crystallized Cognition score (ß= -3.4, CI= -5.6, -1.3) than food-secure peers. Findings were attenuated to non-significance after adjustment for demographics. Among T2D participants, no associations were observed. In participants with T1D effect modification by glycemic levels were found in the association between FI and composite Fluid Cognition score but adjustment for socioeconomic characteristics attenuated the interaction (p=0.0531). Conclusions: Food-insecure youth and young adults with T1D or T2D did not have different cognition compared to those who were food-secure after adjustment for confounders. Longitudinal research is needed to further understand relations amongst these factors.

Nutrition interventions for youth with dyslipidemia: a National Lipid Association clinical perspective.

A heart-healthy lifestyle, beginning at an early age and sustained throughout life, may reduce risk for cardiovascular disease in youth. Among youth with moderate to severe dyslipidemia and/or those with familial hypercholesterolemia, lipid-lowering medications are often needed for primary prevention of cardiovascular disease. However, lifestyle interventions are a foundation for youth with dyslipidemia, as well as those without dyslipidemia. There are limited data supporting the use of dietary supplements in youth with dyslipidemia at this time. A family-centered approach and the support of a multi-disciplinary healthcare team, which includes a registered dietitian nutritionist to provide nutrition counseling, provides the best opportunity for primary prevention and improved outcomes. While there are numerous guidelines that address the general nutritional needs of youth, few address the unique needs of those with dyslipidemia. The goal of this National Lipid Association Clinical Perspective is to provide guidance for healthcare professionals caring for youth with disorders of lipid and lipoprotein metabolism, including nutritional guidance that complements the use of lipid lowering medications.

ISPAD Clinical Practice Consensus Guidelines 2022: Type 2 diabetes in children and adolescents.

Since the 2018 ISPAD guidelines on this topic, follow-up of large cohorts from around the globe have continued informing the current incidence and prevalence of co-morbidities and complications in young adults with youth-onset type 2 diabetes (T2D). This chapter focuses on the risk factors, diagnosis and presentation of youth-onset T2D, the initial and subsequent management of youth-onset T2D, and management of co-morbidities and complications. We include key updates from the observational phase of the multi-center Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) clinical trial, the SEARCH for Diabetes in Youth (SEARCH) study and new data from the Restoring Insulin Secretion (RISE) study, a head-to-head comparison of youth onset vs adult-onset T2D. We also include an expanded section on risk factors associated with T2D, algorithms and tables for treatment, management, and assessment of co-morbidities and complications, and sections on recently approved pharmacologic therapies for the treatment of youth-onset T2D, social determinants of health, and settings of care given COVID-19 pandemic.

The Coronavirus Disease 2019 Pandemic is Associated with a Substantial Rise in Frequency and Severity of Presentation of Youth-Onset Type 2 Diabetes.

OBJECTIVES: To evaluate the frequency and severity of new cases of youth-onset type 2 diabetes in the US during the first year of the pandemic compared with the mean of the previous 2 years. STUDY DESIGN: Multicenter (n = 24 centers), hospital-based, retrospective chart review. Youth aged ≤21 years with newly diagnosed type 2 diabetes between March 2018 and February 2021, body mass index ≥85th percentile, and negative pancreatic autoantibodies were included. Demographic and clinical data, including case numbers and frequency of metabolic decompensation, were compared between groups. RESULTS: A total of 3113 youth (mean [SD] 14.4 [2.4] years, 50.5% female, 40.4% Hispanic, 32.7% Black, 14.5% non-Hispanic White) were assessed. New cases of type 2 diabetes increased by 77.2% in the year during the pandemic (n = 1463) compared with the mean of the previous 2 years, 2019 (n = 886) and 2018 (n = 765). The likelihood of presenting with metabolic decompensation and severe diabetic ketoacidosis also increased significantly during the pandemic. CONCLUSIONS: The burden of newly diagnosed youth-onset type 2 diabetes increased significantly during the coronavirus disease 2019 pandemic, resulting in enormous strain on pediatric diabetes health care providers, patients, and families. Whether the increase was caused by coronavirus disease 2019 infection, or just associated with environmental changes and stressors during the pandemic is unclear. Further studies are needed to determine whether this rise is limited to the US and whether it will persist over time.

Longitudinal Changes in Arterial Stiffness and Heart Rate Variability in Youth-Onset Type 1 Versus Type 2 Diabetes: The SEARCH for Diabetes in Youth Study.

OBJECTIVE: We compared arterial stiffness and heart rate variability (HRV) over time by diabetes type and determined the risk factors associated with worsening arterial stiffness and HRV in young adults with youth-onset diabetes. RESEARCH DESIGN AND METHODS: Arterial stiffness (pulse wave velocity, augmentation index) and six indices of heart rate variability were measured twice, 4.5 years apart, among participants with either youth-onset type 1 or type 2 diabetes in the SEARCH for Diabetes in Youth study. Multivariable linear regression models were used to assess risk factors associated with arterial stiffness and HRV at follow-up. RESULTS: Of 1,159 participants studied, 949 had type 1 diabetes (mean age 17.1 ± 4.7 years, 60.3% non-Hispanic White, 55% female) and 210 had type 2 diabetes (mean age 22.1 ± 3.5 years, 23.8% non-Hispanic White, 71% female) at initial assessment when diabetes duration was 7.9 years (both groups). Participants with type 2 versus type 1 diabetes had greater arterial stiffness and more abnormalities in HRV at initial and follow-up assessment and a greater change over time (all P < 0.05). Risk factors associated with worse arterial stiffness and HRV at follow-up in both types of diabetes included higher blood pressure, hemoglobin A1c, waist circumference, and triglycerides over time and longer diabetes duration. CONCLUSIONS: Arterial stiffness and HRV worsened over time with greater changes among participants with type 2 versus type 1 diabetes and among those with features of the metabolic syndrome. The risk factor profile documents potentially modifiable pathways to prevent or limit cardiovascular complications in young adults with youth-onset diabetes.