Clozapine, Diabetes Mellitus, Cardiovascular Risk and Mortality: Results of a 21-Year Naturalistic Study in Patients with Schizophrenia and Schizoaffective Disorder

The goal of this 21-year naturalistic study of clozapine-treated patients was to examine the cardiovascular risk factors following clozapine initiation and resultant mortality estimates from cardiovascular disease. Data were collected from January 1992 to February 2012 medical records from clozapine-treated patients with schizophrenia or schizoaffective disorder. Demographics, clozapine dosage and laboratory results were extracted at 12-month intervals. At clozapine initiation, the mean age of the 96 patients was 36.4 years±7.6 years; n=27 (28%) were women. The mean duration of clozapine use was 13 years. The Kaplan-Meier estimate for 21-year cardiovascular events was 29%, while the Kaplan-Meier estimate for 21-year mortality from cardiovascular disease was 10%. The mean cardiovascular risk increased during the first ten years (p<.01), while a slight decrease occurred beyond ten years (p<.01). Patients involved in cardiometabolic research showed a greater decrease in cardiovascular risk factors over 21 years (p=.05). The Kaplan-Meier estimate for 21-year all-cause mortality was 22%. Forty-one patients were diagnosed with diabetes (42.7%), compared to a nationwide prevalence of 13.7% in a similar age group. These results support the hypothesis that clozapine-treated patients are at risk for cardiovascular events and death secondary to an increased risk of medical disorders. Interventions that target weight loss, smoking cessation, and lipid profile improvement may alleviate the increased risk of cardiovascular mortality.