A Meta-Analysis of Abnormal Glucose Metabolism in First-Episode Drug-Naive Schizophrenia

Abstract

Background:Patients with schizophrenia exhibit a higher mortality rate compared with the general population. This mortality has been attributed predominantly by the high risk of type 2 diabetes mellitus in the patients. We aimed to assess the inherent risk of glucose metabolism abnormalities in first-episode drug-naïve schizophrenia.Subjects and methods: We searched English database (PubMed, EMBASE, MEDLINE, Cochrane Library databases) and Chinese database (Wan Fang Data, CBM disc, VIP, and CNKI) from their inception until Jul 2018 for case-control studies examining glucose metabolism abnormalities. Measurements, such as fasting plasma glucose levels, fasting plasma insulin levels, insulin resistance and HbA1c levels in first-episode antipsychotic-naive patients were used to test for prediabetes. Standardized/weighted mean differences and 95% confidence intervals were calculated and analyzed.Results: 19 studies (13 in English and 6 in Chinese) consisting of 1065 patients and 873 controls were included. Fasting plasma glucose levels (95% CI; 0.02 to 0.29; P=0.03), 2 h plasma glucose levels after an OGTT (95% CI; 0.63 to 1.2; P<0.00001), fasting plasma insulin levels (95% CI; 0.33 to 0.73; P<0.00001), insulin resistance (95% CI; 0.29 to 0.6; P<0.00001) in patients with firstepisode schizophrenia were significant elevated. There was no significant difference in HbA1c level (95% CI; P=0.54) in patients with first-episode schizophrenia compared with controls.Conclusions: This meta-analysis showed that glucose metabolism was impaired in patients with first-episode schizophrenia. Higher quality studies with larger samples are warranted to confirm these findings.

Diagnosis and management of hyperglycaemia in patients treated with antipsychotic drugs

“…In the second meta-analysis, Yang et al showed that patients at the time of the first episode of schizophrenia, compared to healthy patients, had both higher FG and two-hour values in OGTT, higher fasting insulin activity, and HOMA-IR. It is noteworthy that there were no significant differences in the proportion of HbA 1c [21].…”

Insulin effects on core neurotransmitter pathways involved in schizophrenia neurobiology: a meta-analysis of preclinical studies. Implications for the treatment

“…Dysregulation of insulin action has been linked to schizophrenia pathophysiology above and beyond the side effects of pharmacological treatments [1], as shown by the high prevalence of diabetes even before the introduction of antipsychotics in clinical practice [2] and in drug-naïve patients at first-episode psychosis [3]. Although divergent evidence has been reported in the literature [4][5][6][7], a recent meta-analysis showed a significant increase in fasting plasma glucose levels, plasma glucose levels 2 h after an oral glucose load, or insulin resistance in first-episode psychotic patients compared to controls, with heterogeneity across studies likely due to different lifestyles such as diet and smoking, population-specific polymorphisms, and differences in the definition of antipsychotic naïve [3].…”

Risk factors for weight gain in patients with first-episode psychosis

“…Chociaż mechanizm tego zjawiska pozostaje niewyjaśniony, badania sugerują, że osoby ze schizofrenią są podatne na odkładanie się tłuszczu trzewnego, a wynikać to może z wyższych wartości kortyzolu i insuliny u osób z FEP nawet przed włączeniem neuroleptyków, które wraz z nieprawidłową dietą mogą nasilać otyłość centralną [5,8]. Pacjenci z FEP nieleczeni jeszcze lekami przeciwpsychotycznymi mają już zaburzenia metaboliczne, które nie są powiązane z parametrami lipidowymi [9], stwierdza się u nich zaburzenie tolerancji glukozy i wzrost insulinooporności [10,11].…”