Schizophrenia and metabolic dysregulation: shared roots?

Clozapine induces metformin-resistant prediabetes/diabetes that is associated with poor clinical efficacy in patients with early treatment-resistant schizophrenia

BACKGROUND

Two distinct subtypes of treatment-resistant schizophrenia (TRS) have been recently reported, including early-treatment resistance (E-TR) and late-treatment resistance (L-TR). This study was to assess clozapine-induced metformin-resistant prediabetes/diabetes and its correlation with clinical efficacy in schizophrenia E-TR subtype.

METHODS

This prospective cohort study enrolled 230 patients with schizophrenia E-TR subtype and they were treated with adequate doses of clozapine for 16 weeks, during which patients with prediabetes/diabetes were assigned to receive add-on metformin. The main outcomes and measures included incidence of clozapine-induced prediabetes/diabetes and metformin-resistant prediabetes/diabetes, and the efficacy of clozapine as assessed by the Positive and Negative Syndrome Scale (PANSS) score.

RESULTS

Clozapine-induced prediabetes/diabetes occurred in 76.52% of patients (170 prediabetes and 6 diabetes), of which the blood sugar of 43 (24.43%) patients was controlled with metformin. Despite add-on metformin, 47.06% (74/170) of prediabetes patients progressed to diabetes. In total, the incidence of clozapine-induced metformin-resistant prediabetes/diabetes was 75.57% (133/176). On completion of 16-week clozapine treatment, 16.52% (38/230) patients showed clinical improvement with PANSS scores of ≥50% declining. Furthermore, clozapine-induced prediabetes/diabetes was significantly correlated with the poor clinical efficacy of clozapine for schizophrenia E-TR subtype.

CONCLUSIONS

The incidence of clozapine-induced metformin-resistant prediabetes/diabetes was considerably high in the schizophrenia E-TR subtype. Clozapine-induced metformin-resistant prediabetes/diabetes represents an independent risk factor that adversely affects the clinical efficacy of clozapine for the schizophrenia E-TR subtype. This study provided new evidence for re-evaluating the use of clozapine for TRS, especially E-TR subtype, and the use of metformin for the glycemic control of clozapine-induced prediabetes/diabetes.

Maternal diabetes in early pregnancy, and psychotic experiences and depressive symptoms in 10-year-old offspring: A population-based birth cohort study

Epidemiological studies have suggested that maternal diabetes in pregnancy increases the risk of schizophrenia in offspring. A recent cohort study observed that maternal diabetes in early pregnancy is also associated with psychotic experiences in the general adolescent population. However, it remains unclear whether maternal diabetes in early pregnancy is specifically associated with psychotic experiences, or is generally associated with broader mental health problems, including depressive symptoms in adolescence. The present study investigated the longitudinal associations between maternal diabetes in early pregnancy, and psychotic experiences and depressive symptoms in 10-year-old offspring. Our data were derived from the Tokyo Early Adolescence Survey, a population-based survey of early adolescents (N = 4478) and their primary caregivers. Diabetes in early pregnancy was determined by records in the mother's Maternal and Child Health Handbook, documented during the pregnancy. Psychotic experiences and depressive symptoms were established through self-report by the offspring at 10 years of age. Diabetes in early pregnancy was associated with an increased risk of hallucination in the offspring (auditory hallucination [odds ratio {OR} 4.33, 95% confidence interval {CI} 1.12-16.75]; visual hallucination [OR 6.58, 95% CI 1.69-25.66]), even after adjusting for depressive symptoms and other covariates. However, the association between maternal diabetes and delusional thoughts was not significant and diabetes in early pregnancy was not associated with adolescent depressive symptoms. Our investigation suggests that maternal diabetes in early pregnancy may specifically affect the risk of hallucinatory experiences in adolescent offspring.