The Effects of Salsalate on Glycemic Control in Patients With Type 2 Diabetes A Randomized Trial

Background: Salsalate, a nonacetylated prodrug of salicylate, has been shown to decrease blood glucose concentration in small studies. Objective: To compare the efficacy and safety of salsalate at different doses in patients with type 2 diabetes. Design: Parallel randomized trial with computer-generated randomization and centralized allocation. Patients and investigators, including those assessing outcomes and performing analyses, were masked to group assignment. (ClinicalTrials.gov registration number: NCT00392678) Setting: 3 private practices and 14 universities in the United States. Patients: Persons aged 18 to 75 years with fasting plasma glucose concentrations of 12.5 mmol/L or less (<= 225 mg/dL) and hemoglobin A(1c) (HbA(1c)) levels of 7.0% to 9.5% treated by diet, exercise, and oral medication at stable doses for at least 8 weeks. Intervention: After a 4-week, single-masked run-in period, patients were randomly assigned to receive placebo or salsalate in dosages of 3.0, 3.5, or 4.0 g/d for 14 weeks (27 patients each) in addition to their current therapy. Measurements: Change in HbA(1c) was the primary outcome. Adverse effects and changes in measures of coronary risk and renal function were secondary outcomes. Results: Higher proportions of patients in the 3 salsalate treatment groups experienced decreases in HbA(1c) levels of 0.5% or more from baseline (P = 0.009). Mean HbA(1c) changes were -0.36% (P = 0.02) at 3.0 g/d, -0.34% (P = 0.02) at 3.5 g/d, and -0.49% (P = 0.001) at 4.0 g/d compared with placebo. Other markers of glycemic control also improved in the 3 salsalate groups, as did circulating triglyceride and adiponectin concentrations. Mild hypoglycemia was more common with salsalate; documented events occurred only in patients taking sulfonylureas. Urine albumin concentrations increased in all salsalate groups compared with placebo. The drug was otherwise well tolerated. Limitation: The number of patients studied and the trial duration were insufficient to warrant recommending the use of salsalate for type 2 diabetes at this time. Conclusion: Salsalate lowers HbA(1c) levels and improves other markers of glycemic control in patients with type 2 diabetes and may therefore provide a new avenue for treatment. Renal and cardiac safety of the drug require further evaluation.