New study reveals the most common form of arthritis, osteoarthritis, affects 15% of the global population over the age of 30

A new study projects nearly 1 billion people will be living with osteoarthritis, the most common form of arthritis, by 2050. Currently, 15% of individuals aged 30 and older experience osteoarthritis. The research, published today in The Lancet Rheumatology, analyzes 30 years of osteoarthritis data (1990–2020) covering more than 200 countries and was led by the Institute for Health Metrics and Evaluation (IHME) as part of the Global Burden of Disease Study 2021.

The study found that cases increased rapidly over the past three decades because of three main factors: aging, population growth, and obesity. In 1990, 256 million people had osteoarthritis. By 2020, this number rose to 595 million people, which was a 132% increase from 1990. By 2050, this number is projected to approach the 1 billion mark.

“With the key drivers of people living longer and a growing world population, we need to anticipate stress on health systems in most countries,” explains Dr. Jaimie Steinmetz, the paper’s corresponding author and lead research scientist at IHME. “There is no effective cure for osteoarthritis right now, so it’s critical that we focus on strategies of prevention, early intervention, and making expensive, effective treatments like joint replacements more affordable in low- and middle-income countries.”

2050 projections of joint pain

The most common areas for osteoarthritis are knees and hips. By 2050, osteoarthritis is projected to increase by the following percentages based on problem areas of the human body.

• Knee +74.9%
• Hand +48.6%
• Hip +78.6%
• Other (e.g., elbow, shoulder) +95.1%

More women than men are expected to continue grappling with this condition. In 2020, 61% of osteoarthritis cases were in women versus 39% in men. There is a combination of possible reasons behind this gender difference.

“The reasons for gender differences in osteoarthritis prevalence are being investigated, but researchers believe that genetics, hormonal factors, and anatomical differences play a role,” explains Dr. Jacek Kopek, senior author and professor in the School of Population and Public Health at the University of British Columbia.

Obesity

This study shows that obesity or high body mass index (BMI) is an important risk factor for osteoarthritis. If obesity can effectively be addressed in the global population, the osteoarthritis burden would decrease by an estimated 20%. The research also shows that obesity has played a greater role over time as rates of obesity have increased.

In the first year of the study in 1990, obesity was responsible for 16% of the disability due to osteoarthritis, which rose to 20% in the year 2020.

“Health care systems and governments have an opportunity to engage and participate in identifying vulnerable populations, addressing drivers of obesity, and developing management strategies to prevent or slow down the progression of osteoarthritis,” says Dr. Liane Ong, lead research scientist at IHME, who supervised and co-authored the study. “The role that physical inactivity plays in obesity and pain associated with osteoarthritis can have opposite and unintended negative cycles. For example, being physically active can prevent injuries earlier in life and can even be beneficial for someone with joint pain. It’s counterintuitive, but having joint pain doesn’t mean we should remain sedentary.”

The study was funded by the Bill & Melinda Gates Foundation, Institute for Bone and Joint Research (IBJR), Global Alliance for Musculoskeletal Health (GMUSC), and the Commonwealth of Australia. The study team included researchers from the Institute for Health Metrics and Evaluation (IHME) in Seattle, Washington and GBD 2021 collaborators from around the world.

https://www.thelancet.com/journals/lanrhe/article/PIIS2665-9913(23)00163-7/fulltext