Point prevalence of diabetes, obesity, hyperlipidaemia, hypertension and smoking in outpatients on clozapine.

Objectives: Patients with schizophrenia are known to be at higher risk than the general population of cardiovascular disease. Clozapine has been associated in the literature with high levels of cardiovascular risk factors such as weight gain, diabetes, hyperlipidaemia and hypertension. We set out to determine the prevalence of these risk factors in a population of Irish psychiatric patients.

Method: In February 2006 we measured body mass index, fasting blood glucose, haemoglobin A1c (HbA1c), lipid levels, mean blood pressure and smoking rates among all outpatients prescribed clozapine attending an urban, community based mental health service.

Results: There were 50 outpatients (33 male; 17 female) on clozapine and they had been taking it for a mean of 5.4 years (mean daily dose 428.8mg). The mean body mass index was 28.3. Patients had gained a mean of 8kg since commencing clozapine. One patient had been diagnosed with diabetes. Of the other 49 none met diagnostic criteria for diabetes. The mean fasting blood glucose was 5.5mmol/l and the mean HbA1c was 5.7%. One patient was on treatment for hyperlipidaemia. The mean fasting cholesterol among the other 49 patients was 5.4mmol/l, while the mean fasting triglycerides was 2.1 mmol/l. Thirty (61.2%) had a fasting cholesterol greater than 5.0mmol/l, while 18 (36.7%) had triglycerides of greater than 2.0mmol/l. Three patients were on treatment for hypertension. Thirty-six of the 50 (72%) smoked (mean 13 cigarettes per day).

Conclusions: The prevalence of obesity, diabetes, hyperlipidaemia and hypertension in this population was high but lower than might have been expected from US studies. It is important that cardiovascular risk factors are closely monitored and actively addressed in this at risk population.