Impact of Knee Osteoarthritis on Physical Performance and Quality of Life in Obese Adults: A Cross-sectional Study

Introduction: Obese subjects with Knee Osteoarthritis (KOA) demonstrate poor Physical Performance (PP) and impaired Quality Of Life (QOL). The burden of OA in obese subjects is not well understood.

Aim: To evaluate PP and QOL in obese subjects with KOA and in obese subjects without KOA.

Materials and Methods: A cross-sectional observational study was conducted at the Outpatient Physiotherapy Department, Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu, India, from July 2017 to June 2018. Twenty-four obese subjects with and without KOA were included in the current study based on their BMI and American College of Rheumatological criteria for OA knee. The subjects were randomly allocated into two groups with; Obese KOA and Obese non KOA. All subjects were evaluated for anthropometric (BMI, Waist-Hip Ratio and Fat Percentage) and PP {30 Second Chair Stand Test (SCST), Stair Climb Test (SCT), 40 m Fast-Paced Walk Test (40 m FPWT), Timed up and Go test (TUGT), 6 Minute Walk Test (6 MWT)}. Additionally, all subjects responded to self-reported disability measures (KOA Outcome Score - KOOS) and Medical Outcome Study Short Form measure (SF-36).

Results: Intergroup statistical difference was found in both PP and QOL. The PP and QOL was significantly lower in obese KOA subjects when compared with their counterparts, {mean±SD; 30 SCST (8.58±1.62 vs 17.08±3.26), SCT (36.25±13.16 vs 9.58±1.62), 40 m FPWT (64.75±14.35 vs 29.92±3.99), TUGT (17.7±2.42 vs 7.58±1.51), 6 MWT (244.25±63.03 vs 508.83±76.42), KOOS (42.52±5.73 vs 91.42±4.58), SF-36- Physical, Mental Cumulative Health Score (36.23±5.7, 45.52±9.13 ; 53.80±2.15, 53.89±2.47); (p<0.05)}.

Conclusion: The KOA is a predictor for reduction of PP and QOL among obese subjects. Early physiotherapy intervention of obese subjects may prevent KOA and helps to progress or maintain PP and QOL in obese subjects.