The following is a summary of the “Trajectories of body mass index from early adulthood to late midlife and incidence of total knee arthroplasty for osteoarthritis: findings from a prospective cohort study,” published in the March 2023 issue of Osteoarthritis and Cartilage by Hussain, et al.
The purpose of this study was to analyze the correlation between changing body mass index (BMI) patterns from young adulthood to midlife and the likelihood of requiring a total knee replacement due to osteoarthritis. Weight data was gathered between 1990 and 1994, 1995 and 1998, and 2003 and 2007, and height data were obtained between 1990 and 1994 for 24,368 participants in the Melbourne Collaborative Cohort Study. In addition, cohort information was linked to the National Joint Replacement Registry to count incidences of TKA from 2003 through December 2018.
From early adulthood (18-21 years) to late midlife (approximately 62 years), group-based trajectory modeling revealed 6 distinct trajectories (TR) of BMI: lower normal to normal BMI (19.7% of the population), normal BMI to borderline overweight (36.7% of the population), normal BMI to overweight (26.8% of the population), overweight to borderline obese (3.5%), normal BMI to class 1 obesity (10.1% of population), and overweight to class 2 obesity At a mean age of 12.4 years, 1,328 patients (5.8%) underwent TKA. Every TR had higher hazard ratios for TKA than TR1, starting with TR2’s 2.03 (95% CI 1.64-2.52) and going up to TR6’s 8.59 (6.44-11.46).
If people followed the lower trajectory, losing an average of 8-12 kg from early adulthood to late midlife, 28.4% of TKA surgeries might be avoided, saving $AUS 373 million annually. The greatest decreases would be seen in TR2 (attributable population fraction 37.9%, 95% CI 26.7-47.3%) and TR3 (26.8%, 20.0-31.2%). The cost and burden of TKA may be greatly reduced if efforts were made to prevent weight gain from young adulthood to late midlife to reduce overweight/obesity.
Source: sciencedirect.com/science/article/abs/pii/S1063458422009554