PCSK9 mediates dyslipidemia induced by olanzapine treatment in schizophrenia patients

Atypical antipsychotic drugs cause abnormal glucose and lipid metabolism independent of weight gain

This study aimed to investigate whether antipsychotic medications can cause metabolic abnormalities independent of weight gain. Six hundred twenty-four patients treated with olanzapine and risperidone were enrolled. Body weight, body mass index (BMI), biochemical indicators of blood glucose and lipids, the proportion of patients who gained > 7% of their baseline weight, dyslipidemia, and dysglycemia were evaluated. The association between the prevalence of metabolic disturbances and groups was analyzed using logistic regression, adjusting confounding variables including age, sex, weight, duration and Chlorpromazine (CLO)-equivalent dosage. Assessments were conducted at baseline and 4, 8, and 24-weeks post-treatment. The rate of weight gain > 7% at 8-weeks was significantly higher than at 4-weeks in the total population (F = 49.02, p < 0.001) and in patients with abnormal metabolism (F = 29.97, p < 0.001). No significant differences were observed between follow-up time points in the 24-weeks. The proportion of abnormal blood lipids and glucose did not differ significantly between the 4-week and 8-week follow-ups. Logistic regression analyses revealed significant differences between olanzapine and risperidone groups regarding the prevalence of hypertriglyceridemia at week 4 ([adjusted odds ratio; aOR] = 1.710; 95% [ confidence interval; CI] = 1.213-2.410) and week 8 ([aOR] = 1.594; 95% [CI] = 0.859-2.957) and low LDL at week 4 ([aOR] = 1.772; 95%[CI] = 1.014-3.097) and week 8 ([aOR] = 3.851; 95%[CI] = 1.732-5.588). In conclusion, antipsychotics-induced metabolic abnormalities and weight gain are not fully synchronized, and metabolic abnormalities vary significantly across different atypical antipsychotic medication (AAP) groups, even after adjusting BMI. AAPs may have a direct effect on metabolic parameters.

Protective effects of menthol against olanzapine-induced metabolic alterations in female mice

AIM

Metabolic comorbidities such as obesity type 2 diabetes, insulin resistance, glucose intolerance, dyslipidemia are the major contributors for lower life expectancy and reduced patient compliance during antipsychotic therapy in patients with severe mental illnesses such as schizophrenia, bipolar disorder, and depression. TRPM8 activation by menthol is also reported to alleviate high fat diet-induced obesity in mice. Additionally, this TRPM8 activation leads to increase in gene expression of thermogenic genes in white adipocytes and dietary menthol was found to increase browning of WAT along with improved glucose utilization. Therefore, we aimed to evaluate the plausible role of TRPM8 channels in olanzapine-induced metabolic alterations in female balb/c mice.

METHODS

6 weeks olanzapine (6 mg kg-1, per oral) model was used in female balb/c mice. Pharmacological manipulation of TRPM8 channel was done using menthol and N-(3-aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)-benzamide (AMTB), the agonist and antagonist respectively.

KEY RESULTS

Menthol co-treatment for six weeks prevented olanzapine-induced metabolic alterations such as weight gain, increased food intake, decreased energy expenditure, adiposity, liver lipid accumulation, systemic inflammation and insulin resistance. Although no significant change in TRPM8 mRNA expression was found in the hypothalamus, however, some of the protective effects of menthol were absent in presence of AMTB indicating possible involvement of TRPM8 channels.

CONCLUSION

Our results suggest possible therapeutic implications of menthol in the management of antipsychotic-induced weight gain and other metabolic alterations.

Lipids in Psychiatric Disorders: Functional and Potential Diagnostic Role as Blood Biomarkers

Lipids are a crucial component of the human brain, serving important structural and functional roles. They are involved in cell function, myelination of neuronal projections, neurotransmission, neural plasticity, energy metabolism, and neuroinflammation. Despite their significance, the role of lipids in the development of mental disorders has not been well understood. This review focused on the potential use of lipids as blood biomarkers for common mental illnesses, such as major depressive disorder, anxiety disorders, bipolar disorder, and schizophrenia. This review also discussed the impact of commonly used psychiatric medications, such as neuroleptics and antidepressants, on lipid metabolism. The obtained data suggested that lipid biomarkers could be useful for diagnosing psychiatric diseases, but further research is needed to better understand the associations between blood lipids and mental disorders and to identify specific biomarker combinations for each disease.

Effects of statin therapies on individuals taking antipsychotics: a systematic review

Patients taking antipsychotics to treat severe mental illness may develop adverse effects such as dyslipidaemia. We aimed to provide an update to a previous systematic review showing statin therapy lowering lipid levels in individuals taking antipsychotics, while further identifying any safety concerns or changes in BMI or blood pressure. In August 2022, we searched MEDLINE, Embase, PsycINFO, PubMed and Cochrane Central Register of Controlled Trials for studies on the effects of statins on lipid profile measures for individuals with severe mental illness taking first- or second-generation antipsychotic medications. Data extraction was performed in a masked duplicate fashion. On the basis of article type, the risk of bias in each study was assessed using ROBINS-I or RoB-2. The GRADE criteria were used for certainty assessment. Our initial search returned 396 articles, of which 6 were included in our analysis. Five of them (83.3%) identified a significant change between baseline and posttreatment lipids. Of the articles recording blood pressure, BMI or weight and significant safety concerns, no significant changes were found. The certainty assessment for this systematic review was rated as moderate. A meta-analysis was not performed. We found that studies continue to demonstrate the use of statin therapy in dyslipidaemia prevention and treatment and, in relation, decrease cardiovascular disease risk through significantly reduced LDL-C levels. Patients at risk of developing dyslipidaemias secondary to antipsychotic treatment should be considered for lipid-lowering therapy with a statin. The limited number of studies included and their heterogeneity demonstrate areas for improvement for future research.

Drug-drug interactions involving combinations of antipsychotic agents with antidiabetic, lipid-lowering, and weight loss drugs

INTRODUCTION

Patients with severe mental illness (SMI) have a high risk for diabetes, dyslipidemia, and other components of metabolic syndrome. Patients with these metabolic comorbidities and cardiac risk factors should receive not only antipsychotics but also medications aiming to reduce cardiovascular risk. Therefore, many patients may be exposed to clinically relevant drug-drug interactions.

AREAS COVERED

This narrative review summarizes data regarding the known or potential drug-drug interactions between antipsychotics and medications treating metabolic syndrome components, except for hypertension, which has been summarized elsewhere. A literature search in PubMed and Scopus up to 7/31/2021 was performed regarding interactions between antipsychotics and drugs used to treat metabolic syndrome components, aiming to inform clinicians' choice of medication for patients with SMI and cardiometabolic risk factors in need of pharmacologic interventions.

EXPERT OPINION

The cytochrome P450 system and, to a lesser extent, the P-glycoprotein transporter is involved in the pharmacokinetic interactions between antipsychotics and some statins or saxagliptin. Regarding pharmacodynamic interactions, the available information is based mostly on small studies, and for newer classes, like PCSK9 inhibitors or SGLT2 inhibitors, data are still lacking. However, there is sufficient information to guide clinicians in the process of selecting safer antipsychotic-cardiometabolic risk reduction drug combinations.

Metformin Ameliorates Hepatic Steatosis induced by olanzapine through inhibiting LXRα/PCSK9 pathway

Studies have confirmed that olanzapine, the mainstay treatment for schizophrenia, triggers metabolic diseases, including non-alcoholic fatty liver disease (NAFLD). However, the etiology of olanzapine-induced NAFLD is poorly understood. Proprotein convertase subtilisin kexin type 9 (PCSK9) is involved in NAFLD pathogenesis, and metformin can significantly decrease circulating PCSK9. The purpose of this study was to investigate the role of PCSK9 and explore the therapeutic effect of metformin for olanzapine-associated NAFLD. Olanzapine significantly upregulated PCSK9 and promoted lipid accumulation in mouse livers and HepG2 and AML12 cells. Metformin ameliorated these pathological alterations. PCSK9 upstream regulator liver X receptor α (LXRα) was significantly upregulated in olanzapine-induced NAFLD. LXRα antagonist treatment and LXRα overexpression resulted in a decrease and increase of PCSK9, respectively. Hepatic lipogenesis-associated genes FAS and SCD1 were significantly upregulated in olanzapine-induced NAFLD mice and HepG2 cells overexpressing PCSK9, and genes related to lipid β-oxidation (SCAD and PPARα) were downregulated, while metformin reversed these changes. In addition, we found that LXRα overexpression compromised the effect of metformin on PCSK9 levels and intracellular lipid droplet formation. Taken together, our findings suggest that olanzapine enhances hepatic PCSK9 expression by upregulating LXRα, thereby increasing FAS and SCD1 expression as well as decreasing SCAD and PPARα, and promoting lipid accumulation, and, subsequently, NAFLD, which is ameliorated by metformin.