Hospitalized psychiatric patients with both affective and non-affective disorders were given oral glucose tolerance tests (GTT) before and after subacute treatment with lithium carbonate. Increased mean blood glucose levels were noted after lithium carbonate treatment in all diagnostic categories and reached statistical significance at the 60-minute interval of the GTT. There was no consistent correlation between clinical course and decreased glucose tolerance in any patient. Other patients were given single lithium carbonate loads; their blood glucose levels showed significant elevation 30 minutes after lithium carbonate ingestion. As with subacute administration, this increase was independent of psychiatric diagnosis. Implications are that decreased glucose tolerance accompanying lithium carbonate administration is due to a physiological effect of this ion and not related to psychiatric diagnosis or change in clinical state during treatment with this drug.
Baron Shopsin, Steven Stern, Samuel Gershon. Altered Carbohydrate Metabolism During Treatment With Lithium CarbonateAbsence of Diagnostic Specificity in Hospitalized Psychiatric Patients. Arch Gen Psychiatry. 1972;26(6):566–571. doi:10.1001/archpsyc.1972.01750240078012