LABS-2: Bariatric surgery improves pain, physical function and work productivity

Bariatric surgery results in improvements in pain, physical function and work productivity for at least seven years after surgery, according to the outcomes from the National Institutes of Health-funded Longitudinal Assessment of Bariatric Surgery-2 (LABS-2), a prospective, cohort study of US patients undergoing bariatric surgery.

The findings were featured in the paper, ‘A 7-Year Study of the Durability of Improvements in Pain, Physical Function, and Work Productivity After Roux-en-Y Gastric Bypass and Sleeve Gastrectomy’, published in JAMA Newtwork Open, show that improvements persisted even with participants aging over the course of the study. The study’s researchers from the University of Pittsburgh stated that these findings can help inform physicians, health insurance providers and patients, many of whom undergo surgery to alleviate joint pain and improve mobility.

Wendy King

"Adults with severe obesity are much more likely to experience significant joint pain and limits to their physical abilities," said Dr Wendy C King, associate professor of epidemiology in Pitt's School of Public Health. "Obesity leads to an earlier need for knee and hip replacement. However, adults with severe obesity may be denied joint surgery until they lose weight. And, if physical limitations and pain interfere with job performance, losing weight could be necessary to maintain employment."


The researchers undertook the study to evaluate the durability of improvements in pain and physical function seven years after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). The study is part of the LABS-2, a cohort study at ten US hospitals. Adults with severe obesity undergoing bariatric surgery were assessed preoperatively (2006-2009) and followed up annually for as long as sevenyears or until 2015. Of 1,829 participants who underwent RYGB or SG in LABS-2, 338 were excluded from this study because they had a follow-up period of less than five years. Analysis of participants who underwent RYGB or SG and completed research assessments preoperatively and postoperatively for five to seven years was conducted from March to April 2022.


Main outcomes were reoperative-to-postoperative CIIs in pain and physical function scores from the 36-Item Short Form Health Survey and the Western Ontario McMaster Osteoarthritis Index, and 400-meter walk time, using previously established thresholds; and remission of mobility deficit, ie, inability to walk 400 meters in seven minutes or less.


In total, 1,491 individuals were included (1,194 (80%) women; 59 (4%) Hispanic, 164 (11%) non-Hispanic Black, and 1,205 (82%) non-Hispanic White individuals) with a preoperative median (IQR) age of 47 (38-55) years and a preoperative median (IQR) body mass index of 47 (42-52). Between three and seven years after surgery, the percentage of participants with preoperative-to-postoperative CIIs in bodily pain decreased from 50% to 43%, in physical function from 75% to 64% (and in 400-meter walk time from 61% to 50%.

Among participants with a preoperative mobility deficit, remission decreased from 50% to 41% and among participants with severe knee or hip pain or disability (symptoms indicative of osteoarthrosis), the percentage with CIIs in knee and hip pain and function for hip pain decreased from 77% to 65%, and knee function from 77% to 72%.


The new findings build on a previous study by King and her colleagues finding that, in the three years following bariatric surgery, 50% to 70% of study participants reported clinically important improvements in pain levels, physical function and usual walking speed.


"At the time, that research provided the largest and longest-running evaluation of changes in pain and physical function after modern-day bariatric procedures," she explained. "Our new study more than doubles that timespan, giving patients and doctors a better understanding of the likelihood that bariatric surgery will yield lasting results."


The small to moderate declines in pain and physical function improvements are not surprising, considering the participants also aged over the course of the study to a median of 54 years, King said. Previous research shows that some aspects of physical function, such as balance and strength, start to decline when people enter their 50s, and others, such as walking speed and aerobic endurance, typically decline in the sixth decade of life.


"On average, participants experienced durable improvements in walking speed, fitness and almost all metrics of pain.”


In addition, participants reported that pain and health status interfered less with their ability to work post-surgery, with 43% of participants reporting impaired work due to health seven years post-surgery, down from 63% pre-surgery.


"Combined, our study provides great news about the lasting effects of bariatric surgery. But clinicians should look at patients as individuals and consider their complete health history, goals and motivations for weight loss when providing presurgical counselling on potential results."


To access this paper, please click here