The relationship of radiographic severity with BMI, pain, and physical function in elderly women with knee osteoarthritis: A cross-sectional study

Abstract

Objective: The aim of this study was to investigate the relationship between radiographic severity and BMI, pain, and physical function in elderly women with knee osteoarthritis (OA). Methods: A total of 80 elderly women with knee OA were enrolled in this study. Their age, course of disease and body mass index (BMI) were recorded. Radiographic severity was assessed with the Kellgren-Lawrence (K/L) scale, and pain, stiffness, and physical function were assessed with Western Ontario and McMaster University Osteoarthritis Index (WOMAC) scales, objective assessment of patients' functional performance using the Time Up and Go (TUG) test. Spearman correlation analysis was used to assess the relationship between radiographic K/L scores and BMI, pain, and physical function. Logistic regression analysis was used to determine the important factors contributing to knee OA severity. Result：The mean age of the patients was 64.7 ± 6.77 years, and the mean course of disease was 5.02±2.12 years. There was no significant correlation between radiographic severity K/L and normal BMI (p=0.087), but there was a moderate correlation between radiographic severity K/L and high BMI (p=0.02, r=0.457). It was positively correlated with WOMAC pain, stiffness and physical function (p=0.001, r=0.447; p=0.004, r=0.316; p=0.025, r=0.250). In addition, K/L grading was positively correlated with TUG (p= 0.001, r=0.395). On the other hand, BMI, pain, and stiffness may be the important influencing factors of the severity of knee OA, while age, course of disease, and physical function have little influence on the severity of knee OA. Conclusion: The radiographic severity of knee OA was correlated with high BMI, pain, and physical function, and high BMI, knee pain and stiffness were important factors for the severity of knee OA.