Does weight loss reduce the incidence of total knee and hip replacement for osteoarthritis?-A prospective cohort study among middle-aged and older adults with overweight or obesity

Int J Obes (Lond). 2021 Aug;45(8):1696-1704. doi: 10.1038/s41366-021-00832-3. Epub 2021 May 15.


Objective: This study aims to investigate the association between weight change and total knee or hip replacement (TKR or THR) for OA among middle-aged and older adults with overweight or obesity.

Method: Weight data were collected in 2006-2009 and in 2010 from the 45 and Up Study-a population-based cohort aged ≥45 years in New South Wales, Australia. Participants were included if they had a baseline body mass index (BMI) ≥ 25 kg/m2 and no history of TKR or THR. Weight change was categorised into four groups: >7.5% loss; >5-7.5% loss; stable (≤5% change) and >5% gain. Hospital admission data were linked to identify TKR and THR for OA, and multivariable Cox regression was used to assess risk of TKR and THR.

Results: Of 23,916 participants, 2139 lost >7.5% weight, 1655 lost 5-7.5% weight, and 4430 gained >5% weight. Over 5.2 years, 1009 (4.2%) underwent TKR and 483 (2.0%) THR. Compared to weight-stable, weight loss of >7.5% was associated with reduced risk of TKR after adjusting for age, sex, BMI, socioeconomic and lifestyle factors (hazard ratio 0.69, 95%CI 0.54-0.87), but had no association with THR. Weight loss of 5-7.5% was not associated with altered risk of either TKR or THR. Weight gain was associated with increased risk of THR after adjusting for confounders, but not TKR.

Conclusion: This study suggests that a weight loss target >7.5% is required to reduce the risk of TKR in adults with overweight or obesity. Weight gain should be avoided as it increases the risk of THR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Hip / statistics & numerical data*
  • Arthroplasty, Replacement, Knee / statistics & numerical data*
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • New South Wales
  • Obesity / complications*
  • Osteoarthritis* / complications
  • Osteoarthritis* / epidemiology
  • Osteoarthritis* / surgery
  • Overweight / complications
  • Prospective Studies
  • Risk Factors
  • Weight Loss / physiology*