Diazoxide Suppression Test P&F Study

Inclusion Criteria: * Men and women, aged 18-65 years * Body mass index of 30-45 kg/m2 * Able to understand written and spoken English and/or Spanish * Fasting hyperinsulinemia (fasting serum insulin ≥ 13 μU/mL) * Completion of the graded insulin suppression test (GIST) protocol (Group H) * Written informed consent (in English or Spanish) and any locally required authorization (e.g., Health Insurance Portability and Accountability Act) obtained from the participant prior to performing any protocol-related procedures, including screening evaluations. Exclusion Criteria: * Unable to provide informed consent in English or Spanish * Documented weight loss of ≥ 5% of baseline within the previous 3 months * Abnormal blood pressure (including on treatment, if prescribed): Systolic blood pressure \< 90 mm Hg or \> 160 mm Hg, and/or Diastolic blood pressure \< 60 mm Hg or \> 100 mm Hg * Abnormal resting heart rate: \< 60 or ≥ 110 bpm * Sinus brady- or tachycardia that has been worked up and considered benign by the recruit's personal physician may be permitted at the PI's discretion * Abnormal screening electrocardiogram on GIST screening (or if on file, performed within previous 90 d): * Non-sinus rhythm * Heart conduction blocks * Previously unknown ischaemic changes that persist on repeat EKG: * ST elevations * T-wave inversions in a vascular distribution * Laboratory evidence of dysglycemia on GIST screening: * Hemoglobin A1c ≥ 5.7%, and/or * Fasting plasma gluc…