Mental Health, Neurodegenerative, and Cardiovascular Health of Korean Kidney Transplant Recipients in Single-Person Households.

RATIONALE & OBJECTIVE: The prevalence of single-person households is increasing globally. However, the health of kidney transplant recipients (KTRs) who live alone is underexplored. This study investigated the mental health, neurodegenerative, and cardiovascular health outcomes of KTRs living in single-person households. STUDY DESIGN: Nationwide retrospective observational cohort study. SETTING & PARTICIPANTS: 9,134 KTRs who participated in a national health screening program from 2009 to 2017 and were represented in the Korean National Health Insurance Service (NHIS) data. Sub-cohorts ranging in size from 3,790 to 7,452 KTRs were constructed for each outcome. EXPOSURE: Living in single-person household. OUTCOMES: Composite mental health outcome (depression, anxiety, or insomnia), dementia, Parkinson disease, allograft failure, all-cause mortality, and cardiovascular disease (CVD). ANALYTICAL APPROACH: Multivariable Cox proportional hazards models. RESULTS: KTRs in single-person households accounted for 10.0% of the study population, and were more likely to belong to the lowest quintile (52.1% vs 18.8%) and less likely to belong to the highest quintile of income (9.5% vs 30.9%; P <0.001). Over a median follow-up of 6 years, living in a single-person household was associated with a higher risk of the composite mental health outcome (adjusted HR, 1.28; 95% confidence interval [CI], 1.02-1.60), with depression showing the strongest individual association (aHR, 1.42; 95% CI, 1.04-1.94). Single-person households were also associated with a higher risk of dementia (aHR, 1.68; 95% CI, 1.05-2.70), and Parkinson disease (aHR, 4.40; 95% CI, 1.48-13.09), as well as a higher risk of CVD (aHR, 1.40; 95% CI, 1.00-1.96), particularly myocardial infarction (MI) (aHR, 1.80; 95% CI, 1.16-2.80). All-cause mortality and allograft failure rates were comparable between the two groups. LIMITATIONS: Retrospective study design, incompleteness of the NHIS database, and potential inaccuracies in the definition of "single-person households". CONCLUSIONS: KTRs in single-person households have a higher risk of mental health disorders, dementia, Parkinson disease, and MI after kidney transplantation. These findings highlight the need to incorporate comprehensive psychosocial assessments and targeted support into post-transplant care, particularly for socially isolated KTRs.