Olanzapine treatment is associated with reduced high molecular weight adiponectin in serum: a potential mechanism for olanzapine-induced insulin resistance in patients with schizophrenia

Differences in metabolic biomarkers in people with schizophrenia who are of Mexican descent compared to non-Hispanic whites

Metabolic dysfunction is highly prevalent and contributes to premature mortality among people with schizophrenia (PwS), especially in Hispanic/Latino/a/x/e PwS, compared to non-Hispanic White (NHW) PwS. This study evaluated the relative contributions of Mexican descent and schizophrenia diagnosis to metabolic biomarker levels. This cross-sectional study included 115 PwS and 102 non-psychiatric comparison (NC) participants - English-speakers aged 26-66 years, 27% Mexican descent, and 52% women across both groups. Assessments included evaluations of BMI, psychopathology, and fasting metabolic biomarkers. We used ANOVA analyses to compare metabolic outcomes between diagnostic and ethnic subgroups, linear regression models to examine associations between Mexican descent and metabolic outcomes, and Spearman's correlations to examine relationships between metabolic outcomes and illness-related variables in PwS. Mexican PwS had higher hemoglobin A1c levels, insulin resistance, and body mass index than NHW PwS. Mexican descent was associated with higher hemoglobin A1c levels, insulin resistance, body mass index, and leptin levels, controlling for age, sex, depression, education, and smoking. Among Mexican PwS, worse negative symptoms were associated with greater insulin resistance. These findings support the possibility of ethnicity-based differences in metabolic dysregulation, though further investigation is warranted to create targeted health interventions for Hispanic PwS.

Fenofibrate ameliorates olanzapine's side effects without altering its central effect: emphasis on FGF-21-adiponectin axis

The present work was designed to investigate whether fenofibrate could ameliorate olanzapine deleterious effect on insulin resistance via its effect on fibroblast growth factor-21 (FGF-21)-adiponectin axis without affecting olanzapine antipsychotic effect in postweaning socially isolated reared female rats. Treatment with olanzapine (6 mg/kg, intraperitoneally) or fenofibrate (100 mg/kg, orally) have been started 5 weeks after isolation, then behavioral tests, hippocampal content of neurotransmitters, and brain-derived neurotrophic factor (BDNF) were assessed. Moreover, insulin resistance, lipid profile, FGF-21, adiponectin, inflammatory, and oxidative stress markers of adipose tissue were assessed. Treatment of isolated-reared animals with olanzapine, or fenofibrate significantly ameliorated the behavioral and biochemical changes induced by postweaning social isolation. Co-treatment showed additive effects in improving hippocampal BDNF level. Besides, fenofibrate reduced the elevation in weight gain, adiposity index, insulin resistance, lipid profile, and FGF-21 level induced by olanzapine treatment. Also, fenofibrate increased adiponectin level which was reduced upon olanzapine treatment. Moreover, fenofibrate improved both adipose tissue oxidative stress and inflammatory markers elevation as a result of olanzapine treatment. Fenofibrate could ameliorate olanzapine-induced insulin resistance without affecting its central effect in isolated reared rats via its action on FGF-21-adiponectin axis.

Opipramol Inhibits Lipolysis in Human Adipocytes without Altering Glucose Uptake and Differently from Antipsychotic and Antidepressant Drugs with Adverse Effects on Body Weight Control

Treatment with several antipsychotic drugs exhibits a tendency to induce weight gain and diabetic complications. The proposed mechanisms by which the atypical antipsychotic drug olanzapine increases body weight include central dysregulations leading to hyperphagia and direct peripheral impairment of fat cell lipolysis. Several investigations have reproduced in vitro direct actions of antipsychotics on rodent adipocytes, cultured preadipocytes, or human adipose tissue-derived stem cells. However, to our knowledge, no such direct action has been described in human mature adipocytes. The aim of the present study was to compare in human adipocytes the putative direct alterations of lipolysis by antipsychotics (haloperidol, olanzapine, ziprazidone, risperidone), antidepressants (pargyline, phenelzine), or anxiolytics (opipramol). Lipolytic responses to the tested drugs, and to recognized lipolytic (e.g., isoprenaline) or antilipolytic agents (e.g., insulin) were determined, together with glucose transport and amine oxidase activities in abdominal subcutaneous adipocytes from individuals undergoing plastic surgery. None of the tested drugs were lipolytic. Surprisingly, only opipramol exhibited substantial antilipolytic properties in the micromolar to millimolar range. An opipramol antilipolytic effect was evident against isoprenaline-, forskolin-, or atrial natriuretic peptide-stimulated lipolysis. Opipramol did not impair insulin activation of glucose transport but inhibited monoamine oxidase (MAO) activity to the same extent as antidepressants recognized as MAO inhibitors (pargyline, harmine, or phenelzine), whereas antipsychotics were inefficient. Considering its unique properties, opipramol, which is not associated with weight gain in treated patients, is a good candidate for drug repurposing because it limits exaggerated lipolysis, prevents hydrogen peroxide release by amine oxidases in adipocytes, and is thereby of potential use to limit lipotoxicity and oxidative stress, two deleterious complications of diabetes and obesity.

The Role of Adiponectin in the Pathogenesis of Metabolic Disturbances in Patients With Schizophrenia

Antipsychotic-induced metabolic disturbance is a common adverse event occurring in patients treated with antipsychotic drugs. The mechanisms underlying metabolic dysregulation are complex, involving various neurochemical and hormonal systems, the interaction of genetic and lifestyle risk factors, and the antipsychotic drug prescribed. Recently, there has been increasing interest in the relationship between antipsychotic-induced metabolic disturbances and body weight regulatory hormones such as adiponectin. Adiponectin, an adipocyte-derived protein related to insulin sensitivity, weight gain, and anti-inflammation, has attracted great attention because of its potential role of being a biomarker to predict cardiovascular and metabolic diseases. Previous studies regarding the effects of antipsychotics on blood adiponectin levels have shown controversial results. Several factors might contribute to those inconsistent results, including different antipsychotic drugs, duration of antipsychotic exposure, age, sex, and ethnicity. Here we summarize the existing evidence on the link between blood adiponectin levels and metabolic disturbances related to antipsychotic drugs in patients with schizophrenia. We further discuss the effects of individual antipsychotics, patients' gender, ethnicity, age, and treatment duration on those relationships. We propose that olanzapine and clozapine might have a time-dependent biphasic effect on blood adiponectin levels in patients with schizophrenia.

Adipose tissue as a target for second-generation (atypical) antipsychotics: A molecular view

Schizophrenia is a neuropsychiatric disorder that chronically affects 21 million people worldwide. Second-generation antipsychotics (SGAs) are the cornerstone in the management of schizophrenia. However, despite their efficacy in counteracting both positive and negative symptomatology of schizophrenia, recent clinical observations have described an increase in the prevalence of metabolic disturbances in patients treated with SGAs, including abnormal weight gain, hyperglycemia and dyslipidemia. While the molecular mechanisms responsible for these side-effects remain poorly understood, increasing evidence points to a link between SGAs and adipose tissue depots of white, brown and beige adipocytes. In this review, we survey the present knowledge in this area, with a particular focus on the molecular aspects of adipocyte biology including differentiation, lipid metabolism, thermogenic function and the browning/beiging process.

A novel biomarker of cardiometabolic pathology in schizophrenia?

BACKGROUND

Persons with schizophrenia and schizoaffective disorder (PwS) have high rates of cardiometabolic pathology that contributes to premature mortality. Adiponectin is a metabolic hormone affecting insulin sensitivity and inflammation, and is active in the brain. High-molecular weight (HMW) adiponectin is considered a more sensitive marker of metabolic dysfunction than total adiponectin, but has been poorly studied in schizophrenia.

METHODS

This was a cross-sectional study of 100 PwS, age range 26-68 years (46 women), and 93 age- and sex-comparable non-psychiatric comparison (NC) subjects. Assessments included measures of psychopathology, physical health, cognitive function, and circulating biomarkers of metabolic dysfunction (HMW adiponectin, lipids, insulin resistance) and inflammation (high-sensitivity C-reactive protein or hs-CRP, Tumor Necrosis Factor-α, Interleukin-6, and Interleukin-10).

RESULTS

HMW adiponectin levels were lower in PwS compared to NCs. Lower HMW adiponectin levels were associated with higher body mass index (BMI), higher Framingham risk for coronary heart disease, higher number of metabolic syndrome criteria, greater insulin resistance, lower HDL cholesterol, and higher hs-CRP in both groups. Only in PwS, lower HMW adiponectin correlated with younger age. In the best-fit regression models of HMW adiponectin, lower levels were associated with lower HDL cholesterol and minority race/ethnicity in both groups; but with younger age, non-smoking, higher insulin resistance, and a diagnosis of schizoaffective disorder only among PwS, and with male sex, better cognitive functioning, and higher hs-CRP levels in NCs only.

DISCUSSION

HMW adiponectin may be a promising biomarker of cardiometabolic health, especially among PwS. Adiponectin is a potential target for lifestyle and pharmacological interventions. Research on the possible role of HMW adiponectin in modifying cardiometabolic pathology in schizophrenia is needed.

Genetic association and meta-analysis of a schizophrenia GWAS variant rs10489202 in East Asian populations

Previous genome-wide association studies (GWAS) suggest that rs10489202 in the intron of MPC2 (mitochondrial pyruvate carrier 2) is a risk locus for schizophrenia in Han Chinese populations. To validate this discovery, we conducted a replication analysis in an independent case-control sample of Han Chinese ancestry (437 cases and 2031 controls), followed by a meta-analytic investigation in multiple East Asian samples. In the replication analysis, rs10489202 showed marginal association with schizophrenia (two-tailed P = 0.071, OR = 1.192 for T allele); in the meta-analysis using a total of 14,340 cases and 20,349 controls from ten East Asian samples, rs10489202 was genome-wide significantly associated with schizophrenia (two-tailed P = 3.39 × 10^-10, OR = 1.161 for T allele, under the fixed-effect model). We then performed an explorative investigation of the association between this SNP and bipolar disorder, as well as a major depressive disorder, and the schizophrenia-predisposing allele was associated with an increased risk of major depressive disorder in East Asians (two-tailed P = 2.49 × 10^-2, OR = 1.103 for T allele). Furthermore, expression quantitative trait loci (eQTL) analysis in lymphoblastoid cell lines from East Asian donors (N = 85 subjects) revealed that rs10489202 was specifically and significantly associated with the expression of TIPRL gene (P = 5.67 × 10^-4). Taken together, our data add further support for the genetic involvement of this genomic locus in the susceptibility to schizophrenia in East Asian populations, and also provide preliminary evidence for the underlying molecular mechanisms.

Body and liver fat content and adipokines in schizophrenia: a magnetic resonance imaging and spectroscopy study

RATIONALE

Although antipsychotic treatment often causes weight gain and lipid abnormalities, quantitative analyses of tissue-specific body fat content and its distribution along with adipokines have not been reported for antipsychotic-treated patients.

OBJECTIVES

The purposes of the present study were to quantitatively assess abdominal and liver fat in patients with schizophrenia on antipsychotic treatment and age- and body mass index (BMI)-matched healthy controls and to evaluate their associations with plasma leptin and adiponectin levels.

METHODS

In 13 schizophrenia patients on antipsychotic treatment and 11 age- and BMI-matched controls, we simultaneously quantified visceral and subcutaneous fat content using T1-weighted magnetic resonance imaging and liver fat content by ¹H magnetic resonance spectroscopy. Associations of tissue-specific fat content with plasma levels of leptin and adiponectin were evaluated.

RESULTS

Plasma adiponectin level (μg/mL) was not statistically different between groups (7.02 ± 2.67 vs. 7.59 ± 2.92), whereas plasma leptin level (ng/mL) trended to be higher in patients than in controls (11.82 ± 7.89 vs. 7.93 ± 5.25). The values of liver fat (%), visceral fat (L), and subcutaneous fat (L) were 9.64 ± 8.03 vs. 7.07 ± 7.35, 4.41 ± 1.64 vs. 3.31 ± 1.97, and 8.37 ± 3.34 vs. 7.16 ± 2.99 in patients vs. controls, respectively. Liver fat content was inversely correlated with adiponectin in controls (r =  - 0.87, p < 0.001) but not in patients (r =  - 0.26, p = 0.39). In both groups, visceral fat was inversely associated with adiponectin (controls : r =  - 0.66, p = 0.03; patients : r =  - 0.65, p = 0.02), while subcutaneous fat was positively correlated with leptin (controls : r = 0.90, p < 0.001; patients : r = 0.67, p = 0.01).

CONCLUSIONS

These findings suggest that antipsychotic treatment may disrupt the physiological relationship between liver fat content and adiponectin but does not essentially affect the associations of adiponectin and leptin with visceral and subcutaneous compartments.

The effects of antipsychotics on weight gain, weight-related hormones and homocysteine in children and adolescents: a 1-year follow-up study

To analyze weight gain, metabolic hormones, and homocysteine (Hcys) levels in children and adolescents on antipsychotics (AP) during a year-long follow-up. 117 patients, AP-naïve or quasi-naïve (less than 30 days on AP), were included. Weight, body mass index (BMI), BMI z-score (z-BMI), and levels of leptin, insulin, insulin resistance (HOMA-IR), adiponectin, ghrelin, thyroid stimulating hormone (TSH), free thyroxine (FT4), and Hcys were measured at baseline, and at 3, 6, and 12 months, while patients remained on the same AP. Patients (mean age: 14.4 ± 3 years; 64.1 % male) were on risperidone (N = 84), olanzapine (N = 20) or quetiapine (N = 13) from baseline up to 1-year follow-up and significantly increased weight (5.8 ± 4.3 kg at 3-month, 8.1 ± 6.1 kg at 6-month, and 11.6 ± 7.0 kg at 1 year), BMI, and z-BMI. Leptin levels significantly increased from baseline to 3 and 6 months, as did TSH levels from baseline to 3 months, while FT4 levels decreased from baseline to 3 and 6 months. Patients with BMI >85th percentile at baseline (N = 16) significantly increased weight, BMI, and z-BMI, more than patients with normal BMI over time. Higher baseline levels of insulin, HOMA-IR, and leptin were associated with increased weight/BMI during follow-up, while higher baseline levels of FT4, adiponectin, and ghrelin were associated with lower weight/BMI during follow-up. All AP were associated with increased weight and BMI/z-BMI in all of the assessments; however, at 1-year assessment, this increase was significantly higher for patients on quetiapine. Both higher baseline levels of insulin, HOMA-IR, and leptin, as well as being overweight/obese at baseline were associated with increased weight/BMI during 1-year follow-up in children and adolescents on AP. Awareness of weight-related parameters in this population may help inform decisions regarding AP prescriptions.

Adiposity-independent hypoadiponectinemia as a potential marker of insulin resistance and inflammation in schizophrenia patients treated with second generation antipsychotics

OBJECTIVE

The purpose of this study was to explore body fat independent effect of second generation antipsychotics (SGAs) on measures of glucose and adipokine homeostasis, and markers of inflammation.

METHOD

Eight non-diabetic men with schizophrenia (age: 55±3years, BMI: 29.7±1.2kg/m(2)) on SGAs were studied after an overnight fast. DXA and single-cut CT of abdomen were respectively used for the assessment of total body and abdominal fat. Blood samples were collected for measurements of glucose, insulin, leptin, adiponectin, C-reactive protein (CRP), and TNF-α. Data in schizophrenic subjects were compared to eight age (55±2.8years) and BMI (29.6±1.1kg/m(2)) matched healthy men.

RESULTS

The results were significant for markedly decreased serum adiponectin in schizophrenia patients (4.6±0.9 vs 11.1±1.5ng/mL, p=0.001). Lower levels of adiponectin in schizophrenia men were associated with significant increases in insulin resistance (4.2±0.7 vs 1.7±0.4, p=0.004), CRP (3.5±1.2 vs 1.2±0.3, p=0.037), and leptin (12±1.4 vs 8.5±1.4ng/mL, p=0.05). Various measures of adiposity, including fat mass index (FMI) and abdominal fat were not different in the two study groups.

CONCLUSIONS

These findings in the context of comparable age and total body/abdominal fat mass are assumed to be either disease specific, and/or treatment inflicted. The definitive invoking etiology and a presumptive role of hypoadiponectinemia in the development of insulin resistance and increased risk of inflammation warrant future investigation.

Second-generation antipsychotics and adiponectin levels in schizophrenia: A comparative meta-analysis

People with schizophrenia treated with second-generation antipsychotics (SGAs) have lower plasma adiponectin levels, as compared with general population, that may lead to metabolic abnormalities. However, the contribution of different SGAs on adiponectin dysregulation is still unclear. The objective of this systematic review and meta-analysis was to estimate differences in adiponectin levels among people with schizophrenia treated with different SGAs. We systematically searched for observational studies published up to March 2015 in main electronic databases. Different SGAs were included if data on adiponectin were available from at least three different samples involving as a minimum five participants per treatment arm. Standardized mean differences with relevant 95% confidence intervals were generated. I(2) was used to test heterogeneity among studies. Eight studies were included with data suitable for carrying out four different comparisons: Clozapine vs. Olanzapine (including n=877 individuals with schizophrenia); Clozapine vs. Risperidone (n=660); Olanzapine vs. Risperidone (n=738); Quetiapine vs. Risperidone (n=186). There were no differences on adiponectin levels between people taking Clozapine and those taking Olanzapine (p=0.86), but high heterogeneity was detected (I(2)=82%). Both individuals taking Clozapine (p<0.001; I(2)=0%) and those taking Olanzapine (p=0.02; I(2)=9%), but not subjects treated with Quetiapine (p=0.47; I(2)=0%), had adiponectin levels significantly lower than people taking Risperidone. Our findings are consistent with previous evidence showing greater metabolic abnormalities attributable to Clozapine and Olanzapine, as compared with other SGAs. Although mechanisms whereby both these SGAs influence adiponectin remain unexplained, its reduction might mediate relevant abnormalities. Prospective evaluations of long-term effects of different SGAs on adiponectin are needed.

Scoping review of research in Australia on the co-occurrence of physical and serious mental illness and integrated care

The physical health of people with serious mental illness (SMI) has become a focal area of research. The aim of the present study was to ascertain the attention and distribution of research from within Australia on physical illness and SMI co-occurrence, and to identify gaps. A scoping review of peer-reviewed research literature from Australia, published between January 2000 and March 2014, was undertaken through an electronic literature search and coding of papers to chart trends. Four trends are highlighted: (i) an almost threefold increase in publications per year from 2000-2006 to 2007-2013; (ii) a steady release of literature reviews, especially from 2010; (iii) health-related behaviours, smoking, integrated-care programmes, and antipsychotic side-effects as the most common topics presented; and (iv) paucity of randomized, controlled trials on integrated-care models. Despite a marked increase in research attention to poorer physical health, there remains a large gap between research and the scale of the problem previously identified. More papers were descriptive or reviews, rather than evaluations of interventions. To foster more research, 12 research gaps are outlined. Addressing these gaps will facilitate the reduction of inequalities in physical health for people with SMI. Mental health nurses are well placed to lead multidisciplinary, consumer-informed research in this area.

Plasma adiponectin levels in schizophrenia and role of second-generation antipsychotics: a meta-analysis

BACKGROUND

People with schizophrenia are more likely than general population to suffer from metabolic abnormalities, with second-generation antipsychotics (SGAs) increasing the risk. Low plasma adiponectin levels may lead to metabolic dysregulations but evidence in people with schizophrenia, especially for the role of SGAs, is still inconclusive.

OBJECTIVE

To compare plasma adiponectin levels between people with schizophrenia and healthy controls, and to estimate the relative effect of schizophrenia and SGAs on adiponectin.

METHODS

We performed a systematic review and meta-analysis of observational studies published up to 13 June 2014 in main electronic databases. Pooled standardized mean differences (SMDs) between index and control groups were generated. Appropriate subanalyses and additional subgroup analyses were carried out.

RESULTS

Data from 2735 individuals, 1013 with and 1722 without schizophrenia, respectively, were analysed. Schizophrenia was not associated with lower adiponectin levels (SMD of -0.28, 95%CI: -0.59, 0.04; p=0.09). However, individuals with schizophrenia taking SGAs had plasma levels significantly lower than controls (p=0.002), which was not the case of drug free/drug naïve subjects (p=0.52). As regards single antipsychotic drugs clozapine (p<0.001) and olanzapine (p=0.04)--but not risperidone (p=0.88)--were associated with adiponectin levels lower than controls.

CONCLUSIONS

People with schizophrenia per se may not have levels of adiponectin lower than controls, though treatment with SGAs is associated with this metabolic abnormality. This bears clinical significance because of hypoadiponectinemia involvement in cardiovascular diseases, even if mechanisms whereby SGAs affect adiponectin remain unexplained. Longitudinal studies evaluating long-term effects of SGAs on adiponectin are needed.

The effects of atypical antipsychotic usage duration on serum adiponectin levels and other metabolic parameters

OBJECTIVE

Although atypical antipsychotics are well-tolerated and effective treatment options for schizophrenia, they have metabolic side effects, including weight gain and increased risk of Type II Diabetes Mellitus (DM). Adiponectin, produced exclusively in adipocytes, is the most abundant serum adipokine. Low levels of adiponectin are correlated with DM, insulin resistance and coronary heart disease. Usage of atypical antipsychotics may create a risk of metabolic syndrome. The aim of this study was to evaluate the effects of antipsychotic usage on parameters related to development of metabolic syndrome.

MATERIALS AND METHODS

A total of 27 patients (n=27) (13 women and 14 men) were recruited from our out-patient psychiatry clinic. All patients had been treated with atypical antipsychotics for at least 3 months and were in remission. Patients were evaluated for levels of HDL (High Density Lipoprotein), LDL (Low Density Lipoprotein), TG (Triglyceride) total cholesterol and fasting blood glucose, body weight, BMI (Body Mass Index), waist circumference and serum adiponectin levels.

RESULTS

Serum adiponectin levels were significantly lower (p:0.000) and body weights were significantly higher (p:0.003) in the patients who had been using atypical antipsychotics for longer than a year in comparison to patients who had been using atypical antipsychotics for one year or less.

CONCLUSION

Our findings supported the hypothesis that the length of administration of atypical antipsychotics has an effect on metabolic changes. They also highlight the fact that when investigating metabolic changes generated by atypical antipsychotic effects, the length of time that the patient has been on the atypical antipsychotics should also be considered.

Molecular pathophysiology of metabolic effects of antipsychotic medications

Antipsychotic medications are associated with major metabolic changes that contribute to medical morbidity and a significantly shortened life span. The mechanisms for these changes provide us with a broader understanding of central nervous and peripheral organ-mediated metabolic regulation. This paper reviews an extensive literature regarding putative mechanisms for effects of antipsychotic medications on weight regulation and glucose homeostasis as well as potential inherent metabolic risks of schizophrenia itself. We present a model suggesting that peripheral antipsychotic targets play a critical role in drug-induced weight gain and diabetes. We propose that a better understanding of these mechanisms will be crucial to developing improved treatments for serious mental illnesses as well as providing potentially novel therapeutic targets of metabolic disorders including diabetes.

Association study of the HTR2C, leptin and adiponectin genes and serum marker analyses in clozapine treated long-term patients with schizophrenia

Clozapine treatment is associated with weight gain and cardio-metabolic consequences among patients with schizophrenia. Polymorphisms of leptin, serotonin receptor HTR2C and adiponectin genes have been associated with antipsychotic-induced weight gain and metabolic comorbidity. However, the results of the studies so far are inconclusive. The aim of the present study was first to test for a possible role of serum leptin and adiponectin levels as a marker of weight gain in association with inflammatory cytokines/adipokines (IL-6, IL-1Ra, hs-CRP and adipsin), and second to study associations between SNPs LEP rs7799039 (-2548 A/G), ADIPOQ rs1501299 and HTR2C rs1414334 and weight gain and levels of leptin and adiponectin, in 190 patients with schizophrenia on clozapine treatment, with retrospectively assessed weight change and cross-sectionally measured cytokine levels. A strong association was found between serum levels of leptin and weight gain and cytokines/adipokines related to metabolic comorbidity, especially among female patients (in women leptin vs. weight gain, IL-6 and IL-1Ra, P<0.001; in men leptin vs. weight gain, P=0.026, leptin vs. IL-1Ra, P<0.001). In male patients low adiponectin level was a more specific marker of clozapine-induced weight gain (P=0.037). The results of the present study do not support a major role of SNPs LEP rs7799039, ADIPOQ rs1501299 and HTR2C rs1414334 in the regulation of weight gain or association of serum levels of leptin and adiponectin and corresponding studied SNPs in patients with schizophrenia on clozapine treatment.

Cytokine and adipokine alterations in patients with schizophrenia treated with clozapine

Metabolic syndrome is associated with both schizophrenia and antipsychotic medication, especially clozapine, with alterations in inflammatory cytokines and adipokines. However, the data in this field is heterogeneous and the sample sizes of the patients are limited. In this study we assessed the serum levels of cytokines/adipokines IL-6, IL-1Ra, hs-CRP and adiponectin, and components of metabolic syndrome in 190 patients with treatment resistant schizophrenia treated with clozapine. Substantial metabolic comorbidity was found in this patient group; overweight/obesity, smoking, hypertriglyceridemia, low HDL-cholesterol, high HOMA-IR, low adiponectin levels, elevated hs-CRP levels and elevated IL-1Ra levels. Elevated IL-1Ra levels are associated with insulin resistance, obesity and hypertriglyceridemia. Low adiponectin levels were associated with hypertriglyceridemia, low HDL cholesterol and high glucose, and in male patients also with obesity and high IL-1Ra levels. After controlling for confounding factors age and smoking, levels of IL-1Ra and hs-CRP associated with obesity, and the levels of IL-6 associated with obesity in female patients. We conclude that there are partly gender dependent cytokine and adipokine alterations in patients with schizophrenia on clozapine treatment associated with metabolic comorbidity. The genetic background of these cytokine alterations needs to be further investigated.

A novel insulin receptor-signaling platform and its link to insulin resistance and type 2 diabetes

Insulin-induced insulin receptor (IR) tyrosine kinase activation and insulin cell survival responses have been reported to be under the regulation of a membrane associated mammalian neuraminidase-1 (Neu1). The molecular mechanism(s) behind this process is unknown. Here, we uncover a novel Neu1 and matrix metalloproteinase-9 (MMP-9) cross-talk in alliance with neuromedin B G-protein coupled receptor (GPCR), which is essential for insulin-induced IR activation and cellular signaling. Neu1, MMP-9 and neuromedin B GPCR form a complex with IRβ subunit on the cell surface. Oseltamivir phosphate (Tamiflu®), anti-Neu1 antibodies, broad range MMP inhibitors piperazine and galardin (GM6001), MMP-9 specific inhibitor (MMP-9i), and GPCR neuromedin B specific antagonist BIM-23127 dose-dependently inhibited Neu1 activity associated with insulin stimulated rat hepatoma cells (HTCs) that overly express human IRs (HTC-IR). Tamiflu, anti-Neu1 antibodies and MMP-9i attenuated phosphorylation of IRβ and insulin receptor substrate-1 (IRS1) associated with insulin-stimulated cells. Olanzapine, an antipsychotic agent associated with insulin resistance, induced Neu3 sialidase activity in WG544 or 1140F01 human sialidosis fibroblast cells genetically defective in Neu1. Neu3 antagonist 2-deoxy-2,3-didehydro-N-acetylneuraminic acid (DANA) and anti-Neu3 antibodies inhibited sialidase activity associated with olanzapine treated murine Neu4 knockout macrophage cells. Olanzapine attenuated phosphorylation of IGF-R and IRS1 associated with insulin-stimulated human wild-type fibroblast cells. Our findings identify a novel insulin receptor-signaling platform that is critically essential for insulin-induced IRβ tyrosine kinase activation and cellular signaling. Olanzapine-induced Neu3 sialidase activity attenuated insulin-induced IGF-R and IRS1 phosphorylation contributing to insulin resistance.

Fatal diabetic ketoacidosis and antipsychotic medication

Hyperglycemia and new onset diabetes have been described with certain antipsychotic medications and some of the initial presentations are fatal diabetic ketoacidosis (DKA). We report 17 deaths due to DKA in psychiatric patients treated with second generation antipsychotic medications. Death certificates and toxicology data were searched for DKA and hyperglycemia. We reviewed the medical examiner records which included the autopsy, toxicology, police, and medical examiner investigators' reports. The decedents ranged in age from 32 to 57 years (average 48 years). There were 15 men and two women. The immediate cause of death was DKA in all. The psychiatric disorders included: 10 schizophrenia, three bipolar/schizophrenia, two bipolar, and two major depression. The most frequent atypical antipsychotic medications found were quetiapine and olanzapine followed by risperidone. In 16 deaths, we considered the medication as primary or contributory to the cause of death.

Dysregulation of adipocytokines related to second-generation antipsychotics in normal fasting glucose patients with schizophrenia

OBJECTIVE

The underlying mechanism for second-generation antipsychotic (SGA)-related glucose-lipid metabolic dysfunction is not fully understood. Recent studies have suggested a possible impact of SGAs on endocrine regulation, especially on adipocytokines. We examined the effect of each SGA on various adipocytokines in normal fasting glucose (NFG) subjects.

METHOD

The study population comprised 113 Japanese inpatients with schizophrenia who were treated with olanzapine, risperidone, or quetiapine, and 123 healthy control (CONT) volunteers. All of the subjects were diagnosed with NFG. Plasma concentration of adiponectin, leptin, tumor necrosis factor α, total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were compared between the SGA and CONT groups.

RESULTS

Second-generation antipsychotic subjects had significantly higher leptin levels in comparison to the CONT subjects. The plasma concentration of adiponectin, total cholesterol, and high-density lipoprotein cholesterol in the SGA subjects were significantly lower than those in the CONT subjects. There were no significant differences in tumor necrosis factor α, triglyceride, and low-density lipoprotein cholesterol levels between the 2 groups. In a stepwise multiple regression analysis, olanzapine was found to be a factor that contributed to decreased adiponectin levels, and the CONT subjects were detected to be a factor associated with lower leptin levels.

CONCLUSIONS

The present study indicates the possibility that the administration of SGAs may affect adipocytokines in the NFG stage, excluding the impaired fasting glucose group, which is in the transition stage into diabetes mellitus.

Association of plasma retinol-binding protein-4, adiponectin, and high molecular weight adiponectin with metabolic adversities in patients with schizophrenia

OBJECTIVE

Metabolic adversities are prevalent in patients with schizophrenia. Retinol-binding protein 4 (RBP4) and high molecular weight (HMW) adiponectin have been recently found to be associated with metabolic features in non-psychiatric population. The study aimed to evaluate the associations between metabolic features and RBP4, total adiponectin, and HMW adiponectin in patients with schizophrenia.

METHODS

We recruited 109 patients with schizophrenia treated with clozapine or haloperidol and evaluated their body mass index (BMI), waist circumference, blood pressure, and fasting triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), fasting plasma glucose, insulin, RBP4, total adiponectin, and HMW adiponectin levels.

RESULTS

We found that patients with metabolic syndrome (MS) had higher RBP4 level, and lower total adiponectin and HMW adiponectin levels than those without MS. There were no significant differences in metabolic features and adipocytokine levels between patients treated with clozapine and haloperidol. Most of the metabolic indexes were significantly correlated with the levels of adipocytokines. After adjusting the effects of age, gender, and BMI, marginal significant correlations existed between TG and RBP4 levels; HDL-C and total adiponectin and HMW adiponectin; insulin and HOMA-IR and HMW adiponectin. Receiver operating curve analysis showed that all of the three adipocytokines could differentiate patients with MS from those without MS. Meanwhile, total adiponectin and HMW adiponectin, but not RBP4, had the differentiating power for insulin resistance.

CONCLUSION

Higher RBP4 and lower total adiponectin and HMW adiponectin levels were observed in schizophrenic patients with MS. Only HMW adiponectin is marginally correlated with insulin sensitivity. The finding that metabolic profiles, but not the antipsychotic types, are associated with adipocytokine levels should be confirmed in longitudinal studies.

Influence of resting energy expenditure on weight gain in adolescents taking second-generation antipsychotics

BACKGROUND & AIMS

Weight gain is an undesirable side effect of second-generation antipsychotics (SGAs). We performed this study to examine the influence of SGAs on resting energy expenditure (REE) and the relationship of REE to weight gain in adolescent patients.

METHODS

Antipsychotic-naïve or quasi-naïve (<72 h of exposure to antipsychotics) adolescent patients taking olanzapine, quetiapine, or risperidone in monotherapy were followed up for one year. We performed a prospective study (baseline, 1, 3, 6, and 12 months after treatment) based on anthropometric measurements, bioelectrical impedance analysis, and indirect calorimetry (Deltatrac™ II MBM-200) to measure REE. We also analyzed metabolic and hormonal data and adiponectin concentrations.

RESULTS

Forty-six out of the 54 patients that started treatment attended at least 2 visits, and 16 completed 1 year of follow-up. Patients gained 10.8 ± 6.2 kg (60% in the form of fat mass) and increased their waist circumference by 11.1 ± 5.0 cm after 1 year of treatment. The REE/kg body mass ratio decreased (p = 0.027), and the REE/percentage fat-free mass (FFM) ratio increased (p = 0.007) following the fall in the percentage of FFM during treatment. Weight increase was significantly correlated with the REE/percentage FFM ratio at all the visits (1-3-6-12 months) (r = 0.69, p = 0.004 at 12 months).

CONCLUSIONS

SGAs seem to induce a hypometabolic state (reflected as decreased REE/kg body mass and increased REE/percentage FFM). This could explain, at least in part, the changes in weight and body composition observed in these patients.

Weight gain and ghrelin level after olanzapine monotherapy

BACKGROUND

The present study aimed to explore the association between weight gain and ghrelin among schizophrenic patients under olanzapine treatment. The relationships among weight gain and adiponectin, fasting glucose, and lipid profile were also investigated.

METHODS

This case-control study recruited 66 schizophrenic patients from the Chung Shan Medical University Hospital in central Taiwan. All of them were undergoing olanzapine monotherapy and were categorized into weight gain (WG) and non-weight gain (NWG) groups. Subjects in the control group (CG) were recruited from a healthy community population based on a health survey (n=119). Multivariate logistic regression was used to explore the association of ghrelin with weight gain.

RESULTS

The 66 schizophrenic patients had a mean age of 36.3±9.6 years, with 50% females. They received olanzapine treatment for a mean period of 8.3±7.5 years. The control group had a mean age of 38.9±9.3 years and 52.9% were females. Comparing fasting serum ghrelin levels, the WG group had the lowest mean value (822.3±253.1 pg/ml) while the control group had the highest mean value (1261.2±1639.7 pg/ml), with a significant difference between the two (p=0.01). In contrast, there was no difference in adiponectin levels among the three groups. The WG and NWG groups had higher diastolic blood pressure than the control group, but systolic blood pressure was the same in all three groups. There was no difference in the total cholesterol level although the WG and NWG groups had higher triglyceride (TG) and glucose levels than the control group.

CONCLUSIONS

Weight gain after olanzapine treatment is associated with lower ghrelin level. Olanzapine is linked to elevated diastolic pressure, TG, and glucose, regardless of the weight gain.

Converging evidence of blood-based biomarkers for schizophrenia: an update

This chapter has carried out a review of the literature and combined this with the results of in-house studies to identify candidate blood-based biomarkers for schizophrenia and antipsychotic drug response. Literature searches retrieved 185 publications describing a total of 273 schizophrenia biomarkers identified in serum and/or plasma. Examination of seven in-house multicenter studies resulted in the identification of 137 serum/plasma biomarkers. Taken together, the findings suggested an ongoing immunological and inflammatory process in schizophrenia. This was accompanied by altered cortisol levels which suggested activated stress response and altered hypothalamic-pituitary-adrenal axis function in these patients. The authors conclude that such biomarkers may prove useful as additional parameters for characterizing specific immune and/or metabolic or hormonal subsystems in schizophrenia and might, therefore, facilitate the development of future patient stratification and personalized medicine strategies.

Plasma orexin A, ghrelin, cholecystokinin, visfatin, leptin and agouti-related protein levels during 6-week olanzapine treatment in first-episode male patients with psychosis

The objective of the study was to investigate the change of body mass index (BMI), waist circumference, lipid profile, leptin, ghrelin, orexin, visfatin, agouti-related protein, and cholecystokinin levels during 6 weeks of olanzapine treatment in newly diagnosed first-episode drug naive, young adult, nonobese male patients with psychosis. Twenty male participants who were all first-episode drug naive psychotic patients without prominent affective signs and symptoms and 22 healthy male controls of similar age were included. BMI, waist circumference, fasting glucose, and lipid profiles were measured, and Positive and Negative Syndrome Scale and Brief Psychiatric Rating Scale scores were obtained at baseline, during the second and sixth week of treatment, and the aforementioned neuropeptide levels were measured at baseline and during the sixth week of treatment. Treatment was associated with significant increases in BMI, waist circumference, serum triglyceride, and low-density lipoprotein levels. BMI levels increased more than 7% in over 75% of the patients. Leptin increased, and ghrelin and orexin decreased significantly with olanzapine treatment, whereas cholecystokinin, visfatin, and agouti-related protein levels did not change significantly. In conclusion, consistent with previous studies, we found increased BMI, leptin and lipids during olanzapine treatment. Association of neuropeptide level changes with symptom improvement might be mediated by the dopaminergic and serotonergic systems.

Association of adiponectin and metabolic syndrome among patients taking atypical antipsychotics for schizophrenia: a cohort study

INTRODUCTION

Adiponectin, an adipocyte-derived hormone controlling lipid and carbohydrate metabolism, has been suggested to be a biomarker for metabolic syndrome in the general population. This study investigated the association between adiponectin levels and metabolic syndrome in patients treated with atypical antipsychotics.

METHODS

Anthropometric and metabolic parameters and serum adiponectin levels were assessed in hospitalized patients with schizophrenia who had used the same atypical antipsychotic for at least 3 months. Retrospective reviews of the patients' medical records were conducted to obtain demographic data and pretreatment characteristics.

RESULTS

The study included 567 schizophrenia patients treated with clozapine (n=231), olanzapine (n=94) and risperidone (n=242), for an average of 45.8+/-27.8 months. The prevalence of metabolic syndrome among all subjects was 23.8%. The clozapine group had a higher prevalence of metabolic syndrome (28.7%) than did the olanzapine (24.2%) and risperidone groups (19.5%) (P=0.039), and the clozapine group had lower levels of adiponectin (8.46+/-6.02 mg/mL) than did the olanzapine (10.26+/-4. 9 mg/mL) and risperidone groups (10.69+/-7.43 mg/mL) (P=0.001). Adiponectin level was negatively correlated with body mass index (BMI) increase after initiation of antipsychotic treatment. Cross-sectional regression analysis showed that age (OR,=1.042, P=0.001), BMI (OR=1.404, P<0.0001), and adiponectin level (OR=0.862, P<0.0001) were significant factors in the presence of metabolic syndrome. Significant predictors of metabolic syndrome were age at initiation of antipsychotic treatment (OR=1.04, P=.007), BMI at initiation of antipsychotic treatment (OR=1.44, P<0.0001), BMI increase after initiation of antipsychotic treatment (OR=1.40, P<0.0001), and adiponectin level (OR=0.86, P<0.0001).

CONCLUSION

Lower levels of adiponectin and weight gain after taking antipsychotics are associated with higher risk of metabolic syndrome in patients taking atypical antipsychotics.

Hormonal markers of metabolic dysregulation in patients with severe mental disorders after olanzapine treatment under real-life conditions

OBJECTIVE

Dyslipidemia independent of body mass has previously been reported in humans after antipsychotic treatment. The present study investigated the levels of several metabolic regulatory hormones in psychiatric outpatients treated with different antipsychotics under real-life conditions.

METHODS

The study included cross-sectional data from 234 subjects on stable monotherapy with any of the following: olanzapine (n = 72), any other antipsychotic (n = 80), or no medications (n = 82). Groups were well matched for sex, body mass index (BMI), ethnicity, and smoking. After adjustment for differences in age and illness duration, groups were compared for the insulin resistance index (homeostatic model assessment of insulin resistance) and fasting concentrations of glucose, lipids, insulin, sex hormone-binding globulin (SHBG), adiponectin, leptin, and cortisol. Correlations were examined between serum olanzapine and hormonal levels, and between leptin concentrations and BMI in both sexes.

RESULTS

Significant intergroup differences in concentrations of insulin (P = 0.025), SHBG (P = 0.001), adiponectin (P = 0.017), and cortisol (P = 0.003) but no significant difference for homeostatic model assessment of insulin resistance (P = 0.051) were found, independent of body mass. Olanzapine-treated subjects had the highest insulin concentrations and the lowest SHBG, adiponectin, and cortisol concentrations. Olanzapine-treated female subjects had significantly higher leptin (P = 0.005) and lower SHBG (P = 0.023) concentrations than other subjects. In female subjects, serum olanzapine concentrations were correlated with hormonal levels, and a significant proportion of olanzapine-treated female subjects had abnormal correlations between serum leptin levels and BMI.

CONCLUSIONS

Alterations in several interrelated metabolic hormonal markers were associated with olanzapine treatment, independent of body mass, particularly in female subjects.

Adiponectin translation is increased by the PPARgamma agonists pioglitazone and omega-3 fatty acids

Adiponectin, made exclusively by adipocytes, is a 30-kDa secretory protein assembled posttranslationally into low-molecular weight, middle-molecular weight, and high-molecular weight homo-oligomers. PPARgamma ligand thiozolidinediones, which are widely used in the treatment of type II diabetes, increase adiponectin levels. PPARgamma also has several putative ligands that include fatty acid derivatives. Overnight treatment of rat adipocytes with pioglitazone, docosahexaenoic acid (DHA), or eicosapentaenoic acid (EPA) triggered a twofold increase in the synthesis and secretion of HMW adiponectin, and this increase was blocked by the addition of PPARgamma inhibitor GW-9662. Inhibition of glycosylation using 2,2'-dipyridyl decreased the synthesis of high-molecular weight adiponectin by pioglitazone, EPA, and DHA, but there was increased secretion of trimeric adiponectin resulting from increased translation. Although pioglitazone, DHA, and EPA increased adiponectin synthesis by more than 60%, there was no increase in total protein synthesis and no corresponding change in adiponectin mRNA expression, indicating the upregulation of translation. We examined the possibility of transacting factors in the cytoplasmic extracts from adipocytes treated with pioglitazone or DHA. In vitro translation of adiponectin mRNA was inhibited by S-100 fraction of control adipocytes and increased by S-100 extracts from adipocytes treated with pioglitazone or DHA. Consistent with this observation, both pioglitazone and DHA treatments increased the association of adiponectin mRNA with the heavier polysome fractions. Together, these data suggest that pioglitazone and the fish oils DHA or EPA are PPARgamma agonists in adipocytes with regard to adiponectin expression, and the predominant mode of adiponectin stimulation is via an increase in translation.

Comparison of insulin resistance, metabolic syndrome and adiponectin in overweight bipolar patients taking sodium valproate and controls

OBJECTIVE

Metabolic abnormalities in patients with bipolar disorder may be secondary to obesity, aspects of the disorder or its treatment. To investigate this further, the purpose the present study was to compare insulin resistance, components of the metabolic syndrome and adiponectin levels in a group of overweight bipolar patients taking sodium valproate and a group of non-psychiatric control subjects.

METHODS

Data were collected from 60 overweight bipolar patients who had experienced clinically significant weight gain thought to be related to sodium valproate treatment and from 60 control subjects without psychiatric illness matched for age, gender, body mass index and ethnicity.

RESULTS

The frequency of the metabolic syndrome was high in both groups (50% and 32%, respectively), although not significantly different between groups (p = 0.06). Similar frequencies of insulin resistance (HOMA-IR), abdominal obesity, hypertriglyceridaemia, hypertension and fasting hyperglycaemia were found in both groups. High-density lipoprotein cholesterol levels were lower in patients (p = 0.006), while adiponectin was unexpectedly higher than in control subjects (9.6+/-5.9 microg mL(-1) vs 7.4+/-4.3 microg mL(-1), p = 0.03). The frequencies of insulin resistance (HOMA-IR), the metabolic syndrome and its individual components were not significantly different in patients taking atypical antipsychotic medication and patients not on these medications.

CONCLUSIONS

Frequencies of insulin resistance and the metabolic syndrome were similar in bipolar patients taking sodium valproate and matched control subjects, but dyslipidaemia was more frequent. Adiponectin levels were higher in patients. Further research is required to clarify the reasons for these findings.

Preatherosclerosis and adiponectin subfractions in obese adolescents

We evaluated total adiponectin, high-molecular weight (HMW), medium-molecular weight (MMW), low-molecular weight (LMW) adiponectin subfractions, clinical parameters, routine lab parameters, lipids, metabolic, inflammatory biomarkers, and intima-media thickness (IMT) of common carotid arteries in 70 obese juveniles and adolescents with preatherosclerosis and 55 normal weight controls of similar age and gender distribution. Compared with the controls, the obese probands had a significantly increased IMT (P < 0.001) and elevated ultra-sensitive C-reactive protein (P < 0.001) indicating early vascular burden. Total and HMW adiponectin were significantly decreased in the obese cohort. The ratio between HMW and total adiponectin was significantly decreased in obese probands whereas the LMW/total adiponectin ratio was increased. Overall, total-, HMW, and MMW adiponectin were significantly negatively correlated with carotid IMT. The HMW/total adiponectin ratio correlated significantly negatively, and the LMW/total adiponectin ratio significantly positively with the IMT. Furthermore, HMW adiponectin was significantly positively correlated with high-density lipoprotein (HDL)-cholesterol and serum apolipoprotein A1, and negatively with BMI, triglycerides, homeostatic model assessment (HOMA)-index, leptin, liver transaminases, and uric acid. This remained stable after controlling for gender. Multiple regression analysis of body measures and all other lab parameters showed the strongest correlation between HMW adiponectin and carotid IMT (beta = -0.35, P < 0.001). Taken together, our study provides the first evidence that preatherosclerosis in obese juveniles and adolescents is associated with altered subfractions of adiponectin, whereas after multiple testing the HMW subfraction showed a better correlation to IMT compared with total adiponectin.

Effect of antipsychotics on peptides involved in energy balance in drug-naive psychotic patients after 1 year of treatment

Weight gain has become one of the most common and concerning side effects of antipsychotic treatment. The mechanisms whereby antipsychotics induce weight gain are not known. It has been suggested that peptides related to food intake and energy balance could play a role in weight gain secondary to antipsychotic therapy. To better understand the pathophysiology of antipsychotic-induced weight gain, we studied the effects of 3 antipsychotic drugs (haloperidol, olanzapine, and risperidone) on peptides involved in energy balance (insulin, ghrelin, leptin, adiponectin, visfatin, and resistin) in a population of drug-naive patients with first episode of psychosis.A significant increase in weight (10.16 kg [SD, 8.30 kg]; P < 0.001), body mass index (3.56 kg/m [SD, 2.89 kg/m]; P < 0.001), and fasting insulin (3.93 muU/mL [SD, 3.93 muU/mL]; P = 0.028), leptin (6.76 ng/mL [SD, 7.21 ng/mL]; P < 0.001), and ghrelin (15.47 fmol/mL [SD, 47.90 fmol/mL]; P = 0.009) plasma levels were observed. The increments in insulin and leptin concentrations were highly correlated with the increment in weight and body mass index and seem to be a consequence of the higher fat stores. The unexpected increase in ghrelin levels might be related with the causal mechanism of weight gain induced by antipsychotics. Finally, the 3 antipsychotics had similar effects in all parameters evaluated.

Total adiponectin and adiponectin multimeric complexes in relation to weight loss-induced improvements in insulin sensitivity in obese women: the NUGENOB study

AIM

Adiponectin increases insulin sensitivity, protects arterial walls against atherosclerosis, and regulates glucose metabolism, and is decreased in obese, insulin resistant, and type 2 diabetic patients. Adiponectin circulates in plasma as high, medium, and low molecular weight forms (HMW, MMW, and LMW). The HMW form was suggested to be closely associated with insulin sensitivity. This study investigated whether diet-induced changes in insulin sensitivity were associated with changes in adiponectin multimeric complexes.

SUBJECTS

Twenty obese women with highest and twenty obese women with lowest diet induced changes in insulin sensitivity (responders and non-responders respectively), matched for weight loss (body mass index (BMI)=34.5 (s.d. 2.9) resp. 36.5 kg/m(2) (s.d. 4.0) for responders and non-responders), were selected from 292 women who underwent a 10-week low-caloric diet (LCD; 600 kcal/d less than energy requirements). Plasma HMW, MMW, and LMW forms of adiponectin were quantified using Western blot method.

RESULTS

LCD induced comparable weight reduction in responders and non-responders by 8.2 and 7.6 kg. Homeostasis model assessment insulin resistance index decreased by 48.1% in responders and remained unchanged in non-responders. Total plasma adiponectin and the quantity of HMW and MMW remained unchanged in both groups, while LMW increased by 16.3% in non-responders. No differences between both groups were observed at baseline and after the study. Total plasma adiponectin, MMW, and LMW were negatively associated with fasting insulin levels at baseline.

CONCLUSION

No differences in total plasma adiponectin, HMW, MMW, and LMW forms were observed between responders and non-responders following 10-week LCD, suggesting that adiponectin is not a major determinant of weight loss-induced improvements in insulin sensitivity.

Early treatment-related changes in diabetes and cardiovascular disease risk markers in first episode psychosis subjects

OBJECTIVE

To examine prospective changes in cardiovascular disease (CVD) and type-2 diabetes risk factors in young adult first episode psychotic (FEP) patients treated with second generation antipsychotic medications.

METHODS

At baseline, fasting serum and anthropometric measures were obtained from 45 FEP patients and 41 healthy adults (controls) of similar age, ethnicity and sex; sixteen of the FEP patients remained on the same antipsychotic medication and were available for a second blood draw at 24 weeks of treatment. Serum was assayed for glucose, insulin, triglycerides, total cholesterol and high and low density lipoproteins (HDL, LDL), adiponectin, leptin, interleukin 6, E-selectin and VCAM-1. Wilcoxon nonparametric tests were used to compare risk markers between the FEP and control group at baseline and to evaluate pre-post treatment changes within the FEP group.

RESULTS

At baseline, the distributions of risk marker values were similar between the two groups and the percentages of FEP patients and healthy controls who were overweight/obese, dyslipidemic, hyperglycemic, and hyperinsulinemic did not differ. At 24 weeks, compared to baseline, FEP patients showed significant increases in BMI (p=0.0002), glucose (p=0.0449), insulin (p=0.0161), cholesterol (p=0.0129), leptin (p=0.0215), and E-selectin (p=0.0195), and a decrease in adiponectin (p=0.0371).

CONCLUSIONS

Among patients with first episode psychosis, 6-month treatment with second generation antipsychotics is associated with the exacerbation of pre-existing and emergence of new CVD and diabetes risk factors.

Impact of atypical antipsychotic therapy on leptin, ghrelin, and adiponectin

BACKGROUND

Many adverse effects of atypical antipsychotic treatment are associated with antagonism of monoamine receptors; however, data indicate that important metabolic effects, such as hypertriglyceridemia and impairment in glucose/insulin homeostasis, may not be related to these mechanisms, leading investigators to explore alternative hypotheses. Promising candidates include a possible impact of antipsychotics on peptide hormonal regulators of metabolic control such as leptin, ghrelin, and adiponectin. The purpose of this review is to summarize recent data on changes in these hormones during atypical antipsychotic treatment.

METHODS

A Medline search was performed for papers published from January 1999 to January 2007 using key words antipsychotic, atypical antipsychotic, and individual atypical antipsychotic drug names cross-referenced with leptin, ghrelin, and adiponectin.

RESULTS

The bulk of the published work focused on changes in body weight and serum leptin, with far less data on ghrelin, and adiponectin, and nonweight metabolic changes. Leptin changes were directly related to a medication's weight gain liability, with no added antipsychotic effects on leptin signaling. Conflicting results emerged for the other markers, but all three long-term studies on ghrelin showed increased levels in patients on atypical antipsychotics with weight gain liabilities.

CONCLUSIONS

Leptin increases during antipsychotic treatment are a result of weight gain rather than a direct impact of atypical antipsychotics on leptin physiology. Preliminary long-term data show increased ghrelin levels, but this finding must be replicated. The association with antipsychotic effects on glucose and lipid metabolism and these hormones remains virtually unstudied. Future research should indicate whether ghrelin and other peptide hormones may be useful predictors of weight gain or metabolic changes in patients on antipsychotics.

Abnormalities in glucose metabolism in patients with schizophrenia treated with atypical antipsychotic medications

The incidence of carbohydrate intolerance and overt diabetes is increased in patients with schizophrenia treated with the newer atypical antipsychotic agents. The precise mechanism for these abnormalities remains obscure. This review examines the potential interaction between atypical antipsychotic medications and several hormones known to influence appetite regulation and carbohydrate metabolism.

Selective downregulation of the high molecular weight form of adiponectin in hyperinsulinemia and in type 2 diabetes: differential regulation from nondiabetic subjects

OBJECTIVE

Adiponectin is an adipocyte-specific secretory protein found in circulation in several different forms and is present at significantly lower levels in the plasma of diabetic patients compared with that of insulin-sensitive individuals. We wanted to test whether insulin per se is a contributing factor toward lower plasma adiponectin concentrations and, if so, whether the splanchnic bed contributes to this phenomenon.

RESEARCH DESIGN AND METHODS

We sampled femoral artery and hepatic venous samples and measured the high-molecular weight (HMW) and low-molecular weight (LMW) fractions of adiponectin in 11 type 2 diabetic and 7 nondiabetic subjects matched for age, sex, and BMI during basal conditions and during a hyperglycemic (approximately 9.5 mmol/l) hyperinsulinemic (approximately 700 pmol/l) clamp.

RESULTS

Under these conditions, total arterial adiponectin, HMW, and the ratio of HMW to total adiponectin all were lower (P < 0.01) in the diabetic versus nondiabetic subjects, whereas the LMW form did not significantly differ. Under hyperinsulinemic conditions, total adiponectin levels dropped, primarily due to a reduction of the HMW form, whereas LMW forms were not significantly affected.

CONCLUSIONS

HMW adiponectin and the ratio of HMW to total adiponectin are lower in individuals with diabetes than in nondiabetic subjects. We conclude that HMW adiponectin is downregulated in hyperinsulinemia and type 2 diabetes.

An increase in plasma adiponectin multimeric complexes follows hypocaloric diet-induced weight loss in obese and overweight pre-menopausal women

Adiponectin is involved in the regulation of glucose and fatty acid metabolism, influences whole-body insulin sensitivity and protects arterial walls against the development of atherosclerosis. Plasma adiponectin is decreased in obese, insulin-resistant and Type 2 diabetic patients. Adiponectin circulates in plasma as high-, medium- and low-molecular-weight (‘mass’) forms (HMW, MMW and LMW respectively). The HMW form is believed to be closely associated with insulin sensitivity. The aim of the present study was to investigate whether diet-induced changes in body weight and insulin sensitivity were associated with changes in the quantity of adiponectin multimeric complexes. A total of 20 overweight or obese women (age, 39.4±9.5 years; body mass index, 32.2±6.4 kg/m2) underwent 12 weeks of low caloric diet (600 kcal/day less than energy requirements; where 1 kcal≈4.184 kJ). Plasma samples were drawn before and after the study for biochemical analysis and Western blot detection of adiponectin multimeric complexes. The hypocaloric diet resulted in a weight reduction (89.8±16.4 kg compared with 83.1±15.6 kg; P<0.001) and an improvement in whole-body insulin sensitivity, as measured by HOMA (homoeostasis model assessment index; 1.9±0.8 compared with 1.5±0.7; P=0.013). Increases in the quantities of the HMW, MMW and LMW forms by 5.5, 8.5 and 18.1% respectively, were observed (P<0.05 for all of the forms). Total plasma adiponectin was increased by 36% with borderline significance (P=0.08). No correlations between changes in adiponectin complexes and changes in indices of insulin sensitivity were observed. In conclusion, diet-induced weight loss improved insulin sensitivity as well as increased the amount of HMW, MMW and LMW adiponectin complexes in plasma.

Pharmacogenetics of antipsychotics: useful for the clinician?

PURPOSE OF REVIEW

The concept of individualized drug therapy on the basis of pharmacogenetics has become a central focus in psychopharmacology of schizophrenia. This article reviews recent advances in this field with respect to their importance for the clinician.

RECENT FINDINGS

First, there is an increasing agreement about the importance of polymorphisms in cytochrome P450 enzymes and the effects of drug-drug interactions in relation to the incidence of adverse effects. Secondly, prediction of response on the basis of variants in candidate genes is incipient and remains elusive. Thirdly, some advances have been made in understanding the pharmacogenetics of weight gain.

SUMMARY

Despite much effort, only a few of the results are now ready for translation into clinical practice. Cytochrome P450 genotyping would be a big step forward towards a more individualized drug treatment based on molecular diagnostics and could improve treatment, reduce adverse effects and increase compliance of the patients. Another promising field may be that of predicting the antipsychotic-induced weight gain and it is hoped that commercially available DNA tests may be available within the next few years. Prediction of response is still hampered by many methodological and clinical problems and is not yet available to the clinician.

Adipose tissue-derived factors: impact on health and disease

The endocrine functions of the adipose organ are widely studied at this stage. The adipose organ, and in particular adipocytes, communicate with almost all other organs. Although some adipose tissue pads assume the functions as distinct "miniorgans," adipocytes can also be present in smaller numbers interspersed with other cell types. Although fat pads have the potential to have a significant systemic impact, adipocytes may also affect neighboring tissues through paracrine interactions. These local or systemic effects are mediated through lipid and protein factors. The protein factors are commonly referred to as adipokines. Their expression and posttranslational modifications can undergo dramatic changes under different metabolic conditions. Due to the fact that none of the mutations that affect adipose tissue trigger embryonic lethality, the study of adipose tissue physiology lends itself to genetic analysis in mice. In fact, life in the complete absence of adipose tissue is possible in a laboratory setting, making even the most extreme adipose tissue phenotypes genetically amenable to be analyzed by disruption of specific genes or overexpression of others. Here, we briefly discuss some basic aspects of adipocyte physiology and the systemic impact of adipocyte-derived factors on energy homeostasis.