Kidney Function Biomarkers and Longitudinal Changes in Schizophrenia: Evidence From a 14-Year Health Checkup Cohort...

Patients with schizophrenia exhibit decreased kidney function biomarkers in cross-sectional studies, despite their elevated risk of chronic kidney disease. Evidence from large-scale longitudinal studies to better understand this phenomenon remains limited. We aimed to explore the long-term trajectories of kidney biomarkers in patients with schizophrenia.

On the basis of the West China Hospital Alliance Longitudinal Epidemiology wellness (WHALE) study, an ongoing prospective cohort comprising approximately 680,000 participants, 510 schizophrenia patients, and 1490 non-schizophrenia controls were included. Biomarkers, including metabolic waste products, original estimate glomerular filtration rates (eGFRs), and derived eGFRs, were extracted from the electronic health records. Latent class mixed model identified distinct trajectories, and logistic regression assessed the associations between schizophrenia and the identified trajectories.

Distinct kidney biomarkers trajectories were identified. Schizophrenia was associated with increased odds of the stable-to-decline trajectory in the 2012 cystatin C-based equation (eGFRcys12) (odds ratio [OR] = 4.608, P_FDR < 0.001), the decreasing trajectory (OR = 4.300, P_FDR < 0.001) in the combined creatinine-cystatin C equation (eGFRcc), the low stable-to-decline pattern for the mean of the eGFRcys12 and the 2021 creatinine-based equation (mean eGFR) (OR = 2.563, P_FDR = 0.018), and the stable-to-decline pattern for the difference of the eGFRcys12 and the 2021 creatinine-based equation (eGFRdiff) (OR = 11.424, P_FDR < 0.001).

Schizophrenia patients tend to exhibit higher levels of eGFRcys12 and lower levels of mean eGFR and eGFRcc. Heterogeneity in the temporal sensitivity of kidney biomarkers suggests the need for tailored approaches to kidney disease monitoring in this population.