Aging and Chronic Disease
Objectives: Quality of life is a major concern for individuals with OA and great number of individuals suffering from OA have some degree of restriction to their daily activities. The objective of this study was to investigate the relationship between body mass index (BMI), pain and functionality in middle-aged and older overweight and obese adults with mild-to-moderate knee OA. A secondary objective was to investigate the influence of sex and age on this relationship.
Methods: In this study total energy expenditure (TEE) were assessed in 83 participants with diagnosed knee OA (mean age 62.0±9.2 years and BMI 32.5±6.2 Kg/m2). WOMAC questionnaire was used to assess subjective lower extremity pain and function. Objective functionality was measured by the six-minute walk test (6-MWT) and range of motion (ROM) was measured using a computerized isokinetic dynamometer. Statistical analysis was performed using Pearson’s correlations and independent samples t-test for analyzing sex and age differences in participants with significance set at P≤0.05.
Results: Age was negatively associated with total pain scores (r=-0.378, P=0.001) and the 6-MWT was negatively associated with WOMAC scores (r=-0.413, P=0.001). BMI was negatively associated with age (r=-0.349, P=0.001) and positively associated with TEE (r=0.430, P=0.001) and WOMAC scores (r=0.268, P=0.014), while ROM was positively associated with the 6-MWT (r=0.561, P=0.001) and negatively associated with WOMAC (r=-0.338, P=0.002) and pain scores (r=-0.222, P=0.043). Women had significantly greater WOMAC scores (P=0.046) than men. Older individuals (≥65 years old) had significantly lower BMI’s (P=0.002), pain scores (P=0.008), and distance traveled for the 6-MWT (P=0.013) in comparison to middle-aged individuals (
Conclusions: Contrary to expectations, our findings indicate that older overweight and obese individuals with knee OA had lower BMI’s while having greater ROM and less pain and stiffness and on average walked slower than middle-aged individuals. Women reported greater pain, stiffness, and reduced functionality in comparison to men. These data indicate that manifestations of the disease may vary due to sex and age.