Does BMI Affect the Risk of Knee Replacements?

The key to reducing the burden of total knee replacement or surgical resonstruction for osteoarthritis is to prevent weight gain from young adulthood to late midlife, found a new research published in the Osteoarthritis and Cartilage.

The goal was to “examine the association between body mass index (BMI) trajectories from early adulthood to late midlife and risk of total knee arthroplasty (TKA) for osteoarthritis,” explained the authors.

The researchers used information about the weight and height of 24,368 participants from the Melbourne Collaborative Cohort Study. Using group-based trajectory modelling, they separated the data from early adulthood (age 18–21 years) to late midlife (approximately 62 years).

The range of BMI was divided into 6 groups: lower normal to normal BMI (19.7% of the participants), normal BMI to borderline overweight (36.7% of the participants), normal BMI to overweight (26.8% of the participants), overweight to borderline obese (3.5% of the participants), normal BMI to class 1 obesity (10.1% of the participants), overweight to class 2 obesity (3.2% of the participants).

Over an average of 12.4 years, 1,328 (5.4%) had total knee arthroplasty. The hazard ratios for total knee arthroplasty increased as the BMI trajectory went from the fist level to the sixth level.

The results revealed that “28.4% of TKA could be prevented if individuals followed the trajectory one lower, an average weight reduction of 8–12 kg from early adulthood to late midlife, saving $AUS 373 million/year.”

—Priyam Vora

Reference:
Hussain SM, Ackerman IN, Wang Y, English DR, Wluka AE, Giles GG and Cicuttini FM. Trajectories of body mass index from early adulthood to late midlife and incidence of totel knee arthroplasty for osteoarthritis: Findings from a prospective cohort study. Osteoarthritis and Cartilage. Published online: December 12, 2022. DOI: https://doi.org/10.1016/j.joca.2022.11.013