DeFronzo RA, Ferrannini E Insulin resistance. A multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidemia, and atherosclerotic cardiovascular disease. Diabetes Care. 1991 Mar;14(3):173-94. doi: 10.2337/diacare.14.3.173.
DeFronzo RA, Gunnarsson R, Bjorkman O, Olsson M, Wahren J Effects of insulin on peripheral and splanchnic glucose metabolism in noninsulin-dependent (type II) diabetes mellitus. J Clin Invest. 1985 Jul;76(1):149-55. doi: 10.1172/JCI111938.
DeFronzo RA, Simonson D, Ferrannini E Hepatic and peripheral insulin resistance: a common feature of type 2 (non-insulin-dependent) and type 1 (insulin-dependent) diabetes mellitus. Diabetologia. 1982 Oct;23(4):313-9. doi: 10.1007/BF00253736.
O'Rahilly S "Treasure Your Exceptions"-Studying Human Extreme Phenotypes to Illuminate Metabolic Health and Disease: The 2019 Banting Medal for Scientific Achievement Lecture. Diabetes. 2021 Jan;70(1):29-38. doi: 10.2337/dbi19-0037.
Parish R, Petersen KF Mitochondrial dysfunction and type 2 diabetes. Curr Diab Rep. 2005 Jun;5(3):177-83. doi: 10.1007/s11892-005-0006-3.
Petersen MC, Shulman GI Mechanisms of Insulin Action and Insulin Resistance. Physiol Rev. 2018 Oct 1;98(4):2133-2223. doi: 10.1152/physrev.00063.2017.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.