Homocysteine levels and glucose metabolism in non-obese, non-diabetic chronic schizophrenia

Different exposure metrics of rotating night shift work and hyperhomocysteinaemia among Chinese steelworkers: a cross-sectional study

OBJECTIVE

To examine the associations of rotating night shift work with hyperhomocysteinaemia (HHcy) odds by different exposure metrics.

DESIGN

Cross-sectional study.

SETTING

Occupational physical examination centre for steel production workers, Tangshan, China.

PARTICIPANTS

A total of 6846 steelworkers, aged 22-60 years, from the baseline survey of a Chinese occupational cohort.

PRIMARY AND SECONDARY OUTCOME MEASURES

Different exposure metrics of night shift work, including current shift status, duration of night shifts (years), cumulative number of night shifts (nights), cumulative length of night shifts (hours), average frequency of night shifts (nights/month), average length of night shifts (hours/night) and percentage of hours on night shifts, were used to examine the effects of past and current night shift work on HHcy odds. The total homocysteine concentration in the plasma above 15 µmol/L was defined as HHcy.

RESULTS

Compared with those who never worked night shifts, current night shift workers had elevated odds of HHcy (OR 1.23, 95% CI 1.06 to 1.44). Considering a person's lifetime work schedule and compared with individuals who never worked night shifts, duration of night shifts >28 years (OR 1.35, 95% CI 1.12 to 1.61), average frequency of night shifts >7 nights/month (OR 1.25, 95% CI 1.07 to 1.47) and percentage of hours on night shifts >30% (OR 1.23, 95% CI 1.05 to 1.43) were associated with higher HHcy odds. The duration of night shifts >20 years and the average frequency of night shifts >7 nights/month could significantly increase the odds of HHcy regardless of whether the average length of night shifts was greater than 8 hours/night. After stratification by sex, no significant association was found in female workers between different exposure metrics of night shift work and HHcy.

CONCLUSIONS

Long duration and high frequency of night shift work are associated with higher HHcy odds among male steelworkers.

Increased risk for venous thromboembolism among patients with concurrent depressive, bipolar, and schizophrenic disorders

OBJECTIVE

The study aim was to investigate the risk of venous thromboembolism (VTE) in patients with concurrent depressive, bipolar, and schizophrenic disorders.

METHODS

A population-based cohort study was conducted in which information regarding psychiatric illnesses and medical comorbidities in 29,467 patients with concurrent depressive, bipolar, and schizophrenic disorders and regarding 117,868 controls were extracted. We compared the incidence of VTE between the study and control cohorts. Cox proportional hazard regression models were used to analyze the risk of VTE after adjusting for potential confounders, including sex, age, and comorbidities.

RESULTS

Compared with the control cohort, the overall study cohort had a 2.995-fold higher adjusted hazard ratio (aHR) for development of deep vein thrombosis (DVT) and a 2.591-fold higher aHR for development of pulmonary embolism (PE). Moreover, patients with depressive, bipolar, and schizophrenic disorders all exhibited higher aHRs for development of both DVT and PE.

CONCLUSION

The relative risks of DVT and PE were higher in patients with concurrent depressive, bipolar, and schizophrenic disorders than those of the general population. Further research is needed to develop effective prevention strategies for different patient populations.

Antipsychotic Use Among Adult Outpatients and Venous Thromboembolic Disease: A Retrospective Cohort Study

BACKGROUND

Treatment with antipsychotic (AP) agents is associated with incident thromboembolic events. However, the underpinnings of this association remain unknown. We sought to evaluate the effect of AP agents-categorized by their metabolic/sedative and hyperprolactinemia adverse effect profile-on the risk of venous thromboembolic disease during long-term follow-up.

METHODS

A retrospective cohort study of adult patients initiating AP treatment for the first time was conducted. Primary outcome was defined as the time to venous thromboembolism (VTE) (either deep venous thrombosis or acute pulmonary embolism). Antipsychotic agents were categorized by their risk (high vs low) of either drug-induced (a) sedation/metabolic adverse event or (b) hyperprolactinemia. We used a propensity score-adjusted Cox proportional hazards model to control for confounding.

FINDINGS

One thousand eight patients (mean age, 72.4 y) were followed for a median of 36 months. Incident VTE occurred in 6.25% of patients, corresponding to an incidence rate of 184 cases per 10,000 person-years. We found no difference in the hazard of VTE during follow-up between high- and low-risk groups (hazard ratio, 1.23 [95% confidence interval, 0.74-2.04] for drug-induced sedation/metabolic adverse event risk categories, and hazard ratio 0.81 [95% confidence interval, 0.50-1.35] for high versus low hyperprolactinemia risk).

CONCLUSIONS

These results suggest that the risk of thromboembolic events in older adults who started AP treatment for the first time does not seem to be related to these drugs' risk of either sedation/metabolic adverse events or hyperprolactinemia. However, VTE remains a common problem in this subgroup of patients.

Serum folate levels in schizophrenia: A meta-analysis

To clarify the relationship between serum folate and schizophrenia (SZ) risk, the meta-analysis was conducted. PubMed, Embase, and Web of Science were searched without language restrictions. Weighted mean difference (WMD) as a summary statistic was used in this meta-analysis. Subgroup analyses by publication language (English and non-English), ethnicity (Caucasian, Asian, African, Latino, and mixed population), duration (acute, chronic, patients including both acute and chronic SZ, and not mentioned about either chronic or acute), measurement time (before drugs using and after drugs using), gender (male and female) and age (<50 years old and >50 years old) were performed. Power analysis was also conducted to detect the reliability of the meta-analyses' results. In summary, the subgroups which failed to detect significant decreased associations were always with lower statistic power and could not be confirmed. The results supported that decreased serum folate was associated with SZ risk in total studies and subgroups of English publications, Caucasians, Asians, acute SZ patients, measurement after drugs using in SZ patients, and age<50 with the great enough powers, respectively. In conclusion, the present meta-analysis found that folate deficiency is associated to SZ, and subgroups which did not reach enough statistical power need further investigation in the future.

Pathophysiological mechanisms of increased cardiometabolic risk in people with schizophrenia and other severe mental illnesses

Patients with schizophrenia have increased mortality and morbidity compared with the general population. These patients have a 20-year shorter lifespan than peers without schizophrenia, mainly due to premature cardiovascular disease, suicide, and cancer. Patients with severe mental illness are at increased risk for cardiovascular disease related to increased incidence of diabetes, hypertension, smoking, poor diet, obesity, dyslipidaemia, metabolic syndrome, low physical activity, and side-effects of antipsychotic drugs. Some second-generation antipsychotics (eg, clozapine, olanzapine, quetiapine, and risperidone) are associated with an increased risk of weight gain and obesity, impaired glucose tolerance and new-onset diabetes, hyperlipidaemia, and cardiovascular disease. The mechanisms by which schizophrenia and patients with severe mental illness are susceptible to cardiometabolic disorders are complex and include lifestyle risks and direct and indirect effects of antipsychotic drugs. An understanding of these risks might lead to effective interventions for prevention and treatment of cardiometabolic disorders in schizophrenia and severe mental illness.

Homocysteine levels in patients with schizophrenia on clozapine monotherapy

We tested the hypothesis that homocysteine levels are higher in blood of schizophrenic subjects on clozapine monotherapy than in healthy controls and they correlate with anthropometric measurements, laboratory tests and results of bioimpedance analysis of body composition. Data for 24 subjects with schizophrenia treated with clozapine and 24 age- and sex-matched healthy volunteers was analyzed. Regarding the whole group, homocysteine levels were significantly higher in men (17.0 ± 3.4 vs. 12.1 ± 4.0 μmol/L, p = 0.009). Homocysteine levels correlated with waist circumference (R = 0.58, p = 0.003), waist-to-hip ratio (R = 0.57, p = 0.003), basal metabolic rate (R = 0.48, p = 0.01), lean body mass [kg] (R = 0.53, p = 0.008), body water [L] (R = 0.53, p = 0.008) and triglycerides (R = 0.57, p = 0.003). There were no significant differences of homocysteine levels for impaired fasting glucose, abdominal obesity, obesity/overweight, and dyslipidemia. Homocysteine levels did not correlate with age, treatment duration, clozapine dose, weight, body mass index, abdominal circumference, blood pressure, total body fat, cholesterol, high density lipoproteins, low density lipoproteins, uric acid, calcium, glucose, insulin, homoeostasis model assessment of insulin resistance 1, and homoeostasis model assessment of insulin resistance 2. We did not find significant differences in blood homocysteine levels between subjects with schizophrenia and controls. Association with waist circumference may support homocysteine role as an important cardiovascular risk factor. Association with lean weight may explain why men have higher levels of homocysteine than women.

The multidimensional nature of metabolic syndrome in schizophrenia: lessons from studies of one-carbon metabolism and DNA methylation

Large data sets indicate that the prevalence of metabolic syndrome (MetS) is significantly higher in patients with schizophrenia in comparison with the general population. Given that interactions between genes and the environment may underlie the etiology of MetS in subjects with schizophrenia, it is feasible that epigenetic phenomena can serve as the etiological consensus between genetic and environmental factors. However, there is still a striking scarcity of studies aimed at investigating the role of aberrant DNA methylation in the development of MetS in this group of patients. This article provides an update on the epigenetics of schizophrenia and reviews studies on the role of one-carbon metabolism and aberrant DNA methylation in the development of MetS.

Determination of olanzapine and N-desmethyl-olanzapine in plasma using a reversed-phase HPLC coupled with coulochemical detection: correlation of olanzapine or N-desmethyl-olanzapine concentration with metabolic parameters

BACKGROUND

Olanzapine (OLZ) is one of the most prescribed atypical antipsychotic drugs but its use is associated with unfavorable metabolic abnormalities. N-desmethyl-olanzapine (DMO), one of the OLZ metabolites by CYP1A2, has been reported to have a normalizing action on metabolic abnormalities, but this remains unclear. Our aim was to explore the correlation between the concentrations of OLZ or DMO with various metabolic parameters in schizophrenic patients.

METHODS

The chromatographic analysis was carried out with a solvent delivery system coupled to a Coulochem III coulometric detector to determine OLZ and DMO simultaneously in OLZ-treated patients. The correlation between the concentration of OLZ or DMO and the metabolic parameters was analyzed by the Spearman rank order correlation method (r s).

PRINCIPAL FINDINGS

The established analytical method met proper standards for accuracy and reliability and the lower limitation of quantification for each injection of DMO or OLZ was 0.02 ng. The method was successfully used for the analysis of samples from nonsmoking patients (n = 48) treated with OLZ in the dosage range of 5-20 mg per day. There was no correlation between OLZ concentrations and tested metabolic parameters. DMO concentrations were negatively correlated with glucose (r s = -0.45) and DMO concentrations normalized by doses were also negatively correlated with insulin levels (r s = -0.39); however, there was a marginally positive correlation between DMO and homocysteine levels (r s = +0.38).

CONCLUSIONS

The observed negative correlations between levels of DMO and glucose or insulin suggest a metabolic normalization role for DMO regardless of its positive correlation with a known cardiovascular risk factor, homocysteine. Additional studies of the mechanisms underlying DMO's metabolic effects are warranted.

A systematic review of the nutritional status of women of a childbearing age with severe mental illness

Little is known about the nutritional status of pregnant women with severe mental illness. We therefore carried out a systematic review to investigate whether pregnant women and childbearing aged women with severe mental illness have significantly greater nutritional deficiencies compared with pregnant women and childbearing aged women with no mental illness. We carried out a search using MEDLINE, EMBASE and PsycINFO from January 1980 to January 2011 for studies on nutritional status of childbearing aged women with psychotic disorders. Identification of papers and quality rating of papers (using a modified version of the Newcastle-Ottawa scale) was carried out by two reviewers independently. We identified and screened 4,130 potentially relevant studies from the electronic databases. Fifteen studies met the inclusion criteria (n = 587 women). There were no studies of pregnant women. There was some evidence of low serum folate and vitamin B(12) levels and elevated homocysteine levels in childbearing aged women with psychotic disorders. Further research into the nutritional status of childbearing aged women with severe mental illness is needed. Maternal nutrition has a profound impact on foetal outcome, is a modifiable risk factor and therefore needs prioritising in the care of all childbearing aged women with severe mental illness.

Risk of venous thromboembolism during treatment with antipsychotic agents

The evidence to date on the relation between the risk of venous thromboembolic disease (VTE) and antipsychotic agents derives primarily from observational and case history studies. While an increased risk of VTE has been associated with first-generation low-potency antipsychotic agents, particularly clozapine, there appears to be a growing number of reports on the occurrence of this adverse reaction during the use of second-generation antipsychotics, such as risperidone and olanzapine. The highest risk of pathological blood clotting emerges during the first 3 months after initiation of treatment with the product. Potential etiopathogenetic factors leading to VTE during treatment with antipsychotic agents include sedation, obesity, elevation of antiphospholipid antibodies, increased platelet activation and aggregation, hyperhomocysteinemia, and hyperprolactinemia. Diagnoses of schizophrenia and/or bipolar affective disorder, as well as hospitalization or stress with sympathetic activation and elevation of catecholamine levels, have been reported as known prothrombogenic factors. The present article contains the new version of the guideline for the prevention of VTE in psychiatric patients with limited mobility. Further prospective studies are necessary to elucidate the biological mechanisms of the relations between antipsychotic agents and VTE.

Venous thromboembolism in recipients of antipsychotics: incidence, mechanisms and management

Since chlorpromazine was introduced to the market in the early 1950s, the use of antipsychotic drugs has been associated with venous thromboembolism (VTE) in a number of reports. During the last decade the evidence has been strengthened with large epidemiological studies. Whether all antipsychotics increase the risk for VTE or the risk is confined to certain drugs is still unclear. The aim of this article is to present an updated critical review focusing on the incidence, mechanisms and management of VTE in users of antipsychotics. After searching the databases PubMed and Scopus for relevant articles we identified 12 observational studies, all of which were published after the year 2000. In most of these studies an elevated risk of VTE was observed for antipsychotic drugs, with the highest risk for clozapine, olanzapine and low-potency first-generation antipsychotics. The risk seems to be correlated with dose. The elderly, who mainly use lower doses, do not show an increased risk of VTE to the same extent as younger subjects. The underlying biological mechanisms explaining the association between antipsychotic medication and VTE are to a large extent unknown. Several hypotheses have been proposed, such as body weight gain, sedation, enhanced platelet aggregation, increased levels of antiphospholipid antibodies, hyperprolactinaemia and hyperhomocysteinaemia. The risk of VTE in schizophrenia and other psychotic disorders may also be related to the underlying disease rather than the medication. Very limited evidence exists to guide how cases of VTE in subjects using antipsychotics should be handled. An attempt to compile an algorithm where the patients' individual risk of VTE is assessed and preventive clinical measures are suggested has been published recently. Strong consideration should be given to discontinuation of the offending antipsychotic drug in patients experiencing a VTE, and another antipsychotic drug with a presumably lower risk should be chosen if antipsychotic drug treatment is still indicated. It is essential that physicians and patients are aware that VTE may be an adverse drug reaction to the antipsychotic treatment so the condition is identified early and treated appropriately.

The oxidative stress may be induced by the elevated homocysteine in schizophrenic patients

The mechanisms of oxidative stress in schizophrenic patients are not fully understood. In the present study, we investigated the effect of elevated level of homocysteine (Hcys) on some parameters of oxidative stress, namely thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation in plasma, the level of carbonyl groups in plasma proteins, as well as the amount of 3-nitrotyrosine in plasma proteins isolated from schizophrenic patients. Patients hospitalised in I and II Psychiatric Department of Medical University in Lodz, Poland were interviewed with special questionnaire (treatment, course of diseases, dyskinesis and other EPS). According to DSM-IV criteria all patients had diagnosis of paranoid type. They were treated with antipsychotic drugs (clozapine, risperidone, olanzapine). Mean time of schizophrenia duration was about 5 years. High-performance liquid chromatography was used to analyse the total level of homocysteine in plasma. Levels of carbonyl groups and 3-nitrotyrosine residues in plasma proteins were measured by ELISA and a competition ELISA, respectively. The lipid peroxidation in plasma was measured by the level of TBARS. Our results showed that in schizophrenic patients the amount of homocysteine in plasma was higher in comparison with the control group. We also observed a statistically increased level of biomarkers of oxidative/nitrative stress such as carbonyl groups or 3-nitrotyrosine in plasma proteins from schizophrenic patients. Moreover, our experiments indicate that the correlation between the increased amount of homocysteine and the oxidative stress exists. Considering the data presented in this study, we suggest that the elevated Hcys in schizophrenic patients may stimulate the oxidative stress.

Effect of folic acid supplementation on biochemical indices in overweight and obese men with type 2 diabetes

AIMS

This study performed to determine the effects of folate supplementation on indices of glycemic control, insulin resistance and lipid profile in overweight and obese men with type 2 diabetes under metformin (at least 1500 mg daily) treatment.

METHODS

The study was a double-blind randomized controlled clinical trial. Forty-eight overweight and obese men (aged 58.2±8.9 years; BMI=28.6±2.9 kg/m(2)) with type 2 diabetes participated in the study. Patients were divided randomly into two groups of folic acid (5 mg/d) and placebo. All patients received the tablets for eight weeks.

RESULTS

Supplementation with folic acid led to 8% decrease in HbA1C (p=0.048), 7.5% in fasting blood glucose (p=0.051), 16.2% in serum insulin (p=0.021), 20.5% in insulin resistance (p=0.041) and 21.2% in plasma homocysteine (p=0.000). A significant increase in serum folate and B12 levels (19% and 17.3%, p=0.000, respectively) were observed in the folic acid group, whereas no significant changes occurred in the placebo group. Also, in the folic acid and placebo groups, there were no significant changes in body weight.

CONCLUSIONS

Folic acid supplementation lowered plasma level of homocysteine, improved glycemic control and insulin resistance in patients with type 2 diabetes.

Risk of venous thromboembolism due to antipsychotic drug therapy

An increasing number of reports suggest a link between venous thromboembolism (VTE) and the use of antipsychotics. To better understand this association the available body of evidence has been critically scrutinised. Relevant articles were identified in the databases Scopus and PubMed. Several observational studies using different methodologies show an increased risk of VTE in psychiatric patients. This elevated risk seems to be related to the use of antipsychotic medication and in particular to the use of clozapine and low-potency first-generation drugs. Many studies investigating the association have, however, methodological limitations. The biological mechanisms involved in the pathogenesis of this possible adverse reaction are largely unknown but several hypotheses have been suggested such as drug-induced sedation, obesity, increased levels of antiphospholipid antibodies, enhanced platelet aggregation, hyperhomocysteinemia and hyperprolactinemia. The association may also be related to underlying risk factors present in psychotic patients. Physicians need to be aware of this possible adverse drug reaction. Although supporting evidence has not been published they should consider discontinuing or switching the antipsychotic treatment in patients experiencing VTE. In addition, although data is lacking, the threshold for considering prophylactic antithrombotic treatment should be low when risk situations for VTE arise, such as immobilisation, surgery and so on.

Associations of blood homocysteine concentrations in Arab schizophrenic patients

BACKGROUND

This study aimed to evaluate the blood homocysteine concentration in Arab patients with schizophrenia and assess its associations with clinical phenotypes of the disease.

SUBJECTS AND METHODS

Two age-matched groups of subjects were studied: (1) Healthy Controls, HC, n=165; (2) patients with schizophrenia, SZ: n=207. Each subject was evaluated with a standard questionnaire for age at disease onset, family history, disease severity and outcome. Plasma homocysteine levels (Hcys) were measured by immunoassay and serum levels of other biochemical parameters were measured by routine Autoanalyzer techniques.

RESULTS AND DISCUSSION

Group HC was heavier (body mass index, BMI) while SZ had greater waist-hip ratio (WHR) and plasma Hcys levels. In SZ, there were significant correlations between Hcys and BMI, triglycerides and HDL. Hcys levels in SZ were highest in the younger male patients.

CONCLUSION

Schizophrenic patients have increased blood Hcys levels which correlate with components of the metabolic syndrome. Hcys levels were highest in the younger male patients and were not influenced by prognostic features of the disease.