Link between neuropathic pain and obesity
Now days, obesity has been a risk factor for the musculoskeletal system disorders such as low back pain, osteoarthritis, and neck pain. Obesity is associated with other painful conditions, like as a risk factor for postoperative pain. Obese participants have been reported to have high pain-detection threshold, which remained unaffected, even after surgery-induced weight loss.
Pain can be caused by a variety of physical and/or psychological factors, which are categorized as nociceptive, neuropathic, or a combination of both. Nociceptive pain is caused by tissue damage including musculoskeletal degeneration, vascular disease, and surgical wounds, as well as from injury to organs, like as due to cancer. Thus, the relationship between obesity and pain is still controversial.
A study was conducted to determine if obesity affects neuropathic pain, usually considered unrelated to the weight-load on the musculoskeletal system. Using a cut-off body mass index value of 25, 44 patients with neuropathic pain were grouped into a “high-BMI” group and a “normal-BMI” group.
After analysis, numeric rating scale of high BMI group was significantly higher than normal-weight group. The total NPSI scores were significantly higher and the paroxysmal pain and the negative symptoms were more serious in the high-BMI group than normal-BMI group. The high-BMI subjects also had significantly higher SF-MPQ scores. However, physical and mental health status on the SF-36 were comparable between the groups.
It was concluded that the neuropathic pain that did not arise from musculoskeletal damage was higher in the high-BMI patients. Paroxysmal pain was more severe which suggested that the neural damage might be aggravated by obesity-associated inflammation. However, these findings still need the confirmation in future studies.