Association of weight-adjusted waist index with all-cause and cardiovascular mortality in individuals with osteoarthritis

BACKGROUND: The Weight-Adjusted waist index (WWI) is a novel obesity assessment parameter that has been shown to be associated with mortality in various chronic disease populations and is also linked to the onset of osteoarthritis (OA). The aim of this study is to investigate whether WWI is associated with all-cause and cardiovascular mortality in OA population. METHODS: The study analyzed a cohort of 3,554 OA patients drawn from the National Health and Nutrition Examination Survey (NHANES) conducted between 2005 and 2018. Kaplan-Meier survival curves, Cox proportional hazards regression models, and subgroup analyses were utilized to assess the association between WWI and mortality outcomes. The dose-response relationship was examined using a restricted cubic spline (RCS) model. RESULTS: Among the 3,554 OA individuals, 611 participants were determined as deceased (13%), and 26% of the deaths were due to cardiovascular causes. The fully adjusted Cox proportional hazards model revealed that elevated WWI values were significantly associated with a higher risk of all-cause mortality (HR = 1.28, 95% CI 1.07‒1.52). The association between WWI and cardiovascular mortality in OA patients was only observed in the minimally adjusted model (HR = 1.43, 95% CI 1.12‒1.81). A similar conclusion was observed when the participants were grouped according to WWI tertiles. Kaplan-Meier survival curves demonstrated elevated mortality rates among individuals with higher WWI. The dose-response analysis indicated a linear positive relationship between WWI and mortality rates. The above associations remained consistent across all subgroups. CONCLUSION: Elevated WWI levels were associated with a higher risk of all-cause mortality in OA individuals independently. CLINICAL TRIAL NUMBER: Not applicable.