Study to Understand the Genetics of the Acute Response to Metformin and Glipizide in Humans

Inclusion Criteria: * Male or non-pregnant female \> 18 years of age * Investigators will target preferentially people at risk of diabetes or requiring diabetes meds * The first tier of risk will be illustrated by one of the following variables (e.g. established type 2 diabetes on diet therapy alone, elevated random glucose in electronic medical record, PCOS, metabolic syndrome, obesity, history of gestational diabetes, etc.) * The second tier of risk will be illustrated by other features that correlate with diabetes risk, such as a history of hypertension or dyslipidemia * Otherwise healthy subjects may also be candidates for the study. * Able and willing to give consent relevant to genetic investigation Exclusion Criteria: * Pregnant, nursing or at risk of becoming pregnant * Currently taking any medications for the treatment of diabetes * Currently on metformin for any other indication (e.g. PCOS) * Onset of diabetes in a family member before age 25, with autosomal transmission of diabetes across three generations * History of liver or kidney disease * Known severe allergic reactions to sulfonamides * History of porphyria * Documented estimated glomerular filtration rate (GFR) \< 60 ml/min/1.73 m2, based on the most recent serum creatinine measurement available in the electronic medical record, and calculated by the Modification of Diet in Renal Disease equation (49) available at http://www.nephron.com/cgi-bin/MDRD\_GFR.cgi * Currently taking medications known to affect…