Could the key to understanding and treating fibromyalgia involve insulin resistance?
An estimated 10 million adults in the United States live with fibromyalgia — a condition that causes pain throughout the body, sometimes to the point where it’s difficult to function.
It can be a tricky condition to diagnose and treat, but researchers from the University of Texas Medical Branch (UTMB) at Galveston found that metformin, a drug intended to combat insulin resistance in people with diabetes, was effective at reducing pain in people with fibromyalgia.
They publishedTrusted Source their findings earlier this month in the medical journal PLOS ONE.
The data is preliminary and more research is needed.
However, the research is already helping shine new light on what causes fibromyalgia, along with how it can be managed.
Diagnosis of elimination
Once treated with the insulin resistance-targeting drug, fibromyalgia patients in the study saw pain levels go down dramatically.
But getting to that point of diagnosis is a story in itself.
“The hard thing is that fibromyalgia is still based on a diagnosis of exclusion, so you have to rule out other neuropathies before you can say someone has fibromyalgia,” Dr. Edward Rubin, pain management specialist at Long Island Jewish Medical Center in New York, told Healthline.
“Is it true diabetic neuropathy, or could it come from the lower back?” he noted. “There are a lot of different issues that you would have to rule out before you call it fibromyalgia. It’s not like there’s an MRI or a lab test that definitively diagnoses it.”
To that end, the UTMB researchers needed to develop two groups to study: one with fibromyalgia and one without.
Dr. Miguel Pappolla, UTMB professor of neurology and a study author, told Healthline that, for the first time, his research team used a common blood test to identify patients with fibromyalgia.
“In the observation of my own fibromyalgia patients, there’s a very high prevalence of borderline, or slightly elevated, hemoglobin A1c,” he explained.
While a possible connection between elevated A1C levels (a marker of blood sugar in the body) and fibromyalgia had been suggested in the past, the premise had been mostly rejected because many people with fibromyalgia had A1C levels that were considered normal.
“However, those values considered currently normal may not be so, because when you adjust for age the values are not quite normal when you compare with groups of other patients at the same age group,” said Pappolla. “In clinical practice, most doctors don’t do the age adjustment.”
Once the researchers adjusted for age, it was found that the vast majority of patients with fibromyalgia studied had elevated A1C levels.
“Within all the neuropathic issues we see in diabetic patients with peripheral neuropathy and other pain syndromes we see with diabetes, it definitely makes sense that this diffuse neuropathic pain that fibromyalgia patients experience could have some underlying connection to poor sugar control,” said Rubin.
