Obesity subtypes and longitudinal trajectories of function over 7‐years of follow‐up: data from the Multicenter Osteoarthritis Study

BACKGROUND: , is a risk factor for functional limitations in people with knee osteoarthritis (OA). However, function varies among such individuals. Our objective was to evaluate the implications of obesity subtypes on longitudinal patterns of physical functioning in people with or at risk for knee OA. METHODS: and DXA-measured body composition. Three obesity subtypes were defined: 1) obesity with low muscle mass (OLM) and high fat mass; 2) obesity with cardiometabolic comorbidities (OCC) but without low muscle mass; and 3) uncomplicated obesity (UO), i.e., neither OLM nor OCC. We examined the relation of these 3 obesity subtypes to self-reported WOMAC physical function at baseline, and 7-years, using linear regression at both timepoints, and to their longitudinal functional trajectory patterns using multinomial logistic regression. RESULTS: ), 49.1% were UO, 34.4% OLM, and 16.5% OCC. Compared to UO, the OLM and OCC groups had worse physical function at baseline. Five distinct trajectories of functioning were identified over 7-years, with 23%, 38.5%, 26%, 4.5%, and 8% of the sample in groups 1-5, respectively. Compared to UO, OLM and OCC groups had higher odds of being in the persistent poorest functioning trajectory [OR 1.9, 2.6, respectively]. CONCLUSIONS: Individuals with obesity and concurrent low muscle or cardiometabolic comorbidities have persistent worse functioning over a 7-year period compared to those with obesity alone. Distinguishing obesity subtypes may enable personalized interventions to delay or avoid extended mobility disability.