It's well known that weight loss can reduce pain in obese people, but that's been generally assumed to apply to pain in load-bearing joints like the knees, hips, and back. A new study from Michigan Medicine at the University of Michigan revealed a surprising new link between obesity and overall pain. The study was published in The Journal of Pain. It found that a 10 percent reduction in body weight helped patients with obesity reduce pain in places like the abdomen, arm, chest, and jaw, in addition to the expected weight-bearing areas.
The study was carried out on 123 volunteers who were participating in the University's Weight Management Program. The subjects were tracked over a 12-week period of supervised weight loss on a low-calorie liquid diet. Ninety-nine of the patients lost more than 10 percent of their body weight. They reported widespread improvements in pain compared to those who did not meet that goal. Blood samples showed a spike in an anti-inflammatory molecule called interleukin-10, which has been linked to pain and inflammation. The study also documented improvements in depression and fatigue.
Andrew Schrepf is a research investigator at Michigan Medicine's Chronic Pain and Fatigue Research Center. "Where they lost the pain was not confined just to those joints that tend to hurt when a person is really obese, like the hips and the lower back and the knees, but it was actually all over their body that they showed improvement," says Shrepf.
The findings suggest that obesity may affect pain, depression, and fatigue through a link to the central nervous system. His team is planning followup studies to learn about that mechanism.