Kidney function in patients with bipolar disorder with and without lithium treatment
Key Takeaways
Kidney function, as determined by the estimated glomerular filtration rate (eGFR), was shown to follow a steeper downward trajectory in patients with bipolar and schizoaffective disorders who are prescribed lithium than the general population.
The expected downward trajectory of kidney function due to aging in patients with bipolar and schizoaffective disorders is accelerated by lithium.
Putting It Into Practice
Despite the efficacy of lithium in the treatment of bipolar disorder I, lithium prescriptions are on the decline due to concerns of lithium nephrotoxicity. The evidence based on the extant literature suggests that approximately 1.5% of long-term lithium users will develop chronic kidney disease.
Thus, lithium prescribers must weigh the risk of treatment efficacy and/or relapse in patients with bipolar disorder.
Why this study matters
Although it is known that lithium use is associated with nephrogenic diabetes insipidus in up to 87% of patients, the association between lithium use and chronic kidney disease is less certain.
The current study showed that long-term lithium use (i.e., 10 y) accelerated the decline in eGFR attributed to aging.
Study design
This was a cross-sectional cohort study.
Medical records were reviewed from patients enrolled in the Lithium-Study into Effects and Side-effects (LiSIE) and the Monitoring of Trends and Determinants in Cardiovascular Disease (MONICA). The former cohort of patients (n=785; mean age = 49.8 y) were diagnosed with bipolar or schizoaffective disorder and prescribed lithium. The latter cohort of patients (n=1549; mean age = 51.9 y) were a representative sample of the general Swedish population.
The primary outcome was age-associated decline in the eGFR.
Results and conclusion
After adjustment for lithium use, the eGFR declined by 0.57 ml/min/1.73 m2/y in the LiSIE and MONICA cohorts.
Lithium use augmented the eGFR decline by 0.54 ml/min/1.73 m2/y; the steepest decline in eGFR occurred after 10 y of lithium use.
Lithium nephropathy was the most common cause of moderate-to-severe chronic kidney disease.
Original Source
Fransson F, Werneke U, Harju V, et al. Kidney function in patients with bipolar disorder with and without lithium treatment compared with the general population in northern Sweden: Results from the LiSIE and MONICA cohorts. The Lancet Psychiatry 2022;9:804-14.