Effects of chronic treatment of olanzapine and haloperidol on peptide YY binding densities in the rat brain

Diabetes and Cardiovascular Care Among People with Severe Mental Illness: A Literature Review

Close to 19 million US adults have severe mental illnesses (SMI), and they die, on average, 25 years earlier than the general population, most often from cardiovascular disease (CVD). Many of the antipsychotic medications used to treat SMI contribute to CVD risk by increasing risk for obesity, type 2 diabetes, dyslipidemia, and hypertension. Based on compelling evidence, the American Diabetes Association and the American Psychiatric Association developed guidelines for metabolic screening and monitoring during use of these medications.In this manuscript, we have reviewed the evidence on diabetes and other CVD risk screening, prevalence, and management among populations with SMI. We also review differences in screening among subpopulations with SMI (e.g., racial/ethnic minorities, women, and children). We found that despite national guidelines for screening for diabetes and other cardiovascular risk factors, up to 70 % of people taking antipsychotics remain unscreened and untreated. Based on estimates that 20 % of the 19 million US adults with SMI have diabetes and 70 % of them are not screened; it is likely that over 2 million Americans with SMI have unidentified diabetes. Given that undiagnosed diabetes costs over $4,000 per person, this failure to identify diabetes among people with SMI represents a missed opportunity to prevent morbidity and translates to over $8 billion in annual preventable costs to our healthcare system.Given the high burden of disease and significant evidence of suboptimal medical care received by people with SMI, we propose several clinical and policy recommendations to improve diabetes and other CVD risk screening and care for this highly vulnerable population. These recommendations include reducing antipsychotic medication dose or switching antipsychotic medications, enhancing smoking cessation efforts, sharing electronic health records between physical and mental health care systems, and promoting integration of care.

Behavioral Weight Loss Treatment in Antipsychotic Treated Youth

BACKGROUND

Antipsychotic-treated youth have increased risk for the development of obesity and type 2 diabetes. Behavioral weight loss treatments show promise in reducing obesity and diabetes risk in antipsychotic treated adults, but have received no study in antipsychotic treated youth.

OBJECTIVE

We describe a rationale for behavioral weight loss interventions in high-weight antipsychotic treated youth, and report behavioral, anthropomorphic, and metabolic findings from a case series of obese antipsychotic-treated adolescents participating in a short-term, family-based behavioral weight loss intervention.

METHODS

We adapted the Traffic Light Plan, a 16-week family-based weight loss intervention that promotes healthy energy balance using the colors of the traffic light to categorize the nutritional value of foods and intensity of physical activity, adapting a social ecological framework to address health behavior change in multiple social contexts. The intervention was administered to three obese adolescents with long-term antipsychotic medication exposure. Efficacy of the intervention was evaluated with a battery of anthropomorphic and metabolic assessments including weight, body mass index percentile, whole body adiposity, liver fat content, and fasting plasma glucose and lipids. Participants and their parents also filled out a treatment satisfaction questionnaire upon study completion.

RESULTS

Two males and 1 female (all aged 14 years) participated. All 3 participants attended all 16 sessions, and experienced beneficial changes in adiposity, fasting lipids and liver fat content associated with weight stabilization or weight loss. Adolescents and their parents all reported a high level of satisfaction with the treatment.

CONCLUSIONS

Family-based behavioral weight loss treatment can be feasibly delivered and is acceptable to antipsychotic-treated youth and their families. Randomized controlled trials are needed to fully evaluate the effectiveness and acceptability of behavioral weight loss interventions in antipsychotic treated youth and their families.

Recent advances in understanding and mitigating adipogenic and metabolic effects of antipsychotic drugs

Although offering many benefits for several psychiatric disorders, antipsychotic drugs (APDs) as a class have a major liability in their tendency to promote adiposity, obesity, and metabolic dysregulation in an already metabolically vulnerable population. The past decade has witnessed substantial research aimed at investigating the mechanisms of these adverse effects and mitigating them. On July 11 and 12, 2011, with support from 2 NIH institutes, leading experts convened to discuss current research findings and to consider future research strategies. Five areas where significant advances are being made emerged from the conference: (1) methodological issues in the study of APD effects; (2) unique characteristics and needs of pediatric patients; (3) genetic components underlying susceptibility to APD-induced metabolic effects; (4) APD effects on weight gain and adiposity in relation to their acute effects on glucose regulation and diabetes risk; and (5) the utility of behavioral, dietary, and pharmacological interventions in mitigating APD-induced metabolic side effects. This paper summarizes the major conclusions and important supporting data from the meeting.

Atypical antipsychotic-induced weight gain: insights into mechanisms of action

Prescriptions for second-generation antipsychotics (SGAs) have surpassed those for first-generation agents in the treatment of schizophrenia and bipolar disorder. While SGAs have the benefit of a much reduced risk of causing movement disorders, they have been associated with weight gain and metabolic effects. These adverse reactions are not uncommon, and threaten to have a significant impact on the patient's health over the long-term treatment that the patient requires. Currently, the aetiology of these effects is not known. This article reviews the data exploring the weight gain phenomenon. The literature was reviewed from searches of PubMed and the references of major articles in the field. The SGAs present a heterogeneous risk for weight gain. In addition, different individuals receiving the same drug can exhibit substantially different weight changes. This pattern suggests that a group of factors are associated with the weight gain phenomenon rather than a single mechanism. Coupled with the genetic profile that the patient brings to the treatment, the risk for SGA-induced weight gain will be different for different drugs and different individuals. Targets for exploration of the weight gain phenomenon include receptor interactions involving serotonin, histamine, dopamine, adrenergic, cannabinoid and muscarinic receptors. The association of SGA-induced weight gain and the role of orexigenic and anorexigenic peptides are reviewed. Also, a brief discussion of genetic factors associated with SGA-induced weight gain is presented, including that of the serotonin 5-HT(2C) receptor gene (HTR2C) and the cannabinoid 1 receptor gene (CNR1). The most promising data associated with SGA-induced weight gain include investigations of the histamine H(1), 5-HT(2A), 5-HT(2C), muscarinic M(3) and adrenergic receptors. In addition, work in the genetic area promises to result in a better understanding of the variation in risk associated with different individuals.

Effects of simvastatin and 6-hydroxydopamine on histaminergic H1 receptor binding density in rat brains

Statins have been widely used for the treatment of a variety of medical conditions including psychoneurological disorders beyond their original use in lowering cholesterol. Histamine receptors play an important role in the regulation of neural activity, however, it is unknown whether statins act on histamine receptors, particularly for their neural regulatory effects. This study examined the effects of simvastatin and 6-hydroxydopamine (6-OHDA) lesions on histamine H1 receptors using [(3)H] pyrilamine binding autoradiography. Compared to the saline group, simvastatin (1 mg/kg/day) significantly decreased H1 receptor bindings in the primary motor cortex (M1), ventromedial hypothalamic nucleus (VMH), caudate putamen (CPu), accumbens core (AcbC) and prefrontal cortex (PfC) (all p<0.05); however 10 mg/kg/day simvastatin increased H1 receptor density only in the medial amygdaloid nucleus (Mep) (p<0.05), but had no significant effect in other regions examined. The 6-OHDA lesion did not alter H1 receptor binding density in most brain areas, except a trend decrease in the hippocampus (p=0.07) and a trend increase in the cingulate cortex (p=0.06). These results suggested that simvastatin has different effects on the H1 receptors in different rat brain regions depending on the doses. Therefore, simvastatin can modulate histaminergic neurotransmission in the brain, and support the role of H1 receptors in psychoneurological disorders.

Olanzapine treatment and metabolic dysfunction: a dose response study in female Sprague Dawley rats

Second generation antipsychotics are commonly prescribed for the treatment of schizophrenia, however some can induce metabolic dysfunction side-effects such as weight gain, obesity and diabetes. Clinical reports suggest olanzapine alters satiety signals, although findings appear conflicting. Previous animal model studies have utilised a range of olanzapine dosages, however the dosage that better mimics the human scenario of olanzapine-induced weight gain is unclear. Female Sprague-Dawley rats were treated orally, three times daily with olanzapine (0.25mg/kg, 0.5mg/kg, 1.0mg/kg, 2.0mg/kg), self-administered in a sweet cookie dough pellet at eight-hourly intervals) or vehicle (n=12/group) for 14-days. Olanzapine orally self-administered in multiple doses (eight-hourly intervals) may circumvent a drop in plasma drug concentration and ensure the maintenance of a consistently high olanzapine level in the rat. Olanzapine increased body weight (0.5mg/kg, 1.0mg/kg, 2.0mg/kg), food intake (2.0mg/kg) and feeding efficiency (0.5-2.0mg/kg), with no effect on water intake. Subcutaneous inguinal (1.0mg/kg, 2.0mg/kg) and intra-abdominal perirenal fat were increased (2.0mg/kg), but not interscapula brown adipose tissue. Olanzapine increased circulating ghrelin and cholecystokinin, but had no effect on peptide YY((3-36)). Olanzapine decreased insulin (0.25-2.0mg/kg) and locomotor activity in the open field arena (0.5-2.0mg/kg). A low dosage of 0.25mg/kg olanzapine had no effect on most parameters measured. Olanzapine-induced weight gain is associated with hyperphagia, enhanced feeding efficiency and adiposity, decreased locomotor activity and altered satiety signaling. The animal model used in the present study of self-administered oral olanzapine treatment (t.i.d.) at a dosage range of 0.5-2.0mg/kg (but not 0.25mg/kg) mimics aspects of the clinic.

Alterations in 5-HT2A receptor binding in various brain regions among 6-hydroxydopamine-induced Parkinsonian rats

The serotonergic system has close interactions with the dopaminergic system and is strongly implicated in the pathophysiological mechanisms and therapeutic paradigms of Parkinson's disease (PD). This study aims to investigate regional changes in 5-hydroxytryptamine (5-HT) 2A receptors in the rat brain 3 weeks after unilateral medial forebrain bundle lesion by 6-hydroxydopamine (6-OHDA). 5-HT 2A receptor distributions and alterations in the postmortem rat brain were detected by [(3)H]ketanserin-binding autoradiography. In the 6-OHDA-induced Parkinson's rat model, nigrostriatal dopaminergic neuron loss significantly mediated the decreased [(3)H]ketanserin binding, predominantly in the agranular insular cortex (17.3%, P = 0.03), cingulate cortex (18.2%, P < 0.001), prefrontal cortex (8%, P = 0.043), primary somatosensory cortex (17.7%, P = 0.002), and caudate putamen (14.5%, P = 0.02) compared to controls while a profound reduction of tyrosine hydroxylase (TH) immunostaining in the striatum was also observed. Alterations in [(3)H]ketanserin binding in the examined brain areas may represent the specific regions that mediate cognitive dysfunctions via the serotonin system. The downregulation of 5-HT(2A) receptor binding in this study also provides indirect evidence for plasticity in the serotonergic system in the rat brains. This study contributes to a better understanding of the critical roles of 5-HT(2A) receptors in treating neurodegenerative disorders and implicates 5-HT(2A) receptors as a novel therapeutic target in the treatment of PD.

Short-term treatment with olanzapine does not modulate gut hormone secretion: olanzapine disintegrating versus standard tablets

BACKGROUND

Treatment with olanzapine (atypical antipsychotic drug) is frequently associated with various metabolic anomalies, including obesity, dyslipidemia, and diabetes mellitus. Recent data suggest that olanzapine orally disintegrating tablets (ODT), which dissolve instantaneously in the mouth, might cause less weight gain than olanzapine standard oral tablets (OST).

DESIGN AND METHODS

Ten healthy men received olanzapine ODT (10 mg o.d., 8 days), olanzapine OST (10 mg o.d., 8 days), or no intervention in a randomized crossover design. At breakfast and dinner, blood samples were taken for measurement of pancreatic polypeptide, peptide YY, glucagon-like peptide-1, total glucagon, total ghrelin, and cholecystokinin (CCK) concentrations.

RESULTS

With the exception of pre- and postprandial concentration of ghrelin at dinner and preprandial CCK concentrations at breakfast, which were all slightly increased (respectively P=0.048, P=0.034 and P=0.042), olanzapine did not affect gut hormone concentrations. Thus, olanzapine ODT and OST had similar effects on gut hormone secretion.

CONCLUSION

Short-term treatment with olanzapine does not have major impact on the plasma concentration of gut hormones we measured in healthy men. Moreover, despite pharmacological difference, gut hormone concentrations are similar during treatment with olanzapine ODT and OST. The capacity of olanzapine to induce weight gain and diabetes is unlikely to be caused by modulation of the secretion of gut hormones measured here. We cannot exclude the possibility that olanzapine's impact on other gut hormones, to impair insulin sensitivity and stimulate weight gain, exists.

High dose of simvastatin induces hyperlocomotive and anxiolytic-like activities: The association with the up-regulation of NMDA receptor binding in the rat brain

Statins are widely being used for the treatment of a variety of conditions beyond their original indication for lowering cholesterol. We have previously reported that simvastatin affected the dopaminergic system in the rat brain. This study aims to investigate locomotor and anxiety effects along with the regional changes of N-methyl-d-aspartate (NMDA) receptors in the rat brain after 4-week administration of simvastatin. Hyperlocomotive and anxiolytic-like activities in the rat were observed after chronic administration of high dose simvastatin (10 mg/kg/day). Distributions and alterations of NMDA receptors in the post-mortem rat brain were detected by [(3)H] MK-801 binding autoradiography. Simvastatin increased [(3)H] MK-801 binding, predominantly in the prefrontal cortex (20%, p=0.003), primary motor cortex (20%, p<0.001), cingulate cortex (28%, p<0.001), hippocampus (41%, p<0.001), caudate putamen (30%, p=0.029), nucleus accumbens (27%, p=0.035) and amygdala (45%, p<0.001) compared to controls. Significant positive correlations were identified between hyperlocomotive as well as anxiolytic-like activities and the upregulation of NMDA receptors in different brain regions. Our results also provide strong evidence that chronic high dose simvastatin administration is to exhibit NMDA antagonist-like effects, which would partially explain the anxiolytic and hyperlocomotor activities. These findings contribute to a better understanding of the critical roles of simvastatin in modulating psycho-neurodegenerative disorders, via NMDA receptors.

Chronic treatment with simvastatin upregulates muscarinic M1/4 receptor binding in the rat brain

Statins are increasingly being used for the treatment of a variety of conditions beyond their original indication for cholesterol lowering. We previously reported that simvastatin affected the dopaminergic system in the rat brain. This study aims to investigate regional changes of muscarinic M1/4 receptors in the rat brain after 4-week administration of simvastatin (1 or 10 mg/kg/day). M1/4 receptor distribution and alterations in the post-mortem rat brain were detected by [(3)H]pirenzepine binding autoradiography. Simvastatin (1 mg/kg/day) increased [(3)H]pirenzepine binding, predominantly in the prefrontal cortex (171%, P<0.001), primary motor cortex (153%, P=0.001), cingulate cortex (109%, P<0.001), hippocampus (138%, P<0.001), caudate putamen (122%, P=0.002) and nucleus accumbens (170%, P<0.001) compared with controls; while lower but still significant increases of [(3)H]pirenzepine binding were observed in the examined regions following simvastatin (10 mg/kg/day) treatment. Our results also provide strong evidence that chronic simvastatin administration, especially at a low dosage, up-regulates M1/4 receptor binding, which is likely to be independent of its muscarinic agonist-like effect. Alterations in [(3)H]pirenzepine binding in the examined brain areas may represent the specific regions that mediate the clinical effects of simvastatin treatment on cognition and memory via the muscarinic cholinergic system. These findings contribute to a better understanding of the critical roles of simvastatin in treating neurodegenerative disorders, via muscarinic receptors.