Monitor Lithium-Related Renal, Thyroid Dysfunction in Bipolar Disorder

Lithium remains a treatment of choice for bipolar disorder, as it is very effective in stabilizing mood and reducing suicide risk. However, its use is associated with adverse renal and thyroid effects.

A team of investigators recently reviewed lithium’s long-term effects on kidney and endocrine systems. With more than 50 years’ experience with lithium treatment, this team looked to explain the risks more clearly.

The investigators retrospectively analyzed adult patients who had at least 2 creatinine, thyrotropin, calcium, glycated hemoglobin, or lithium measurements taken between Oct 1, 1982, and March 31, 2014, and then compared them to similar control subjects with no lithium laboratory measurements on file.

They found patients who received lithium were significantly more likely to experience reduced renal function and hypothyroidism than matched controls. The risk of stage 3 chronic kidney disease (CKD) was almost double in lithium-treated patients, and the risk of hypothyroidism was more than double.

Lithium-treated patients also tended to have elevated total calcium concentrations—a marker of parathyroid function—but this association was weaker than the relationships seen for CKD and hypothyroidism.

Women aged younger than 60 years were at greater risk for developing renal and thyroid disorders, though all women had higher risk than men.

Higher than median serum lithium concentrations were associated with increased risk for all long-term complications from lithium use, but this finding was tempered by the fact that those treated the longest had reduced risk. This suggests that when adverse renal and endocrine effects occur, they appear early.

The authors encouraged clinicians to take baseline measures of renal, thyroid, and parathyroid function and monitor these laboratory values routinely and chronically in patients receiving lithium.