High prevalence of prediabetes and metabolic abnormalities in overweight or obese schizophrenia patients treated with clozapine or olanzapine.

OBJECTIVE

To assess the prevalence of prediabetes and metabolic abnormalities among overweight or obese clozapine- or olanzapine-treated schizophrenia patients, and to identify characteristics of the schizophrenia group with prediabetes.

METHODS

A cross-sectional study assessing the presence of prediabetes and metabolic abnormalities in schizophrenia clozapine- or olanzapine-treated patients with a body mass index (BMI) ≥27 kg/m2. Procedures were part of the screening process for a randomized, placebo-controlled trial evaluating liraglutide vs placebo for improving glucose tolerance. For comparison, an age-, sex-, and BMI-matched healthy control group without psychiatric illness and prediabetes was included. Prediabetes was defined as elevated fasting plasma glucose and/or impaired glucose tolerance and/or elevated glycated hemoglobin A1c.

RESULTS

Among 145 schizophrenia patients (age = 42.1 years; males = 59.3%) on clozapine or olanzapine (clozapine/olanzapine/both: 73.8%/24.1%/2.1%), prediabetes was present in 69.7% (101 out of 145). While schizophrenia patients with and without prediabetes did not differ regarding demographic, illness, or antipsychotic treatment variables, metabolic abnormalities (waist circumference: 116.7±13.7 vs 110.1±13.6 cm, P = 0.007; triglycerides: 2.3±1.4 vs 1.6±0.9 mmol/L, P = 0.0004) and metabolic syndrome (76.2% vs 40.9%, P<0.0001) were significantly more pronounced in schizophrenia patients with vs without prediabetes. The age-, sex-, and BMI-matched healthy controls had significantly better glucose tolerance compared to both groups of patients with schizophrenia. The healthy controls also had higher levels of high-density lipoprotein compared to patients with schizophrenia and prediabetes.

CONCLUSION

Prediabetes and metabolic abnormalities were highly prevalent among the clozapine- and olanzapine-treated patients with schizophrenia, putting these patients at great risk for later type 2 diabetes and cardiovascular disease. These results stress the importance of identifying and adequately treating prediabetes and metabolic abnormalities among clozapine- and olanzapine-treated patients with schizophrenia.