Long-term use of prescription opioids for chronic pain is more common among people who are overweight or obese, a new study finds.
As a group, these individuals are more likely to use prescription opioids for pain in the back, joints, muscles, and nerves, researchers write in the journal Pain.
Andrew Stokes of the Boston University School of Public Health and colleagues analyzed data for more than 25,000 participants in the National Health and Nutrition Examination Surveys, ages 35 to 79, to understand the relationship between obesity and prescription opioid use.
Overall, in survey results from 2013–2014 and 2015–2016, seven percent of participants reported prescription opioid use. Compared to people with a body mass index (BMI) in the normal range, people with BMI in the overweight range had 11 percent higher odds of chronic prescription opioid use. Among people with BMI in the overweight range, the odds of regular use of opioids for pain rose from being 26 percent higher to being 233 percent higher, with increasing severity of obesity.
People in higher BMI categories were also more likely to use stronger opioids that were similar to morphine.
Obesity is one of the five major contributors to chronic pain, according to the Institute of Medicine. It raises risks for arthritis, back pain, diabetes-associated nerve pain, fibromyalgia, and migraine, for example, though factors such as biomechanical strain on joints and chronic inflammation in the body.
In the current study, back pain was the most common reason reported for prescription opioid use in higher BMI categories, followed by joint pain and muscle/nerve pain.
The researchers calculate that 14 percent of prescription opioid use is attributable to obesity. They estimate that each year in the United States, 1.5 million fewer people would be chronic opioid users if obese individuals were non-obese.
At the same time, the study authors acknowledge the difficulty of addressing this problem.
“The roots of the opioid crisis are complex and cannot to be reduced to any single factor,” Stokes said. “Obesity has likely interacted with other factors, such as drug oversupply and social and economic despair, to fuel high rates of opioid prescribing in the U.S.”
A limitation of this study, he added, is that the survey included self-reported data, and it didn’t include a question about prescription opioid dosages.
“Overweight and obesity have a strong association with seeking care for low back pain and chronic low back pain,” said Dr. Rahman Shiri of the Finnish Institute of Occupational Health in Helsinki, Finland. Shiri, who wasn’t involved with this study, has researched the association between obesity and low back pain.
At the same time, Shiri told Reuters Health, “there is little information on the prevention of low back pain with weight reduction via lifestyle modification.”
By Carolyn Crist