Glycosylated hemoglobin as a screening test for hyperglycemia in antipsychotic-treated patients: a follow-up study

Abstract

Purpose

To assess the point prevalence of undetected prediabetes (preDM) and diabetes mellitus (DM) in patients treated with antipsychotics and to compare metabolic parameters between patients with normoglycemia (NG), preDM, and DM. Furthermore, conversion rates for preDM and DM were determined in a 1-year follow-up.

Patients and methods

In a naturalistic cohort of 169 patients, fasting glucose (FG) and hemoglobin A_1c (HbA_1c) criteria were applied at baseline and at follow-up after 1 year. A distinction was made between baseline patients diagnosed according to FG (B-FG) and those diagnosed according to HbA_1c (B-HbA_1c). Conversion rates in the 1-year follow-up were compared between B-FG and B-HbA_1c.

Results

At baseline, preDM and DM were present in 39% and 8%, respectively. As compared to patients with NG, metabolic syndrome was significantly more prevalent in patients with preDM (62% vs 31%). Although the majority of patients were identified by the FG criterion, HbA_1c contributed significantly, especially to the number of patients diagnosed with preDM (32%). Regarding the patients with preDM, conversion rates to NG were much higher in the B-FG group than in the B-HbA_1c group (72% vs 18%). In patients diagnosed with DM, conversion rates were found for B-FG only.

Conclusion

PreDM and DM are highly prevalent in psychiatric patients treated with antipsychotic drugs. HbA_1c was shown to be a more stable parameter in identifying psychiatric patients with (an increased risk for) DM, and it should therefore be included in future screening instruments.

Keywords:

• severe mental illness
• prediabetes
• diabetes
• fasting glucose
• HbA_1c

Acknowledgments

The authors are indebted to the patients, their caregivers, and the nursing staff for their willingness to participate in the study. All patients provided informed consent that was noticed in their medical records. Somatic screening was performed by Hans DH Kok, general practitioner at the Vincent van Gogh Institute for Psychiatry. Laboratory analyses were performed by the biochemical laboratories of the general hospital VieCuri in Venray/Venlo, the Netherlands. This study was partially supported by unrestricted grants from Astra-Zeneca, Janssen Pharmaceuticals, and Lundbeck BV.

Disclosure

The authors report no conflicts of interest in this work.