Prolactin and estradiol serum levels in unmedicated male paranoid schizophrenia patients

Effects of aripiprazole on prolactin levels and differences in effectiveness in patients with schizophrenia: a post-hoc analysis of the real-world data of a multicenter study

Objectives

To investigate the effect of aripiprazole on prolactin levels in patients with schizophrenia and analyze whether varying baseline prolactin levels affect the effectiveness and safety of aripiprazole, in a real-life diagnostic and therapeutic setting in a post-hoc analysis.

Methods

In this post-hoc analysis, patients with schizophrenia in the acute phase were divided into an elevated-prolactin group and a normal-prolactin group. After 8 weeks of aripiprazole treatment, changes in the proportion of patients with an abnormal prolactin level were analyzed in both groups, and the efficacy and safety of aripiprazole were compared between the two groups.

Results

The elevated-prolactin group had more women, a longer duration of disease, and lower Positive and Negative Syndrome Scale (PANSS) total and subscale scores at baseline compared with the normal-prolactin group (all P < 0.05), and there was no significant difference in the proportion of patients with prior use of antipsychotic medication between the two groups. Regardless of previous antipsychotic use, patients in both groups developed hyperprolactinemia (23/168 [13.7%] in those who had taken antipsychotics vs. 43/375 [11.4%] in those who had not). After 8 weeks of aripiprazole treatment, the proportion of patients with abnormal prolactin in the elevated-prolactin group significantly decreased with prolonged treatment (P < 0.001), and aripiprazole had no significant effect on the normal-prolactin group (P = 0.250). Normal-prolactin group showed better efficacy than the elevated-prolactin group, and the differences in efficacy between the two groups was observed from week 4 to the endpoint (all p<0.05). In total, 87.2% (68/78) patients experienced mild to moderate adverse events in the elevated-prolactin group, which was significantly more frequent compared with the normal-prolactin group 71.0% (365/514).

Conclusions

In this real-world study, for patients with acute schizophrenia, aripiprazole was effective in lowering the proportion of patients with abnormal prolactin levels, while it had no significant effect on patients with normal baseline prolactin. After adjusting for factors such as sex, age, prior antipsychotic drugs use history and disease severity, effectiveness and safety of aripiprazole in patients with normal baseline prolactin was significantly better than that in patients with elevated baseline prolactin.

Brain-derived neurotrophic factor, sex hormones and cognitive decline in male patients with schizophrenia receiving continuous antipsychotic therapy

BACKGROUND

There are systematic differences in clinical features between women and men with schizophrenia (SCZ). The regulation of sex hormones may play a potential role in abnormal neurodevelopment in SCZ. Brain-derived neurotrophic factor (BDNF) and sex hormones have complex interacting actions that contribute to the etiology of SCZ.

AIM

To investigate the influence of BDNF and sex hormones on cognition and clinical symptomatology in chronic antipsychotic-treated male SCZ patients.

METHODS

The serum levels of follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), progesterone, testosterone (T), prolactin (PRL) and BDNF were compared between chronic antipsychotic-treated male (CATM) patients with SCZ (n = 120) and healthy controls (n = 120). The Positive and Negative Syndrome Scale was used to quantify SCZ symptoms, while neuropsychological tests were used to assess cognition. Neuropsychological tests, such as the Digit Cancellation Test (DCT), Semantic Verbal Fluency (SVF), Spatial Span Test (SS), Paced Auditory Serial Addition Test (PASAT), Trail Making Task (TMT-A), and Block Design Test (BDT), were used to assess executive functions (BDT), attention (DCT, TMT-A), memory (SS, PASAT), and verbal proficiency (SVF).

RESULTS

Although E2 levels were significantly lower in the patient group compared to the healthy controls, T, PRL, and LH levels were all significantly higher. Additionally, the analysis revealed that across the entire sample, there were positive correlations between E2 Levels and BDNF levels as well as BDNF levels and the digital cancellation time. In CATM patients with SCZ, a significant correlation between the negative symptoms score and PRL levels was observed.

CONCLUSION

Sex hormones and BDNF levels may also be linked to cognitive function in patients with chronic SCZ.

Prolactin and morning cortisol concentrations in antipsychotic naïve first episode psychosis: A systematic review and meta-analysis

IMPORTANCE

Alterations in prolactin and cortisol levels have been reported in antipsychotic naïve patients with first episode psychosis (FEP). However, it has been studied in very small samples, and inter-group variability has never been studied before.

OBJECTIVE

To provide estimates of standardized mean differences (SMD) and inter-group variability for prolactin, cortisol awakening response (CAR) and morning cortisol concentrations in antipsychotic naïve FEP (AN-FEP) patients and healthy controls (HC).

DATA SOURCES

BIOSIS, KCI, MEDLINE, Russian Science Citation Index, SciELO, Cochrane, PsycINFO, Web of Science were searched from inception to February 28, 2022.

STUDY SELECTION

Peer-reviewed cohort studies that reported on prolactin or cortisol blood concentrations in AN- FEP patients and HC were included.

DATA EXTRACTION AND SYNTHESIS

Study characteristics, means and standard deviations (SD) were extracted from each article. Inter group differences in magnitude of effect were estimated using Hedges g. Inter-group variability was estimated with the coefficient of variation ratio (CVR). In both cases estimates were pooled using random-effects meta-analysis. Differences by study-level characteristics were estimated using meta-regression. PRISMA guideline was followed (No. CRD42022303555).

MAIN OUTCOMES AND MEASURES

Prolactin, CAR and morning cortisol blood concentrations in AN-FEP group in relation to HC group.

RESULTS

Fourteen studies for prolactin (N = 761 for AN-FEP group, N = 687 for HC group) and twelve studies for morning cortisol (N = 434 for AN-FEP group, N = 528 for HC group) were included. No studies were found in CAR in AN-FEP patients. Mean SMD for prolactin blood concentration was 0.88 (95% CI 0.57, 1.20) for male and 0.56 (95% CI 0.26, 0.87) for female. As a group, AN-FEP presented greater inter-group variability for prolactin levels than HC (CVR=1.28, 95% CI 1.02, 1.62). SMD for morning cortisol concentrations was non-significant: 0.34 (95% CI -0.01, 0.69) and no inter-group variability significant differences were detected: CVR= 1.05 (95% CI 0.91, 1.20). Meta-regression analyses for age and quality were non-significant. Funnel plots did not suggest a publication bias.

CONCLUSIONS AND RELEVANCE

Increased prolactin levels were found in AN-FEP patients. A greater inter-group variability in the AN-FEP group suggests the existence of patient subgroups with different prolactin levels. No significant abnormalities were found in morning cortisol levels. Further research is needed to clarify whether prolactin concentrations could be used as an illness biomarker.

Effects of urban particulate matter on gut microbiome and partial schizophrenia-like symptoms in mice: Evidence from shotgun metagenomic and metabolomic profiling

BACKGROUND

Epidemiological evidence reported that particulate matter (PM) was associated with increased schizophrenia (SCZ) risk. Disturbance of gut microbiome was involved in SCZ. However, it remains unclear whether PM induces SCZ-like symptoms and how gut microbiome regulates them. Therefore, a multi-omics animal experiment was conducted to verify how urban PM induces SCZ-like behavior and altered gut microbiota and metabolic pathways.

METHODS

Using a completely random design, mice were divided into three groups: PM group, control group and MK801 group, which received daily tracheal instillation of PM solution, sterile PBS solution and intraperitoneal injection of MK801 (establish SCZ model), respectively. After a 14-day intervention, feces were collected for multi-omics testing (shotgun metagenomic sequencing and untargeted metabolomic profiling), followed by open field test, tail suspension test, and passive avoidance test. Besides, fecal microbiome of PM group and control group were transplanted into "pseudo-sterile" mice, then behavioral tests were conducted.

RESULTS

Similar to MK801 group, mice in PM group showed SCZ-like symptoms, including increased spontaneous activity, excitability, anxiety and decreased learning and spatial memory. PM exposure significantly increased the relative abundance of Verrucomicrobia and decreased that of Fibrobacteres et al. The metabolism pathways of estrogen signaling (estriol, 16-glucuronide-estriol and 21-desoxycortisol) and choline metabolism (phosphocholine) were significantly altered by PM exposure. Verrucomicrobia was negatively correlated with the level of estriol, which was correlated with decreased learning and spatial memory. Fibrobacteres and Deinococcus-Thermus were positively correlated with the level of phosphocholine, which was correlated with increased spontaneous activity, excitability and anxiety. Fecal microbiome transplantation from PM group mice reproduced excitability and anxiety symptoms.

CONCLUSIONS

Exposure to PM may affect composition of gut microbiome and alterations of estrogen signaling pathway and choline metabolism pathway, which were associated with partial SCZ-like behaviors. But whether gut microbiome regulates these metabolic pathways and behaviors remains to be determined.

Prospective analysis of serum prolactin levels, clinical symptomatology and sexual functions in patients with schizophrenia switched to paliperidone palmitate 3-monthly from paliperidone palmitate 1-monthly: Preliminary findings of the first 3 months

OBJECTIVE

Long-acting injectable (LAI) antipsychotics were developed to improve adherence to schizophrenia treatment. Paliperidone palmitate (PP) has two LAI forms: Monthly (PP1M) and three-monthly (PP3M). PP3M shows less difference in Peak-to-Trough drug concentration levels. This could be related to a lower incidence of hyperprolactinemia, which may negatively affect adherence. We aimed to compare prolactin levels and investigate relationships between prolactin levels, symptomatology and sexual function in patients with schizophrenia after switching from PP1M to PP3M.

METHODS

Twenty-five patients were enrolled. The sociodemographic data form, the Positive and Negative Syndromes Scale (PANSS) and the Arizona Sexual Experience Scale (ASEX) were used. Morning blood samples were drawn to determine prolactin levels.

RESULTS

Prolactin level (p < 0.001), the total score and arousal sub-score of ASEX (respectively; p = 0.015, p = 0.020) and the total score and positive scale of PANSS (respectively; p = 0.017, p = 0.021) were decreased on the 90th day (±15 days).

CONCLUSIONS

After switching to PP3M, the decreases in prolactin levels and potentially related sexual side effects was statistically significant. There may be a difference between two formulations of the same drug in terms of side effects, and there is a need for prospective follow-up studies with larger samples.

Estrogens in schizophrenia: progress, current challenges and opportunities

PURPOSE OF REVIEW

Schizophrenia is a heterogeneous psychiatric disorder with a different, but not necessarily milder clinical presentation in women as compared to men. These sex differences have largely been attributed to the protective role of estrogens. This article reviews the current state of estrogen research in schizophrenia.

RECENT FINDINGS

Estrogens regulate important pathophysiological pathways in schizophrenia, including dopamine activity, mitochondrial function, and the stress system. Estrogen deficiency is common in both sexes and is associated with increases in psychotic symptoms. Hyperprolactinemia causes secondary estrogen deficiency and can be a reaction to stress, or secondary to prolactin-raising antipsychotics. Therefore, prolactin-sparing antipsychotics should be preferred especially in premenopausal women, who are more prone to hyperprolactinemia. Premenopausal women furthermore require lower doses of antipsychotics than men, since estrogens raise the availability and efficacy of antipsychotics.

SUMMARY

The past years have established the importance of estrogens in the pathophysiology of schizophrenia and have shown its relevance to clinical practice through its influence on antipsychotic drug efficacy. Future research should focus on the neurobiological and clinical effect of contraceptives in premenopausal women with schizophrenia. Furthermore, the potential of estrogen-like augmentation with raloxifene and phytoestrogens in schizophrenia should be established in the coming years.

Plasma prolactin is higher in major depressive disorder and females, and associated with anxiety, hostility, somatization, psychotic symptoms and heart rate

Background

Major Depressive Disorder (MDD) is linked to poor physical health including an increased risk of developing cardiometabolic disease (CMD), yet the underlying physiology of this relationship is not clear. One pathophysiological mechanism that may underlie this relationship is neuroendocrine dysregulation, including that of the hormone prolactin. Prolactin has a role in the regulation of stress, and it is linked to anxiety, hostility, and weight gain, which are all implicated in MDD and increased CMD risk. However, little research has examined plasma prolactin in association with psychological symptoms of MDD or biometric indices of CMD risk. Method: Plasma samples of 120 participants (n ​= ​60 meeting DSM-5 criteria for MDD and n ​= ​60 control; age and sex matched) were analysed to assess prolactin concentration. Biometric data (BMI, waist circumference, blood pressure and heart rate) were collected, and participants completed the Brief Symptom Inventory (BSI) and Depression Anxiety Stress Scale (DASS).

Results

Plasma prolactin was higher in participants with MDD versus controls (8.79 ​± ​5.16 ​ng/mL and 7.03 ​± ​4.78 ​ng/mL, respectively; F ​= ​4.528, p ​= ​0.035) and among females versus males (9.14 ​± ​5.57 ​ng/mL and 6.31 ​± ​3.70 ​ng/mL, respectively; F ​= ​9.157, p ​= ​0.003). Prolactin was correlated with several psychological symptoms including anxiety, hostility and somatization, and with heart rate, but not with any other biometric measures.

Conclusions

The results of this study indicate that neuroendocrine dysregulation in MDD may extend to the hormone prolactin, with prolactin being specifically associated with a subset of related psychometric and cardiovascular measures.

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Plasma prolactin is higher in major depressive disorder group than in controls.

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Plasma prolactin is significantly higher in females versus males.

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Prolactin is significantly correlated with heart rate.

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Prolactin is correlated with paranoid ideation, anxiety, hostility, somatization.

The association between prolactin concentration and aggression in female patients with schizophrenia

OBJECTIVES

This study assessed the association between serum prolactin (PRL) concentration and aggression in female patients with schizophrenia.

METHODS

Female patients with schizophrenia (N = 120) were diagnosed using SCID-5 based on the DSM-5 criteria. They were sampled at the University Psychiatric Hospital Vrapce during the period from March 2017 to March 2019. Aggression was evaluated using the Positive and Negative Syndrome Scale (PANSS), and Overt Aggression Scale (OAS). Patients were subdivided into aggressive and non-aggressive groups. PRL was determined in serum using electrochemiluminescence (ECLIA) method.

RESULTS

Aggressive patients with schizophrenia had significantly (p < 0.0001) increased PRL concentration compared to non-aggressive patients. Higher PRL concentration was significantly (p < 0.0001) associated with pronounced aggressive symptoms determined by the OAS scores. When patients were subdivided into those who were treated with risperidone, haloperidol, paliperidone, amisulpride, and a group that was not treated with these antipsychotics, aggressive patients in both groups had significantly higher PRL concentrations than non-aggressive patients. Higher antipsychotic dose was related to increased PRL concentration (p = 0.004).

CONCLUSIONS

Our findings suggest that higher PRL is significantly associated with aggression, irrespective of the antipsychotic medication, in female patients with schizophrenia.

Abnormally low prolactin levels in schizophrenia patients after switching to aripiprazole in a randomized trial: a biomarker for rebound in psychotic symptoms?

BACKGROUND

Switching to aripiprazole from other antipsychotics can avoid antipsychotic-induced hyperprolactinemia but may result in an abnormally low prolactin level. This study aimed to assess whether the aripiprazole-induced abnormally low prolactin level was a biomarker for subsequent rebound of positive symptoms in schizophrenia patients.

METHODS

Participants were 63 patients in an 8-week trial of switching to aripiprazole, in which preswitching antipsychotics were maintained for the first 2 weeks and aripiprazole was fixed at 15 mg orally throughout the trial. A prolactin level of < 3.7 ng/ml was defined as abnormally low, and an increase of two or more points in the positive subscore of the Positive and Negative Syndrome Scale at two adjacent ratings was defined as a psychotic rebound.

RESULTS

Among 63 patients, 25 (39.7%) had an abnormally low prolactin level and 21 (33.3%) had a psychotic rebound after switching to aripiprazole. In patients with abnormally low prolactin levels, 48.0% of them had a rebound in psychotic symptoms, whereas in those without abnormally low prolactin levels 23.7% did so. Multivariable logistic regression analysis with adjustment for sex, early age at onset, and preswitching medications revealed that abnormally low prolactin levels were associated with psychotic rebound (adjusted odds ratio = 3.55, 95% confidence interval = 1.02, 12.5). Furthermore, there was concurrency between the trend of the cumulative proportion of patients having an abnormally low prolactin level and that of the cumulative proportion of patients having a rebound in psychotic symptoms.

CONCLUSIONS

An abnormally low prolactin level after switching to aripiprazole in schizophrenia patients was a potential warning sign of a psychotic rebound. Hence, monitoring of prolactin levels after switching to aripiprazole may help avoid such rebound in schizophrenia.

TRIAL REGISTRATION

NCT00545467 ; Date of registration: 17/10/2007.

Impact of Bisphenol A on Gonadotropic Hormone Levels in Children with Autism Spectrum Disorders

Early developmental exposures to endocrine disruptors including bisphenol A (BPA) may affects the body's endocrine system producing adverse neurologic, reproductive, cardiovascular, metabolic, and immune effects in humans. Many studies show the effect of BPA on human reproduction at lower concentrations than that of the safety limit recommendations. However, limited studies have been associated between environmental exposure of BPA and gonadotropic hormone levels in children with autism spectrum disorders (ASDs). This study was done to evaluate association between the serum levels of hormones; follicle-stimulating (FSH), inhibin B (INHB), and estradiol (E2) and BPA in 49 ASD children compared with 40 healthy control children. Serum levels of FSH, INHB, and E2 were lower in ASD group than that of control. Correlations between BPA and FSH, INHB, and E2 within autistic children were not significant. The observed results revealed that BPA may cause endocrine dysfunction in ASD children.

Serum prolactin level and its correlation with psychopathology in drug free/drug naïve schizophrenia a case control study

BACKGROUND

There is a discrepancy in literature regarding level of prolactin in drug free/ drug naïve patients with non-affective psychosis. Few earlier studies have found low levels of prolactin whereas recent studies have found high levels of prolactin when compared to controls. Most of these studies have not considered the possible confounding factors. Also ours is the first study that evaluated the correlation between psychopathology & prolactin levels after considering the confounding agents.

METHOD

It was a cross sectional, hospital based case control study. Purposive sampling was done to identify the cases of schizophrenia. 59 cases and 59 controls fulfilling inclusion and exclusion criteria were taken for the study after taking consent. Socio-demographic and other relevant clinical data were collected. Scores of PANSS AND BPRS were collected on the day of admission. Blood samples were collected from 8 to 10 am in the morning. Samples were centrifuged and the serum was stored in sterile vials at minus 80° centigrade. Serum Prolactin, free T3, freeT4, Thyroid Stimulating Hormone & Cortisol levels were evaluated for both cases and controls and correlation between them and with psychopathology of cases was seen.

RESULTS

Our study showed that prolactin level was increased in drug free/naïve cases of schizophrenia. Significant difference was found between T4 levels of cases and controls. No correlation was found between prolactin and psychopathology.

CONCLUSION

Prolactin is increased in drug free/ drug naïve patients of schizophrenia and this is not related to confounding factors. There was no significant correlation between prolactin and psychopathology.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Psychotropics and Male Reproduction

Psychotropic drugs, including antidepressants, antipsychotics, and anticonvulsants, all have negative effects on sexual function and semen quality. These adverse events vary among men and are less pronounced for some medications, allowing their effects to be managed to some extent. Use of specific serotonin reuptake inhibitors (SSRIs) is prevalent in men of reproductive age; and application to treat premature ejaculation increases the number of young men on SSRI therapy. Oxidative damage to sperm can result from prolonged residence in the male reproductive tract. The increase in ejaculatory latency seen with SSRIs likely underlies some of their negative effects on semen quality, including higher sperm DNA fragmentation, seen in all SSRIs evaluated thus far. These medications increase prolactin (PRL) levels in some men, and this is often credited with inhibitory effects on male reproduction; however, testosterone levels are generally normal, reducing the likelihood of direct HPG axis inhibition by PRL. The tricyclic antidepressants have also been shown to increase PRL levels in some studies but not in others. The exception is the tricyclic antidepressant clomipramine, which profoundly increases PRL levels and may depress semen quality. Other antidepressants modulating synaptic levels of serotonin, norepinephrine, and/or dopamine may have toxicity similar to SSRIs, but most have not been evaluated. In limited studies, norepinephrine-dopamine reuptake inhibitors (NDRIs) and serotonin agonist/reuptake inhibitors (SARIs) have had minimal effects on PRL levels and on sexual side effects. Antipsychotic medications increase PRL, decrease testosterone, and increase sexual side effects, including ejaculatory dysfunction. The greatest evidence is for chlorpromazine, haloperidol, reserpine, risperidone, and thioridazine, with less effects seen with aripiprazole and clozapine. Remarkably few studies have looked at antipsychotic effects on semen quality, and this is an important knowledge gap in reproductive pharmacology. Lithium increases PRL and LH levels and decreases testosterone although this is informed by few studies. The anticonvulsants, many used for other indications, generally decrease free or bioavailable testosterone with variable effects on the other reproductive hormones. Valproate, carbamazepine, oxcarbazepine, and levetiracetam decrease semen quality; other anticonvulsants have not been investigated for this adverse reaction. Studies are required evaluating endpoints of pregnancy and offspring health for psychotropic medications.

Prolactin levels in drug-naïve patients with schizophrenia and other psychotic disorders

OBJECTIVE

Hyperprolactinaemia as a side effect of dopamine receptor blockers is common in patients with schizophrenia and other psychotic disorders and may lead to amenorrhoea, galactorrhoea, hypogonadism, subfertility and osteoporosis. The aim of our study was to determine whether hyperprolactinaemia occurs also in patients with schizophrenia and other psychotic disorders prior to any antipsychotic treatment.

METHODS

Serum prolactin, thyroid-stimulating hormone (TSH), triiodothyronine (T3), free tetraiodothyronine (FT4) and cortisol levels were measured in 40 newly diagnosed, drug naïve, patients with schizophrenia and other psychotic disorders and in 40 age and gender matched healthy subjects.

RESULTS

The median prolactin value was 12.5 ng/ml (range: 2-38 ng/ml) for patients and 8.6 ng/ml (range: 4-17.6 ng/ml) for healthy subjects (p = 0.011). Patients had lower levels of T3 compared to healthy controls (mean: 1.08 ng/ml, SD: 0.16 vs. 1.18 ng/ml, 0.18, respectively; p = 0.008). Serum TSH, FT4 and cortisol levels were similar between the two groups. Multiple regression analysis revealed that the difference in serum prolactin values was independent of thyroid function (TSH, FT4, T3) and serum cortisol levels.

CONCLUSIONS

A higher serum prolactin level was found in drug naïve, newly diagnosed patients with schizophrenia and other psychotic disorders compared to healthy controls, prior to starting any antipsychotic treatment.

Prolactin concentrations in antipsychotic-naïve patients with schizophrenia and related disorders: A meta-analysis

OBJECTIVE

The use of dopaminergic antagonist antipsychotics is associated with hyperprolactinemia, but some studies have found increased prolactin concentrations in antipsychotic-naive patients with schizophrenia and related disorders. We conducted a systematic review and meta-analysis of studies of prolactin in antipsychotic-naïve patient with these disorders (PRISMA No. CRD42015016337).

DATA SOURCES

PubMed (Medline), PsycInfo, and Web of Science were searched for articles from 1950 to the present in English.

STUDY SELECTION

Seven studies of males (N=141 for patients, N=191 for control subjects) and five studies of females (N=67 and N=116) met criteria for inclusion: data on blood prolactin concentrations for both control subjects and antipsychotic-naive patients with schizophrenia or a related disorder, with data available separately for males and females.

DATA EXTRACTION

Data was extracted from the papers by one author and independently verified by a second.

RESULTS

The mean effect size for males was 1.02 (95% CI, 0.77, 1.26; p<0.001) and 0.43 for females (95% CI 0.11, 0.76; p<0.01). Meta-regression analyses for age, smoking, body mass index (BMI), year of publication, and cortisol were not significant. Funnel plots did not suggest the presence of a publication bias.

CONCLUSIONS

Our meta-analyses found significantly increased prolactin levels in both male and female antipsychotic-naïve patients with schizophrenia and related disorders. The small number of studies and limited matching for potentially confounding variables in some of the studies were limitations of this analysis. Prolonged hyperprolactinemia may lead to sexual dysfunction and osteoporosis, and some antipsychotics cause additional elevation of prolactin concentrations.

An Emerging Role of micro-RNA in the Effect of the Endocrine Disruptors

Endocrine-disrupting chemicals (EDCs) are diverse natural and synthetic chemicals that may alter various mechanisms of the endocrine system and produce adverse developmental, reproductive, metabolic, and neurological effects in both humans and wildlife. Research on EDCs has revealed that they use a variety of both nuclear receptor-mediated and non-receptor-mediated mechanisms to modulate different components of the endocrine system. The molecular mechanisms underlying the effects of EDCs are still under investigation. Interestingly, some of the effects of EDCs have been observed to pass on to subsequent unexposed generations, which can be explained by the gametic transmission of deregulated epigenetic marks. Epigenetics is the study of heritable changes in gene expression that occur without a change in the DNA sequence. Epigenetic mechanisms, including histone modifications, DNA methylation, and specific micro-RNAs (miRNAs) expression, have been proposed to mediate transgenerational transmission and can be triggered by environmental factors. MiRNAs are short non-coding RNA molecules that post-transcriptionally repress the expression of genes by binding to 3′-untranslated regions of the target mRNAs. Given that there is mounting evidence that miRNAs are regulated by hormones, then clearly it is important to investigate the potential for environmental EDCs to deregulate miRNA expression and action.

Relationship between prolactin, breast cancer risk, and antipsychotics in patients with schizophrenia: a critical review

OBJECTIVE

A recent meta-analysis showed that breast cancer probably is more common in female patients with schizophrenia than in the general population (effect size = 1.25, P < 0.05). Increasing experimental and epidemiological data have alerted researchers to the influence of prolactin (PRL) in mammary carcinogenesis. We therefore investigated the possible relationship between antipsychotic-induced hyperprolactinemia (HPRL) and breast cancer risk in female patients with schizophrenia.

METHOD

A literature search (1950 until January 2015), using the MEDLINE database, was conducted for English-language published clinical trials to identify and synthesize data of the current state of knowledge concerning breast cancer risk (factors) in women with schizophrenia and its (their) relationship between HPRL and antipsychotic medication.

RESULTS

Although an increasing body of evidence supports the involvement of PRL in breast carcinogenesis, results of human prospective studies are limited, equivocal, and correlative (with risk ratios ranging from 0.70 to 1.9 for premenopausal women and from 0.76 to 2.03 for postmenopausal women). Moreover, these studies equally do not take into account the local production of PRL in breast epithelium, although amplification or overexpression of the local autocrine/paracrine PRL loop may be a more important mechanism in tumorigenesis. Until now, there is also no conclusive evidence that antipsychotic medication can increase the risk of breast malignancy and mortality.

CONCLUSION

Other breast risk factors than PRL, such as nulliparity, obesity, diabetes mellitus, and unhealthy lifestyle behaviours (alcohol dependence, smoking, low physical activity), probably are of greater relevance in individual breast cancer cases within the population of female patients with schizophrenia.

Review of endocrine disorders associated with environmental toxicants and possible involved mechanisms

Endocrine disrupting chemicals (EDC) are released into environment from different sources. They are mainly used in packaging industries, pesticides and food constituents. Clinical evidence, experimental models, and epidemiological studies suggest that EDC have major risks for human by targeting different organs and systems in the body. Multiple mechanisms are involved in targeting the normal system, through estrogen receptors, nuclear receptors and steroidal receptors activation. In this review, different methods by which xenobiotics stimulate signaling pathways and genetic mutation or DNA methylation have been discussed. These methods help to understand the results of xenobiotic action on the endocrine system. Endocrine disturbances in the human body result in breast cancer, ovarian problems, thyroid eruptions, testicular carcinoma, Alzheimer disease, schizophrenia, nerve damage and obesity. EDC characterize a wide class of compounds such as organochlorinated pesticides, industrial wastes, plastics and plasticizers, fuels and numerous other elements that exist in the environment or are in high use during daily life. The interactions and mechanism of toxicity in relation to human general health problems, especially endocrine disturbances with particular reference to reproductive problems, diabetes, and breast, testicular and ovarian cancers should be deeply investigated. There should also be a focus on public awareness of these EDC risks and their use in routine life. Therefore, the aim of this review is to summarize all evidence regarding different physiological disruptions in the body and possible involved mechanisms, to prove the association between endocrine disruptions and human diseases.

The effects of novel and newly approved antipsychotics on serum prolactin levels: a comprehensive review

Since the 1970s, clinicians have increasingly become more familiar with hyperprolactinemia (HPRL) as a common adverse effect of antipsychotic medication, which remains the cornerstone of pharmacological treatment for patients with schizophrenia. Although treatment with second-generation antipsychotics (SGAs) as a group is, compared with use of the first-generation antipsychotics, associated with lower prolactin (PRL) plasma levels, the detailed effects on plasma PRL levels for each of these compounds in reports often remain incomplete or inaccurate. Moreover, at this moment, no review has been published about the effect of the newly approved antipsychotics asenapine, iloperidone and lurasidone on PRL levels. The objective of this review is to describe PRL physiology; PRL measurement; diagnosis, causes, consequences and mechanisms of HPRL; incidence figures of (new-onset) HPRL with SGAs and newly approved antipsychotics in adolescent and adult patients; and revisit lingering questions regarding this hormone. A literature search, using the MEDLINE database (1966-December 2013), was conducted to identify relevant publications to report on the state of the art of HPRL and to summarize the available evidence with respect to the propensity of the SGAs and the newly approved antipsychotics to elevate PRL levels. Our review shows that although HPRL usually is defined as a sustained level of PRL above the laboratory upper limit of normal, limit values show some degree of variability in clinical reports, making the interpretation and comparison of data across studies difficult. Moreover, many reports do not provide much or any data detailing the measurement of PRL. Although the highest rates of HPRL are consistently reported in association with amisulpride, risperidone and paliperidone, while aripiprazole and quetiapine have the most favorable profile with respect to this outcome, all SGAs can induce PRL elevations, especially at the beginning of treatment, and have the potential to cause new-onset HPRL. Considering the PRL-elevating propensity of the newly approved antipsychotics, evidence seems to indicate these agents have a PRL profile comparable to that of clozapine (asenapine and iloperidone), ziprasidone and olanzapine (lurasidone). PRL elevations with antipsychotic medication generally are dose dependant. However, antipsychotics having a high potential for PRL elevation (amisulpride, risperidone and paliperidone) can have a profound impact on PRL levels even at relatively low doses, while PRL levels with antipsychotics having a minimal effect on PRL, in most cases, can remain unchanged (quetiapine) or reduce (aripiprazole) over all dosages. Although tolerance and decreases in PRL values after long-term administration of PRL-elevating antipsychotics can occur, the elevations, in most cases, remain above the upper limit of normal. PRL profiles of antipsychotics in children and adolescents seem to be the same as in adults. The hyperprolactinemic effects of antipsychotic medication are mostly correlated with their affinity for dopamine D2 receptors at the level of the anterior pituitary lactotrophs (and probably other neurotransmitter mechanisms) and their blood-brain barrier penetrating capability. Even though antipsychotics are the most common cause of pharmacologically induced HPRL, recent research has shown that HPRL can be pre-existing in a substantial portion of antipsychotic-naïve patients with first-episode psychosis or at-risk mental state.

Prolactin and psychopathology in schizophrenia: a literature review and reappraisal

Secretion of the anterior pituitary hormone prolactin can be significantly increased by antipsychotic drugs, leading to a range of adverse effects in patients with schizophrenia. However, there is evidence from a variety of studies that prolactin may also be related to symptom profile and treatment response in these patients, and recent work has identified variations in prolactin secretion even in drug-free patients. In this paper, a selective review of all relevant studies pertaining to prolactin and schizophrenia, including challenge and provocation studies, is presented. The implications of this work are discussed critically. A tentative model, which synthesizes these findings and argues for a significant role for prolactin in the development of schizophrenia, is outlined.

Prolactin serum levels in first-episode neuroleptic-naive patients with pituitary microadenoma and comorbid psychosis

This study was designed to explore the relationship between pituitary microadenoma and psychosis and to evaluate the role that prolactin plays in pituitary microadenoma and comorbid psychosis. In this study, the prolactin serum levels were compared between 74 first-episode drug-naive patients with a pituitary microadenoma with psychosis (PMP), and 58 patients with a pituitary microadenoma with no psychosis (PMNP). Patients with PMP had significantly higher prolactin serum levels; male patients with PMP had a mean [S.D.] prolactin level of 705.4 uIU/ml [226.1] vs. 433.1 uIU/ml [58.4] for male patients with PMNP, while female patients with PMP had a mean prolactin level of 1890.1 uIU/ml [1138.7] vs. 978.6 uIU/ml [657.9] for female patients with PMNP. The size of microadenoma in the patients with PMP was larger than those in the patients with PMNP, regardless of sex. Our data suggested that a higher prolactin serum level is a characteristic of first-episode neuroleptic-naive patients with PMP.

Genetic correlates of medical comorbidity associated with schizophrenia and treatment with antipsychotics

PURPOSE OF REVIEW

High comorbidity rates for various medical conditions have been documented in schizophrenia, being explained by factors either inherent to the disease or associated with antipsychotic treatment. The aim of this study is to review the genetic factors contributing to medical comorbidity in schizophrenia.

RECENT FINDINGS

Based on clinical genetic studies in schizophrenia, comorbid impaired glucose tolerance/type 2 diabetes mellitus, most autoimmune disorders and cardiac autonomic dysregulation have the strongest evidence for familial predisposition. Similarly, of antipsychotic-induced adverse drug reactions, tardive dyskinesia, neuroleptic malignant syndrome, and antipsychotic-induced weight gain have some evidence for familial clustering. On the molecular genetic level, schizophrenia seems to share specific genes with type 2 diabetes mellitus and with autoimmune disorders. Various genes have been proposed to account for the reduced incidence of rheumatoid arthritis and cancer in schizophrenic patients and their relatives. Many pharmacogenetic association studies have pinpointed numerous, though often contradictory or poorly replicated, genes of modest effect size for tardive dyskinesia, neuroleptic malignant syndrome, clozapine-induced agranulocytosis, hyperprolactinaemia, antipsychotic-induced weight gain, and antipsychotic-induced QT prolongation.

SUMMARY

Unravelling the genetic underpinnings of medical comorbidity associated with schizophrenia and its treatment is expected to highlight new pathogenetic pathways in both schizophrenia and comorbid medical conditions, and introduce personalized treatment strategies for schizophrenia patients.

Prolactin concentrations in newly diagnosed, antipsychotic-naïve patients with nonaffective psychosis

BACKGROUND

Previous studies have found increased prolactin concentrations in antipsychotic-naïve patients with schizophrenia. However, the roles of other hormones, and of potentially confounding variables such as gender and smoking, have not been considered.

METHODS

Blood from newly diagnosed, antipsychotic-naïve patients with nonaffective psychosis (13 women and 20 men) and matched controls (12 women and 21 men) was assayed for prolactin, as well as three other hormones that impact prolactin concentrations: thyrotropin-stimulating hormone (TSH), ghrelin, and cortisol.

RESULTS

Patients had significantly higher prolactin concentrations: female patients had a mean [SD] of 37.1 ng/mL [24.9] vs. 13.5 ng/mL [7.2] for female control subjects (p=.001), while male patients had a mean of 15.3 ng/mL [9.5] vs. 7.6 ng/mL [2.2] for male control subjects (p=.006). Patients and control subjects did not differ on concentrations of TSH, ghrelin, or cortisol. The group differences could not be attributed to differences in age, gender, smoking, body mass index, ethnicity, or the socioeconomic status of the family of origin.

CONCLUSIONS

Increased prolactin concentrations in antipsychotic-naïve patients do not appear to be due to important confounding variables, or to the effects of elevated TSH, ghrelin, or cortisol.

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.

Effects of bisphenol-A and other endocrine disruptors compared with abnormalities of schizophrenia: an endocrine-disruption theory of schizophrenia

In recent years, numerous substances have been identified as so-called "endocrine disruptors" because exposure to them results in disruption of normal endocrine function with possible adverse health outcomes. The pathologic and behavioral abnormalities attributed to exposure to endocrine disruptors like bisphenol-A (BPA) have been studied in animals. Mental conditions ranging from cognitive impairment to autism have been linked to BPA exposure by more than one investigation. Concurrent with these developments in BPA research, schizophrenia research has continued to find evidence of possible endocrine or neuroendocrine involvement in the disease. Sufficient information now exists for a comparison of the neurotoxicological and behavioral pathology associated with exposure to BPA and other endocrine disruptors to the abnormalities observed in schizophrenia. This review summarizes these findings and proposes a theory of endocrine disruption, like that observed from BPA exposure, as a pathway of schizophrenia pathogenesis. The review shows similarities exist between the effects of exposure to BPA and other related chemicals with schizophrenia. These similarities can be observed in 11 broad categories of abnormality: physical development, brain anatomy, cellular anatomy, hormone function, neurotransmitters and receptors, proteins and factors, processes and substances, immunology, sexual development, social behaviors or physiological responses, and other behaviors. Some of these similarities are sexually dimorphic and support theories that sexual dimorphisms may be important to schizophrenia pathogenesis. Research recommendations for further elaboration of the theory are proposed.

Toward defining schizophrenia as a more useful clinical concept

Delineating schizophrenia remains elusive despite considerable interest and study for more than a century. During this time, a variety of terms and defining features have been ascribed to the construct. The predominant contemporary construct, for which substantial limitations persist, has changed little in the past 30 years. With the approaching arrival of the DSM-V, interest in the nosology of schizophrenia has rebounded. Recent publications have focused principally on the following: integrating dimensional approaches to diagnosis, subtypes of schizophrenia, endophenotypes, and identifying those at early risk as part of a staging process. Some have even suggested replacing the term. Although an etiopathic diagnosis remains out of reach, contemporary research is marching down several distinct paths toward defining schizophrenia as a construct of greater clinical utility.

Effect of antipsychotics on pituitary gland volume in treatment-naïve first-episode schizophrenia: a pilot study

The objective of this study was to examine the effect of antipsychotics on pituitary volume in schizophrenic subjects. Pituitary volumes were measured in 16 patients with schizophrenia at baseline and 12 months after treatment with an antipsychotic medication using magnetic resonance imaging (MRI). A group of 12 healthy controls was evaluated at baseline and after 12 months. Pituitary volume significantly increased in the schizophrenic subjects after treatment (12% increase). This appeared to be specific to the prolactin-elevating drugs. In controls, pituitary volume did not change significantly (3% decrease). Pituitary volume may be a useful biomarker for treatments that affect neuroendocrine function.