Body weight and weight gain in early and middle adulthood predict the risk of knee and hip replacement for osteoarthritis

Greater weight and BMI at age 18-21 years is associated with a 1.25-fold increased risk of total knee replacement.

• Increased weight and body mass index (BMI) during early and middle adulthood may elevate the risk of knee and hip replacements due to osteoarthritis.
• Weight gain and persistent overweight from early to middle adulthood are linked to a higher risk of total knee and hip replacement.
• The risk associated with middle age weight and BMI is stronger for knee replacement compared to hip replacement.
• For every 5 kg increase in middle age weight, the risk for knee replacement increases by 1.25 times, while the increase for hip replacement is 1.11 times.
• Adult weight gain also significantly elevates the risk for knee replacement more than for hip replacement.

Simplified