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JAMA Insights
May 22, 2020

Using Insulin to Treat Poorly Controlled Type 2 Diabetes in 2020

Author Affiliations
  • 1University of Washington School of Medicine, Seattle
  • 2Braden Diabetes Center, Greenbrae, California
JAMA. 2020;323(23):2419-2420. doi:10.1001/jama.2020.1303

The prevalence of type 2 diabetes in the US has continued to increase, and, in 2015, was estimated to affect 9.4% of US adults.1 Recent American Diabetes Association (ADA) guidelines for diabetes treatment recommend choosing second-line therapies after metformin based on the presence of cardiovascular-and/or kidney-related comorbidities, risks of weight gain and hypoglycemia, and cost (Figure).2 There is little evidence or guidance regarding how treatment might differ based on how much a patient’s hemoglobin A1c (HbA1c) is above the treatment target after metformin is started. The guidelines recommend that patients who have established atherosclerotic cardiovascular disease (ASCVD), chronic kidney disease (CKD), or heart failure should be treated with a sodium-glucose cotransporter 2 (SGLT2) inhibitor or glucagon-like peptide 1 receptor (GLP-1R) agonist, irrespective of HbA1c.2 Exceptions include obvious signs of catabolism such as unintentional weight loss, an HbA1c higher than 10.0%, or glucose levels higher than 300 mg/dL, in which cases insulin may be considered. For patients who do not have ASCVD or CKD, other antihyperglycemic agents, such as dipeptidyl peptidase 4 inhibitors or thiazolidinediones, are recommended when risks for hypoglycemia need to be minimized. When mitigating weight gain (or promoting weight loss) is a primary objective, the use of SGLT2 inhibitors and GLP-1R agonists is suggested. When cost is the major challenge, the use of sulfonylureas and thiazolidinediones is emphasized. All of these recommendations precede those for initiating insulin therapy, which is recommended at or near the end of each treatment algorithm. When cost is the major consideration, basal insulin with the lowest acquisition cost is recommended, and this will usually be neutral protamine Hagedorn (NPH) insulin. Nevertheless, the overall magnitude of poorly controlled diabetes as manifested by HbA1c levels is not a factor in recommended treatment decisions until it exceeds 10.0%.