Meta-analysis of comorbid diabetes and family history of diabetes in non-affective psychosis

A whole-brain neuromark resting-state fMRI analysis of first-episode and early psychosis: Evidence of aberrant cortical-subcortical-cerebellar functional circuitry

Psychosis (including symptoms of delusions, hallucinations, and disorganized conduct/speech) is a main feature of schizophrenia and is frequently present in other major psychiatric illnesses. Studies in individuals with first-episode (FEP) and early psychosis (EP) have the potential to interpret aberrant connectivity associated with psychosis during a period with minimal influence from medication and other confounds. The current study uses a data-driven whole-brain approach to examine patterns of aberrant functional network connectivity (FNC) in a multi-site dataset comprising resting-state functional magnetic resonance images (rs-fMRI) from 117 individuals with FEP or EP and 130 individuals without a psychiatric disorder, as controls. Accounting for age, sex, race, head motion, and multiple imaging sites, differences in FNC were identified between psychosis and control participants in cortical (namely the inferior frontal gyrus, superior medial frontal gyrus, postcentral gyrus, supplementary motor area, posterior cingulate cortex, and superior and middle temporal gyri), subcortical (the caudate, thalamus, subthalamus, and hippocampus), and cerebellar regions. The prominent pattern of reduced cerebellar connectivity in psychosis is especially noteworthy, as most studies focus on cortical and subcortical regions, neglecting the cerebellum. The dysconnectivity reported here may indicate disruptions in cortical-subcortical-cerebellar circuitry involved in rudimentary cognitive functions which may serve as reliable correlates of psychosis.

Meta-analysis of a family history of diabetes in schizophrenia

OBJECTIVE

Type 2 diabetes (T2DM) is common in patients with schizophrenia and non-affective psychosis. These patients also have an increased prevalence of a family history of T2DM. We performed a systematic review and meta-analysis of the association between a family history of T2DM and schizophrenia.

METHOD

We searched electronic databases from inception until July 2022 for studies of a family history of T2DM or gestational diabetes in patients with schizophrenia and controls. We performed random effects meta-analysis, calculating odds ratios (ORs) and 95 % confidence intervals (CI) and meta-regression analyses.

RESULTS

Nine studies were included, comprising 2953 patients with non-affective psychosis and 4484 controls. Schizophrenia was associated with an over two-fold increased odds of a family history of T2DM or gestational diabetes (OR = 2.18, 95 % CI 1.61-2.96, p < 0.01). In meta-regression analyses, age, sex, study quality score, and year of publication were all unrelated to the association.

CONCLUSION

We found that patients with schizophrenia had a 2.2-fold increased odds of a family history of T2DM versus controls. This association may be relevant to both the pathophysiology of schizophrenia and the reported increased risk of development of diabetes with antipsychotic treatment.

Longitudinal changes in brain metabolites in healthy controls and patients with first episode psychosis: a 7-Tesla MRS study

Seven Tesla magnetic resonance spectroscopy (7T MRS) offers a precise measurement of metabolic levels in the human brain via a non-invasive approach. Studying longitudinal changes in brain metabolites could help evaluate the characteristics of disease over time. This approach may also shed light on how the age of study participants and duration of illness may influence these metabolites. This study used 7T MRS to investigate longitudinal patterns of brain metabolites in young adulthood in both healthy controls and patients. A four-year longitudinal cohort with 38 patients with first episode psychosis (onset within 2 years) and 48 healthy controls was used to examine 10 brain metabolites in 5 brain regions associated with the pathophysiology of psychosis in a comprehensive manner. Both patients and controls were found to have significant longitudinal reductions in glutamate in the anterior cingulate cortex (ACC). Only patients were found to have a significant decrease over time in γ-aminobutyric acid, N-acetyl aspartate, myo-inositol, total choline, and total creatine in the ACC. Together we highlight the ACC with dynamic changes in several metabolites in early-stage psychosis, in contrast to the other 4 brain regions that also are known to play roles in psychosis. Meanwhile, glutathione was uniquely found to have a near zero annual percentage change in both patients and controls in all 5 brain regions during a four-year follow-up in young adulthood. Given that a reduction of the glutathione in the ACC has been reported as a feature of treatment-refractory psychosis, this observation further supports the potential of glutathione as a biomarker for this subset of patients with psychosis.

Obsessive-compulsive disorder, insulin signaling and diabetes - A novel form of physical health comorbidity: The sweet compulsive brain

BACKGROUND

While a growing body of research highlights a bi-directional link between diabetes and mood disorders, little is known about the relationship between diabetes and obsessive-compulsive disorder (OCD). The aim of the present review is to investigate current evidence linking OCD, insulin-signaling and diabetes.

METHODS

A PubMed search was conducted to review all the available studies assessing diabetes, glucose metabolism and insulin-signaling in OCD patients and vice versa.

RESULTS

Some clinical and epidemiological studies show a higher prevalence of diabetes in OCD and vice versa compared to the general population. Animal and genetic studies suggest a possible role of insulin-signaling in the pathophysiology of OCD. Deep brain stimulation (DBS) studies suggest that abnormal dopaminergic transmission in the striatum may contribute to impaired insulin sensitivity in OCD. While DBS seems to increase insulin sensitivity, a possible protective role of serotonin reuptake-inhibitors on diabetic risk needs further studies.

CONCLUSION

Despite their preliminary nature, these data highlight the importance of further investigations aimed at assessing metabolic features in OCD patients and OCD symptoms in diabetes patients to understand the impact of each condition on the pathophysiology and course of the other. Understanding the role of insulin in the obsessive-compulsive brain could open new treatment pathways for OCD.

Prevalence of type 2 diabetes in psychiatric disorders: an umbrella review with meta-analysis of 245 observational studies from 32 systematic reviews

AIMS/HYPOTHESIS

Estimates of the global prevalence of type 2 diabetes vary between 6% and 9%. The prevalence of type 2 diabetes has been investigated in psychiatric populations but a critical appraisal of the existing evidence is lacking, and an overview is needed. This umbrella review summarises existing systematic reviews of observational studies investigating the prevalence of type 2 diabetes in people with a psychiatric disorder.

METHODS

We searched PubMed, EMBASE, PsycINFO and the Cochrane Database of Systematic Reviews from inception to 17 January 2021 and screened reference lists of included systematic reviews. On the basis of prespecified criteria, we included systematic reviews investigating the prevalence of type 2 diabetes in adults (aged ≥18 years) with a psychiatric disorder. Titles and abstracts of 5155 identified records and full texts of 431 selected studies were screened by two independent reviewers, based on predefined eligibility criteria and an a priori developed extraction form, following the PRISMA and MOOSE guidelines. Risk of bias was assessed with the ROBIS instrument. Data extracted from primary studies were synthesised using random-effects meta-analyses.

RESULTS

A total of 32 systematic reviews with 245 unique primary studies were identified and met inclusion criteria. Twelve had low risk of bias. They reported type 2 diabetes prevalence estimates ranging from 5% to 22% depending on the specific psychiatric disorder. We meta-analysed data for ten categories of psychiatric disorders and found the following prevalence estimates of type 2 diabetes: in people with a sleep disorder: 40%; binge eating disorder: 21%; substance use disorder: 16%; anxiety disorder: 14%; bipolar disorder: 11%; psychosis: 11%; schizophrenia: 10%; a mixed group of psychiatric disorders: 10%; depression: 9%; and in people with an intellectual disability 8%. All meta-analyses revealed high levels of heterogeneity.

CONCLUSIONS/INTERPRETATION

Type 2 diabetes is a common comorbidity in people with a psychiatric disorder. Future research should investigate whether routine screening for type 2 diabetes and subsequent prevention initiatives for these people are warranted. PROSPERO registration no. CRD42020159870.

Abnormal glucose metabolism is associated with clinical symptoms of adolescent-onset patients with first-episode drug-naive schizophrenia

Extensive studies have reported alterations in glucose metabolism in adult-onset patients with schizophrenia, but less attention has been paid to adolescent-onset patients with first-episode drug-naive (FEDN) schizophrenia. The purpose of this study was to compare glucose metabolism between adolescent-onset patients with FEDN schizophrenia and healthy controls and to investigate the relationship between glucose metabolism and clinical symptoms in patients with schizophrenia. This study compared the glycometabolism parameters between 51 adolescents-onset patients with FEDN schizophrenia and 51 age- and sex-matched healthy controls. The Chinese version of the Positive and Negative Syndrome Scale (PANSS), Hamilton Anxiety Rating Scale, and Hamilton Depression Rating Scale were used to assess patients' psychiatric, anxiety, and depressive symptoms. The results showed that compared with healthy controls, the patients had a significantly higher prevalence of impaired fasting glucose and insulin resistance, as well as higher fasting plasma glucose, fasting plasma insulin, homeostasis model assessment of insulin resistance index (HOMA-IR) and triglycerides, but lower high-density lipoprotein cholesterol levels. Moreover, HOMA-IR was negatively associated with PANSS general psychopathology, while glucose was positively correlated with depressive symptoms among patients. In sum, adolescent-onset patients with FEDN schizophrenia are more likely to have abnormal glucose metabolism and dyslipidemia than their healthy counterparts. Moreover, abnormal glucose metabolism may be closely related to the psychopathological symptoms of schizophrenia in the early stage of the disease.

Pharmacological Management of Glucose Dysregulation in Patients Treated with Second-Generation Antipsychotics

Fasting hyperglycemia, impaired glucose tolerance, prediabetes, and diabetes are frequently present in patients treated with second-generation antipsychotics (SGAPs) for schizophrenia, bipolar disorder, and other severe mental illnesses. These drugs are known to produce weight gain, which may lead to insulin resistance, glucose intolerance, and metabolic syndrome, which constitute important risk factors for the emergence of diabetes. The aim of this review was to formulate therapeutic guidelines for the management of diabetes in patients treated with SGAPs, based on the association between SGAP-induced weight gain and glucose dysregulation. A  systematic search in PubMed from inception to March 2020 for randomized controlled trials (RCTs) of diabetes or prediabetes in patients treated with SGAPs was performed. PubMed was also searched for the most recent clinical practice guidelines of interventions for co-morbid conditions associated with diabetes mellitus (DM) (arterial hypertension and dyslipidemia), lifestyle interventions and switching from high metabolic liability SGAPs to safer SGAPs. The search identified 14 RCTs in patients treated with SGAPs. Drug therapy using metformin as first-line therapy and glucagon-like peptide-1 receptor agonists (GLP-1 RAs) or perhaps sodium-glucose cotransporter-2 (SGLT2) inhibitors as add-on therapy, might be preferred in these patients as well, as they favorably influence glucose metabolism and body mass index, and provide cardio-renal benefits in general to the DM population, although for the SGLT-2 inhibitors there are no RCTs in this specific patient category so far. Metformin is also useful for treatment of prediabetes. Arterial hypertension should be treated with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and statins should be used for correction of dyslipidemia. The outcome of lifestyle-changing interventions has been disappointing. Switching from clozapine, olanzapine, or quetiapine to lower cardiometabolic-risk SGAPs, like aripiprazole, brexpiprazole, cariprazine, lurasidone, or ziprasidone, has been recommended.

Mechanisms Underlying the Comorbidity of Schizophrenia and Type 2 Diabetes Mellitus

The mortality rate of patients with schizophrenia is high, and life expectancy is shorter by 10 to 20 years. Metabolic abnormalities including type 2 diabetes mellitus (T2DM) are among the main reasons. The prevalence of T2DM in patients with schizophrenia may be epidemiologically frequent because antipsychotics induce weight gain as a side effect and the cognitive dysfunction of patients with schizophrenia relates to a disordered lifestyle, poor diet, and low socioeconomic status. Apart from these common risk factors and risk factors unique to schizophrenia, accumulating evidence suggests the existence of common susceptibility genes between schizophrenia and T2DM. Functional proteins translated from common genetic susceptibility genes are known to regulate neuronal development in the brain and insulin in the pancreas through several common cascades. In this review, we discuss common susceptibility genes, functional cascades, and the relationship between schizophrenia and T2DM. Many genetic and epidemiological studies have reliably associated the comorbidity of schizophrenia and T2DM, and it is probably safe to think that common cascades and mechanisms suspected from common genes' functions are related to the onset of both schizophrenia and T2DM. On the other hand, even when genetic analyses are performed on a relatively large number of comorbid patients, the results are sometimes inconsistent, and susceptibility genes may carry only a low or moderate risk. We anticipate future directions in this field.

Quality of diabetes care in patients with schizophrenia: a case-control study in Qatar

BACKGROUND

Patients with schizophrenia are at least twice as likely to develop diabetes mellitus compared to the general population. This is of significance in Qatar given the high prevalence of obesity and diabetes. Furthermore, the lifespan of people with schizophrenia is shortened by approximately 15 years, partly due to long-term microvascular and macrovascular complications. High quality diabetes care can significantly reduce morbidity and mortality. We assessed the level of diabetes care delivered to patients in Qatar with schizophrenia and diabetes compared to those with diabetes alone.

METHODS

We performed a retrospective chart review of patients with diabetes mellitus with (n = 73) and without (n = 73) schizophrenia. Demographic information and electronic medical records were reviewed to determine adherence to American Diabetes Association standards of diabetes care in the last 6 and 12 months. Optimal diabetes care was defined as having completed glycated hemoglobin (HbA1c), lipid profile and retinal examination within 12 months.

RESULTS

Optimal diabetes care was significantly lower in patients with schizophrenia and diabetes compared to diabetes alone [26.0% (n = 19/73) vs 52.1% (n = 38/73), p = 0.002]. Patients with diabetes and schizophrenia were also significantly less likely to have had body mass index recorded within 6 months (p = 0.008) and HbA1c (p = 0.006), lipid profile (p = 0.015), estimated glomerular filtration rate (eGFR) (p = 0.001) and order for retinal examination (p = 0.004) over 12 months. After adjusting for multiple comparisons, only assessment of eGFR (p = 0.01) and order for retinal examination (p = 0.04) remained significant.

CONCLUSION

Patients in Qatar with schizophrenia and diabetes, receive sub-optimal diabetes care compared to those with diabetes alone.

Glucose homeostasis in unaffected first-degree relatives of schizophrenia patients: A systematic review and meta-analysis

It has been proposed that type 2 diabetes and schizophrenia-spectrum disorders share overlapping genetic backgrounds. Therefore, we aimed to perform a systematic review and meta-analysis of studies comparing fasting levels of glucose and insulin, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), glucose levels during the oral glucose tolerance test (OGTT) and the levels of glycated hemoglobin (HbA1c) in unaffected first-degree relatives of patients with schizophrenia and controls. Online searches covered the publication period from database inception until May 8th 2020. Meta-analyses were performed using random-effects models with Hedges' g as the effect size estimate. Out of 2556 records identified, 12 studies representing 672 relatives of schizophrenia patients and 6446 controls were found to be eligible. There were no significant differences in fasting levels of glucose (g = 0.54, 95%CI = -0.26 to 1.35, p = 0.188) and insulin (g = 0.07, 95%CI = -0.14 to 0.29, p = 0.491), HOMA-IR (g = 0.12, 95%CI = -0.19 to 0.43, p = 0.433), and the levels of HbA1c (g = 0.38, 95%CI = -0.02 to 0.77, p = 0.061) between relatives of schizophrenia patients and controls. Two studies demonstrated significantly higher 2-hour glucose levels during OGTT in relatives of patients with schizophrenia (g = 0.90, 95%CI = 0.49 to 1.31, p < 0.001). Our findings do not support the hypothesis that familial liability to psychosis is related to altered fasting parameters of glucose homeostasis. However, this population might show impaired glucose tolerance. More studies are needed to confirm these observations.

Meta-analysis of total and differential white blood cell counts in schizophrenia

OBJECTIVE

Schizophrenia is associated with alterations in blood inflammatory markers, including cytokines. Total white blood cell (WBC) count is a marker of low-grade inflammation. We conducted a meta-analysis of total and differential WBC counts in patients with schizophrenia.

METHOD

Articles were identified through a systematic search of PsycINFO, Pub Med, Web of Science, and the associated references. Data were analyzed using a random effects approach.

RESULTS

Twenty-four studies met the inclusion criteria. Blood total WBC, monocytes, and neutrophils were significantly higher in schizophrenia vs. controls with small-to-medium effect sizes (standardized mean difference [SMD] = 0.39-0.53, P < 0.01 for each). In first-episode psychosis compared with controls, neutrophils and monocytes were significantly increased with similar effect sizes (SMD = 0.40-0.41, P ≤ 0.01 for each), and there was a trend for higher total WBC (SMD = 0.46, P = 0.05).

CONCLUSIONS

Consistent with studies of other inflammatory markers, we found evidence for increased total and differential WBC counts in schizophrenia. Our results complement other studies of WBC counts in schizophrenia. These findings are relevant to the pathophysiology and potentially the treatment of schizophrenia.

Birth weight, family history of diabetes and diabetes onset in schizophrenia

INTRODUCTION

The prevalence of diabetes in schizophrenia is twice that in the general population, but there are few reliable predictors of which individuals will develop glucose dysregulation.

OBJECTIVE

To test if abnormal birth weight (either too low or too high) and parental diabetes, both variables that can be ascertained in the clinic, can predict diabetes onset in patients with schizophrenia.

RESEARCH DESIGN AND METHODS

Electronic records of a cohort of 190 clozapine-treated patients (37% treated for more than 20 years) and Cox regression survival analysis (with any type of glucose dysregulation as the event) to account for differences in length of treatment before the event and age at clozapine treatment initiation.

RESULTS

Age at clozapine initiation (Exp(B)=1.098; p<0.001), family history of diabetes (Exp(B)=2.299; p=0.049) and birth weight² (Exp(B)=0.999; p=0.013) were significant predictors of glucose dysregulation onset, while gender was not (Exp(B)=0.1.350; p=0.517). Among individuals with 10 years of follow-up, 80% of those with both abnormal birth weight and a family history of diabetes developed diabetes compared with 56% with only abnormal birth weight, 40% with only a family history of diabetes and 20% in those with neither.

CONCLUSIONS

Since 48% of cases had at least one risk factor and 6% had both risk factors, there is a substantial proportion of patients for whom preventive strategies could be implemented.