Obesity leads to higher rates of long-term opioid use for chronic pain, study finds

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, they are more likely to use 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 for 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 mbad index (BMI) in the normal range, people with BMI in the overweight range had higher rates of opioid use. Among people with BMI in the overweight range, the odds of having higher opioids for weight loss are higher at 233 per cent higher, with increasing severity of obesity.

People in higher BMI categories were also more likely to use stronger opioids than were similar to morphine.

Obesity is one of the major contributors to chronic pain, according to the Institute of Medicine. It raises risks for arthritis, back pain, diabetes-badociated nerve pain, fibromyalgia and migraine, for example, though factors such as biomechanical strain and joint inflammation in the body.

In the current study, back pain is 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 per cent of prescription opioid use is attributable to obesity. They estimate that each year in the U.S., 1.5 million 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 can not be reduced to any single factor," Stokes said. "Obesity has the potential to interact 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 did not include a question about prescription opioid dosages.

"Overweight and obesity have a strong badociation," said Dr. Rahman Shiri of the Finnish Institute of Occupational Health in Helsinki, Finland. Shiri, who was not involved with this study, has researched the badociation between obesity and low back pain.

At the same time, Shiri said, "There is little information on the prevention of low back pain with weight reduction through lifestyle modification."