Late-Life Mobility Limitations Linked to Obesity After Arthroplasty for OA in Women

In older women who undergo total hip replacement (THR) or total knee replacement (TKR) as treatment for osteoarthritis (OA), baseline general and abdominal obesity are associated with an elevated risk for late-life mobility limitations, according to the results of a prospective study from the Women’s Health Initiative (WHI) published in Arthritis Care & Research.

The investigators sought to examine the relationship between body mass index (BMI), waist circumference (WC), and waist/hip ratio (WHR) with survival to age 85 with mobility limitation or death prior to age 85 in older women who had undergone THR and TKR for OA.

The participants were all age 65 to 79 at baseline, recruited from the WHI from 1993 to 1998, and followed through 2012. WHI data linked to Medicare data were used to determine the number of TKRs and TKRs for OA (n=1867 and n=944, respectively). All women were followed for up to 18 years after their surgery to establish their mobility status at age 85.

When they were compared with normal-weight women, overweight (25 to 29.9 kg/m²), obese I (30 to 34.9 kg/m²), and obese II (≥35.0 kg/m²) women who underwent THR had a significantly increased risk for survival to age 85 with mobility limitations (P <.001 for linear trend), with the greatest risk reported in obese II women (odds ratio [OR], 4.37; 95% CI, 1.96-9.74). Moreover, in obese II women who underwent THR an increased risk for death prior to age 85 was also reported.

Furthermore, obese II women who underwent THR and had a WC >88 cm vs ≤88 cm had an increased risk for surviving to age 85 with mobility limitations (OR, 1.65; 95% CI, 1.17-2.33) but did not have an increased risk for mortality prior to age 85.

High BMI, WC, and WHR were all associated with a significantly increased risk for late-life mobility limitations and death in women with OA who underwent TKR.

The investigators concluded that the findings of this study support the maintenance of a healthy body weight in women with OA of the hip or knee who are scheduled to undergo THR or TKR in order to reduce the burden associated with loss of mobility in later life.

Reference

Shadyab AH, Li W, Eaton CB, LaCroix AZ. General and abdominal obesity as risk factors for late-life mobility limitation after total knee or hip replacement for osteoarthritis among women [published online October 3, 2017; April 25, 2018]. Arthritis Care Res (Hoboken).  doi:10.1002/acr.23438