Prevalence and correlates of renal disease in older lithium users: a population-based study

Objective — Lithium is an important treatment for mood disorders, but concern about its association with renal disease has contributed to its limited use, particularly in older adults. Because high-quality evidence examining renal disease in this population is lacking, this study aims to quantify the prevalence and identify clinical correlates of renal disease in geriatric lithium users.

Methods — In a population-based cross-sectional study on 2,480 lithium users aged 70 or more years, the authors searched the provincial administrative health data from Ontario, Canada between April 1, 2005 and March 31, 2011. Prevalence of chronic kidney disease (CKD), acute kidney injury (AKI), and nephrogenic diabetes insipidus (NDI) was measured using International Classification of Diseases, Tenth Revision codes. Logistic regression analyses were used to identify independent correlates of renal disease.

Results — The 6-year prevalence rates of CKD, AKI, and NDI were 13.9%, 1.3%, and 3.0%, respectively. Hypertension (odds ratio [OR]: 2.05; 95% confidence interval [CI]: 1.50-2.79), diabetes mellitus (OR: 1.86; 95% CI: 1.45-2.38), ischemic heart disease (OR: 1.65; 95% CI: 1.24-2.20), NDI (OR: 2.54; 95% CI: 1.47-4.40), AKI (OR: 11.7; 95% CI: 5.26-26.1), lithium use for more than 2 years (OR: 1.71; 95% CI: 1.05-2.81), loop diuretic use (OR: 1.74; 95% CI: 1.26-2.41), hydrochlorothiazide use (OR: 1.48; 95% CI: 1.07-2.05), and atypical antipsychotic use (OR: 1.49; 95% CI: 1.17-1.89) were all independently associated with CKD.

Conclusion — Older lithium users have high rates of CKD. Lithium use duration was independently associated with CKD. Longitudinal studies including individuals without lithium exposure will be necessary to confirm whether lithium is indeed a risk factor for CKD in older adults.