Prediabetic increase in hemoglobin A1c compared with impaired fasting glucose in patients receiving antipsychotic drugs European Neuropsychopharmacology, 06/12/2012

Manu P et al. – The hemoglobin A1c in the 5.7–6.4% range is common in euglycemic patients receiving antipsychotic drugs and this prediabetic pattern has metabolic and pharmacological features that differentiates it from impaired fasting glucose (IFG).

• Body mass index, waist circumference, fasting glucose, insulin, lipids, hemoglobin A1c, and insulin resistance assessed with the homeostatic model (HOMA–IR) were measured in a consecutive cohort of adult psychiatric inpatients with NGT (N=423), hemoglobin A1c 5.7–6.4% (N=130), IFG (N=52) and IFG plus hemoglobin A1c 5.7–6.4% (n=39).

• The hemoglobin A1c 5.7–6.4% group had lower fasting insulin levels (9.8±5.6 vs. 15.5±11.4μU/mL, p<0.0001) and HOMA–IR (2.1±1.2 vs. 4.1±3.1, p<0.0001) than the IFG group, but were metabolically similar to those with NGT.
• The hemoglobin A1c 5.7–6.4% was the predominant prediabetic pattern in patients treated with antipsychotics other than clozapine or olanzapine.
• Patients with hemoglobin A1c 5.7–6.4% and those with IFG were statistically similar in age (40.1±13.6 vs. 39.7±10.3 years), body mass index (26.0±4.8 vs. 26.3±4.9) and waist circumference 93.1±13.9 vs. 98.1±12.1cm for males and 92.5±13.5 vs. 90.7±15.8cm for females.