Metformin Initiation Cuts Gout Risk in Prediabetes

TOPLINE:

Metformin use lowers the risk for gout by 32% in individuals with prediabetes; however, the treatment doesn't change serum urate or C-reactive protein levels.

METHODOLOGY:

• Individuals with prediabetes not only are at an elevated risk for diabetes but also face an increased risk for incident gout. Many previous reports have demonstrated the efficacy of antidiabetic medications in reducing the risk for gout in adults with diabetes.
• This study assessed the gout-lowering properties of metformin in 25,064 individuals with prediabetes (age ≥ 18 years; A1c levels, 5.7%-6.4%) who had never reported A1c levels > 6.4%.
• Patients who were initiated on metformin within 18 months after the diagnosis of prediabetes (n = 1154) were propensity score–matched with those who did not initiate metformin or other antidiabetic medications in this period (n = 13,877) and were followed for a median of 3.9 years for the primary outcome of incident gout.

TAKEAWAY:

• Initiation vs no initiation of metformin resulted in 2.4 fewer cases of gout per 1000 person-years and a 32% reduced relative risk for incident gout (hazard ratio, 0.68; 95% CI, 0.48-0.96).
• The results were consistent across different subgroups stratified on the basis of sex, age (≤ 60 vs > 60 years), estimated glomerular filtration rate (≥ 90 vs < 90 mL/min/1.73 m²), and baseline diuretic use.
• Metformin initiation was not associated with significant changes in serum urate or C-reactive protein levels.
• Metformin use was associated with a reduction in A1c levels and body mass index.

IN PRACTICE:

The authors suggested that "metformin may be important in lowering gout risk in individuals with prediabetes."

SOURCE:

Javier Marrugo, MD, Department of Medicine, Brigham and Women's Hospital, Boston, led this study, which was published online on May 15 in Annals of the Rheumatic Diseases.

LIMITATIONS:

Although gout is more commonly observed in men, around 60% of the study population consisted of women. Owing to the observational nature of this study, exposure misclassifications might have occurred. Misclassification of the outcome is also possible due to the presence of two or more diagnostic codes for gout and/or the combination of urate-lowering therapies or colchicine with at least one diagnostic code.

DISCLOSURES:

This work was supported by the National Institutes of Health. Some authors declared serving as consultants or receiving salary support or consulting fees from various sources.