Screening for Early Evidence of Diabetes

Inclusion Criteria: Age greater than or equal to 45 years OR Age 18 to 44 years, with two or more of the following risk factors: * Overweight (BMI ≥ 25 kg/m2) * Elevated waist circumference, \>35 inches for women and \>40 inches for men * Habitually physically inactive * Has a first-degree relative with diabetes * African American, Latino, Native American, Asian American, Pacific Islander * Delivered a baby weighing \>9 lb or diagnosed with gestational diabetes * Hypertension (\>130/\>85 mm Hg) or being treated for hypertension * HDL cholesterol \<35 mg/dL and/or triglycerides \>250 mg/dL or being treated for dyslipidemia with medication * Previously diagnosed with Polycystic Ovary Syndrome (PCOS) * Abnormal Glucose Tolerance on previous testing within the last 3 years * Has a condition associated with insulin resistance (e.g., acanthosis nigricans) * History of vascular disease (e.g., heart attack, stroke, angina, coronary heart disease, atherosclerosis, congestive heart failure, or peripheral arterial disease) Exclusion Criteria: * Prior bariatric surgery * Diagnosed with type 1 or 2 diabetes * Taking glucose lowering medications * Receiving dialysis or having known renal compromise * Receiving investigational treatments * Scars, tattoos, rashes or other disruption/discoloration on the left volar forearm * Recent or current oral steroid therapy or topical steroids applied to the left forearm * Current chemotherapy, or chemotherapy within the past 12 months * Conditions that cause secondary diabetes (e.g., Cushing's syndrome, acromegaly, hemochromatosis, pancreatitis, or cystic fibrosis) * Receiving other investigational treatments * Receiving drugs that fluoresce (e.g., Doxorubicin, Daunomycin, Camptothecin, Protoporphyrin, Fluoroquinolones, Tetracycline, Hydroxychloroquine or Quinidine) * Known to be pregnant * Psychosocial issues that interfere with an ability to follow study procedures * Known to have, or at risk for, photosensitivity reactions (e.g., sensitive to ultraviolet light, or taking medication known to cause photosensitivity