Psycho-socio-economic factors and cardiorenal multimorbidity in middle to older-aged adults: cross-sectional results from the Canadian Longitudinal Study on Aging

Psycho-socio-economic factors (PSEFs) such as income, education, housing, and social support are known to influence health outcomes, yet their relationship with cardiorenal multimorbidity (CRM) remains poorly understood. This study aimed to estimate the prevalence of CRM and examine its associations with PSEFs in a large, nationally representative Canadian sample. We analyzed baseline data from 19,370 participants (mean age: 60 years; 49.8% men) in the Canadian Longitudinal Study on Aging, a prospective cohort of community-dwelling adults aged 45-85 years recruited between 2010 and 2015. CRM was defined as the co-existence of at least one cardiovascular disease and kidney disease. PSEFs assessed included household income, education, homeownership, marital status, employment status, and psychosocial variables. Survey-weighted multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for prevalent CRM. The overall prevalence of CRM was 0.83% (160 individuals), equivalent to 3.90 per 1000 individuals (95% CI 2.81-5.41). Prevalence increased with age and was higher among men than women (4.57 vs. 3.35 per 1000) and slightly higher in rural than urban areas (4.47 vs. 3.84 per 1000). Homeownership was associated with significantly lower odds of CRM (OR = 0.56; 95% CI 0.33-0.94). A household income of $50 K-99 K was associated with lower odds of CRM (OR = 0.63; 95% CI 0.39-1.00). No other PSEFs showed clear associations with prevalent CRM. CRM is relatively uncommon but shows variation by age, sex, and geography. Among the PSEFs assessed, homeownership and, to a lesser extent, moderate income were associated with reduced odds of prevalent CRM. These findings highlight the potential role of housing and economic stability in mitigating CRM risk. Longitudinal studies are needed to assess the impact of PSEFs on the development and progression of CRM over time.