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The following is a summary of “Risk of chronic kidney disease in individuals on lithium therapy in Iceland: a nationwide retrospective cohort study,” published in the December 2024 issue of Psychiatry by Gislason et al. 

The link between lithium use and chronic kidney disease (CKD) remains unclear. Comorbidities may influence this association. 

Researchers conducted a retrospective study to assess the risk of developing stage 3 or higher CKD in individuals undergoing lithium therapy. 

They conducted a retrospective, population-based cohort study of all adults (aged ≥18 years) in Iceland treated with lithium for a mood disorder between 2008 and 2017. Individuals with 2 or more serum creatinine measurements were identified from the Prescription Medicines Register or blood lithium measurements. The control group included outpatients with mood disorders (ICD-10 codes F30–F39) who did not receive lithium. Those with pre-existing CKD, glomerular disease, genetic or congenital kidney disease, or small kidneys were excluded. Risk of developing stage 3 or higher CKD was assessed using time-to-event regression, accounting for competing risk of death. 

The results showed that 4,310 individuals were identified, with 3,198 included in the study. The lithium group (n=2,025) had 75.1% inclusion (57.5% female, 42.5% male), and the control group (n=1,173) had 72.6% inclusion (62.8% female, 37.2% male). The mean age was 46.6 years (SD 16.4, range 18.5–98.9). In the lithium group, 211 (10.4%) developed stage 3 or higher CKD, compared with 35 (3.0%) in the control group (HR 1.90, 95% CI 1.32–2.75). The risk was higher for lithium concentrations of 0.60–0.79 mmol/L (HR 2.93, 95% CI 1.97–4.36) and 0.80–0.99 mmol/L (HR 4.31, 95% CI 2.66–6.99), but not for 0.30–0.59 mmol/L (HR 1.22, 95% CI 0.78–1.90). Age, initial eGFR, diabetes, and acute kidney injury history were significant risk factors. 

Investigators found that lithium treatment increased the risk of stage 3 or higher CKD, influenced by blood lithium levels and other factors. They recommended monitoring lithium levels and using the lowest effective dose. 

Source: thelancet.com/journals/lanpsy/article/PIIS2215-0366(24)00324-9/abstract