This article is more than 5 years old. Information may no longer be current.
Metformin recommended as first-line therapy for patients with type 2 diabetes
Click Here to Manage Email Alerts
In adult patients with type 2 diabetes, metformin is the recommended first-line treatment, demonstrating relative safety and positive effects on HbA1c, weight and cardiovascular death, according to recent findings.
In the systematic review and meta-analysis, researchers queried databases for terms related to various monotherapy drugs and certain metformin-based combination regimens in adult patients with type 2 diabetes. Studies identified for analysis included head-to-head monotherapy comparisons of metformin, thiazolidinediones, sulfonylureas, DPP-IV inhibitors, SGLT2 inhibitors and glucagon-like peptide-1 receptor agonists; also included were comparisons of metformin with metformin-based combinations.
Study titles, abstracts and full-text articles were independently screened by two reviewers, and differences were reconciled through consensus adjudication. They identified 204 studies (179 trials and 25 observational studies) and pooled the mean differences between groups for continuous outcomes. Pooled odds ratios for dichotomous outcomes were calculated by using the intention-to-treat denominator.
The researchers found moderate strength of evidence that monotherapy with metformin was linked to lower long-term (≥ 2 years) CV death vs. sulfonylurea monotherapy. This result was based on consistent findings from two randomized controlled trials and three observational studies with low-bias risk. In both of the randomized controlled trials, a lower risk for CV mortality was revealed with metformin vs. sulfonylureas. Less consistent results were seen in comparisons of all-cause mortality and CV morbidity; based on the same set of randomized controlled trials and observational studies, a lower risk of these outcomes was seen in metformin vs. sulfonylureas, but the evidence was found to be low strength.
Most of the monotherapy diabetes medications had comparable short-term effects in reducing HbA1c, with the exception of DPP-IV inhibitors, which demonstrated less efficacy in this outcome vs. metformin or sulfonylureas. There was an increase in body weight with metformin vs. DPP-IV inhibitors, whereas sulfonylureas yielded slightly less weight gain vs. thiazolidinediones. Weight loss was greater with the SGLT2 inhibitors vs. metformin, whereas metformin decreased the rate more than DPP-IV inhibitors. Sulfonylureas in combination with metformin also were linked to increased risk for severe hypoglycemia vs. metformin plus a DPP-IV inhibitor or metformin plus an SGLT2 inhibitor. Mild, moderate or total hypoglycemia was higher with sulfonylureas alone and in combination with metformin vs. all other monotherapies and metformin combinations. An increased risk for genital mycotic infections was seen with SGLT2 inhibitors.
“The evidence from this systemic review supports current guidelines with metformin as the recommended first-line agent to treat adults with type 2 diabetes, given its beneficial effects on HbA1c, weight and [CV] mortality and relative safety profile,” the researchers wrote. “In the absence of more evidence on the effects of glucose-lowering medications on long-term diabetes complications, patient factors and preferences regarding the known comparative effects, tolerance of uncertainty in risk, and logistical considerations should continue to drive the selection of a second or alternative agent to metformin in the treatment of type 2 diabetes.” – by Jennifer Byrne
Disclosure: The researchers report no relevant financial disclosures.
Click Here to Manage Email Alerts