Association between lithium treatment and vascular calcification in bipolar disorder: A retrospective cohort study

Patients with bipolar disorder (BD) have an increased risk of cardiovascular disease, though the association between lithium treatment and vascular calcification remains unclear. This study aimed to investigate lithium therapy and vascular calcification and identify the clinical factors associated with aortic calcification (AC) and coronary artery calcification (CAC).

In this retrospective cohort study, 177 patients with BD who had available baseline and approximately 10-year follow-up chest radiographs were classified according to their lithium treatment status. AC and CAC were assessed using follow-up chest X-rays. Multivariable logistic regression analyses with least absolute shrinkage and selection operator (LASSO)-based variable selection were performed. Prediction models were developed and validated using a random split-sample approach.

Lithium treatment was independently associated with lower odds of both AC (adjusted odds ratio [OR] = 0.11, 95% confidence interval [CI]: 0.03-0.32, P < 0.001) and CAC (adjusted OR = 0.19, 95% CI: 0.06-0.62, P = 0.006). Greater illness burden, reflected by higher mood episodes, was independently associated with AC. Traditional cardiovascular risk factors, including aging and diabetes, also contributed to vascular calcification. The LASSO-based prediction models showed acceptable exploratory performance in random split-sample validation.

Lithium treatment was independently associated with lower odds of AC and CAC in patients with BD. The exploratory prediction models incorporating lithium exposure and other clinical factors may provide preliminary insights into vascular calcification assessment in this population.