Obesity, Previous Injury, Occupational Physical Activity Are Key Drivers of Knee Osteoarthritis

New research has emphasized the need for new strategies to address known risk factors for developing knee osteoarthritis (KOA), including obesity, knee injuries and occupational physical activity.1

“Knee osteoarthritis is a debilitating condition that affects over 500 million people around the world and is a leading cause of disability. Our research found that while factors such as eating ultra-processed foods and being overweight increase the risk, addressing lifestyle factors – such as losing weight or adopting a better diet – could significantly improve people’s health,” investigator Christina Abdel Shaheed, BPharm, PhD, Associate Professor, Sydney Musculoskeletal Health, Kolling Institute, Faculty of Medicine and Health, University of Sydney, Australia, said in an statement.2

Shaheed and colleagues conducted a systematic review and meta- analysis of longitudinal cohort studies or randomized controlled trials evaluating participants who developed incident symptomatic and/or radiographic KOA. Two independent reviewers screened and extracted data. Investigators pooled estimates using a random effects model, used Grading of Recommendations, Assessment, Development and Evaluation to determine the certainty of evidence, and calculated [population attributable fractions, including risk factors significantly associated with radiographic KOA.

“Women were twice as likely to develop the condition than men, and older age was only mildly associated with increased risk,” investigator David Hunter, MBBS, MSc, PhD, professor of medicine, Kolling Institute and University of Sydney, said.2

The analysis included 131 studies evaluating over 150 risk factors in participants ranging from 20 to 80 years of age. The investigators found that previous knee injury (odds ratio [OR], 2.67 [95% CI, 1.41-5.05]), older age (OR, 1.15 [95% CI, 1.00-1.33]) and high bone mineral density (OR, 1.82 [95% CI, 1.12-2.94]) were associated with an increased risk of incident radiographic KOA based on the pooled analysis, with moderate-to-high certainty. Notably, being overweight or having obesity (aOR 1.19 [95% CI, 1.12-1.27]) and previous knee injury accounted for 14% of incident radiographic KOA. The odds ratio of developing KOA after previous knee injury ranged from 1.57 (95% CI, 1.13, 2.19) to 2.08 (95% CI, 1.3, 3.31).1

Several pooled study analyses also identified additional modifiable risk factors, including occupational physical activity, which contributed to radiographic or symptomatic KOA. Non-modifiable risk factors included female sex, which was found to be associated with almost double the odds of developing incident radiographic KOA compared to males (aOR, 1.93 [95% CI, 1.25-2.98]) in pooled results from 7 studies. Factors based on moderate certainty evidence positively associated with KOA included parity (5–12 births), poor sleep quality, high intake of ultra-processed foods and depressive symptoms were associated while a mediterranean diet, high dietary fiber and consumption of cereal, dark bread and green tea were inversely associated with KOA.1

“Eliminating obesity and knee injuries combined could potentially reduce the risk of developing knee osteoarthritis by 14 percent across the population,” lead investigator Vicky Duong, BSc, DPT, PhD, postdoctoral researcher at the Kolling Institute,” added.2 “We urge governments and the healthcare sector to take this seriously and to implement policy reforms that address occupational risks, subsidize knee injury prevention programs, and promote healthy eating and physical activity to reduce obesity.”

REFERENCES

1. Duong V, Shaheed CA, Ferreira ML, et al. Risk factors for the development of knee osteoarthritis across the lifespan: A systematic review and meta-analysis. Osteoarthritis Cartilage. Published online March 31, 2025. doi.org/10.1016/j.joca.2025.03.003

2. Obesity a leading cause of knee osteoarthritis. News release. University of Sydney. May 7, 2025.https://www.eurekalert.org/news-releases/1082950