Centre for Epidemiology Versus Arthritis, Division of Musculoskeletal and Dermatological Sciences, The University of Manchester, Manchester, United Kingdom.
NIHR Manchester Biomedical Research Centre, Manchester University NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom.
Front Public Health. 2022 Dec 19;10:1053304. doi: 10.3389/fpubh.2022.1053304. eCollection 2022.
To assess the longitudinal associations of socioeconomic position (SEP) with functional limitations and knee joint replacement surgery (JRS) in people with symptomatic knee osteoarthritis (OA), and whether body mass index (BMI) mediated these relationships.
Data came from the English Longitudinal Study of Ageing, a national longitudinal panel study of adults aged ≥50 years. A total of 1,499 participants (62.3% female; mean age 66.5 (standard deviation (SD) 9.4) years; 47.4% obese) self-reporting an OA diagnosis and knee pain, with at least one BMI measurement were included. Mixed effect models estimated longitudinal associations of each SEP variable (education, occupation, income, wealth and deprivation index) and obesity (BMI ≥30.0 kg/m) with repeated measures of functional limitations. Cox regression analyses estimated associations between SEP indicators and obesity at baseline and risk of knee JRS at follow-up. Structural equation modeling estimated any mediating effects of BMI on these relationships.
Lower SEP and obesity at baseline were associated with increased odds of functional limitations in people with knee OA [e.g., difficulty walking 100 yards: no qualification vs. degree adjOR 4.33 (95% CI 2.20, 8.55) and obesity vs. no obesity adjOR 3.06 (95% CI 2.14, 4.37); similar associations were found for the other SEP indicators]. A small proportion of the association between lower SEP and functional limitations could be explained by BMI (6.2-12.5%). Those with lower income, lower wealth and higher deprivation were less likely to have knee JRS [e.g., adjHR most vs. least deprived 0.37 (95% CI 0.19, 0.73)]; however, no clear association was found for education and occupation. Obesity was associated with increased hazards of having knee JRS [adjHR 1.87 (95% CI 1.32, 2.66)]. As the direction of the associations for SEP and obesity with knee JRS were in opposite directions, no mediation analyses were performed.
Lower SEP was associated with increased odds of functional limitations but lower hazards of knee JRS among people with knee OA, potentially indicating underutilization of JRS in those with lower SEP. Obesity partially mediated the relationship between lower SEP and increased odds of functional limitations, suggesting adiposity as a potential interventional target.
评估社会经济地位（SEP）与有症状性膝骨关节炎（OA）患者功能障碍和膝关节置换手术（JRS）的纵向关联，并探讨体重指数（BMI）是否介导了这些关联。
数据来自英国老龄化纵向研究，这是一项针对≥50 岁成年人的全国性纵向面板研究。共纳入 1499 名参与者（62.3%为女性；平均年龄 66.5（标准差 9.4）岁；47.4%为肥胖），自述 OA 诊断和膝关节疼痛，且至少有一次 BMI 测量值。混合效应模型估计了每个 SEP 变量（教育、职业、收入、财富和剥夺指数）和肥胖（BMI≥30.0kg/m）与重复测量的功能障碍之间的纵向关联。Cox 回归分析估计了基线时 SEP 指标和肥胖与随访时膝关节 JRS 风险之间的关系。结构方程模型估计了 BMI 对这些关系的任何中介效应。
基线时较低的 SEP 和肥胖与膝 OA 患者功能障碍的发生风险增加相关[例如，行走 100 码困难：无资格 vs. 学位调整优势比（adjOR）4.33（95%可信区间[CI]：2.20，8.55）和肥胖 vs. 不肥胖 adjOR 3.06（95% CI：2.14，4.37）；其他 SEP 指标也存在类似的关联]。较低的 SEP 与功能障碍之间的关联可部分由 BMI 解释（6.2%-12.5%）。收入较低、财富较低和剥夺程度较高的人接受膝关节 JRS 的可能性较小[例如，最 vs. 最不贫困的调整 HR 0.37（95% CI：0.19，0.73）]；然而，教育和职业与膝关节 JRS 之间无明显关联。肥胖与膝关节 JRS 的发生风险增加相关[调整危险比（adjHR）1.87（95% CI：1.32，2.66）]。由于 SEP 和肥胖与膝关节 JRS 之间的关联方向相反，因此未进行中介分析。
在膝 OA 患者中，较低的 SEP 与功能障碍的发生风险增加相关，但与膝关节 JRS 的发生风险降低相关，这可能表明较低 SEP 患者中膝关节 JRS 的利用不足。肥胖部分介导了较低 SEP 与功能障碍发生风险增加之间的关系，提示肥胖是潜在的干预靶点。
