Advanced glycation end products and cognitive impairment in schizophrenia

The aim of the study was to identify the cognitive function that is specifically affected by AGEs in patients with schizophrenia.

Fifty-eight patients with schizophrenia (mean age: 46.8 ± 11.4 years; 41 men, 17 women), including three patients with schizoaffective disorder, were recruited. Plasma pentosidine levels were measured using high-performance liquid chromatography (HPLC). Neuropsychological and cognitive functions were evaluated using the Wechsler Adult Intelligence Scale, Third Version, and the Wisconsin Card Sorting Test Keio-FS version. Psychotic symptoms were assessed using the Manchester Scale-Japanese version (MS-J), and clinical information including age, sex, body mass index, duration of illness, age of onset, duration of hospitalization, number of hospitalizations, level of education, and dose of antipsychotic medication were collected from a brief interview at the time of blood sampling or from the clinical records of each patient.

Multiple regression analysis adjusted for age, sex, body mass index, educational years, daily dose of antipsychotics, and psychotic symptoms revealed that processing speed was significantly associated with plasma pentosidine levels (standardized β = -0.425, p = 0.009, Table 1).

Considering preceding evidence that impaired processing speed is related to poor functional outcome, interventions targeted at reducing advanced glycation end products may contribute to promoting recovery of patients with schizophrenia as well as cognitive function improvement.