Relationship between insulin resistance, dyslipidaemia and positive symptom in Chinese antipsychotic-naive first-episode patients with schizophrenia

Clinical and Diagnostic Value of High-Density Lipoprotein-Based Inflammatory Indices and Lipid Ratios in Young Adults with Schizophrenia

Purpose

This study aimed to assess High-density Lipoprotein (HDL)-based Inflammatory Indices and lipid profile changes in antipsychotic-naive first-episode schizophrenia (AN-FES) patients, chronic schizophrenia (CS) patients, and explore the clinical and predictive value of these parameters for schizophrenia.

Patients and Methods

The study cohort included 52 AN-FES patients, 46 CS patients, and 52 healthy controls (HCs), with an average age of 24 years. Upon admission, patients underwent complete blood count and lipid profile analyses. Various ratios were calculated, including neutrophil-to-HDL (NHR), monocyte-to-HDL (MHR), lymphocyte-to-HDL (LHR), and platelet-to-HDL (PHR), as well as lipid ratios like triglycerides/HDL, non-HDL/HDL, total cholesterol/HDL, and low-density lipoprotein/HDL. For the AN-FES group, these evaluations were repeated after two months of treatment with atypical antipsychotics. Statistical analyses included correlation analysis, Receiver Operating Characteristic (ROC) curve analysis, and univariate and multivariate regression.

Results

Compared to HCs, CS patients exhibited significantly higher MHR and NHR values, while AN-FES patients showed elevated levels of PHR, MHR, and NHR. No significant differences were observed in LHR or lipid ratios across the three groups. In the AN-FES cohort, MHR correlated positively with neutrophil counts, and NHR with monocyte counts. Additionally, white blood cell counts were positively associated with both MHR and NHR. Following treatment, NHR levels decreased, whereas TG/HDL ratios increased, with MHR and PHR remaining elevated. ROC analysis highlighted NHR as the most diagnostically valuable parameter (AUC = 0.799), with 86.5% specificity at an optimal cutoff of 3.534, outperforming MHR and PHR. Regression analyses recognized NHR (OR=2.225) as an independent risk factor for schizophrenia, even after adjusting for confounders.

Conclusion

HDL-based inflammatory indices, particularly NHR, may serve as valuable diagnostic and prognostic markers in young adults with schizophrenia, even though significant alterations in lipid ratios were not observed in this demographic.

Gender Differences in Prevalence and Associated Factors of Dyslipidemia in Initial-Treatment and Drug-Naïve Schizophrenia Patients

Background

Dyslipidemia is frequently comorbid with schizophrenia (SCZ), and both conditions often demonstrate significant gender differences in their clinical features. This study specifically focuses on investigating the prevalence of dyslipidemia and the factors that contribute to it in initial-treatment and drug-naïve (ITDN) SCZ patients, specifically focusing on gender differences.

Methods

A total of 224 male ITDN SCZ patients and 424 female ITDN SCZ patients were included in this study. Socio-demographic and general clinical data of the patients were collected, and routine biochemical parameters, such as lipid levels, fasting blood glucose, thyroid function, renal function, and blood cell counts, were measured. Patients were also assessed for psychopathology and disease severity using the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale - Severity of Illness (CGI-SI), respectively. In addition, a lipids score was calculated for assessing the severity of dyslipidemia.

Results

The study revealed that the prevalence of dyslipidemia in male patients was 34.02% (83/224), whereas 33.25% (141/424) in females, indicating no statistically significant difference (χ2 = 0.04, p = 0.841). For males, the risk factors for dyslipidemia were high education levels and diastolic blood pressure (DBP), while red blood cell count (RBC) as a protective factor. Additionally, DBP was identified as a risk factor for dyslipidemia score. In females, systolic blood pressure (SBP) was identified as a risk factor for dyslipidemia, while being married and creatinine (CRE) levels were found to be protective factors. Moreover, SBP was revealed as a risk factor for dyslipidemia score.

Conclusion

No significant gender differences were observed in the prevalence of dyslipidemia among the ITDN SCZ patients. However, notable gender differences were identified in the factors influencing dyslipidemia and its severity within this group. These findings suggest the necessity of implementing gender-specific interventions to address the potential risk factors associated with dyslipidemia.

Association of clinical variables and thyroid-stimulating hormone with psychotic symptoms in patients with first-episode and drug-naïve major depressive disorder with elevated fasting blood glucose: preliminary exploratory study with a large sample

BACKGROUND

Psychotic symptoms and elevated fasting blood glucose (FBG) are frequently observed in people with major depressive disorder (MDD), but there is a lack of research into this relationship within this cohort.

AIMS

This study aimed to preliminarily explore the prevalence of psychotic symptoms and their predictors among patients with MDD and elevated FBG.

METHOD

This study enrolled 1718 patients with first-episode and drug-naïve (FEDN) MDD. Sociodemographic data and physical and biochemical indicators were collected. Clinical symptoms were assessed with tools such as the Hamilton Rating Scale for Anxiety, Hamilton Rating Scale for Depression (HRSD) and Positive and Negative Syndrome Scale positive subscale.

RESULTS

The odds ratio for psychotic symptoms in those with MDD and elevated FBG (18.7%) was 2.33 times higher than those with MDD without elevated FBG. Presence of psychotic symptoms was significantly correlated with HRSD score, suicide attempts, and total cholesterol and thyroid-stimulating hormone levels. The combination of HRSD score, suicide attempts and thyroid-stimulating hormone levels among patients with MDD and elevated FBG effectively distinguished between individuals with and without psychotic symptoms, achieving an area under the curve of 0.87.

CONCLUSIONS

Psychotic symptoms are frequently observed among FEDN MDD patients with elevated FBG, and depressive symptoms, suicide attempts and thyroid-stimulating hormone levels are related to psychotic symptoms in this cohort.

Prefrontal cortical dopamine deficit may cause impaired glucose metabolism in schizophrenia

The brain neurotramsmitter dopamine may play an important role in modulating systemic glucose homeostasis. In seven hundred and four drug- naïve patients with first-episode schizophrenia, we provide robust evidence of positive associations between negative symptoms of schizophrenia and high fasting blood glucose. We then show that glucose metabolism and negative symptoms are improved when intermittent theta burst stimulation (iTBS) on prefrontal cortex (PFC) is performed in patients with predominantly negative symptoms of schizophrenia. These findings led us to hypothesize that the prefrontal cortical dopamine deficit, which is known to be associated with negative symptoms, may be responsible for abnormal glucose metabolism in schizophrenia. To explore this, we optogenetically and chemogenetically inhibited the ventral tegmental area (VTA)-medial prefrontal cortex (mPFC) dopamine projection in mice and found both procedures caused glucose intolerance. Moreover, microinjection of dopamine two receptor (D2R) neuron antagonists into mPFC in mice significantly impaired glucose tolerance. Finally, a transgenic mouse model of psychosis named Disc1tr exhibited depressive-like symptoms, impaired glucose homeostasis, and compared to wild type littermates reduced D2R expression in prefrontal cortex.

New insights into the interaction between polycystic ovary syndrome and psychiatric disorders: A narrative review

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disease characterized by hyperandrogenism, ovulatory dysfunction, and ovarian polycystic changes, which combines with reproductive problems, metabolic disorders, and psychological disorders to exhibit a far-reaching impact on the physical and mental health of women. We reviewed previous research and discovered that psychiatric disorders are more common in PCOS patients and their children, potentially exacerbating the condition and creating a vicious loop. To understand the reasons, relevant articles were collected following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines from PubMed, Web of Science, and Cochrane Library, through December 2022. Evidence suggested that PCOS-related clinical manifestations, hyperandrogenism, insulin resistance, obesity, gut dysbiosis, and other variables may increase the risk of psychiatric disorders in patients. In turn, psychiatric disorders may aggravate the pathologic process of PCOS and increase the difficulty of the treatment. We systematically reported the mechanisms underlying the psychiatric disorders-PCOS interactions, intending to provide potential ways to break the vicious cycle and lay the groundwork for future research. However, research on PCOS and psychiatric disorders were still in initial stages, which limited the scope of this review. More studies are needed to further verify our findings.

Mdm2-mediated ubiquitination of PKCβII is responsible for insulin-induced heterologous desensitization of dopamine D3 receptor

The insulin and dopaminergic systems in the brain are associated with schizophrenia and Parkinson's disease with respect to etiology and treatment. The present study investigated the crosstalk between the insulin receptor (IR) and dopamine receptor and found that insulin stimulation selectively inhibits signaling of D3 R in a PKCβII-dependent manner. Upon insulin stimulation, E3 ligase enzyme Mdm2 moves out of the nucleus to ubiquitinate PKCβII. Subsequently, ubiquitinated PKCβII translocates to the cell membrane and interacts with D3 R in a phosphorylation-dependent manner at S229/257, resulting in the attenuation of D3 R signaling and initiating clathrin-mediated endocytosis and downregulation. Considering that both IR and D3 R are closely related to some neuropsychosis, this study could provide new molecular insight into the etiology of the disorder.

Insulin Resistance/Diabetes and Schizophrenia: Potential Shared Genetic Factors and Implications for Better Management of Patients with Schizophrenia

Schizophrenia is a complex psychotic disorder with co-occurring conditions, including insulin resistance and type 2 diabetes (T2D). It is well established that T2D and its precursors (i.e., insulin resistance) are more prevalent in patients with schizophrenia who are treated with antipsychotics, as well as in antipsychotic-naïve patients experiencing their first episode of psychosis, compared with the general population. However, the mechanism(s) underlying the increased susceptibility, shared genetics, and possible cause-effect relationship between schizophrenia and T2D remain largely unknown. The objective of this narrative review was to synthesize important studies, including Mendelian randomization (MR) analyses that have integrated genome-wide association studies (GWAS), as well as results from in vitro models, in vivo models, and observational studies of patients with schizophrenia. Both GWAS and MR studies have found that schizophrenia and T2D/insulin resistance share genetic risk factors, and this may mediate a connection between peripheral or brain insulin resistance and T2D with cognition impairment and an increased risk of developing prediabetes and T2D in schizophrenia. Moreover, accumulating evidence supports a causal role for insulin resistance in schizophrenia and emphasizes the importance of a genetic basis for susceptibility to T2D in patients with schizophrenia before they receive psychotic treatment. The present findings and observations may have clinical implications for the development of better strategies to treat patients with schizophrenia, with both pharmacological (i.e., samidorphan, empagliflozin) and/or nonpharmacological (i.e., lifestyle changes) approaches. Additionally, this review may benefit the design of future studies by physicians and clinical investigators.

Association of clinical symptoms and cardiometabolic dysregulations in patients with schizophrenia spectrum disorders

BACKGROUND

Patients with schizophrenia spectrum disorders (SSD) have a shortened life expectancy related to cardiovascular diseases. We investigated the association of cognitive, positive, and negative symptoms with cardiometabolic dysregulations in SSD patients.

METHODS

Overall, 1,119 patients from the Genetic Risk and Outcome in Psychosis (GROUP) study were included. Cognitive function, positive and negative symptoms were assessed at baseline, 3-year, and 6-year. Cardiometabolic biomarkers were measured at 3-year follow-up. We used linear and multinomial logistic regression models to test the association between cardiometabolic biomarkers and clinical trajectories and performed mediation analyzes, while adjusting for clinical and demographic confounders.

RESULTS

Cognitive performance was inversely associated with increased body mass index (mean difference [β], βhigh = -1.24, 95% CI = -2.28 to 0.20, P = 0.02) and systolic blood pressure (βmild = 2.74, 95% CI = 0.11 to 5.37, P = 0.04). The severity of positive symptoms was associated with increased glycated hemoglobin (HbA1c) levels (βlow = -2.01, 95% CI = -3.21 to -0.82, P = 0.001). Increased diastolic blood pressure (ORhigh-decreased = 1.04, 95% CI = 1.01 to 1.08, P = 0.02; ORhigh-increased = 1.04, 95% CI = 1.00 to 1.08, P = 0.048) and decreased high-density lipoprotein (OR high-increased = 6.25, 95% CI = 1.81 to 21.59, P = 0.004) were associated with more severe negative symptoms. Increased HbA1c (ORmoderate = 1.05, 95% CI = 1.01 to 1.10, P = 0.024; ORhigh = 1.08, 95% CI = 1.02 to 1.14, P = 0.006) was associated with more severe positive symptoms. These associations were not mediated by antipsychotics.

CONCLUSIONS

We showed an association between cardiometabolic dysregulations and clinical and cognitive symptoms in SSD patients. The observed associations underscore the need for early identification of patients at risk of cardiometabolic outcomes.

Clinical improvement in schizophrenia during antipsychotic treatment in relation to changes in glucose parameters: A systematic review

Antipsychotics (APs) are the cornerstone of treatment for schizophrenia (SCZ) spectrum disorders. Previous research suggests that there may be a positive association between AP-induced weight gain and/or dyslipidemia and improvement in psychiatric symptoms, often referred to as a "metabolic threshold". To determine whether a similar relationship exists for glucose parameters, we conducted a systematic search in six databases from inception to June 2022 for all longitudinal studies that directly examined the relationship between changes in glucose-related outcomes and changes in psychopathology among patients with SCZ treated with APs. We identified 10 relevant studies and one additional study that considered cognition. In most cases, we found that increased levels of fasting glucose and insulin following treatment were associated with clinical improvement. These findings contribute to existing literature that could suggest a common mechanism between AP action and metabolic side effects and support a need for additional work aimed at exploring the validity of a glucose-psychopathology relation in SCZ.

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

Impairment of insulin action and metabolic dysregulation have traditionally been associated with schizophrenia, although the molecular basis of such association remains still elusive. The present meta-analysis aims to assess the impact of insulin action manipulations (i.e., hyperinsulinemia, hypoinsulinemia, systemic or brain insulin resistance) on glutamatergic, dopaminergic, γ-aminobutyric acid (GABA)ergic, and serotonergic pathways in the central nervous system. More than one hundred outcomes, including transcript or protein levels, kinetic parameters, and other components of the neurotransmitter pathways, were collected from cultured cells, animals, or humans, and meta-analyzed by applying a random-effects model and adopting Hedges'g to compare means. Two hundred fifteen studies met the inclusion criteria, of which 180 entered the quantitative synthesis. Significant impairments in key regulators of synaptic plasticity processes were detected as the result of insulin handlings. Specifically, protein levels of N-methyl-D-aspartate receptor (NMDAR) subunits including type 2A (NR2A) (Hedges' g = -0.95, 95%C.I. = -1.50, -0.39; p = 0.001; I2 = 47.46%) and 2B (NR2B) (Hedges'g = -0.69, 95%C.I. = -1.35, -0.02; p = 0.043; I2 = 62.09%), and Postsynaptic density protein 95 (PSD-95) (Hedges'g = -0.91, 95%C.I. = -1.51, -0.32; p = 0.003; I2 = 77.81%) were found reduced in insulin-resistant animal models. Moreover, insulin-resistant animals showed significantly impaired dopamine transporter activity, whereas the dopamine D2 receptor mRNA expression (Hedges'g = 3.259; 95%C.I. = 0.497, 6.020; p = 0.021; I2 = 90.61%) increased under insulin deficiency conditions. Insulin action modulated glutamate and GABA release, as well as several enzymes involved in GABA and serotonin synthesis. These results suggest that brain neurotransmitter systems are susceptible to insulin signaling abnormalities, resembling the discrete psychotic disorders' neurobiology and possibly contributing to the development of neurobiological hallmarks of treatment-resistant schizophrenia.

Metabolic syndrome following a first episode of psychosis: results of a 1-year longitudinal study conducted in metropolitan Lisbon, Portugal

Objective

We aimed to assess the prevalence and course of metabolic syndrome (MetS) and the associated metabolic parameters during the year following a first episode pf psychosis (FEP).

Methods

We performed a 1-year longitudinal observation of 60 patients who experienced FEP. MetS was defined using the modified definition of the National Cholesterol Education Program Adult Treatment Panel III. We assessed the metabolic parameters and socio-demographic and psychopathological data for the participants.

Results

The mean age of the participants was 27.1 years, and 33.3% of them were women. There was an increase in the prevalence of MetS from 6.7% to 11.7% during the year following the baseline assessment during the year following the baseline assessment (p = 0.250). There were also significant increases in the prevalences of abnormal triglyceride concentration, waist circumference, and high-density lipoprotein (HDL)-cholesterol concentration during this period. In addition, there was a considerable worsening of the metabolic profile of the participants. No baseline parameters were identified to be predictors of MetS over the 1-year follow-up period.

Conclusions

We can conclude that metabolic abnormalities are common in patients with FEP and that these rapidly worsen during the first year following the diagnosis of FEP. Studies on interventions are needed to reduce metabolic risk to cardiovascular diseases following the FEP.

Social isolation triggers oxidative status and impairs systemic and hepatic insulin sensitivity in normoglycemic rats

Drug-naïve psychotic patients show metabolic and hepatic dysfunctions. The rat social isolation model of psychosis allows to investigate mechanisms leading to these disturbances to which oxidative stress crucially contributes. Here, we investigated isolation-induced central and peripheral dysfunctions in glucose homeostasis and insulin sensitivity, along with redox dysregulation. Social isolation did not affect basal glycemic levels and the response to glucose and insulin loads in the glucose and insulin tolerance tests. However, HOMA-Index value were increased in isolated (ISO) rats. A hypothalamic reduction of AKT phosphorylation and a trend toward an increase in AMPK phosphorylation were observed following social isolation, accompanied by reduced GLUT-4 levels. Social isolation also induced a reduction of phosphorylation of the insulin receptor, of AKT and GLUT-2, and a decreased phosphorylation of AMPK in the liver. Furthermore, a significant reduction in hepatic CPT1 and PPAR-α levels was detected. ISO rats also showed significant elevations in hepatic ROS amount, lipid peroxidation and NOX4 expression, whereas no differences were detected in NOX2 and NOX1 levels. Expression of SOD2 in the mitochondrial fraction and SOD1 in the cytosolic fraction was not altered following social isolation, whereas SOD activity was increased. Furthermore, a decrease of hepatic CAT and GSH amount was observed in ISO rats compared to GRP animals. Our data suggest that the increased oxidant status and antioxidant capacity modifications may trigger hepatic and systemic insulin resistance, by altering signal hormone pathway and sustaining subsequent alteration of glucose homeostasis and metabolic impairment observed in the social isolation model of psychosis.

Disrupted relationship between blood glucose and brain dopamine D2/3 receptor binding in patients with first-episode schizophrenia

An elemental function of brain dopamine is to coordinate cognitive and motor resources for successful exploitation of environmental energy sources. Dopamine transmission, goal-directed behavior, and glucose homeostasis are altered in schizophrenia patients prior to and after initiation of pharmacological treatment. Thus, we investigated the relationship between blood glucose levels and brain dopamine signaling in drug-naïve patients with first-episode psychosis. We quantified blood glucose levels and binding of the dopamine D_2/3 receptor agonist radioligand (+)-[¹¹C]-PHNO in 15 medication-naïve patients and 27 healthy volunteers employing positron emission tomography. Whole-brain voxel-wise linear model analysis identified two clusters of significant interaction between blood glucose levels and diagnosis on (+)-[¹¹C]-PHNO binding-potential values. We observed positive relationships between blood glucose levels and binding-potential values in healthy volunteers but negative ones in patients with first episode psychosis in a cluster surviving rigorous multiple testing correction located in the in the right ventral tegmental area. Another cluster of homologous behavior, however at a lower level of statistical significance, comprised the ventral striatum and pallidum. Extracellular dopamine levels are a major determinant of (+)-[¹¹C]-PHNO binding in the brain. In line with the concept that increased dopamine signaling occurs when goal-directed behavior is needed for restoring energy supply, our data indicate that in healthy volunteers, extracellular dopamine levels are high when blood glucose levels are low and vice-versa. This relationship is reversed in patients with first-episode psychosis, possibly reflecting an underlying pathogenic alteration that links two seemingly unrelated aspects of the illness: altered dopamine signaling and dysfunctional glucose homeostasis.

Evidence for the atherogenic index of plasma as a potential biomarker for cardiovascular disease in schizophrenia

BACKGROUND

Schizophrenia is known to be accompanied with increased cardiovascular mortality, which causes reduced life expectancy.

AIM

The aim of the current study was to investigate if atherogenic index of plasma (AIP) could be a good marker in assessing cardiovascular disease (CVD) risk in patients with schizophrenia.

METHODS

Patients with schizophrenia (n = 328) and healthy controls (n = 141) were recruited. Schizophrenia patients were evaluated according to the presence of antipsychotic (AP) drug use as AP(+)Sch group and AP(-)Sch group. Atherogenic indices, such as AIP, Castelli's risk index-I (CRI-I), Castelli's risk index-II (CRI-II), and atherogenic coefficient (AC), were calculated according to the laboratory examination of serum lipid parameters.

RESULTS

According to the comparison of serum lipid levels, triglyceride (TG) levels were found to be highest and high-density lipoprotein-cholesterol levels were lowest in AP(+)Sch group than AP(-)Sch group and control group (CG) (p < 0.001). AIP, CRI-I, and CRI-II scores were found to be significantly higher in AP(+)Sch group than AP(-)Sch group, and in AP(-)Sch than healthy controls (p < 0.001). Mean AC scores were higher in AP(+)Sch group than both AP(-)Sch and CG and were similar in AP(-)Sch and control subjects (p < 0.001). According to the correlation analysis, AIP scores were positively correlated with duration of disease (r = 0.235; p = 0.002) and age (r = 0.226; p = 0.003) in AP(+)Sch group but not in drug-free subjects. In all groups, atherogenic indices of CRI-I, CRI-II, and AC scores were found to be positively correlated with AIP scores (p < 0.001).

CONCLUSION

Our results suggest that AIP is an easily calculable and reliable marker for determining the CVD risk in both drug-free schizophrenia patients and patients under AP treatment.

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.

Extensive bidirectional genetic overlap between bipolar disorder and cardiovascular disease phenotypes

Patients with bipolar disorder (BIP) have a high risk of cardiovascular disease (CVD), despite considerable individual variation. The mechanisms underlying comorbid CVD in BIP remain largely unknown. We investigated polygenic overlap between BIP and CVD phenotypes, including CVD risk factors and coronary artery disease (CAD). We analyzed large genome-wide association studies of BIP (n = 51,710) and CVD phenotypes (n = 159,208-795,640), using bivariate causal mixture model (MiXeR), which estimates the total amount of shared genetic variants, and conjunctional false discovery rate (FDR), which identifies specific overlapping loci. MiXeR revealed polygenic overlap between BIP and body mass index (BMI) (82%), diastolic and systolic blood pressure (20-22%) and CAD (11%) despite insignificant genetic correlations. Using conjunctional FDR < 0.05, we identified 129 shared loci between BIP and CVD phenotypes, mainly BMI (n = 69), systolic (n = 53), and diastolic (n = 53) blood pressure, of which 22 are novel BIP loci. There was a pattern of mixed effect directions of the shared loci between BIP and CVD phenotypes. Functional analyses indicated that the shared loci are linked to brain-expressed genes and involved in neurodevelopment, lipid metabolism, chromatin assembly/disassembly and intracellular processes. Altogether, the study revealed extensive polygenic overlap between BIP and comorbid CVD, implicating shared molecular genetic mechanisms. The mixed effect directions of the shared loci suggest variation in genetic susceptibility to CVD across BIP subgroups, which may underlie the heterogeneity of CVD comorbidity in BIP patients. The findings suggest more focus on targeted lifestyle interventions and personalized pharmacological treatment to reduce CVD comorbidity in BIP.

Prevalence of obesity and clinical and metabolic correlates in first-episode schizophrenia relative to healthy controls

OBJECTIVE

People with schizophrenia exhibit a high obesity rate. However, little is known about the prevalence of obesity and its relationship with clinical symptoms and metabolic indicators in first-episode drug-naïve (FEDN) schizophrenia.

METHODS

Demographic and lipid parameters were gathered from 297 FEDN schizophrenia and 325 healthy controls. The patients' symptomatology was evaluated by the Positive and Negative Syndrome Scale (PANSS).

RESULTS

The obesity rate of FEDN patients was 10.77%, similar to that of controls (10.5%). The prevalence of overweight plus obesity of patients was 44.8%, significantly higher than that of controls (36.6%). Compared with non-obese patients, obese patients had higher levels of cholesterol (4.81 ± 0.93 vs 4.22 ± 1.00 mmol/L), triglyceride (0.27 ± 0.21 vs 0.14 ± 0.24 mg/dL), low-density lipoprotein (0.48 ± 0.12 vs 0.40 ± 0.12 mg/dL), greater ratio of triglyceride/high-density lipoprotein (2.01 ± 1.23 vs 1.44 ± 1.26), and higher PANSS positive symptom subscale score (29.81 ± 6.29 vs 27.05 ± 6.15), general psychopathology subscale score (70.75 ± 11.74 vs 66.87 ± 11.37), and total score (149.81 ± 21.08 vs 140.64 ± 21.58), but lower high-density lipoprotein level (1.09 ± 0.21 vs 1.27 ± 0.34 mg/dL) (all p < 0.05). Correlation analysis revealed that body mass index (BMI) was positively correlated with triglyceride, cholesterol, high-density lipoprotein, low-density lipoprotein, triglyceride/high-density lipoprotein ratio, PANSS positive symptoms, general psychopathology, and total scores (all p < 0.05, r = 0.124 ~ 0.335). Multiple regression analysis confirmed that PANSS positive symptoms, total score, and cholesterol level were significantly associated with BMI (all p < 0.05, β: 0.126-0.162).

CONCLUSION

There was no significant difference in the prevalence of obesity between FEDN patients and the control group. Moreover, BMI was positively associated with positive symptom severity in FEDN patients.

Unveiling the Metabolic Profile of First-Episode Drug-Naïve Schizophrenia Patients: Baseline Characteristics of a Longitudinal Study Among Han Chinese

Objective: Metabolic and other medical conditions are frequently comorbid with schizophrenia. As they might be the side-effects of antipsychotic treatment, studying first-episode drug-naïve schizophrenia (FDSZ) provides a unique opportunity to investigate a direct pathogenic link between metabolic changes and schizophrenia. Here, we presented the methods and baseline unique metabolic profile of FDSZ patients without medical comorbidities unveiling subthreshold indices of metabolic disturbances. Method: Drug-naïve individuals diagnosed with schizophrenia but without any previous medical conditions were invited to participate in the study. Participants were submitted to structured psychiatric and cognitive assessments, laboratory and neuroimaging tests. Subjects will be followed after antipsychotic treatment at 6, 24 and 48 weeks. Results: During an 8-month-period, out of 103 patients presenting with first episode psychosis, 67 subjects (43.3% men, 56.7% women) were enrolled in the study. They had a mean ± SD age of 32.1 ± 8.7 years, with a mean BMI of 21.1 kg/m² and 11.3 ± 3.6 years of schooling. Less than 1/3 reported a family history of mental illness. Upon laboratory assessment, 10.4%, 7.5%, and 11.9% of patients were identified with hyperhomocysteinemia, hypertriglyceridemia and hyperprolactinemia, respectively, with percentages of women relatively higher than men except for hypertriglyceridemia. Conclusions: First episode schizophrenia patients, especially women, present subclinical metabolic abnormalities, independent of antipsychotic treatment.

Diabetes in late-life schizophrenia: Prevalence, factors, and association with clinical symptoms

OBJECTIVE

The prevalence of diabetes mellitus has been found to be higher in patients with schizophrenia. Older patients are the fastest-growing segment of the schizophrenia population. However, few studies have explored diabetes in older patients with schizophrenia. Therefore, this study aimed to determine the prevalence and characteristics of factors associated with diabetes in Chinese patients with late-life schizophrenia (LLS), which has not been reported in previous studies.

METHODS

A total of 289 inpatients aged 60 or above who met the DSM-IV criteria for schizophrenia were recruited. The severity of psychopathology was assessed by the Positive and Negative Syndrome Scale (PANSS). Diabetes was diagnosed by fasting blood glucose tests, or oral glucose tolerance tests.

RESULTS

The overall prevalence of diabetes in LLS patients was 25.3%. The prevalence of diabetes in female patients was significantly higher than that in male patients (35% vs. 21.53%). Other factors associated with diabetes included higher BMI, greater waistline (only for males), higher levels of triglyceride, and more severe positive symptoms.

CONCLUSION

These results indicate that the prevalence of diabetes in LLS patients is similar to that in the age-matched general population. Female gender, excess weight and abdominal obesity, dyslipidemia, and clinical symptoms can be potential risk factors of diabetes in the LLS patient group.

Childhood trauma and glucose metabolism in patients with first-episode psychosis

Although the associations between first-episode psychosis (FEP) and metabolic abnormalities on one side, and childhood trauma (CT) and risk of developing psychosis on the other are both well established, evidence on the relationship between CT and metabolic dysregulation in terms of abnormal glucose metabolism is very limited. We tested whether, already at illness onset, FEP patients with a history of CT show dysregulation of a broad range of glucose metabolism markers. In particular, in 148 FEP patients we evaluated serum concentrations of c-peptide, insulin, plasminogen-activator-inhibitor-1 (PAI-1), resistin, visfatin, glucagon, glucagon-like peptide-1 (GLP-1), gastric-inhibitor-peptide (GIP), leptin, and ghrelin. We also assessed CT with the Childhood Experience of Care and Abuse Questionnaire, and stressful life events (SLEs) with a semi-structured interview. Psychopathology, cannabis and tobacco habits, Body Mass Index (BMI) were recorded. Serum concentrations of markers were analyzed from peripheral blood. Ninety-five patients (56 % males, mean age 29.5) reported CT. Multivariate models showed that CT is associated only with the concentrations of c-peptide and insulin after adjusting for age, sex, BMI and SLEs. FEP patients who had experienced CT showed higher c-peptide and insulin serum concentrations. Our study reports that CT might be associated with the metabolic abnormalities in the first stage of psychosis, suggesting that a thorough anamnestic evaluation at psychosis onset that would include the history of CT could be helpful for clinicians in order to implement early programmes of healthy lifestyle education and to guide choice of therapeutic interventions for trauma.

The prevalence, risk factors, and clinical characteristics of insulin resistance in Chinese patients with schizophrenia

BACKGROUND

Studies have shown that patients with schizophrenia are at a high risk of developing insulin resistance (IR). We investigated the prevalence of IR and its clinical correlates in hospitalized Chinese patients with schizophrenia.

METHODS

A total of 193 patients with schizophrenia (113 males and 80 females) were recruited for the study. We collected their demographic and clinical data, including data on their plasma glucose and lipid levels. All patients were rated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to assess cognitive function, while Positive and Negative Syndrome Scale (PANSS) was used to assess psychopathology. The cut-off value for the homeostasis model assessment of insulin resistance (HOMA-IR) was set at 1.7.

RESULTS

The prevalence of IR was 37.82% (73/193). The IR patients had significantly higher waist-to-hip ratio and body mass index (BMI), and higher fasting plasma glucose (FPG), triglyceride (TG), and low density lipoprotein (LDL) levels compared to non-IR patients (all p<.05). Binary logistic regression analysis showed that smoking, BMI, and TG and LDL levels are significant predictors of IR. In addition, correlation analysis showed that IR was significantly correlated with the waist-to-hip ratio, BMI, and LDL level (Bonferroni corrected p<.05). The multivariable linear regression analysis indicated that the BMI and FPG are associated with the IR index. There was no significant difference in IR index between patients who were taking different antipsychotics.

CONCLUSION

We found a high prevalence of IR and its risk factors in Chinese patients with schizophrenia. Active weight control to reduce the BMI and waist circumference and reducing the number of cigarettes consumed, may be essential to decrease the incidence of IR in patients with schizophrenia.

Shared pathways for neuroprogression and somatoprogression in neuropsychiatric disorders

Activated immune-inflammatory, oxidative and nitrosative stress (IO&NS) pathways and consequent mitochondrial aberrations are involved in the pathophysiology of psychiatric disorders including major depression, bipolar disorder and schizophrenia. They offer independent and shared contributions to pathways underpinning medical comorbidities including insulin resistance, metabolic syndrome, obesity and cardiovascular disease - herein conceptualized as somatoprogression. This narrative review of human studies aims to summarize relationships between IO&NS pathways, neuroprogression and somatoprogression. Activated IO&NS pathways, implicated in the neuroprogression of psychiatric disorders, affect the pathogenesis of comorbidities including insulin resistance, dyslipidaemia, obesity and hypertension, and by inference, metabolic syndrome. These conditions activate IO&NS pathways, exacerbating neuroprogression in psychiatric disorders. The processes whereby proinflammatory cytokines, nitrosative and endoplasmic reticulum stress, NADPH oxidase isoforms, PPARγ inactivation, SIRT1 deficiency and intracellular signalling pathways impact lipid metabolism and storage are considered. Through associations between body mass index, chronic neuroinflammation and FTO expression, activation of IO&NS pathways arising from somatoprogression may contribute to neuroprogression. Early evidence highlights the potential of adjuvants targeting IO&NS pathways for treating somatoprogression and neuroprogression.

Alterations in body mass index and waist-to-hip ratio in never and minimally treated patients with psychosis: A systematic review and meta-analysis

BACKGROUND

Obesity is up to 4 times higher in patients with schizophrenia than in the general population. However, the link between obesity and schizophrenia in the absence of antipsychotic use is unclear. Therefore, we aimed to examine differences in obesity measures (body mass index (BMI), waist circumference (WC), and waist-to-hip ratio (WHR)) in antipsychotic-naive and minimally treated (up to 2 weeks of lifetime antipsychotic exposure) patients with psychosis compared to healthy controls (HCs).

METHODS

A systematic search was conducted using Ovid Medline®, PsycINFO, and Embase. Standardized mean differences (SMDs) in obesity measures between groups were calculated. Separate sensitivity analyses were performed to examine the effects of age, sex, and ethnicity; antipsychotic exposure; and schizophrenia-related psychosis on SMDs.

RESULTS

A total of 23 studies were included in the meta-analysis (BMI = 23, WC = 9, WHR = 5). BMI was lower (SMD = -0.19, 95% CI = -0.34 to -0.05, P = 0.009) and WHR was elevated (SMD = 0.34, 95% CI = 0.14 to 0.55, P = 0.001) in patients. These differences remained after analyses were restricted to patients matched with HCs for age, sex, and ethnicity; to antipsychotic-naive patients; and to patients with schizophrenia-related diagnoses.

CONCLUSIONS

Differences in BMI and WHR were observed in never and minimally treated patients with psychosis compared to HCs. Future research is warranted to understand these alterations in the context of body fat biomarkers and neuropathology of psychiatric disorders, independent of the effects of antipsychotics.

Brain insulin action: Implications for the treatment of schizophrenia

Insulin action in the central nervous system is a major regulator of energy balance and cognitive processes. The development of central insulin resistance is associated with alterations in dopaminergic reward systems and homeostatic signals affecting food intake, glucose metabolism, body weight and cognitive performance. Emerging evidence has highlighted a role for antipsychotics (APs) to modulate central insulin-mediated pathways. Although APs remain the cornerstone treatment for schizophrenia they are associated with severe metabolic complications and fail to address premorbid cognitive deficits, which characterize the disorder of schizophrenia. In this review, we first explore how the hypothesized association between schizophrenia and CNS insulin dysregulation aligns with the use of APs. We then investigate the proposed relationship between CNS insulin action and AP-mediated effects on metabolic homeostasis, and different domains of psychopathology, including cognition. We briefly discuss a potential role of CNS insulin signaling to explain the hypothesized, but somewhat controversial association between therapeutic efficacy and metabolic side effects of APs. Finally, we propose how this knowledge might inform novel treatment strategies to target difficult to treat domains of schizophrenia. This article is part of the issue entitled 'Special Issue on Antipsychotics'.

Clinical Correlates of Insulin Resistance in Chronic Schizophrenia: Relationship to Negative Symptoms

Higher prevalence of physical comorbidity and premature mortality in persons with schizophrenia (PwS) results primarily from heightened cardiovascular and metabolic risks. The literature suggests that insulin resistance precedes the development of obesity, smoking, and use of antipsychotic medications, although these likely play a compounding role later in the course of the disorder. It is thus important to discover the clinical characteristics of PwS with high insulin resistance, as these individuals may represent an etiopathologically distinct subgroup with a distinct course and treatment needs. We conducted a cross-sectional study and compared insulin resistance between 145 PwS and 140 nonpsychiatric comparison (NC) participants, similar in age, sex, and race distribution. In addition, we examined correlates of insulin resistance in PwS. As expected, PwS had higher levels of insulin resistance [Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)] and body mass index (BMI) compared to the NC participants. HOMA-IR in the PwS was most associated with negative symptoms, BMI, and non-White race/ethnicity. The mechanistic relationships between insulin resistance and negative symptoms in schizophrenia patients warrant further investigation, and future studies should examine outcomes of PwS with this cluster of physical and mental symptoms and determine how management of insulin resistance might improve health of these individuals.

Is psychosis a multisystem disorder? A meta-review of central nervous system, immune, cardiometabolic, and endocrine alterations in first-episode psychosis and perspective on potential models

People with psychotic disorders show abnormalities in several organ systems in addition to the central nervous system (CNS); and this contributes to excess mortality. However, it is unclear how strong the evidence is for alterations in non-CNS systems at the onset of psychosis, how the alterations in non-CNS systems compare to those in the CNS, or how they relate to symptoms. Here, we consider these questions, and suggest potential models to account for findings. We conducted a systematic meta-review to summarize effect sizes for both CNS (focusing on brain structural, neurophysiological, and neurochemical parameters) and non-CNS dysfunction (focusing on immune, cardiometabolic, and hypothalamic-pituitary-adrenal (HPA) systems) in first-episode psychosis (FEP). Relevant meta-analyses were identified in a systematic search of Pubmed and the methodological quality of these was assessed using the AMSTAR checklist (A Measurement Tool to Assess Systematic Reviews). Case-control data were extracted from studies included in these meta-analyses. Random effects meta-analyses were re-run and effect size magnitudes for individual parameters were calculated, as were summary effect sizes for each CNS and non-CNS system. We also grouped studies to obtain overall effect sizes for non-CNS and CNS alterations. Robustness of data for non-CNS and CNS parameters was assessed using Rosenthal's fail-safe N. We next statistically compared summary effect size for overall CNSand overall non-CNS alterations, as well as for each organ system separately. We also examined how non-CNS alterations correlate CNS alterations, and with psychopathological symptoms. Case-control data were extracted for 165 studies comprising a total sample size of 13,440. For people with first episode psychosis compared with healthy controls, we observed alterations in immune parameters (summary effect size: g = 1.19), cardiometabolic parameters (g = 0.23); HPA parameters (g = 0.68); brain structure (g = 0.40); neurophysiology (g = 0.80); and neurochemistry (g = 0.43). Grouping non-CNS organ systems together provided an effect size for overall non-CNS alterations in patients compared with controls (g = 0.58), which was not significantly different from the overall CNS alterations effect size (g = 0.50). However, the summary effect size for immune alterations was significantly greater than that for brain structural (P < 0.001) and neurochemical alterations (P < 0.001), while the summary effect size for cardiometabolic alterations was significantly lower than neurochemical (P = 0.04), neurophysiological (P < 0.001), and brain structural alterations (P = 0.001). The summary effect size for HPA alterations was not significantly different from brain structural (P = 0.14), neurophysiological (P = 0.54), or neurochemical alterations (P = 0.22). These outcomes remained similar in antipsychotic naive sensitivity analyses. We found some, but limited and inconsistent, evidence that non-CNS alterations were associated with CNS changes and symptoms in first episode psychosis. Our findings indicate that there are robust alterations in non-CNS systems in psychosis, and that these are broadly similar in magnitude to a range of CNS alterations. We consider models that could account for these findings and discuss implications for future research and treatment.

Metabolic-inflammatory status as predictor of clinical outcome at 1-year follow-up in patients with first episode psychosis

BACKGROUND

Metabolic abnormalities and peripheral inflammation have been increasingly reported in patients at the onset of psychosis and associated with important physical health disorders and increased mortality. However, the impact of an abnormal metabolic-inflammatory status on the psychiatric outcome of these patients has not yet been investigated.

OBJECTIVES

The aims of this study were 1) to explore whether, in a sample of patients at their first episode of psychosis (FEP), an overall metabolic-inflammatory status may be measured, by combining metabolic and inflammatory variables in metabolic-inflammatory factors; 2) to explore the association between these factors and clinical outcome at 1-year follow-up (FU), in terms of symptoms severity and treatment response.

METHODS

In this longitudinal study we recruited 42 FEP patients and 46 healthy controls (HC) matched with patients for age, gender and ethnicity. At baseline (T1) we measured high sensitivity C-reactive protein (hsCRP) as biomarker of inflammation, and body mass index (BMI), lipid profile and gluco-metabolic parameters (glycated hemoglobin (HbA1c) and fasting glucose) as metabolic variables. A principal component analysis (PCA) was then used to reduce the dimensionality of the dataset accounting for both inflammation and metabolic status. In FEP patients, we assessed symptoms severity at T1 and at 1-year FU (T2) as well as treatment response to antipsychotics at T2.

RESULTS

at T1, FEP showed higher HbA1c (p = 0.034), triglycerides (TG) (p = 0.045) and BMI (p = 0.026) than HC. PCA identified 3 factors: factor 1 accounting for hsCRP, TG and BMI, factor 2 accounting for LDL and cholesterol, and factor 3 accounting for fasting glucose and HbA1c. Factor 1 was associated with T1 negative symptoms severity (p = 0.021) and predicted T2 positive (p = 0.004) and overall symptoms severity (0.001), as well as general psychopathology (p < 0.001) and T2 treatment response (p = 0.007).

CONCLUSION

In this sample of FEP patients, inflammation and metabolism, closely correlated at the onset of psychosis, proved to play a key role as predictors of the clinical course of psychosis when combined in a single factor. These findings offer an important potential target for early screening and interventions.

Hyperprolactinemia and insulin resistance in drug naive patients with early onset first episode psychosis

BACKGROUND

Hyperprolactinemia and glucose and lipid metabolism abnormalities are often found in patients with schizophrenia and are generally considered secondary to the use of antipsychotic drugs. More recent studies have shown these same neuroendocrine and metabolic abnormalities in antipsychotic naïve patients with first episode psychosis (FEP), rising the hypothesis that schizophrenia itself may be related to an abnormal regulation of prolactin secretion and to impaired glucose tolerance. The aim of this study was to compare prolactin levels, glycometabolism parameters and lipid profile between a sample of 31 drug-naive adolescents in the acute phase of FEP and a control group of 23 subjects at clinical high risk (CHR) of developing psychosis.

METHODS

The assessment involved anthropometric data (weight, height, BMI index, pubertal stage) and blood tests (levels of glucose, glycated hemoglobin, serum insulin, triglycerides, total and fractionated cholesterol, prolactin). Insulin resistance (IR) was calculated through the homeostatic model of assessment (HOMA-IR), assuming a cut-off point of 3.16 for adolescent population. FEP patients and CHR controls were compared by using Student's t-distribution (t-test) for parametric data. P < 0.05 was considered significant.

RESULTS

Significant higher level of prolactin was found in FEP group than in CHR group (mean = 28.93 ± 27.16 vs 14.29 ± 7.86, P = 0.009), suggesting a condition of hyperprolactinemia (HPRL). Patients with FEP were more insulin resistant compared to patients at CHR, as assessed by HOMA-IR (mean = 3.07 ± 1.76 vs 2.11 ± 1.11, P = 0.043). Differences of fasting glucose (FEP = 4.82 ± 0.71, CHR = 4.35 ± 0.62, P = 0.016) and HbA1c (FEP = 25.86 ± 13.31, CHR = 33.00 ± 2.95, P = 0.013), were not clinically significant as the mean values were within normal range for both groups. No significant differences were found for lipid profile. A BMI value within the range of normal weight was found for both groups, with no significant differences.

CONCLUSION

We suggested that HPRL, increase in HOMA-IR, and psychotic symptoms may be considered different manifestations of the acute onset of schizophrenia spectrum psychosis, with a common neurobiological vulnerability emerging since adolescence. The influence of age and gender on clinical manifestations of psychotic onset should be considered for early prevention and treatment of both schizophrenia spectrum psychosis and neuroendocrine-metabolic dysfunctions.

Increase in serum HDL level is associated with less negative symptoms after one year of antipsychotic treatment in first-episode psychosis

BACKGROUND

A potential link between increase in total cholesterol and triglycerides and clinical improvement has been observed during antipsychotic drug treatment in chronic schizophrenia patients, possibly due to drug related effects on lipid biosynthesis. We examined whether changes in serum lipids are associated with alleviation of psychosis symptoms after one year of antipsychotic drug treatment in a cohort of first-episode psychosis (FEP) patients.

METHODS

A total of 132 non-affective antipsychotic-treated FEP patients were included through the Norwegian Thematically Organized Psychosis (TOP) project. Data on antipsychotic usage, serum lipids (total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides (TG)), body mass index (BMI) and clinical state were obtained at baseline and after 12months. The Positive and Negative Syndrome Scale (PANSS) was used to assess psychotic symptoms. Mixed-effects models were employed to examine the relationship between serum lipids and psychotic symptoms while controlling for potential confounders including BMI.

RESULTS

An increase in HDL during one year of antipsychotic treatment was associated with reduction in PANSS negative subscores (B=-0.48, p=0.03). This relationship was not affected by concurrent change in BMI (adjusted HDL: B=-0.54, p=0.02). No significant associations were found between serum lipids, BMI and PANSS positive subscores.

CONCLUSION

We found that an increase in HDL level during antipsychotic treatment is associated with improvement in negative symptoms in FEP. These findings warrant further investigation to clarify the interaction between lipid pathways and psychosis.

Immune and metabolic alterations in first episode psychosis (FEP) patients

The molecular underpinnings associated to first episode psychosis (FEP) remains to be elucidated, but compelling evidence supported an association of FEP with blood alterations in biomarkers related to immune system, growth factors and metabolism regulators. Many of these studies have not been already confirmed in larger samples or have not considered the FEP diagnostic subgroups. In order to identify biochemical signatures of FEP, the serum levels of the growth factors BDNF and VEGF, the immune regulators IL-1RA, IL-6, IL-10 and IL-17, RANTES/CCL5, MIP-1b/CCL4, IL-8 and the metabolic regulators C-peptide, ghrelin, GIP, GLP-1, glucagon, insulin, leptin, PAI-1, resistin and visfatin were analysed in 260 subjects collected in the GET UP project. The results indicated an increase of MIP-1b/CCL4, VEGF, IL-6 and PAI-1, while IL-17, ghrelin, glucagon and GLP-1 were decreased in the whole sample of FEP patients (p < 0.01 for all markers except for PAI-1 p < 0.05). No differences were evidenced for these markers among the diagnostic groups that constitute the FEP sample, whereas IL-8 is increased only in patients with a diagnosis of affective psychosis. The principal component analysis (PCA) and variable importance analysis (VIA) indicated that MIP-1b/CCL4, ghrelin, glucagon, VEGF and GLP-1 were the variables mostly altered in FEP patients. On the contrary, none of the analysed markers nor a combination of them can discriminate between FEP diagnostic subgroups. These data evidence a profile of immune and metabolic alterations in FEP patients, providing new information on the molecular mechanism associated to the psychosis onset for the development of preventive strategies and innovative treatment targets.

Higher schizotypy predicts better metabolic profile in unaffected siblings of patients with schizophrenia

RATIONALE

Type 2 diabetes (T2D) is more frequent in schizophrenia (Sz) than in the general population. This association is partly accounted for by shared susceptibility genetic variants.

OBJECTIVE

We tested the hypotheses that a genetic predisposition to Sz would be associated with higher likelihood of insulin resistance (IR), and that IR would be predicted by subthreshold psychosis phenotypes.

METHODS

Unaffected siblings of Sz patients (n = 101) were compared with a nonclinical sample (n = 305) in terms of IR, schizotypy (SzTy), and a behavioural experiment of "jumping to conclusions". The measures, respectively, were the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR), Structured Interview for Schizotypy-Revised (SIS-R), and the Beads Task (BT). The likelihood of IR was examined in multiple regression models that included sociodemographic, metabolic, and cognitive parameters alongside group status, SIS-R scores, and BT performance.

RESULTS

Insulin resistance was less frequent in siblings (31.7%) compared to controls (43.3%) (p < 0.05), and negatively associated with SzTy, as compared among the tertile groups for the latter (p < 0.001). The regression model that examined all relevant parameters included the tSzTy tertiles, TG and HDL-C levels, and BMI, as significant predictors of IR. Lack of IR was predicted by the highest as compared to the lowest SzTy tertile [OR (95%CI): 0.43 (0.21-0.85), p = 0.015].

CONCLUSION

Higher dopaminergic activity may contribute to both schizotypal features and a favourable metabolic profile in the same individual. This is compatible with dopamine's regulatory role in glucose metabolism via indirect central actions and a direct action on pancreatic insulin secretion. The relationship between dopaminergic activity and metabolic profile in Sz must be examined in longitudinal studies with younger unaffected siblings.

Reduced insulin sensitivity may be related to less striatal glutamate: An 1H-MRS study in healthy non-obese humans

Levels of striatal dopamine (DA) may be positively correlated with levels of striatal glutamate (Glu). While reduced insulin sensitivity (%S) has been associated with reduced striatal DA levels in healthy non-obese persons, whether reduced %S is also associated with reduced striatal Glu levels has not yet been established. Using ¹H-MRS, we measured levels of several neurometabolites in the striatum and dorsolateral prefrontal cortex (DLPFC) of seventeen healthy non-obese persons (9 female, mean age: 28.35 ± 9.53). Insulin sensitivity was estimated for each subject from fasting plasma glucose and insulin using the Homeostasis Model Assessment II. We hypothesized that %S would be positively related with levels of Glu and Glu + glutamine (Glx) in the striatum. Exploratory analyses were also conducted between other fasting markers of metabolic health and neurometabolites measured with ¹H-MRS. In the right striatum, %S was positively correlated with levels of Glu (r(15) = .49, p = .04) and Glx (r(15) = .50, p = .04). In the left striatum, there was a trend positive correlation between %S and Glu (r(15) = .46, p = .06), but not Glx levels (r(15) = .20, p = .44). The relationships between %S and striatal Glu levels remained after controlling for age, sex, and BMI (right: r(12) = .73, β = .52, t = 2.55, p = .03; left: (r(12) = .63, β = .53, t = 2.25, p = .04) These preliminary findings suggest that %S may be related to markers of glutamatergic functioning in the striatum of healthy non-obese persons. These findings warrant replication in larger samples and extension into neuropsychiatric populations where altered striatal DA, Glu, and %S are implicated.

The Complex Relationship between Antipsychotic-Induced Weight Gain and Therapeutic Benefits: A Systematic Review and Implications for Treatment

Background: Antipsychotic-induced weight gain (AIWG) and other adverse metabolic effects represent serious side effects faced by many patients with psychosis that can lead to numerous comorbidities and which reduce the lifespan. While the pathophysiology of AIWG remains poorly understood, numerous studies have reported a positive association between AIWG and the therapeutic benefit of antipsychotic medications.

Objectives: To review the literature to (1) determine if AIWG is consistently associated with therapeutic benefit and (2) investigate which variables may mediate such an association.

Data Sources: MEDLINE, Google Scholar, Cochrane Database and PsycINFO databases were searched for articles containing all the following exploded MESH terms: schizophrenia [AND] antipsychotic agents/neuroleptics [AND] (weight gain [OR] lipids [OR] insulin [OR] leptin) [AND] treatment outcome. Results were limited to full-text, English journal articles.

Results: Our literature search uncovered 31 independent studies which investigated an AIWG-therapeutic benefit association with a total of 6063 enrolled individuals diagnosed with schizophrenia or another serious mental illness receiving antipsychotic medications. Twenty-two studies found a positive association while, 10 studies found no association and one study reported a negative association. Study variables including medication compliance, sex, ethnicity, or prior antipsychotic exposure did not appear to consistently affect the AIWG-therapeutic benefit relationship. In contrast, there was some evidence that controlling for baseline BMI/psychopathology, duration of treatment and specific agent studied [i.e., olanzapine (OLZ) or clozapine (CLZ)] strengthened the relationship between AIWG and therapeutic benefit.

Limitations: There were limitations of the reviewed studies in that many had small sample sizes, and/or were retrospective. The heterogeneity of the studies also made comparisons difficult and publication bias was not controlled for.

Conclusions: An AIWG-therapeutic benefit association may exist and is most likely to be observed in OLZ and CLZ-treated patients. The clinical meaningfulness of this association remains unclear and weight gain and other metabolic comorbidities should be identified and treated to the same targets as the general population. Further research should continue to explore the links between therapeutic benefit and metabolic health with emphasis on both pre-clinical work and well-designed prospective clinical trials examining metabolic parameters associated, but also occurring independently to AIWG.

Cardiovascular Risk in Early Psychosis: Relationship with Inflammation and Clinical Features 6 Months after Diagnosis

BACKGROUND

We aimed to investigate the state of cardiovascular risk/protection factors in early psychosis patients.

METHODS

A total 119 subjects were recruited during the first year after their first episode of psychosis. Eighty-five of these subjects were followed during the next 6 months. Cardiovascular risk/protection factors were measured in plasma and co-variated by sociodemographic/clinical characteristics. Multiple linear regression models detected the change of each biological marker from baseline to follow-up in relation to clinical scales, antipsychotic medication, and pro-/antiinflammatory mediators.

RESULTS

Glycosylated hemoglobin is a state biomarker in first episode of psychosis follow-up patients and inversely correlated to the Global Assessment of Functioning scale. We found opposite alterations in the levels of VCAM-1 and E-selectin in first episode of psychosis baseline conditions compared with control that were absent in the first episode of psychosis follow-up group. Adiponectin levels decreased in a continuum in both pathological time points studied. E-Selectin plasma levels were inversely related to total antipsychotic equivalents and adiponectin levels inversely co-related to the Global Assessment of Functioning scale. Finally, adiponectin levels were directly related to antiinflammatory nuclear receptor PPARγ expression in first episode of psychosis baseline conditions and to proinflammatory nuclear factor nuclear factor κB activity in follow-up conditions, respectively.

CONCLUSIONS

Our results support the need for integrating cardiovascular healthcare very early after the first episode of psychosis.

Exploring the Relationship Between Body Mass Index and Positive Symptom Severity in Persons at Clinical High Risk for Psychosis

Metabolic health and positive symptom severity has been investigated in schizophrenia, but not in clinical high risk (CHR) patients. We hypothesized that greater body mass index (BMI) in CHR patients would be related to less positive symptoms. We examined this relationship in CHR patients being treated with 1) no psychotropic medications (n = 58), 2) an antipsychotic (n = 14), or 3) an antidepressant without an antipsychotic (n = 10). We found no relationship between BMI and positive symptoms in unmedicated CHR patients, the majority of whom had a narrow BMI range between 20 and 30. However, in the smaller sample of CHR patients taking an antidepressant or antipsychotic, BMI was negatively correlated with positive symptoms. Although potentially underpowered, these preliminary findings provide initial steps in elucidating the relationships between metabolic health, neurochemistry, and symptom severity in CHR patients.

Associated illness severity in schizophrenia and diabetes mellitus: A systematic review

OBJECTIVE

We aimed to elucidate whether schizophrenia and type II diabetes mellitus may present with associated illness severity, in light of accumulating evidence to suggest both conditions have important shared inflammatory components with many shared inflammatory genetic factors.

METHODS

We conducted a systematic review employing PRISMA criteria, searching EMBASE, Ovid MEDLINE, PsychInfo, Web of Science and Google Scholar to February 1st, 2017, for clinical studies assessing schizophrenia severity alongside dysglycaemia. A narrative synthesis was employed to discuss and compare findings between studies.

RESULTS

Eleven observational studies were included in the analysis. Ten presented evidence in support of an association between schizophrenia severity and dysglycaemia. This association appeared particularly strong regarding negative symptomatology and impaired cognitive function, between which there may be some overlap. Studies examining positive symptomatology returned mixed results.

CONCLUSION

Whilst study design varied amongst the included studies, the results suggest that further work examining the effect of hyperglycaemia on schizophrenia severity may be relevant, particularly longitudinal studies assessing negative symptomatology and cognitive function. To the authors' knowledge, this is the first systematic review conducted to address this question.

Impaired Glucose Homeostasis in First-Episode Schizophrenia: A Systematic Review and Meta-analysis

IMPORTANCE

Schizophrenia is associated with an increased risk of type 2 diabetes. However, it is not clear whether schizophrenia confers an inherent risk for glucose dysregulation in the absence of the effects of chronic illness and long-term treatment.

OBJECTIVE

To conduct a meta-analysis examining whether individuals with first-episode schizophrenia already exhibit alterations in glucose homeostasis compared with controls.

DATA SOURCES

The EMBASE, MEDLINE, and PsycINFO databases were systematically searched for studies examining measures of glucose homeostasis in antipsychotic-naive individuals with first-episode schizophrenia compared with individuals serving as controls.

STUDY SELECTION

Case-control studies reporting on fasting plasma glucose levels, plasma glucose levels after an oral glucose tolerance test, fasting plasma insulin levels, insulin resistance, and hemoglobin A1c (HbA1c) levels in first-episode antipsychotic-naive individuals with first-episode schizophrenia compared with healthy individuals serving as controls. Two independent investigators selected the studies.

DATA EXTRACTION

Two independent investigators extracted study-level data for a random-effects meta-analysis. Standardized mean differences in fasting plasma glucose levels, plasma glucose levels after an oral glucose tolerance test, fasting plasma insulin levels, insulin resistance, and HbA1c levels were calculated. Sensitivity analyses examining the effect of body mass index, diet and exercise, race/ethnicity, and minimal (≤2 weeks) antipsychotic exposure were performed.

DATA SYNTHESIS

Of 3660 citations retrieved, 16 case-control studies comprising 15 samples met inclusion criteria. The overall sample included 731 patients and 614 controls. Fasting plasma glucose levels (Hedges g = 0.20; 95% CI, 0.02 to 0.38; P = .03), plasma glucose levels after an oral glucose tolerance test (Hedges g = 0.61; 95% CI, 0.16 to 1.05; P = .007), fasting plasma insulin levels (Hedges g = 0.41; 95% CI, 0.09 to 0.72; P = .01), and insulin resistance (homeostatic model assessment of insulin resistance) (Hedges g = 0.35; 95% CI, 0.14 to 0.55; P = .001) were all significantly elevated in patients compared with controls. However, HbA1c levels (Hedges g = -0.08; CI, -0.34 to 0.18; P = .55) were not altered in patients compared with controls.

CONCLUSIONS AND RELEVANCE

These findings show that glucose homeostasis is altered from illness onset in schizophrenia, indicating that patients are at increased risk of diabetes as a result. This finding has implications for the monitoring and treatment choice for patients with schizophrenia.

Toward a unified theory of childhood trauma and psychosis: A comprehensive review of epidemiological, clinical, neuropsychological and biological findings

There is a growing body of research focused on the relationship between childhood trauma and the risk of developing psychosis. Numerous studies, including many large-scale population-based studies, controlling for possible mediating variables, provide persuasive evidence of a dose-response association and are indicative of a causal relationship. Existing evidence supports the specificity model, showing differential associations between particular adversities and clinical symptoms, with cumulative adversity causing less favorable clinical and functional outcomes in psychotic patients. To date, several psychological and biological models have been proposed to search for underlying developmental trajectories leading to the onset of psychosis, influencing psychopathological manifestation and negative functional outcomes due to a history of childhood trauma. In this article, we provide a unified review on the relationship between childhood trauma and psychosis by integrating results of epidemiological, clinical, neuropsychological and biological studies. The question whether psychosis with a positive history of childhood trauma should be considered as a new psychotic phenotype, requiring specific therapeutic interventions, warrants further investigation.

Metabolic syndrome or glucose challenge in first episode of psychosis?

Patients with schizophrenia exhibit a reduced life expectancy. Although unhealthy lifestyle or suicide risk plays a role, the main causes are diverse medical conditions such as cardiovascular diseases, type 2 diabetes mellitus and metabolic syndrome. Albeit pharmacological secondary side effects might also trigger previous conditions, studies in naïve patients reflect diverse anomalies at the onset. Patients with a first episode of psychosis, display a wide scope of metabolic abnormalities, ranging from normality till pathological values depending on the parameters studied. We attempted to evaluate the metabolic syndrome and glycemic homeostasis in a subset of antipsychotic-naïve patients with a first episode of non-affective psychosis. Patients (n = 84) showed a similar prevalence of metabolic syndrome compared with a matched control sample (n = 98) (6% vs 4%, P = 0.562), while glucose homeostasis values differed significantly (14% vs. 5%, P = 0.034). Our results suggest that metabolic syndrome is not a useful clinical condition to be evaluated in patients before pharmacological treatment. Abnormal glycemic homeostasis at the onset of the disease requires specific diagnostic tools and preventive measures in order to avoid future cardiovascular events. New strategies must be implemented in order to evaluate the cardiovascular risk and subsequent morbidity in patients at the onset of the disease.

Impaired glucose tolerance in first-episode drug-naïve patients with schizophrenia: relationships with clinical phenotypes and cognitive deficits

BACKGROUND

Schizophrenia patients have a higher prevalence of type 2 diabetes mellitus with impaired glucose tolerance (IGT) than normals. We examined the relationship between IGT and clinical phenotypes or cognitive deficits in first-episode, drug-naïve (FEDN) Han Chinese patients with schizophrenia.

METHOD

A total of 175 in-patients were compared with 31 healthy controls on anthropometric measures and fasting plasma levels of glucose, insulin and lipids. They were also compared using a 75 g oral glucose tolerance test and the homeostasis model assessment of insulin resistance (HOMA-IR). Neurocognitive functioning was assessed using the MATRICS Consensus Cognitive Battery (MCCB). Patient psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

Of the patients, 24.5% had IGT compared with none of the controls, and they also had significantly higher levels of fasting blood glucose and 2-h glucose after an oral glucose load, and were more insulin resistant. Compared with those patients with normal glucose tolerance, the IGT patients were older, had a later age of onset, higher waist or hip circumference and body mass index, higher levels of low-density lipoprotein and triglycerides and higher insulin resistance. Furthermore, IGT patients had higher PANSS total and negative symptom subscale scores, but no greater cognitive impairment except on the emotional intelligence index of the MCCB.

CONCLUSIONS

IGT occurs with greater frequency in FEDN schizophrenia, and shows association with demographic and anthropometric parameters, as well as with clinical symptoms but minimally with cognitive impairment during the early course of the disorder.

Polygenic risk for type 2 diabetes mellitus among individuals with psychosis and their relatives

BACKGROUND

An elevated prevalence of Type 2 diabetes (T2D) has been observed in people with psychotic disorders and their relatives compared to the general population. It is not known whether this population also has increased genetic risk for T2D.

METHODS

Subjects included probands with schizophrenia, schizoaffective disorder, or psychotic bipolar I disorder, their first-degree relatives without psychotic disorders, and healthy controls, who participated in the Bipolar Schizophrenia Network for Intermediate Phenotypes study. We constructed sets of polygenic risk scores for T2D (PGRST2D) and schizophrenia (PGRSSCHIZ) using publicly available data from genome-wide association studies. We then explored the correlation of PGRST2D with psychiatric proband or relative status, and with self-reported diabetes. Caucasians and African-Americans were analyzed separately. We also evaluated correlations between PGRSSCHIZ and diabetes mellitus among Caucasian probands and their relatives.

RESULTS

In Caucasians, PGRST2D was correlated with self-reported diabetes mellitus within probands, but was not correlated with proband or relative status in the whole sample. In African-Americans, a PGRST2D based on selected risk alleles for T2D in this population did not correlate with proband or relative status. PGRSSCHIZ was not correlated with self-reported diabetes within Caucasian probands.

CONCLUSION

Differences in polygenic risk for T2D do not explain the increased prevalence of diabetes mellitus observed in psychosis probands and their relatives.

Male sex may be associated with higher metabolic risk in first-episode schizophrenia patients: A preliminary study

BACKGROUND

High incidence of metabolic syndrome has been evidenced in schizophrenia patients. However, gender-specific relationship with risk of metabolic disorders in first-episode schizophrenia has received poor systematic study.

AIM

We aimed at exploring the impact of sex difference on the parameters of glucolipid metabolism in first-episode psychosis schizophrenia (FEP) patients.

METHODS

We performed a post hoc analysis of data from our previously performed clinical trial. A total of 60 FEP patients and 28 healthy sex- and age-matched volunteers were included. Blood glucose and lipid metabolic profiles, as well as schizophrenia-related clinical symptoms were assessed. The body mass index, level of blood insulin and the homeostasis model assessment-insulin resistance index (HOMA-IR) were measured.

RESULTS

The FEP patients demonstrated significant increases in blood insulin concentration, insulin resistance and blood triglyceride when compared with healthy controls. In FEP patients, there were no differences in psychopathology measurements between the genders. BMI and HOMA-IR were significantly greater in male vs female FEP patients. In addition, a more severe dyslipidemia was also observed in male FEP patients, including an increased triglyceride level, an augmented LDL content and a decreased HDL concentration. Multivariate linear regression analysis demonstrated that the gender was significantly correlated to HOMA-IR.

CONCLUSION

These preliminary results suggest that male FEP patients may be more predisposed to insulin resistance and dyslipidemia than female FEP patients. These results could contribute to the understanding of prevention and treatment of metabolic syndrome in FEP patients.

Metabolic dysregulation in first-episode schizophrenia patients with respect to genetic variation in one-carbon metabolism

The aim of this study was to investigate the prevalence of metabolic disturbances in patients with first-episode schizophrenia (FES) and test the hypothesis that genetic variation in one-carbon metabolism may account for metabolic dysregulation in early psychosis. We measured fasting glucose, lipid profile parameters, homocysteine, folate and vitamin B12 in 135 patients with FES and 146 healthy controls (HCs). Polymorphisms in the following genes were determined: MTHFR (C677T and A1298C), MTHFD1 (G1958A), MTRR (A66G) and BHMT (G742A). Serum levels of folate and high-density lipoproteins (HDL) were significantly lower in patients with FES compared to HCs. In turn, serum levels of homocysteine and triglycerides were significantly higher in patients with FES than in HCs. Prevalence of hyperhomocysteinemia, low folate and HDL levels together with dyslipidemia was significantly higher in patients with FES compared to HCs. Higher homocysteine levels, lower vitamin B12 levels and the presence of metabolic syndrome were associated with higher severity of negative symptoms. None of studied polymorphisms was associated with schizophrenia risk. Several associations between studied polymorphisms and cardio-metabolic parameters were found. None of them remained significant after Bonferroni correction. Our results indicate that metabolic dysregulation in patients with FES is not associated with genetic variation in one-carbon metabolism.

Glucose disturbances in first-episode drug-naïve schizophrenia: Relationship to psychopathology

Accumulating evidence shows abnormal glucose metabolism in schizophrenia, even at the onset of psychosis. This study aims to examine the glucose and lipid metabolism in first-episode and drug naïve (FEDN) patients with schizophrenia and to explore their relationships with psychopathology, which have been under-investigated. Fasting glucose and lipid profiles, as well as homeostasis model of assessment-insulin resistance (HOMA-IR) index were determined in 120 never-medicated first-episode and 31 healthy control subjects matched for gender and age. The schizophrenia symptomatology was assessed by the positive and negative syndrome scale (PANSS). Our results showed that schizophrenia patients had a significantly higher level of fasting plasma glucose (p<0.0001) and insulin (p=0.038). HOMA, an indicator of insulin resistance was higher in the patients than in the healthy controls (p=0.008). No differences were found between the patients and healthy subjects in the levels of plasma triglycerides, high-density lipoprotein, and low-density lipoprotein, except that the cholesterol level was higher in the patients than health subjects (p=0.016). A significant negative association between plasma glucose levels and the PANSS positive symptom subscores was observed (p=0.013). Stepwise multiple regression analysis identified insulin resistance, insulin and the PANSS positive symptom subscore as significant predictor factors for glucose level. These results suggest that abnormal glucose metabolism may be associated with the pathogenesis and psychopathology of schizophrenia in the early phases of the disease process.

Parameters of glucose and lipid metabolism at the fasted state in drug-naïve first-episode patients with psychosis: Evidence for insulin resistance

Diabetes and dyslipidemia are common in patients with psychosis; this association may be partly related to adverse metabolic effects of antipsychotic medications. We assessed glucose and lipid metabolism during the fasted state in drug-naïve patients with psychosis. Fasting serum concentrations of total cholesterol, triglycerides, high density lipoprotein (HDL), glucose, insulin, connecting peptide (C-peptide), homeostatic model assessment index (HOMA-IR), glycated hemoglobin (HbA1C) and serum cortisol were compared between a group of 40 newly diagnosed drug-naïve, first-episode patients with psychosis and a group of 40 healthy controls, matched for age, sex and BMI. Total cholesterol, triglycerides and fasting glucose levels were similar, whereas insulin and C-peptide levels were higher and HDL marginally lower in the patients' group compared to those in healthy controls. Drug-naïve patients with psychosis were more insulin resistant (as assessed by the HOMA-R index) compared to healthy controls. Serum cortisol did not differ between the two groups. There is evidence that drug-naïve, first-episode patients with psychosis are more insulin resistant compared to healthy controls.

Reduced insulin-receptor mediated modulation of striatal dopamine release by basal insulin as a possible contributing factor to hyperdopaminergia in schizophrenia

Schizophrenia is a severe and chronic neuropsychiatric disorder which affects 1% of the world population. Using the brain imaging technique positron emission tomography (PET) it has been demonstrated that persons with schizophrenia have greater dopamine transmission in the striatum compared to healthy controls. However, little progress has been made as to elucidating other biological mechanisms which may account for this hyperdopaminergic state in this disease. Studies in animals have demonstrated that insulin receptors are expressed on midbrain dopamine neurons, and that insulin from the periphery acts on these receptors to modify dopamine transmission in the striatum. This is pertinent given that several lines of evidence suggest that insulin receptor functioning may be abnormal in the brains of persons with schizophrenia. Post-mortem studies have shown that persons with schizophrenia have less than half the number of cortical insulin receptors compared to healthy persons. Moreover, these post-mortem findings are unlikely due to the effects of antipsychotic treatment; studies in cell lines and animals suggest antipsychotics enhance insulin receptor functioning. Further, hyperinsulinemia - even prior to antipsychotic use - seems to be related to less psychotic symptoms in patients with schizophrenia. Collectively, these data suggest that midbrain insulin receptor functioning may be abnormal in persons with schizophrenia, resulting in reduced insulin-mediated regulation of dopamine transmission in the striatum. Such a deficit may account for the hyperdopaminergic state observed in these patients and would help guide the development of novel treatment strategies. We hypothesize that, (i) insulin receptor expression and/or function is reduced in midbrain dopamine neurons in persons with schizophrenia, (ii) basal insulin should reduce dopaminergic transmission in the striatum via these receptors, and (iii) this modulation of dopaminergic transmission by basal insulin is reduced in the brains of persons with schizophrenia.

Reduced insulin sensitivity is related to less endogenous dopamine at D2/3 receptors in the ventral striatum of healthy nonobese humans

BACKGROUND

Food addiction is a debated topic in neuroscience. Evidence suggests diabetes is related to reduced basal dopamine levels in the nucleus accumbens, similar to persons with drug addiction. It is unknown whether insulin sensitivity is related to endogenous dopamine levels in the ventral striatum of humans. We examined this using the agonist dopamine D2/3 receptor radiotracer [(11)C]-(+)-PHNO and an acute dopamine depletion challenge. In a separate sample of healthy persons, we examined whether dopamine depletion could alter insulin sensitivity.

METHODS

Insulin sensitivity was estimated for each subject from fasting plasma glucose and insulin using the Homeostasis Model Assessment II. Eleven healthy nonobese and nondiabetic persons (3 female) provided a baseline [(11)C]-(+)-PHNO scan, 9 of which provided a scan under dopamine depletion, allowing estimates of endogenous dopamine at dopamine D2/3 receptor. Dopamine depletion was achieved via alpha-methyl-para-tyrosine (64mg/kg, P.O.). In 25 healthy persons (9 female), fasting plasma and glucose was acquired before and after dopamine depletion.

RESULTS

Endogenous dopamine at ventral striatum dopamine D2/3 receptor was positively correlated with insulin sensitivity (r(7)=.84, P=.005) and negatively correlated with insulin levels (r(7)=-.85, P=.004). Glucose levels were not correlated with endogenous dopamine at ventral striatum dopamine D2/3 receptor (r(7)=-.49, P=.18). Consistently, acute dopamine depletion in healthy persons significantly decreased insulin sensitivity (t(24)=2.82, P=.01), increased insulin levels (t(24)=-2.62, P=.01), and did not change glucose levels (t(24)=-0.93, P=.36).

CONCLUSION

In healthy individuals, diminished insulin sensitivity is related to less endogenous dopamine at dopamine D2/3 receptor in the ventral striatum. Moreover, acute dopamine depletion reduces insulin sensitivity. These findings may have important implications for neuropsychiatric populations with metabolic abnormalities.

Telomere length in blood cells is related to the chronicity, severity, and recurrence rate of schizophrenia

INTRODUCTION

Telomere shortening is strongly associated with higher mortality rates and has been shown in a number of age-related diseases, such as cardiovascular disorders, diabetes mellitus, Alzheimer's disease, and psychiatric disorders. Oxidative stress is known to induce DNA breaks and genome instability. Telomeric DNA rich in guanosine is particularly sensitive to such oxidative damages. Psychosis is associated with a disequilibrium between free radical production and antioxidative defense. Although telomere attrition has been demonstrated in schizophrenia, no relationship has been reported between telomere length and severity of schizophrenia.

AIM

The aim of the present study was to identify differences in telomere length in peripheral blood cells between patients with chronic schizophrenia (C-SCZ) and early schizophrenia (E-SCZ) and to identify any relationship between telomere length and disease chronicity and severity.

METHODS

Relative average telomere lengths were determined using qPCR assay in patients with E-SCZ (n=42) and C-SCZ (n=44) hospitalized due to schizophrenia exacerbation. E-SCZ was diagnosed when less than 2 years had passed since the beginning of psychotic symptoms. The severity of symptoms was assessed using appropriate scales.

RESULTS

The severity of schizophrenia symptoms, as well as the number of psychotic episodes and hospital admissions, correlated significantly with telomere length in univariate analyses. Regression analysis revealed that a model incorporating study group (E-SCZ or C-ECZ), sex, and age, as well as the combined number of documented psychotic episodes and hospital admissions, can significantly predict the length of telomeres in patients with schizophrenia, with over 50% of variance in telomere length explained by the model (adjusted R (2)=0.512).

CONCLUSION

The results of the current study indicate that the recurrence of psychotic symptoms as well as their intensity and chronicity may be correlated with telomere attrition, which is well known to contribute to the development of premature senescence and age-related diseases.