Youth-Onset Type 2 Diabetes and Heart Disease: The Young at Heart Prospective Cohort Study

Eligibility Criteria

• * Participants with Y-T2DM
• * Age 12-25 years
• * Type 2 diabetes mellitus as defined by fasting blood glucose \>= 126 mg/dL OR postprandial blood sugar \>= 200 mg/dL OR Hemoglobin A1c \>= 6.5 percent per American Diabetes Association Criteria OR documentation of type 2 diabetes diagnosed at \<=25 years of age
• * Youth with overweight/ obesity (Y-OW)
• * Age 12-25 years
• * For participants \< 18 years of age, BMI \>= 85th percentile (overweight) and \>= 95th percentile (obesity) for age and sex OR
• * For participants \>= 18 years of age, BMI \>=25\<30 kg/m\^2 (overweight) or \>=30 kg/m\^2 (obesity)
• * Participants with obesity may have a diagnosis of prediabetes, defined as fasting blood glucose 100-125 mg/dL OR postprandial blood sugar 140-199 mg/dL OR HbA1c 5.7-6.4 percent (either during testing at NIH or as previously documented on outside medical record).
• * Healthy control lean participants (Y-Lean)
• * Age 12-25 years
• * For participants \< 18 years of age, BMI \<= 85th percentile for age and sex OR
• * For participants \>=18 years of age, BMI 18-24.99 kg/m\^2.
• * HbA1c \<5.7 percent (either during testing at NIH or as previously documented on outside medical record).
• * Biological parents of Y-T2DM, Y-OW and Y-Lean participants
• * Biological parent of enrolled Y-T2DM, Y-OW and Y-Lean by self-report.
• * Y-T2DM, Y-OW and Y-Lean Participants:
• * Type 1 diabetes or the presence of \>2 diabetes auto-antibodies (e.g., GAD-65, IA-2 antigen, Zinc transporter 8 autoantibodies).
• * Medical, psychiatric or cognitive disorders that will, in the opinion of the investigators, limit the subject s ability to comply with study procedures (specific obesity-related comorbidities are explicitly permitted, including hypertension, hyperlipidemia, obstructive sleep apnea and non-alcoholic steatohepatitis).
• * Serious medical illnesses or diseases thought to alter metabolism (including moderate to severe renal disease (\< 30 mL/min/1.73m\^2), congenital heart disease, Cushing s syndrome, cancer, or other metabolic diseases associated with diabetes or excess weight).
• * For participants enrolled at the NIH, dietary allergies, intolerances or eating patterns that would preclude them from consuming metabolic meals.
• * Unwilling to comply with all study procedures or to adhere to Lifestyle Considerations throughout study duration.
• * Pregnancy at the time of the screening visit.
• * Clinically significant anemia OR Hematocrit below the lower limit of normal for age and sex cutoffs.
• * Y-Lean participants:
• * Current use of prescription or non-prescription medication. Certain exceptions are permitted, including topical medications, vitamins, and hormonal contraceptives. Other medications may be permitted at the discretion of the investigators.
• * Recent (past 2 months) use of drugs or supplements that alter glucose or lipid metabolism (e.g., niacin, fish oil, red yeast rice)
• * History of diabetes or abnormal glucose tolerance
• * Abnormal screening labs, including the following:
• * ALT or AST \>2 times the upper limit of normal
• * Glycosuria
• * Low eGFR (\<90 mL/min/1.73m\^2)Any other abnormality that, in the opinion of the investigator, will increase risk to the subject from participation, or interfere with interpretation of study data
• * Biological Parents
• * No Exclusion Criteria