A preliminary study shows salsalate reduced blood sugar levels and helped with glycemic control at a variety of doses in people with type 2 diabetes. However, it also has been shown to increase protein in the urine and its long-term safety will need further investigation.
Like aspirin, salsalate is an anti-inflammatory drug derived from salicylate and is often used to treat arthritis. Researchers say the first reports of salicylate-based drugs aiding in the treatment of diabetes were published more than a century ago.
More recently, inflammation has been implicated in development of the insulin resistance that leads to elevated blood sugar levels associated with type 2 diabetes. Aspirin has also been shown to lower blood sugar levels, but the high doses required are associated with a risk of bleeding, which limits its utility.
That prompted researchers to take another look at salsalate in reducing blood sugar levels. Salsalate contains the same active ingredient as aspirin but is associated with fewer side effects.
In the study, published in the Annals of Internal Medicine, researchers randomly assigned 108 people with type 2 diabetes to receive 3, 3.5, or 4 grams per day of salsalate or a placebo in addition to their current diabetes therapy for 14 weeks.
The results showed those who took salsalate at each of the dosage levels experienced a beneficial decrease in blood sugar A1c levels of 0.5% or more. Other markers of glycemic control and heart disease risk also improved in the three salsalate groups compared with the placebo group. No single dose of salsalate seemed safer or more effective than another.
Although only minor side effects of salsalate use were reported, researchers say salsalate users tended to develop more protein in their urine. Elevated protein levels in the urine may indicate negative effects on kidney function.
Due to the small size of the study and short follow-up time, researchers say it's too soon to recommend use of salsalate for the treatment of type 2 diabetes. But the results do merit further research.
"Because of salsalate's anti-inflammatory effects, our results suggest that inflammation plays a role in the pathogenesis of type 2 diabetes and that anti-inflammatory therapy may be useful for treating diabetes," write researchers Allison B. Goldfine, MD, of the Joslin Diabetes Center in Boston, and colleagues. "We are conducting a larger trial involving more patients with type 2 diabetes to further establish whether a salsalate dosage of 3.5g/day provides durable and safe control of blood glucose in this population."