Serum cortisol and insulin-like growth factor 1 levels in major depressive disorder and schizophrenia.

The pathophysiology underlying major depressive disorder (MDD) and schizophrenia is related to endocrine system functions and includes changes in the blood levels of cortisol and insulin-like growth factor 1 (IGF-1). However, these hormones have not been investigated simultaneously in patients with MDD and schizophrenia. We investigated the differences in serum cortisol and IGF-1 levels among patients with MDD and schizophrenia and controls. We included 129 patients with MDD, 71 patients with schizophrenia, and 71 healthy volunteers. Blood tests were performed between 6:00 am and 11:00 am after fasting. Serum cortisol levels were significantly higher in patients with schizophrenia than in patients with MDD and controls. Serum cortisol levels were significantly higher in patients with MDD than in controls. Serum IGF-1 levels were higher in both patient groups than in controls, whereas there was no significant difference between patients with MDD and schizophrenia. Both cortisol and IGF-1 levels were positively correlated with the Hamilton Rating Scale for Depression score in patients with MDD, whereas cortisol level was positively correlated and IGF-1 level was negatively correlated with the Brief Psychiatric Rating Scale score in patients with schizophrenia. The differences in the level of these hormones suggest pathophysiological differences between these disorders.

Role of insulin-like growth factor 1, sex and corticosteroid hormones in male major depressive disorder.

BACKGROUND: Hormones of the hypothalamic-pituitary-gonadal (HPG), hypothalamic-pituitary-adrenal (HPA), and hypothalamic-pituitary-somatotropic (HPS) axes are potentially involved in major depressive disorder (MDD), but these hormones have not been simultaneously investigated in male patients with MDD. We investigated the association between male MDD symptoms and estradiol, testosterone, cortisol, dehydroepiandrosterone sulfate (DHEAS), and insulin-like growth factor 1 (IGF1). METHODS: Serum estradiol, testosterone, cortisol, DHEAS, and IGF1 levels were measured in 54 male patients with MDD and 37 male controls and were compared with clinical factors. We investigated the associations between hormone levels and Hamilton Depression Rating Scale (HAM-D) scores. The correlations among hormones were also investigated. RESULTS: Patients had significantly lower estradiol levels than controls (22.4 ± 8.4 pg/mL vs. 26.1 ± 8.5 pg/mL, P = 0.040). Serum estradiol levels were negatively correlated with HAM-D scores (P = 0.000094) and positively correlated with Global Assessment of Functioning scores (P = 0.000299). IGF1 levels and the cortisol:DHEAS ratio were higher in patients than in controls (IGF1: 171.5 ± 61.8 ng/mL vs. 144.1 ± 39.2 ng/mL, P = 0.011; cortisol:DHEAS ratio: 0.07 ± 0.05 vs. 0.04 ± 0.02, P = 0.001). DHEAS levels were lower in patients than in controls (227.9 ± 108.4 µg/dL vs. 307.4 ± 131.2 µg/dL, P = 0.002). IGF1, cortisol:DHEAS ratio, and DHEAS were not significantly correlated with HAM-D scores. Cortisol and testosterone levels were not significantly different between patients and controls. Serum estradiol levels were positively correlated with DHEAS levels (P = 0.00062) in patients, but were not significantly correlated with DHEAS levels in controls. CONCLUSION: Estradiol may affect the pathogenesis and severity of patients with MDD in men, and other hormones, such as those in the HPA and HPS axes, may also be involved in male MDD. Additionally, a correlation between estradiol and DHEAS may affect the pathology of MDD in men.

Hormonal Dynamics Effect of Serum Insulin-Like Growth Factor I and Cortisol/Dehydroepiandrosterone Sulfate Ratio on Symptom Severity of Major Depressive Disorder.

BACKGROUND: Insulin-like growth factor I (IGF-I) is a neurotrophic factor produced by the hypothalamic-pituitary-somatotropic axis and is considered a potential contributor to the pathology of major depressive disorder (MDD). Although it is known that the hypothalamic-pituitary-adrenal axis and cortisol are involved in the pathology of MDD, the association with dehydroepiandrosterone sulfate (DHEAS) remains unclear. The current study sought to clarify the relationship between these hormones and the pathology of MDD. METHODS: Subjects were 91 Japanese patients with a diagnosis of MDD. Serum IGF-I, cortisol, and DHEAS were measured. Samples were taken before breakfast after overnight fasting. Depressive symptoms were assessed using the Hamilton Rating Scale for Depression (HAM-D). RESULTS: Subjects included 59 men and 32 women with an average age of 44.1 ± 13.1 years (mean ± SD). The blood IGF-I level was 152.0 ± 50.0 ng/mL, the cortisol level was 10.1 ± 4.6, and the DHEAS level was 201.3 ± 112.7 µg/dL. The mean HAM-D score was 13.9 ± 9.0. Serum IGF-I levels were not correlated with cortisol. Higher IGF-I, cortisol, and cortisol/DHEAS ratios were associated with higher HAM-D scores (adjusted R = 0.240, P < 0.001), and higher IGF-I and cortisol were associated with higher melancholic or suicide subscores (adjusted R = 0.200, P < 0.001; adjusted R = 0.273, P < 0.001). CONCLUSIONS: Our findings suggest that hormonal dysregulation of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-somatotropic axes may be related to the symptom severity of MDD, melancholia, and suicide-related factors.

Effects of olanzapine on resting heart rate in Japanese patients with schizophrenia.

It has long been known that antipsychotic drugs (ATP) causes tachycardia, however details such as the differences between ATP are not well known. In recent years, the relationship between the rise in resting heart rate (RHR) and the increased risk of death in the general population has been garnering attention. In this study, we examined the difference in action on RHR between olanzapine (OLZ) and aripiprazole (ARP). The changes in the RHR on switching from OLZ to ARP and on increasing from the starting OLZ dose to the final one were evaluated in 19 outpatients (Study 1) and in 29 outpatients with schizophrenia (Study 2), respectively. To analyze the RHR, electrocardiographic measurements were obtained. At the same day, the Brief Psychiatric Rating Scale (BPRS) was evaluated, and fasting blood samples were drawn after an overnight fast of at least 8 h to examine electrolytes. Both Study 1 and 2 were conducted with the approval of the Gene Ethics Committee of Niigata University Graduate School of Medical and Dental Sciences, and the patients were treated at the outpatient psychiatric clinic at Niigata University Medical and Dental Hospital. All patients had been diagnosed with schizophrenia based on the DSM-IV-TR. In the Study 1, OLZ of 14.6 ± 9.2mg (mean ± standard deviation) was switched to ARP of 20.8 ± 8.1mg. Significant decreases were observed in the mean RHR after the switch to ARP (73.7 ± 9.7 vs 65.8 ± 10.9 beats/min, p = 0.008). In the Study 2, the starting OLZ dose was 7.2 ± 3.2mg and the increasing OLZ dose was 18.3 ± 7.4mg. Significant increases were observed in the mean RHR after increasing OLZ (69.7 ± 14.0 vs 75.6 ± 14.3 beats/min, p = 0.004). In this study, it was shown that OLZ has a stronger RHR enhancing effect compared to ARP and its effects are dose-dependent. If the increase in RHR increases the mortality rate of patients with schizophrenia, it may be necessary to further investigate the differences between ATP in terms of the effect on RHR of second-generation antipsychotics with a strong anticholinergic action or phenothiazine antipsychotics.

Effect of GWAS-Identified Genetic Variants on Maximum QT Interval in Patients With Schizophrenia Receiving Antipsychotic Agents: A 24-Hour Holter ECG Study.

BACKGROUND: Users of antipsychotics (APs) have a risk of sudden cardiac death (SCD). Sudden cardiac death in such patients is thought to be largely due to drug-induced QT prolongation. It has been reported that many subjects with drug-induced torsades de pointes (TdP) have risk alleles associated with subclinical congenital long QT syndrome. METHODS: We investigated the effects of the risk alleles associated with long QT on the QT interval in patients receiving APs using 24-hour Holter electrocardiograms to take into account the circadian fluctuation of QT intervals. We investigated 8 single-nucleotide polymorphisms identified on a GWAS. RESULTS: We found that increased numbers of risk alleles at rs7188697 in NDRG4 and rs11970286 in PLN were the major predictors of an increased maximum QT interval over 24 hours in users of APs. CONCLUSIONS: It could be useful to perform a DNA-based analysis before the initiation of APs to reduce the risk of drug-induced torsades de pointes and SCD.

Effect of Serum Leptin on Weight Gain Induced by Olanzapine in Female Patients with Schizophrenia.

BACKGROUND: Olanzapine (OLZ) treatment is associated with a high risk of weight gain, and may cause abnormalities in glycolipid metabolism. Therefore, the underlying mechanism of OLZ-related weight gain is needed to clarify but not yet been adequately determined. In recent years, adipocytokines such as leptin, adiponectin, and tumor necrosis factor (TNF)-α, which play important roles in energy homeostasis, have been suggested as biomarkers of weight gain. Here, we determined if baseline plasma concentrations of leptin, adiponectin, and TNF-α predict weight gain following OLZ treatment. METHODS: We recruited 31 schizophrenia outpatients (12 men and 19 women, 28.8 ± 10.2 years old) that were unmedicated or on another antipsychotic monotherapy medication. Baseline body mass index (BMI) and plasma levels of leptin, adiponectin, and TNF-α were obtained. All patients started or were switched to OLZ monotherapy for a maximum of 1 year. BMI was also obtained at the endpoint. RESULTS: Mean BMI change following OLZ treatment was 2.1 ± 2.7 kg/m2. BMI change from baseline to endpoint negatively-correlated with baseline leptin levels in female patients (r = -0.514, P = 0.024), but not male patients. Baseline adiponectin or TNF-α levels were not correlated with BMI change. CONCLUSION: Baseline plasma leptin can have an effect on subsequent weight gain following OLZ treatment in female patients with schizophrenia.

Improvement of dumping syndrome and oversecretion of glucose-dependent insulinotropic polypeptide following a switch from olanzapine to quetiapine in a patient with schizophrenia.

Among the most important adverse effects of antipsychotics is abnormal glucose metabolism, which includes not only hyperglycemia but hyperinsulinemia and hypoglycemia. We have previously described five patients who experienced hypoglycemia during treatment with antipsychotics. Thus, an anamnesis of gastric surgery, which often causes dumping syndrome, and treatment with antipsychotics may synergistically induce hypoglycemia. We describe here a patient with schizophrenia under treatment of olanzapine and an anamnesis of gastric surgery, who experienced late dumping syndrome, hyperinsulinemia and overactivation of glucose-dependent insulinotropic polypeptide. Dumping syndrome, however, was improved after the patient was switched from olanzapine to quetiapine.

GIPR Gene Polymorphism and Weight Gain in Patients With Schizophrenia Treated With Olanzapine.

Association between gastric inhibitory polypeptide receptor polymorphism, rs10423928, and body mass index in olanzapine-treated schizophrenia was examined. Body mass index change for the A/T+A/A genotypes was significantly higher than that for the T/T genotype. rs10423928 may predict weight gain in schizophrenia.

Promoter variation in the catechol-O-methyltransferase gene is associated with remission of symptoms during fluvoxamine treatment for major depression.

We investigated the association between remission of depressive symptoms in fluvoxamine treatment and catechol-O-methyltransferase (COMT) gene. Sixteen SNPs in the COMT gene were investigated in 123 outpatients with major depression. Three single nucleotide polymorphisms located in the 5' region were associated with remission in fluvoxamine-treated outpatients with moderate to severe depression.

Changes in PR and QTc intervals after switching from olanzapine to risperidone in patients with stable schizophrenia.

AIM: We examined the difference between the effects of olanzapine (OLZ) and risperidone (RIS) on PR and QT intervals among patients with stable schizophrenia using a cohort analysis. METHODS: Twenty-one subjects treated with OLZ were enrolled in the study. Following baseline assessments, which included PR and QT intervals, OLZ was switched to RIS for each subject. The same parameters were evaluated following the switch to RIS. RESULTS: All patients who had been treated with OLZ were successfully switched to RIS. In all patients, we observed a significant decrease in PR interval (t = 2.397, P = 0.029) and no change in either QTc or RR interval. In female patients, the QTc interval was significantly decreased (t = 3.495, P = 0.008) following the switch, while in male patients, the QTc interval did not change. No patients showed a PR interval of >200 ms or a QTc interval of >500 ms. CONCLUSION: OLZ treatment has a greater prolonging effect on PR and QT intervals compared with RIS. Careful attention may need to be paid to the cardiac conduction system in addition to QT prolongation during OLZ treatment.

High prevalence of underweight and undernutrition in Japanese inpatients with schizophrenia.

AIMS: In Europe and North America, schizophrenia patients treated with antipsychotic agents have a higher prevalence of obesity and metabolic syndrome compared with healthy individuals. In Japan, the prevalence of overweight/obesity in the general population is considerably lower than that in Europe and North America. The purpose of this study was to investigate the prevalence of underweight and overweight/obesity as well as laboratory data in Japanese inpatients with schizophrenia. METHODS: The subjects were 333 inpatients with schizophrenia and 191 age- and sex-matched healthy volunteers. Overweight/obesity was defined as body mass index (BMI) ≥ 25 kg/m(2) , standard weight was defined as BMI ≥ 18.5 to <25 kg/m(2) and underweight was defined as BMI < 18.5 kg/m(2) . RESULTS: A significant difference in the prevalence of the three BMI levels was observed between schizophrenia patients and controls (P < 0.001). The prevalence of underweight was significantly higher in schizophrenia patients than that in controls (P < 0.001). The prevalence of hypoproteinemia (P < 0.001) and of hypocholesterolemia (P < 0.001) were significantly higher in schizophrenia patients than in controls. In schizophrenia patients, the prevalence of hypotriglyceridemia was significantly higher in the underweight group than in the standard weight group (P = 0.003) and in the overweight/obesity group (P < 0.001). CONCLUSIONS: The prevalence of underweight in Japanese inpatients with schizophrenia may be higher compared with that in the general population. Therefore, the physical health of inpatients should be more carefully taken into account in clinical practice.

The prevalence of glucose intolerance in Japanese schizophrenic patients with a normal fasting glucose level.

BACKGROUND: The prevalence of diabetes in patients with schizophrenia is 2- to 3-fold higher than in the general population. Glucose abnormalities were detected in 11.9% of Japanese schizophrenic patients in a recent cross-sectional study that included fasting glucose monitoring. However, detailed studies of glucose intolerance using the glucose tolerance test have been limited in Japanese patients with schizophrenia. We investigated the prevalence of abnormal glucose tolerance after glucose loading among Japanese inpatients with schizophrenia, with normal fasting glucose levels. METHOD: A total of 258 inpatients with schizophrenia participated in this study after giving their written informed consent. A 75-g oral glucose tolerance test was conducted in the morning after a 12-hour overnight fast. RESULTS: Among patients with normal fasting glucose, 81.3% had normal glucose tolerance, 17.3% had impaired glucose tolerance, and 1.3% were diagnosed with diabetes. CONCLUSIONS: This study showed that the frequency of impaired glucose tolerance in patients with schizophrenia with normal fasting glucose levels might be higher than in the general population. Careful monitoring and screening of patients with schizophrenia for abnormal glucose metabolism might therefore be necessary.

Impact of the ABCB1 gene polymorphism on plasma 9-hydroxyrisperidone and active moiety levels in Japanese patients with schizophrenia.

9-Hydroxyrisperidone (9-OH-RIS) is an active metabolite of the antipsychotic drug risperidone (RIS). The total active moiety level, in other words the sum of the RIS and 9-OH-RIS serum levels, may be important for estimating the clinical effects of RIS treatment. However, there have been no consistent results reported regarding the relationship between cytochrome P450 (CYP) 2D6 or adenosine triphosphate-binding cassette subfamily B member 1 (ABCB1) variant alleles and 9-OH-RIS or total active moiety plasma levels. Seventy-four Japanese patients treated with RIS were examined in the present study. Steady-state plasma RIS and 9-OH-RIS were measured. The CYP2D6*5, CYP2D6*10, ABCB1 3435C>T, and ABCB1 2677G>T/A genotypes were detected. Multiple regression analysis showed that the dose-corrected plasma RIS levels were significantly correlated with the number of CYP2D6 variant alleles and ABCB1 3435C>T genotypes, whereas the 9-OH-RIS and total active moiety levels were significantly correlated with the ABCB1 3435C>T genotypes and with age. On the other hand, the ABCB1 2677G>T/A genotypes did not affect plasma RIS, 9-OH-RIS, or total active moiety levels. The ABCB1 3435C>T genetic polymorphism may predict plasma 9-OH-RIS and total active moiety levels.

Sex differences in the effect of four second-generation antipsychotics on QTc interval in patients with schizophrenia.

OBJECTIVE: We examined sex differences in the effect of olanzapine (OLZ), risperidone (RIS), aripiprazole (ARP), or quetiapine (QTP) on mean corrected QT (QTc) intervals among 222 patients with schizophrenia. METHODS: Subjects were patients with schizophrenia who were treated with either OLZ (n = 69), RIS (n = 60), ARP (n = 62), or QTP (n = 31). Electrocardiographic measurements were conducted, and the QT interval was corrected using Bazett's correction formula. RESULTS: The mean QTc interval of the QTP group was significantly longer than that of the RIS group (p = 0.002) or ARP group (p = 0.029). The mean QTc interval of the OLZ group was also significantly longer than that of the RIS group (p = 0.006). In female participants, the difference in the mean QTc interval among the four second-generation antipsychotic (SGA) groups was statistically significant (p = 0.002), whereas in male patients, there was no significant difference in the mean QTc interval among the four SGA groups. Post hoc analyses showed that sex differences in QTc interval were observed only in OLZ treatment group (p = 0.007). CONCLUSION: To our knowledge, this is the first study to demonstrate sex differences in the effect of four SGAs on the QTc interval.

Low prevalence of metabolic syndrome and its prediction in Japanese inpatients with schizophrenia.

OBJECTIVES: There have so far been few papers studying the metabolic syndrome (MetS) prevalence rate in Japanese patients with schizophrenia. We studied the MetS prevalence rate in Japanese controls and inpatients with schizophrenia and compared the prediction factors for the occurrence of MetS. METHODS: The subjects were 319 inpatients with schizophrenia and 154 controls. The predictive utilities of body mass index (BMI) and the individual components of MetS for MetS diagnosis were evaluated. RESULTS: The prevalence of MetS did not differ between schizophrenia and control subjects. Subjects with schizophrenia showed higher prevalences of the MetS criteria for high-density lipoprotein cholesterol (HDL) (p < 0.001) and waist circumference (WC) (p < 0.001). In subjects with schizophrenia, the predictive power was found to be highest for HDL, followed by WC, BMI, triglyceride, diastolic blood pressure (BP), systolic BP and fasting plasma glucose. However, in control subjects, the predictive power was found to be highest for triglyceride, followed by WC, systolic BP, BMI, HDL, diastolic BP and fasting plasma glucose. HDL was the component most predictive of MetS in subjects with schizophrenia treated with antipsychotics. CONCLUSION: Because, in normal clinical practice, it is difficult to obtain temporal measurements for all of the MetS criteria, measurement of HDL may be useful for predicting the MetS.

Differences in plasma prolactin levels in patients with schizophrenia treated on monotherapy with five second-generation antipsychotics.

Although second-generation antipsychotics (SGAs) are characterized by fewer prolactin (PRL)-related side effects compared with first-generation antipsychotics, the detailed effects of SGAs on the plasma PRL levels still remain unclear. We examined the differences in plasma PRL levels among 268 patients treated for schizophrenia with olanzapine (OLZ), risperidone (RIS), aripiprazole (ARP), quetiapine (QTP), or perospirone (PER). The participants had received antipsychotic monotherapy with stable doses of OLZ, RIS, ARP, QTP, or PER for ≥ 3 weeks, and fasting blood samples were drawn to examine plasma PRL levels. The differences in median plasma PRL levels in all (P<0.001), male (P<0.001) and female patients (P<0.001) among the five SGA groups were statistically significant. A stepwise multiple regression analysis showed that ARP treatment was found to contribute to lower plasma PRL level, while female sex, RIS, OLZ and chlorpromazine equivalent dose were found to contribute to a higher plasma PRL level. The median value of plasma PRL level in the RIS group was twice as much compared with that in the OLZ group, although this was not statistically significant. In this study, OLZ had a considerable effect on plasma PRL level, similar to RIS, while PER did not affect plasma PRL levels, similar to QTP. Further studies are needed to clarify the differences in plasma PRL levels among SGAs.

Changes in QT interval after switching to quetiapine in Japanese patients with schizophrenia.

OBJECTIVES: There are few reports regarding quetiapine (QTP)-related QT prolongation. We examined the change in QT interval after switching from aripiprazole (ARP), olanzapine (OLZ), or risperidone (RIS) to QTP. METHODS: Twenty subjects treated with ARP, OLZ, or RIS were enrolled in the study. Following baseline assessments, which included QT interval and electrolytes, these three drugs were switched to QTP for each subject. The same parameters were evaluated following a switch to QTP. RESULTS: All 20 patients who had been treated with ARP, OLZ, or RIS were successfully switched to QTP. Significant increases were observed in the total mean corrected QT (QTc) interval after switching (p = 0.014). The coefficient of variation for the extent of change in QTc interval was 1.66. The mean QTc with ARP treatment was significantly increased after QTP treatment (p = 0.004). CONCLUSIONS: Quetiapine might have a greater effect on QTc interval than other second-generation antipsychotics. However, because there was a considerable variability in the extent of QTc prolongation after switch to QTP, further studies are required to clarify the effect of QTP on QTc interval.

Excessive insulin secretion in Japanese schizophrenic patients treated with antipsychotics despite normal fasting glucose levels.

The development of impaired glucose tolerance induced by antipsychotics (APs) is of concern as a serious adverse effect of psychiatric drug therapy. However, the mechanism by which APs cause dysfunction of the glucose-insulin response is not fully understood. Recent studies have shown that patients treated with APs for schizophrenia were more likely to exhibit impaired glucose tolerance after a glucose load compared with healthy control subjects, even if fasting glucose levels were within the reference range. To explain these findings, we hypothesized that insulin secretion is increased in schizophrenic patients treated with AP, even those normal fasting glucose (NFG) levels. Therefore, oral glucose tolerance tests were conducted in 159 Japanese inpatients with AP-treated schizophrenia and in 90 healthy subjects without schizophrenia. Plasma glucose and serum insulin concentrations were measured before (0 minute) and at 30, 60, 90, and 120 minutes after the oral glucose load. Although insulin levels at 0 minute were similar in both groups of subjects, insulin levels were significantly higher in the patients treated with AP at all times after the glucose load than in the healthy subjects. In analyses of NFG subjects, insulin levels were significantly higher in the patients treated with AP compared with the healthy subjects at all times after glucose loading. Overall, we found that insulin secretion in response to a glucose load was significantly higher in the patients treated with AP, irrespective of NFG. These results suggest that APs affect the glucose-insulin response, which may lead to subclinical insulin resistance before the onset of overt glucose intolerance.