Association between bipolar spectrum disorder and bone health: a meta-analysis and systematic review protocol

Causal associations of brain structure with bone mineral density: a large-scale genetic correlation study

In this study, we aimed to investigate the causal associations of brain structure with bone mineral density (BMD). Based on the genome-wide association study (GWAS) summary statistics of 1 325 brain imaging-derived phenotypes (BIDPs) of brain structure from the UK Biobank and GWAS summary datasets of 5 BMD locations, including the total body, femoral neck, lumbar spine, forearm, and heel from the GEFOS Consortium, linkage disequilibrium score regression (LDSC) was conducted to determine the genetic correlations, and Mendelian randomization (MR) was then performed to explore the causal relationship between the BIDPs and BMD. Several sensitivity analyses were performed to verify the strength and stability of the present MR outcomes. To increase confidence in our findings, we also performed confirmatory MR between BIDPs and osteoporosis. LDSC revealed that 1.93% of BIDPs, with a false discovery rate (FDR) < 0.01, were genetically correlated with BMD. Additionally, we observed that 1.31% of BIDPs exhibited a significant causal relationship with BMD (FDR < 0.01) through MR. Both the LDSC and MR results demonstrated that the BIDPs "Volume of normalized brain," "Volume of gray matter in Left Inferior Frontal Gyrus, pars opercularis," "Volume of Estimated Total Intra Cranial" and "Volume-ratio of brain segmentation/estimated total intracranial" had strong associations with BMD. Interestingly, our results showed that more left BIDPs were causally associated with BMD, especially within and around the left frontal region. In conclusion, a part of the brain structure causally influences BMD, which may provide important perspectives for the prevention of osteoporosis and offer valuable insights for further research on the brain-bone axis.

Study protocol for the systematic review and meta-analyses of the association between schizophrenia and bone fragility

INTRODUCTION

Individuals with schizophrenia are known to be at higher risk of comorbid conditions, both physical and psychological. Osteoporosis is possibly one of these, leading to public health concerns due to higher rates of associated mortality and morbidity. We aim to systematically search all available evidence across electronic databases regarding the relationship between schizophrenia and bone fragility.

METHODS AND ANALYSIS

A systematic search of the research databases CINAHL, MEDLINE Complete, Embase and PsycINFO will be conducted and identified papers reviewed for eligibility, with a second reviewer confirming inclusions. Searches will be run from database inception to 1 October 2020 and supplemented by the hand checking of references of identified articles. A previously published scoring system will be used for assessing the methodological quality and risk of bias. A meta-analysis is planned.

ETHICS AND DISSEMINATION

Due to including published literature only, ethical permission will not be necessary. Results of this study will be published in a relevant scientific journal and presented at a conference in the field of interest.

PROSPERO REGISTRATION NUMBER

CRD42020171959.

Disrupted Regional Homogeneity in Drug-Naive Patients With Bipolar Disorder

OBJECTIVE

Studies on alterations in the regional neural activity in the brain of patients with bipolar disorder (BD) have provided conflicting results because of different medications used and study designs. A low bone mineral density (BMD) is also observed in patients with BD. This study aimed to further explore regional neural activities in unmedicated patients with BD and their association with BMD.

METHODS

In this study, 40 patients with BD and 42 healthy controls were scanned through resting-state functional magnetic resonance imaging (fMRI). Imaging data were analyzed with regional homogeneity (ReHo) and pattern classification. Pearson's correlation analyses were performed to explore the correlations between abnormal ReHo and BMD.

RESULTS

A significant increase in ReHo values in the left inferior frontal gyrus (IFG)/temporal pole, left cerebellum vermis I/vermis II/parahippocampal gyrus/brainstem, and right superior temporal gyrus (STG) and a decrease in ReHo in the occipital gyrus (OG; left middle OG/superior OG/bilateral cuneus) were found in the patients with BD (p < 0.05) compared with those in the healthy controls. No significant correlation was observed between the abnormal ReHo values in any of the brain regions of the patients with BMD.Support vector machine (SVM) analyses revealed that the ReHo values in the right STG for distinguishing patients from healthy controls showed an accuracy of 91.89%, a sensitivity of 75.68%, and a specificity of 83.78%. The ReHo values in the left cerebellum vermis I/vermis II/parahippocampal gyrus/brainstem indicated an accuracy of 78.38%, a sensitivity of 75.68%, and a specificity of 81.08%.

CONCLUSION

This study further confirms the abnormal brain activities in extensive regions, and these brain regions are primarily located in the fronto-temporal-occipital circuit and the cerebellum vermis of patients with BD. The regional neural activity in the right STG and the left cerebellum vermis I/vermis II/parahippocampal gyrus/brainstem may serve as potential imaging markers to distinguish patients with BD from healthy controls.

Bone health in bipolar disorder: a study protocol for a case-control study in Australia

INTRODUCTION

Little is known about the bone health of adults with bipolar disorder, aside from evidence purporting bone deficits among individuals with other mental illnesses, or those taking medications commonly used in bipolar disorder. In this paper, we present the methodology of a case-control study which aims to examine the role of bipolar disorder as a risk factor for bone fragility.

METHODS AND ANALYSIS

Men and women with bipolar disorder (~200 cases) will be recruited and compared with participants with no history of bipolar disorder (~1500 controls) from the Geelong Osteoporosis Study. Both cases and controls will be drawn from the Barwon Statistical Division, south-eastern Australia. The Structured Clinical Interview for DSM-IV-TR Research Version, Non-patient edition is the primary diagnostic instrument, and psychiatric symptomatology will be assessed using validated rating scales. Demographic information and detailed lifestyle data and medical history will be collected via comprehensive questionnaires. Participants will undergo dual energy X-ray absorptiometry scans and other clinical measures to determine bone and body composition. Blood samples will be provided after an overnight fast and stored for batch analysis.

ETHICS AND DISSEMINATION

Ethics approval has been granted from Barwon Health Research Ethics Committee. Participation in the study is voluntary. The study findings will be disseminated via peer-reviewed publications, conference presentations and reports to the funding body.

New drug candidates for bipolar disorder-A nation-wide population-based study

OBJECTIVE

Drug repurposing is an increasingly promising idea in many fields of medicine. We systematically used Danish nation-wide population-based registers to investigate whether continued use of non-aspirin non-steroidal anti-inflammatory drugs (NSAIDs), low-dose aspirin, high-dose aspirin, statins, allopurinol, and angiotensin agents decrease the rate of incident mania/bipolar disorder.

METHODS

A nation-wide population-based longitudinal study using Poisson regression analyses including all persons in Denmark who purchased the exposure medication of interest and a random sample of 30% of the Danish population. The follow-up period comprised a 10 years period from 2005 to 2015. Two different outcome measures were included, (1) a diagnosis of mania/bipolar disorder at a psychiatric hospital contact as inpatient or outpatient and (2) a combined measure of a diagnosis of mania/bipolar disorder or initiation of lithium use.

RESULTS

A total of 1,605,365 subjects were exposed to one of the six drugs of interest during the exposure period from 2005 to 2015, median age 57 years [quartiles: 43;69], and female proportion of 53.1%. Continued use of low-dose aspirin, statins, and angiotensin agents were associated with decreased rates of incident mania/bipolar disorder on both outcome measures. Continued uses of non-aspirin NSAIDs as well as high-dose aspirin were associated with an increased rate of incident bipolar disorder. There were no statistically significant associations for allopurinol.

CONCLUSIONS

The study supports the potential of agents acting on inflammation and the stress response system in bipolar disorder and illustrates that population-based registers can be used to systematically identify drugs with repurposing potentials.

Bipolar disorder and bone health: A systematic review

BACKGROUND

Bipolar disorder is a chronic, episodic mental illness, affecting around 2.4% of the population worldwide. Psychological and/or physiological comorbidities are a common consequence, and osteoporosis is one such possible comorbidity. Thus, this systematic review aimed to collate, evaluate, and discuss the literature examining the link between bipolar disorder and bone health.

METHODS

We conducted an e-search of PubMed/OVID/MEDLINE, PsychINFO and CINAHL to identify studies that investigated associations between bipolar disorder and bone in adults aged ≥18. Two reviewers determined eligibility according to pre-determined criteria, and methodological quality was assessed using a previously published methodological scoring system. Due to heterogeneity, a best-evidence synthesis was performed.

RESULTS

Our search yielded 1409 articles, of which three (all cohorts) met predetermined criteria. The studies from Taiwan and the United States of America analysed administrative data, albeit spanning different years, and comprised a total of 344,497 participants. No studies investigating bone quantity or quality were identified. Bipolar disorder was associated with an increased risk of fracture (range 20-80%); and fracture-free survival time for those with bipolar disorder decreased substantially with advancing age, and for women (10-30% shorter than men). Fracture incidence per 1000 person years (py) was 21.4 and 10.8 in those with and without bipolar disorder, respectively.

LIMITATIONS

Limited data and marked methodological heterogeneity prevented the pooling of these data for a numerical synthesis.

CONCLUSIONS

Increased fracture risk was observed in individuals with bipolar disorder, independent of older age, sex, comorbidities and medication use. The operative mechanisms, risk and treatment factors warrant further enquiry.