Aspirin-like drug may help diabetics control blood sugar

Over the years, I’ve written and edited many articles for medical journals. I have to say I’m now finding it a bit odd to be on the flip side as the subject of such an article (along with 285 other people). A couple years ago, I volunteered to take part in a clinical trial testing whether an old, aspirin-like drug called salsalate could help control blood sugar in people with type 2 diabetes. The results of that trial, called TINSAL-T2D, are reported in the current issue of Annals of Internal Medicine.

All 286 volunteers were given blue pills to take every day for nearly a year. Half of us got pills containing salsalate; the others got placebo pills. Over the course of the trial, those in the salsalate group had lower blood sugar levels, and some were even able to reduce dosages of other diabetes medications they were taking.

“We were very pleased with the findings of the TINSAL-T2D study,” said lead author Dr. Allison B. Goldfine, associate professor of medicine at Harvard-affiliated Joslin Diabetes Center. “They indicate that salsalate, a drug that has been marketed for over 40 years for the treatment of arthritis, could be an inexpensive additional therapeutic option to treat patients with diabetes.”

Inflammation and diabetes

Salsalate is an old drug that’s closely related to aspirin. Use of these drugs and their natural precursor use can be traced back at least 3,500 years. Today, salsalate is used to treat arthritis pain. One advantage it has over aspirin and other nonsteroidal anti-inflammatory drugs is that it doesn’t irritate the digestive tract.

No one knows exactly how salsalate helps control blood sugar. But its effectiveness supports the idea that inflammation plays a role in type 2 diabetes. In addition to improving blood sugar control, salsalate lowered counts of white blood cells involved in inflammation. It also boosted levels of adiponectin, a potentially heart-protecting protein made by fat cells.

Not ready for prime time

The TINSAL-T2D results are promising. Salsalate helps lower blood sugar. It has a good safety profile. It has been used for years for other purposes. And it is relatively inexpensive. But it won’t be prescribed any time soon for people with type 2 diabetes.

Three safety blips appeared during the trial. 1) Those taking salsalate gained an average of two pounds during the trial while those taking the placebo lost about a pound. Over time, extra weight can lead to poorer blood sugar control. 2) Harmful LDL cholesterol rose about 10 points in the salsalate group, compared to no change in the placebo group. 3) The amount of a protein called albumin excreted in the urine was higher in the salsalate group. That could be a sign of potentially worrisome changes in the kidneys.

What we really need to know about a new or repurposed drug is how its long-term benefits and risks stack up against each other. The relatively short length of the TINSAL-T2D trial and the relatively small number of volunteers don’t provide enough information on that. According to the researchers, more work is needed before salsalate can be recommended for widespread use by people with type 2 diabetes.

Some of that work is already underway. The TINSAL-CVD study is testing salsalate’s effects on cholesterol-filled plaque in the arteries that nourish the heart. (Heart disease is the leading cause of death among people with type 2 diabetes.) If that study shows that salsalate slows the growth or spread of plaque, “a larger and longer outcome study would be needed before the FDA would provide a new indication for the use of salsalate beyond its current indication for pain management in patients with arthritis,” said Dr. Goldfine.

A personal note

I never found out whether I was taking salsalate or a placebo. It never really mattered. But I got a lot out of taking part in TINSAL-T2D. I received excellent diabetes care from an engaged diabetes specialist (Dr. Goldfine) and trial coordinator (Kathy Foster). I experienced first-hand some tests I’ve often written about. I learned that I had a late-onset type 1 diabetes called latent autoimmune diabetes of the adult, rather than type 2 diabetes. And it felt good to take part in medical research, not just write about it.

Thousands of clinical trials are in need of volunteers. If you are interested in participating in one, take a look at ClinicalTrials.gov, put together by the National Institutes of Health. It lists the nearly 70,000 clinical trials now underway in the United States.