Metformin Emerging as New Treatment for Fibromyalgia As Study Links Insulin Resistance As The Cause
Fibromyalgia is one of the most common existing conditions causing chronic pain and disability. The economic impact of fibromyalgia worldwide is phenomenal -- in the U.S. alone, related health care costs linked to this condition is about $100 billion annually. Despite extensive research the cause of fibromyalgia is unknown, hence there is no specific diagnostics or therapies for this condition other than pain-reducing drugs including controversial opioids in certain cases.
However, researchers from The University of Texas Medical Branch at Galveston were recently able to demonstrate the correlation between insulin resistance and fibromyalgia. They dramatically reduced the pain of fibromyalgia patients with medications that targeted insulin resistance. Metformin was the preferred drug in the study.
“This discovery could drastically alter the way that chronic pain can be identified and managed.” Dr. Miguel Pappolla, UTMB professor of neurology in an exclusive interview with Thailand Medical News. “It may lead to a revolutionary change on how fibromyalgia and related forms of chronic pain are treated. The new approach has the potential to save billions of dollars to the health care system and decrease many peoples' dependence on opiates for pain management.”
The UTMB team of researchers, along with collaborators from across the U.S., were able for the first time, t separate patients with fibromyalgia from normal individuals using a common blood test for insulin resistance, or pre-diabetes. They then treated the fibromyalgia patients with a medication targeting insulin resistance, in this case metformin was used. This dramatically reduced their pain levels of patients in the study.
“Studies in the past indicated that insulin resistance causes dysfunction within the brain's small blood vessels. Since this issue is also present in fibromyalgia, we studied whether insulin resistance is the missing link or component in this disorder," Pappolla said. "We discovered that most patients with fibromyalgia can be identified by their A1c levels, which reflects average blood sugar levels over the past two to three months."
It was discovered in the study that pre-diabetics with slightly elevated A1c values carry a higher risk of developing central (brain) pain, a key feature of fibromyalgia and other chronic pain disorders."
The researchers identified patients who were referred to a subspecialty pain medicine clinic to be treated for widespread muscular/connective tissue pain. All patients who met the criteria for fibromyalgia were separated into smaller groups by age. When compared with age-matched controls, the A1c levels of the fibromyalgia patients were significantly higher than the rest.
"Considering extensive research on fibromyalgia in the past, we were surprised that prior studies had overlooked this simple correlation," said Pappolla. "The main reason for this oversight is that about half of fibromyalgia patients have A1c values perceived to be within the normal range. However, this is the first study to analyze these levels normalized for the person's age, as optimal A1c levels do vary throughout life. Adjustment for the patients' age was a critical factor in highlighting the differences between patients and control subjects."
For the fibromyalgia patients, metformin, a drug developed to combat insulin resistance was added to their current medications. They showed dramatic reductions in their pain levels, paving the way that metformin could also now be used for fibromyalgia treatments instead of opioids.
Reference:Miguel A. Pappolla, Laxmaiah Manchikanti, Clark R. Andersen, Nigel H. Greig, Fawad Ahmed, Xiang Fang, Michael A. Seffinger, Andrea M. Trescot. Is insulin resistance the cause of fibromyalgia? A preliminary report. PLOS ONE, 2019; 14 (5): e0216079 DOI: 10.1371/journal.pone.0216079