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Metformin Helps Those Who Normally Couldn’t Use It

Metformin is a medication many with type 2 diabetes may be familiar with. It has long been recommended as a first-line therapy for type 2 diabetes, but has had several exclusions for its use. These exclusions include having type 2 diabetes with comorbid chronic kidney disease (CKD), congestive heart failure (CHF), or chronic liver disease (CLD) with accompanying hepatic impairment. The main fear of taking metformin with these conditions was the development of lactic acidosis, a fear that has largely been debunked. While more research is ongoing, there has been enough evidence to specifically support the conclusion that lactic acidosis is not a factor for those with moderate CKD taking metformin. The January 2017 updated type 2 diabetes care guidelines have even expanded to include moderate CKD as being eligible for metformin treatment.

Increase to the inclusion criteria of metformin

Since metformin is a crucial first-line therapy, recent studies have centered around debunking old myths and increasing the inclusion criteria for the treatment. A prime observation of this was published in Annals of Internal Medicine, and led by Matthew J Crowley, MD, from Durham Veteran’s Affairs Medical Center and Duke University in Durham, NC. This study completed a systematic review of 17 different observational studies including individuals with type 2 diabetes as well as CKD, CHF, of CLD. While the data is limited to observational methods, an interesting correlation was found.

Overall, the authors concluded that there was reduced all-cause mortality in patients with T2D and any or all of three comorbid conditions when treated with metformin. Additionally, there was a lower rate of hospital admissions for CHF-related complications in patients with type 2 diabetes and CKD or CHF, who were also on metformin. Furthermore, the authors found a decreased risk of hypoglycemia for individuals with CKD who were on metformin as well.

Metformin’s benefits

With the lactic acidosis risk proving to be less and less of a concern, this study focused on other potential long-term issues of metformin with accompanying additional conditions, to determine if it should be utilized in these populations. The fact that the effect found wasn’t a neutral one, but rather an actual decrease in risk of developing many complications including cardiovascular outcomes, was huge and could change the way treatment for type 2 diabetes is structured moving forward. Critics of the study indicate that there needs to be more research surrounding metformin’s benefits to these patients over other common treatments such as glucagon-like peptide 1 agonists (GLP-1) or sodium-glucose cotransporter type 2 (SGLT2) inhibitors, but it does provide a valuable starting point.

Metformin is much less expensive treatment, and therefore, could provide a more feasible treatment plan for many who were previously excluded from its use. Hopefully, others will build on this new information, and can create more set-in-stone guidelines expanding its use in the near future!

  1. Tucker, Miriam E. “Metformin Benefits Patients Historically Kept From Using It.” Medscape. 3 Jan 2017. Available from: