Metabolic obesity and the risk of knee osteoarthritis progression in elderly community residents: A 3-year longitudinal cohort study

Objective Metabolic syndrome is a major health problem worldwide associated with obesity, thus drawing attention to its relation to osteoarthritis (OA). However, it is still uncertain whether metabolic syndrome or body fat distribution is associated with knee OA. The aim of this longitudinal study was to elucidate the association between metabolic obesity and adverse structural changes of knee OA assessed by magnetic resonance imaging (MRI). Methods Participants were recruited from the Hallym Aging Study cohort in Korea. Knee MRI scans, along with dual-energy X-ray absorptiometry, were assessed in 226 participants at baseline and after 3 years. The structural progression in the tibiofemoral joint was evaluated using the semi-quantitative Whole-Organ MRI Score (WORMS) for cartilage morphology and bone marrow lesions (BML). Logistic regression with generalized estimating equation was performed for associations of metabolic risk factors with worsening of WORMS scores at the subregional level. Results In the medial compartment, fat mass in women was associated with cartilage loss, but the statistical significance disappeared after adjusting for body mass index. Metabolic syndrome and each of its components were not associated with cartilage loss or increase of BML. On the other hand, the interaction effects of metabolic syndrome on the association between obesity and knee OA progression were not significant. Conclusion In this cohort, metabolic effects of obesity on knee cartilage damage and BML were not demonstrated. Further large-scale studies are required to prove the causal relationship between metabolic obesity and knee OA.

Automated summary

This study aimed to elucidate the association between metabolic obesity and adverse structural changes of knee OA assessed by MRI. The results showed that in this cohort, the metabolic effects of obesity on knee cartilage damage and BML were not demonstrated, suggesting further large-scale studies are needed to prove the causal relationship between metabolic obesity and knee OA.