After weight-loss surgery, many patients experience improved mobility and less joint pain, although others continue to have significant pain and disability, according to study results presented at ObesityWeek 2015. The researchers also identified several factors that are independently related to improvements in mobility and pain.
While previous studies have shown dramatic short-term improvements after bariatric surgery, they have not examined whether these improvements lasted long-term, nor have they examined the variability in postsurgery results.
For this study, Wendy King, PhD, Associate Professor of Epidemiology at the University of Pittsburgh Graduate School of Public Health, and colleagues assessed 2221 patients from the Longitudinal Assessment of Bariatric Surgery (LABS) 2 study, an observational study of patients undergoing bariatric surgery in 10 hospitals across the country. The majority of the participants were women (79%) and white (87%), with a median age of 47 years and a median body mass index (BMI) of 46 kg/m². Roux-en-Y gastric bypass was performed in 70% of the participants, 25% underwent laparoscopic adjustable gastric band, and 5% underwent other procedures.
The researchers had the study participants complete a timed 400-meter walk at their usual pace and also assessed their pain, related medication use, physical function, and potential confounders at baseline and annually following surgery.
They found that 3 years after surgery, 57% of participants who had mobility problems before surgery no longer had them, 46% of participants who had been taking prescription narcotics for pain stopped taking them, 50% of participants had clinically important improvements in bodily pain, and 70% had clinically important improvements in physical function.
However, despite these encouraging findings, the researchers also found that at 3 years following surgery approximately 1 in 6 (16.6%) participants reported using narcotic pain medications and 44% had an objectively determined mobility deficit. Large variations were also identified in several measures of pain, disability, and physical function.
The researchers found that characteristics associated with improvements in pain and mobility included younger age, male sex, annual income above $25,000, lower BMI, and less body pain and depressive symptoms before surgery. Characteristics negatively related to improvements included history of stroke, cardiovascular disease, diabetes, and venous edema with ulceration following surgery.
“Obesity can affect the knees and hips and cause bodily pain because of all the added stress it puts on the joints. As a result, musculoskeletal problems are quite common among bariatric patients,” said John M. Morton, MD, MPH, president of the American Society for Metabolic and Bariatric Surgery (ASMBS) and Chief of Bariatric and Minimally Invasive Surgery at Stanford University School of Medicine, in a press release. He was not involved in the study.
“Bariatric surgery can help reduce or reverse [body] pain and improve function, but the longer one lives with obesity, the less improvement one may have,” he said. “In certain cases, some damage to the joints may be irreversible.”
The researchers note that these findings are important because functional status after bariatric surgery is an important topic that is not often studied, and they shed light on certain factors that may affect how well patients respond after bariatric surgery.
King WC, Chen JY, Belle SH, et al. Factors related to improvement in joint pain and physical function following bariatric surgery. Presented at: 32nd ASMBS Annual Meeting at ObesityWeek 2015; November 2-6, 2016; Los Angeles, CA. Abstract #A109.