Possible Association Between Tardive Dyskinesia and Altered Carbohydrate Metabolism

To the Editor.— In reviewing the medical records of 35 patients who fulfilled research criteria1for persistent terdive dyskinesia (TD) in a previously reported study,2we found that five patients (14%) had diabetes mellitus (DM). In a subsequent study of 131 bipolar patients (S.M., A.W., R.B., H.A.S., unpublished data), we found that six (18%) of the 34 patients with persistent TD had DM, and four other patients had TD and a positive family history of DM in their first-degree relatives. The prevalence of DM was in excess of the expected population prevalence of 1% to 2% in both samples. The mean ± SD ages of the patients in the persistent TD groups were 51.2 and 46.8 years, respectively, in the two samples. To explore this issue further, we recently examined the fasting blood sugar (FBS) levels of 56 patients (mean age, 40.6±13.7 years) who were admitted to a