Pos0384 Associations Between Metabolic Status and All-Cause Mortality Among Individuals With Osteoarthritis: A Prospective Cohort Study From the Uk Biobank and Nhanes Datasets

Background: Individuals with osteoarthritis (OA) often experience significant changes in their metabolic status and have a higher risk of mortality compared to the general population. However, no study has quantified the metabolic status of OA patients. Moreover, the association between metabolic status and risk of mortality among OA patients remains unclear. Objectives: To define the metabolic status in individuals with OA and to investigate its potential correlation with mortality among OA patients. Methods: This study included a total of 44,055 individuals with OA from the UK Biobank (UKBB) study as the training set, and a total of 3,376 participants with OA from the National Health and Nutrition Examination Survey (NHANES) 1999-2018, as the validating set. In UKBB, osteoarthritis diagnosis was primarily based on clinical assessment and patient-reported data, while in NHANES, OA classification relied predominantly on questionnaire responses. To assess metabolic status, a composite score was created based on factors including, body mass index, waist-hip ratio, blood pressure, fasting plasma glucose and hemoglobin A1c levels for blood glucose assessment, levels of C-reactive protein, triacylglycerols, and lipoproteins. The primary outcome of interest was all-cause mortality, which was collected via data linkage. Restricted cubic splines were used to determine the healthy range for each indicator in relation to all-cause mortality risk. Each metabolic factor was assigned a value of 1, if it felt within the healthy range, otherwise 0. The total metabolic score ranged from 0 to 7 points, with higher scores indicating healthier metabolic status. A score of 4 or more was considered as good metabolic health. The traditional definition of metabolic syndrome established by National Cholesterol Education Adult Treatment Panel III (ATPIII criteria) was employed as a (traditional) comparison. Associations between metabolic score, metabolic health, and all-cause mortality were examined in both UKBB and NHANES datasets, using Cox proportional hazards models. Age, sex, education level, Townsend deprivation index, smoking and drinking status, regular physical activity, and glucosamine use were adjusted in multivariable regression models. The Integrated Discrimination Improvement (IDI) were performed to assess the discriminatory capacity of different metabolic health definitions in predicting all-cause mortality over ten years, while the Net Reclassification Improvement (NRI) evaluated their reclassification performance for predicting all-cause mortality over the same timeframe. Results: Among the 44,055 participants with OA in the UKBB (mean age, 60.6 years; female, 60.4%), 76% were classified as metabolically unhealthy (mean scores: 3.86), while the remaining were categorized as metabolically healthy (mean scores: 1.26). Among the 3,376 participants in the NHANES dataset (mean age, 66.3 years; female, 63.7%), only 10.5% individuals were classified as metabolically healthy. After adjusting for the covariates, it was found that, individuals classified as metabolically unhealthy had a significantly increased risk of all-cause mortality [hazard ratios (HR), 1.49; 95%CI (1.4, 1.58) in UKBB and HR, 1.36; 95%CI (1.05, 1.77) in NHANES, respectively], compared to those who were metabolically healthy. In UKBB, compared to ATP III definition, the changes in IDI and NRI for our newly-established definition were 0.2 (0.1, 0.2) and 8.8 (0.9, 16.6), respectively. Our new definition showed a stronger association with mortality based on more prominent IDI and NRI than those of the ATP III definition. Conclusion: This study had proposed a new definition to quantify the metabolic status of individuals with OA. We found that OA individuals with poorer metabolic health had a significantly higher risk of mortality. Furthermore, our newly defined metabolic status in OA patients demonstrated superior predictive capabilities compared to the previous definition. REFERENCES: NIL. Acknowledgements: We thank all the participants and staff in the UK Biobank and NHANES. Disclosure of Interests: None declared.