Doctors discover three distinct patient clusters, a finding that could help tailor treatment for the chronic disorder.
By Kathleen Doheny
Fibromyalgia patients, who suffer pain in the muscles, joints, ligaments and tendons, are not all the same and can be classified into three distinct subgroups, a recent study suggests.
Researchers from the University of Michigan and other institutions are hopeful the discovery, published in October’s  issue of Arthritis & Rheumatism, will help to better tailor treatment for the chronic disorder.
“Fibromyalgia patients are such a diverse group of patients, they cannot all be the same,” says study co-author Dr. Thorsten Giesecke, a University of Michigan research fellow.
For reasons unknown, people with fibromyalgia have increased sensitivity to pain that occurs in areas called their “tender points.” Common ones are the front of the knees, the elbows, the hip joints, the neck and spine. People may also experience sleep disturbances, morning stiffness, irritable bowel syndrome, anxiety and other symptoms.
Fibromyalgia affects an estimated 3 million to 6 million Americans, primarily women of childbearing age, according to the American College of Rheumatology.
Giesecke and his fellow researchers evaluated 97 fibromyalgia patients, including 85 women and 12 men. The patients underwent a two-day series of tests, answering questions about their coping strategies and personality traits — particularly their emotional well-being. They were also tested for sensitivity to pressure and pain.
After the evaluations, the researchers found the patients fell into three subgroups that refute conventional wisdom. “It’s generally been thought that fibromyalgia patients who have higher distress have higher pain sensitivities,” Giesecke says.
In other words, it was believed that those with fibromyalgia who were prone to emotional difficulties such as depression and anxiety were more likely to experience greater physical pain. But in his study, that didn’t bear out.
The first subgroup, with 50 patients, included those who had moderate levels of anxiety and depression. They also felt they had moderate control over their pain, and they experienced moderate to low levels of pain.
The second group, with 31 patients, had high levels of anxiety and depression. They felt they had the least control over their pain, and they suffered high levels of tenderness.
But the third group, with 16 patients, reported the lowest levels of anxiety and depression and the highest control over their pain. Yet the testing showed they experienced the highest levels of physical pain.
Some patients have extreme pain but no psychological problems, Giesecke says, while others have moderate pain tenderness but fairly positive moods. Giesecke says a more positive frame of mind may help reduce the levels of pain that sufferers experience.
“Just because they do well in cognitive and psychological tests doesn’t mean they don’t have increased pain sensitivity,” he says.
The findings, he says, may persuade some skeptics that fibromyalgia is a real disease and not “all in one’s head.” The findings may also help tailor treatments, he says.
For instance, antidepressants might not work well on group three, whose members were not depressed. They might benefit from exercise therapy instead, Giesecke says. About 4 percent of the U.S. population has the condition, Giesecke says.
Bruce Naliboff, a professor of medical psychology at the UCLA David Geffen School of Medicine and on staff at the VA Greater Los Angeles Healthcare System, calls the new research “a very good study.”
“To better understand fibromyalgia and to have better treatment, it’s important to find out, is it a homogeneous group?” he says.
Clearly, Giesecke found it is not, Naliboff adds. Some patients who have extreme tenderness don’t have many emotional issues, which was not expected.
“It’s easy to say it’s all in their head,” says Naliboff, who works with patients who have other conditions with psychological components, such as inflammatory bowel disease. The study will help prove that’s not so, he adds.
Source: HealthDay News.