Treatment with antipsychotic drugs is associated with an increased risk for glucose dysregulation.Hyperglycemia that does not fulfil diagnostic criteria for diabetes mellitus (DM) is known as prediabetes (preDM). PreDM is a strong risk factor for the development of DM and cardiovascular events.

To assess the prevalence of preDM and DM in patients on antipsychotic treatment.

To compare cardiometabolic parameters between patients with normoglycemia, preDM and DM. in addition, incidence and reversal rates for preDM and DM were calculated in a one year follow-up.

In a naturalistic cohort of 383 patients the fasting glucose and hemoglobin A1c criteria were applied. in addition, cardiometabolic parameters were measured. After one year, a second assessment was performed in 169 patients out of the total sample.

In the total sample, preDM and DM were present in 39% and 6% of antipsychotic treated patients, respectively. as compared to patients with normoglycemia, cardiometabolic parameters were more prevalent in patients with preDM. Although the majority of patients were diagnosed by the fasting glucose criterion, hemoglobin A1c contributed significantly to the number of patients identified. in a one-year follow-up, it was shown that the course of glucose metabolism can be dynamic.

Systematic evaluation of glucose parameters in antipsychotic treated patients is warranted, in order to recognize glucose abnormalities at an early stage. Especially since fasting laboratory assessments are not required, including hemoglobin A1c as a diagnostic test is of additional value in identifying psychiatric patients (at risk for) DM.