Diet Quality and Co-Occurrence of Arteriosclerosis and Knee Osteoarthritis: A Cross-Sectional Survey Among Chinese Iron Workers from Shougang Group

Background: Arteriosclerosis (AS) and knee osteoarthritis (KOA) pose a major public health challenge, yet evidence linking diet quality to the risk of comorbidity among Chinese occupational groups remains limited. This cross-sectional occupational study examined the association between diet quality indicators and the co-occurrence of AS and KOA among 1538 iron workers from Shougang Group. Methods: Dietary data were collected using the Diet Quality Questionnaire (DQQ) for China. Multivariable logistic regression models were performed with adjustment for relevant covariates. Results: Overall, 627 workers had co-occurrence of AS and KOA, including 579 men and 48 women. Among women, a higher continuous Global Dietary Recommendations (GDR) score was inversely associated with the odds of co-occurrence (OR = 0.75; 95% CI = 0.62–0.91). Compared with a GDR score ≤ −3, a GDR score ≥ 1 was also inversely associated with co-occurrence among women (OR = 0.13; 95% CI = 0.02–0.77); however, no statistically significant associations were observed among men or in the age- and BMI-stratified analyses. Conclusion: These findings provide preliminary evidence of an inverse association between diet quality and AS–KOA co-occurrence among female workers but should be considered exploratory, requiring confirmation in larger prospective studies.