Syndemic approach to chronic kidney disease, cardiovascular disease and educational level: a longitudinal cohort study in northwest Italy

Introduction: Chronic kidney disease (CKD) and end-stage renal disease (ESRD) represent significant public health challenges, linked to an elevated risk of cardiovascular disease (CVD) and influenced by socioeconomic disparities. This longitudinal study investigates the interplay between socioeconomic position (SEP), measured as educational level, CKD/ESRD and CVD using the syndemic framework.

Methods: We used data from the Piedmont Longitudinal Study to establish CKD and ESRD cohorts and to identify incident CVD between January 2013 and December 2017. The educational level was retrieved from census data. We applied an accelerated failure time model to explore the relationships between CKD/ESRD, CVD and educational level with all-cause mortality and emergency room (ER) acuity.

Results: The CKD cohort included 44 220 individuals, with 12 341 deaths and 15 440 ER admissions. The ESRD cohort included 4021 subjects, experiencing 1303 deaths and 1640 ER admissions. After adjusting for confounders, the combination of CKD, low educational level and incident CVD was associated with increased all-cause mortality (time ratios (TR) 0.07, 95% CI 0.05 to 0.08) and ER acuity (TR 0.16, 95% CI 0.14 to 0.17) compared with those with higher education. Instead, patients with ESRD with incident CVD and high educational level had the highest increase in mortality (TR 0.08, 95% CI 0.05 to 0.14) and ER acuity (TR 0.20, 95% CI 0.1 to 0.30).

Conclusions: Patients with CKD with low educational levels and incident CVD may represent a 'syndemic', associated with higher mortality and ER acuity. Our study highlights a potential link between these conditions and socioeconomic disparities, suggesting the need for multifaceted approaches.