Bipolar disorder and the risk of fracture: A nationwide population-based cohort study

Severe mental illness as a risk factor for recorded diagnosis of osteoporosis and fragility fractures in people aged ≥50 years: retrospective cohort study using UK primary care data

BACKGROUND

Severe mental illness (SMI) has been associated with reduced bone density and increased risk of fractures, although some studies have shown inconsistent results.

AIM

To examine the association between SMI and recorded diagnosis of osteoporosis and fragility fracture in people aged ≥50 years.

DESIGN AND SETTING

Population-based cohort study set in UK primary care.

METHOD

Anonymised primary care data (IQVIA Medical Research Database) were used. Patients with a diagnosis of SMI aged 50-99 years (2000-2018) were matched to individuals without SMI. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Analyses were stratified by sex and age, accounting for social deprivation, year, smoking, alcohol, and body mass index.

RESULTS

In total, 444 480 people were included (SMI n = 50 006; unexposed n = 394 474). In men, diagnosis of SMI increased the likelihood of an osteoporosis diagnosis, with differences mainly observed among the youngest (aged 50-54 years: HR 2.12, 95% CI = 1.61 to 2.79) and the oldest (aged 85-99 years: HR 2.15, 95% CI = 1.05 to 4.37), and SMI increased the risk of fragility fractures across all ages. In women, SMI increased the risk of an osteoporosis diagnosis only in those aged 50-54 years (HR 1.16, 95% CI = 1.01 to 1.34), but increased the risk of fragility fractures across all ages. There were more than twice as many men with SMI with fragility fracture records than with an osteoporosis diagnosis: fragility fracture:osteoporosis = 2.10, compared with fragility fracture:osteoporosis = 1.89 in men without SMI. The fragility fracture:osteoporosis ratio was 1.56 in women with SMI versus 1.11 in women without SMI.

CONCLUSION

SMI is associated with an increased likelihood of fragility fractures and osteoporosis underdiagnosis. Interventions should be considered to mitigate the increased risk of fractures in people with SMI.

Sensitivity of Fall Risk Perception and Associated Factors in Hospitalized Patients with Mental Disorders

PURPOSE

To reduce falls in hospitalized patients with mental disorders, the patients should be sensitive to fall risk perception. This study identified the sensitivity to fall risk perceptions and associated factors, including demographic, clinical, and fall-related factors, among inpatients with mental disorders.

METHODS

We used a descriptive, cross-sectional design, recruiting 170 inpatients with mental disorders from two psychiatric hospitals in South Korea. Sensitivity to fall risk perception was classified using fall occurrence and the Fall Risk Perception Questionnaire.

RESULTS

The prevalence of falls was 16.5%. Approximately 47% of falls occurred within 10 days of hospitalization, 67.9% within 1 month, and 85.7% within 2 months. Among the 28 participants who fell, 60.7% had inadequate low sensitivity to fall risk perception. Among the 142 participants who did not fall, 11.3% had inadequate high sensitivity to fall risk perception. A low sensitivity to fall risk perception was related to diagnosis, psychiatric symptoms, and fall history due to the mental disorder. A high sensitivity to fall risk perception was related to age at the onset of the mental disorder, urinary or bowel problems, and fear of falling. The multiple logistic regression analysis found that the diagnosis and fall history due to the mental disorder were associated with inadequate low sensitivity, and age at the onset and fear of falling were associated with inadequate high sensitivity to fall risk perception.

CONCLUSION

Over 60% of patients who fell had low sensitivity to fall risk perception. Inadequate low and high sensitivity to fall risk perception are related to the demographic, clinical, and fall-related characteristics among inpatients with mental disorders. Therefore, nurses should assess fall risk perception, consider these factors together during this assessment, and manage them appropriately in hospitalized patients with mental disorders.

Effect of Kruppel-like factor 4 on PTZ-induced acute seizure mice

Kruppel-like factor 4 (Klf4) is a transcription factor that is involved in neuronal regeneration and the development of glutamatergic systems. However, it is unknown whether Klf4 is involved in acute seizure. To investigate the potential role of Klf4 in pentylenetetrazol (PTZ)-induced seizure, western blotting, immunofluorescence, behaviour test and electrophysiology were conducted in this study. We found that Klf4 protein and mRNA expression were increased in both the hippocampus (HP) and prefrontal cortex (PFC) after PTZ-induced seizure in mice. HP-specific knockout (KO) of Klf4 in mice decreased protein expression of Klf4 and the down-stream Klf4 target tumour protein 53 (TP53/P53). These molecular changes are accompanied by increased seizure latency, reduced immobility time in the forced swimming test and tail suspension test. Reduced hippocampal protein levels for synaptic proteins, including glutamate receptor 1 (GRIA1/GLUA1) and postsynaptic density protein 95 (DLG4/PSD95), were also observed after Klf4-KO, while increased mRNA levels of complement proteins were observed for complement component 1q subcomponent A (C1qa), complement component 1q subcomponent B (C1qb), complement component 1q subcomponent C (C1qc), complement component 3 (C3), complement component 4A (C4a) and complement component 4B (C4b). Moreover, c-Fos expression induced by PTZ was reduced by hippocampal conditional KO of Klf4. Electrophysiology showed that PTZ-induced action potential frequency was decreased by overexpression of Klf4. In conclusion, these findings suggest that Klf4 plays an important role in regulating PTZ-induced seizures and therefore constitutes a new molecular target that should be explored for the development of antiepileptic drugs.

Lithium and the risk of fractures in patients with bipolar disorder: A population-based cohort study

Lithium is considered to be the most effective mood stabilizer for bipolar disorder. Evolving evidence suggested lithium can also regulate bone metabolism which may reduce the risk of fractures. While there are concerns about fractures for antipsychotics and mood stabilizing antiepileptics, very little is known about the overall risk of fractures associated with specific treatments. This study aimed to compare the risk of fractures in patients with bipolar disorder prescribed lithium, antipsychotics or mood stabilizing antiepileptics (valproate, lamotrigine, carbamazepine). Among 40,697 patients with bipolar disorder from 1993 to 2019 identified from a primary care electronic health record database in the UK, 13,385 were new users of mood stabilizing agents (lithium:2339; non-lithium: 11,046). Lithium was associated with a lower risk of fractures compared with non-lithium treatments (HR 0.66, 95 % CI 0.44-0.98). The results were similar when comparing lithium with prolactin raising and sparing antipsychotics, and individual antiepileptics. Lithium use may lower fracture risk, a benefit that is particularly relevant for patients with serious mental illness who are more prone to falls due to their behaviors. Our findings could help inform better treatment decisions for bipolar disorder, and lithium's potential to prevent fractures should be considered for patients at high risk of fractures.

Osteoporosis and low bone mass among schizophrenia and bipolar disorder: A cross-sectional study with newly diagnosed, drug-naïve subjects

BACKGROUND

A growing body of data shows that schizophrenia (SCZ) and bipolar disorder (BD) have substantial metabolic risks; however, few studies have focused on bone metabolism. This study aimed to assess the prevalence and associated influencing factors of low bone mass and osteoporosis in SCZ and BD before pharmacological effects occur.

METHODS

108 healthy controls (HCs) and drug-naïve individuals with SCZ (n = 56) and BD (n = 130) had their lumbar spine (L1-L4) and left femur (Neck/Trochanter/Ward's triangle) bone mineral density (BMD) determined using dual-energy X-ray absorptiometry. Besides, we measured bone turnover markers (BTMs) levels, including procollagen I N-terminal propeptide, osteocalcin, and C-terminal cross-linking telopeptide of type I collagen in different groups.

RESULTS

Individuals with SCZ and BD had significantly lower BMD and significantly higher prevalence of low bone mass and osteoporosis compared with HCs. In the main observation regions of the total lumbar (F = 18.368, p < 0.001) and left femur (F = 14.790, p < 0.001), BMD was lower in individuals with SCZ and BD than HCs, with SCZ showing lower BMD than BD. The osteocalcin (H = 11.421, p = 0.003) levels were significantly higher in SCZ and BD than HCs. Binary regression analysis showed that SCZ or BD was an independent risk factor for low bone mass and osteoporosis. In addition, sex, age, and BTMs also influenced the occurrence of low bone mass and osteoporosis.

LIMITATIONS

Cross-sectional study.

CONCLUSION

The results findings of the study might contribute to our understanding of the increased risk of bone metabolism in SCZ and BD.

CLINICAL TRIAL REGISTRATION

www.chictr.org.cn, identifier ChiCTR1900021379.

Does Decreased Vitamin D Level Trigger Bipolar Manic Attacks?

BACKGROUND

Bipolar disorder is a chronic psychiatric disorder with depression and manic episodes. It is one of the leading causes of disease-related disability worldwide. Despite the presence of various alternative drug options for bipolar disorder, some patients do not adequately benefit from the treatment. Therefore, possible underlying mechanisms need to be clarified. Recently, studies on the relationship between bipolar disorder and vitamin D (Vit D) have attracted attention. Although many studies have found an association between depression and Vit D deficiency, little is known about the relationship between manic episodes and Vit D. The aim of this study was to compare Vit D and related metabolites of bipolar manic episodes prior to treatment, bipolar remission after treatment, and healthy control groups.

METHODS

This case-control study consisted of 34 bipolar manic episode patients and 34 healthy controls. Disease activity was evaluated with the Hamilton Depression Rating Scale (HAM-D) and Young Mania Rating Scale (YMRS). Firstly, serum 25-hydroxy vitamin D (25-OHD), calcium (Ca) and phosphorus (P) levels of patients in the bipolar manic episode were measured and compared with healthy control. Secondly, serum 25-OHD, Ca and P levels in the euthymic periods of the same patients were measured and compared with healthy control.

RESULTS

Bipolar manic episode Vit D levels were lower when compared to healthy controls; while there was no difference in terms of Ca and P levels. There was no significant difference between the bipolar euthymic period patients and the healthy control group in terms of 25-OHD, Ca and P levels.

CONCLUSION

Our results demonstrated low serum Vit D concentrations in the acute manic episode of bipolar disorder. Decreased Vit D level may play a role in the onset of the manic episode, or malnutrition and insufficient sunlight during the manic episode may have caused Vit D deficiency. Future studies are needed to exclude potential confounding factors and to compare all mood episodes.

Association between the pharmacological treatment of bipolar disorder and risk of traumatic injuries: a self-controlled case series study

BACKGROUND

Patients with bipolar disorder (BPD) are prone to engage in risk-taking behaviours and self-harm, contributing to higher risk of traumatic injuries requiring medical attention at the emergency room (ER).We hypothesize that pharmacological treatment of BPD could reduce the risk of traumatic injuries by alleviating symptoms but evidence remains unclear. This study aimed to examine the association between pharmacological treatment and the risk of ER admissions due to traumatic injuries.

METHODS

Individuals with BPD who received mood stabilizers and/or antipsychotics were identified using a population-based electronic healthcare records database in Hong Kong (2001-2019). A self-controlled case series design was applied to control for time-invariant confounders.

RESULTS

A total of 5040 out of 14 021 adults with BPD who received pharmacological treatment and had incident ER admissions due to traumatic injuries from 2001 to 2019 were included. An increased risk of traumatic injuries was found 30 days before treatment [incidence rate ratio (IRR) 4.44 (3.71-5.31), p < 0.0001]. After treatment initiation, the risk remained increased with a smaller magnitude, before returning to baseline [IRR 0.97 (0.88-1.06), p = 0.50] during maintenance treatment. The direct comparison of the risk during treatment to that before and after treatment showed a significant decrease. After treatment cessation, the risk was increased [IRR 1.34 (1.09-1.66), p = 0.006].

CONCLUSIONS

This study supports the hypothesis that pharmacological treatment of BPD was associated with a lower risk of ER admissions due to traumatic injuries but an increased risk after treatment cessation. Close monitoring of symptoms relapse is recommended to clinicians and patients if treatment cessation is warranted.

Alternations of vitamin D and cognitive function in first-diagnosed and drug-naïve BD patients: Physical activity as a moderator

BACKGROUND

The pathophysiological mechanism of cognitive impairments of bipolar disorder (BD) has not yet been completely revealed. It is well known that Vitamin D and physical activity (PA) are associated with BD. However, specific links between Vitamin D and cognitive deficits in BD are still unclear.

METHOD

The serum levels of vitamin D were measured. The cognitive performances of 102 first-diagnosed and drug-naïve BD patients were evaluated for analysis. The repeatable battery for the assessment of neuropsychological status (RBANS) and the Stroop Color-Word test was used in this study. PA was collected by international physical activity questionnaire.

RESULT

Patients with BD had high levels of serum vitamin D. Furthermore, immediate and delayed memory was negatively associated with vitamin D levels in patients' group. The serum levels of vitamin D in patients with low PA were positively associated with memory. However, increased PA attenuated the protective effect of vitamin D on executive cognition.

CONCLUSION

It is concluded that the increased levels of vitamin D were observed in the serum of patients with BD. Thus, it is found that more PA is less beneficial to cognition of patients with BD than longer resting.

Bipolar Disorder and Bone Mineral Density Z-Scores in Relation to Clinical Characteristics and Lithium Medication

Bipolar disorder is associated with a long range of medical comorbidities, including migraine, diabetes, and cardiovascular disease. Bipolar disorder has also been associated with an increased risk of bone fractures. Osteoporosis is a reduction in bone mineral density, which leads to an increased risk for fragility fractures. Currently there is limited research on the association between bipolar disorder and osteoporosis. We aimed to study the association between high and low bone mineral density in relation to disease and treatment history in a sample of bipolar patients. We found that bipolar patients with high bone mineral density were more often on lithium medication, had a more active lifestyle and expressed lower current disease burden. Low mineral density was not associated with any of the addressed aspects of disease and treatment history. In conclusion our results support that patients on lithium treatment have higher bone mineral density; further studies are needed to address if lithium medication causes an increase in bone mineral density, and lowers the risk of bone fractures in bipolar disorder.

Research on biochemical indexes of bone metabolism in bipolar disorder: A cross-sectional study with newly diagnosed, drug-naïve patients

BACKGROUND

In recent years, the metabolic abnormalities associated with bipolar disorder (BD) have attracted people's attention. However, clinical studies on bone metabolism in individuals with BD are unavailable. This study was designed to assess biochemical indexes of bone metabolism and related influencing factors.

METHODS

We measured bone turnover markers (BTMs), including procollagen Ⅰ N-terminal propeptide (PⅠNP), osteocalcin (OC) and C-terminal cross-linking telopeptide of type I collagen (CTX-I), and index of calcium and phosphorus metabolism in 100 drug-naïve individuals with BD (DSM-5) and 91 healthy volunteers. Besides, sociodemographic and clinical assessment were collected. Between-group comparisons and within subgroup analysis were performed.

RESULTS

The PⅠNP (t = 3.715, p < 0.001), OC (t = 2.117, p = 0.036), parathyroid hormone (PTH, t = 3.877, p < 0.001), vitamin D (t = 2.065, p = 0.041), insulin (t = 4.208, p < 0.001) and insulin resistance (t = 2.888, p = 0.004) levels in the drug-naive BD group was significantly higher than those in the healthy control (HC) group. The level of calcium (t = -2.124, p = 0.035) in the drug-naive BD group was significantly lower than that of the HC group. But OC and vitamin D loses statistical significance after Bonferroni correction. However, there was no significant difference in the CTX-I level between the two groups. There are gender differences in the level of BMTs in individuals with BD, but this phenomenon was not found in the HC subgroup. It is shown that diagnosed BD, gender, age and BMI may affect the PINP levels through multiple linear regression analysis.

CONCLUSION

The biochemical indexes of bone metabolism in drug-naive individuals with BD were more active than that of the healthy controls in a sample from the Chinese Han nationality. The finding provides new evidence for our understanding of bone metabolism in individuals with BD.

Hip, vertebral, and wrist fracture risks and schizophrenia: a nationwide longitudinal study

BACKGROUND

Fractures are a great health issue associated with morbidity, quality of life, life span, and health care expenditure. Fractures are correlated with cardiovascular disease, type 2 diabetes mellitus, cerebrovascular disease, and some psychiatric disorders. However, representative national data are few, and longitudinal cohort studies on the association between schizophrenia and the subsequent fracture risk are scant. We designed a nationwide population-based cohort study to investigate the association of schizophrenia with hip, vertebral, and wrist fractures over a 10-year follow-up.

METHODS

Data of patients with schizophrenia (International Classification of Diseases, Ninth Revision, Clinical Modification code 295) and matched over January 2000-December 2009) were extracted from Taiwan National Health Insurance Research Database. A Cox proportional-hazards regression model was constructed to calculate hazard ratios (HRs) for fractures between the schizophrenia and control cohorts.

RESULTS

Of 2028 people with schizophrenia (mean age: 36.3 years, 49.4% female), 89 (4.4%) reported newly diagnosed fractures-significantly higher than the proportion in the control population (257, 3.2%; P = 0.007). The incidences of hip (1.2%, P = 0.009) and vertebral (2.6%, P = 0.011) fractures were significantly higher in the schizophrenia cohort than in the control cohort. In Cox regression analysis, hip (adjusted HR: 1.78, 95% confidence interval [CI]: 1.08-2.93) and vertebral (adjusted HR: 1.40, 95% CI: 1.01-1.95) fracture risks were significantly higher in patients with schizophrenia. Furthermore, a sex-based subgroup analysis revealed that the risk of hip fracture remained significantly higher in female patients with schizophrenia (HR: 2.68, 95% CI: 1.32-5.44) than in female controls. On the other hand, there was no significant interaction between effects of sex and schizophrenia on the risk of fractures.

CONCLUSIONS

Over a 10-year follow-up, hip and vertebral fracture risks were higher in the people with schizophrenia than in the controls. The risk of fractures in patients with schizophrenia does not differ between female and male.

Risk of hospitalised falls and hip fractures in working age adults receiving mental health care

OBJECTIVE

This retrospective cohort study investigates risks of hospitalised fall or hip fractures in working age adults receiving mental health care in South London.

METHODS

Patients aged 18 to 64, who received a first mental illness diagnosis between 2008 and 2016 were included. Primary outcome was hospitalised falls, secondary outcome was hip fractures. Age- and gender-standardised incidence rates and incidence rate ratios (IRRs) compared to local general population were calculated. Multivariate Cox proportionate hazard models were used to investigate which mental health diagnoses were most at risk.

RESULTS

In 50,885 patients incidence rates were 8.3 and 0.8 per 1,000 person-years for falls and hip fractures respectively. Comparing mental health patients to the general population, age-and-gender-adjusted IRR for falls was 3.6 (95% CI: 3.3-4.0) and for hip fractures 7.5 (95% CI: 5.2-10.4). The falls IRR was highest for borderline personality and bipolar disorder and lowest for schizophreniform and anxiety disorder. After adjusting for multiple confounders in the sample of mental health service users, borderline personality disorder yielded a higher and anxiety disorder a lower falls risk.

CONCLUSION

Working age adults using mental health services have almost four times the incidence of hospitalised falls compared to general population. Targeted interventions are warranted.

Effect of medication on risk of traumatic brain injury in patients with bipolar disorder: A nationwide population-based cohort study

BACKGROUND

Increased traumatic brain injury (TBI) risk was found in patients with bipolar disorder (BPD). Whether the medications for BPD and dosage moderate the risk of TBI is not clear.

AIM

This study aimed to determine whether an association exists between BPD and TBI and whether the prescription of psychotropics moderates TBI risk.

METHODS

A total of 5606 individuals who had received diagnoses of BPD between January 1, 1997 and December 31, 2013 and 56,060 matched controls without BPD were identified from Taiwan's National Health Insurance Research Database. Cases and controls were followed until the date of TBI diagnosis.

RESULTS

BPD was associated with a high risk of TBI (adjusted hazard ratio (aHR): 1.85; 95% CI: 1.62-2.11). Patients with BPD, with or without a history of psychiatric hospitalization, had increased risks of TBI (aHR: 1.94, 95% CI: 1.57-2.4 and aHR: 1.82, 95% CI: 1.55-2.1, respectively). The prescription of typical antipsychotics (0 < defined daily dose (DDD) < 28: hazard ratio (HR) = 1.52, 95% CI: 1.19-1.94; ⩾28 DDD: HR = 1.54, 95% CI: 1.15-2.06) and tricyclic antidepressants (TCAs) (0 < DDD < 28: HR = 1.73, 95% CI: 1.26-2.39; ⩾28 DDD: HR = 1.52, 95% CI: 1.02-2.25) was associated with higher TBI risk. Patients receiving higher doses of benzodiazepines (BZDs) (cumulative dose ⩾28 DDD) had a higher TBI risk (HR = 1.53, 95% CI: 1.13-2.06).

CONCLUSION

Patients with BPD have a higher risk of TBI. The use of typical antipsychotics, TCAs, or high-dose BZDs increases the risk of TBI in BPD.

Risk of Hospitalized Falls and Hip Fractures in 22,103 Older Adults Receiving Mental Health Care vs 161,603 Controls: A Large Cohort Study

OBJECTIVES

To investigate the risk of hospitalized fall or hip fracture among older adults using mental health services.

DESIGN

Retrospective cohort study.

SETTING AND PARTICIPANTS

Residents of a South London catchment aged >60 years receiving specialist mental health care between 2008 and 2016.

MEASURES

Falls and/or a hip fracture leading to hospitalization were ascertained from linked national records. Incidence rates and incidence rate ratios (IRRs) were age- and gender-standardized to the catchment population. Multivariable survival analyses were applied investigating falls and/or hip fractures as outcomes.

RESULTS

In 22,103 older adults, incidence rates were 60.1 per 1000 person-years for hospitalized falls and 13.7 per 1000 person-years for hip fractures, representing standardized IRRs of 2.17 [95% confidence interval (CI) 2.07-2.28] and 4.18 (3.79-4.60), respectively. The IRR for falls was high in those with substance-use disorder [IRR = 6.72 (5.35-8.33)], bipolar disorder [IRR = 3.62 (2.50-5.05)], depression [IRR = 2.28 (2.00-2.59)], and stress-related disorders [IRR = 2.57 (2.10-3.11)]. Hip fractures were increased in all populations (IRR > 2.5), with greatest risk in substance use disorders [IRR = 12.64 (7.22-20.52)], dementia [IRR = 4.38 (3.82-5.00)], and delirium [IRR = 4.03 (3.00-5.29)]. Comparing mental disorder subgroups with each other, after the adjustment for 25 potential confounders, patients with dementia and substance use had a significantly increased risk of falls, and patients with dementia also had an increased risk of hip fractures.

CONCLUSION AND IMPLICATIONS

Older people using mental health services have more than double the incidence of falls and 4 times the incidence of hip fractures compared to the general population. Although incidences differ between diagnostic subgroups, all groups have a higher incidence than the general population. Targeted interventions to prevent falls and hip fractures among older adult mental health service users are urgently needed.

Trauma-related mortality of patients with severe psychiatric disorders: population-based study from the French national hospital database

BACKGROUND

Most research on mortality in people with severe psychiatric disorders has focused on natural causes of death. Little is known about trauma-related mortality, although bipolar disorder and schizophrenia have been associated with increased risk of self-administered injury and road accidents.

AIMS

To determine if 30-day in-patient mortality from traumatic injury was increased in people with bipolar disorder and schizophrenia compared with those without psychiatric disorders.

METHOD

A French national 2016 database of 144 058 hospital admissions for trauma was explored. Patients with bipolar disorder and schizophrenia were selected and matched with mentally healthy controls in a 1:3 ratio according to age, gender, social deprivation and region of residence. We collected the following data: sociodemographic characteristics, comorbidities, trauma severity characteristics and trauma circumstances. Study outcome was 30-day in-patient mortality.

RESULTS

The study included 1059 people with bipolar disorder, 1575 people with schizophrenia and their respective controls (n = 3177 and n = 4725). The 30-day mortality was 5.7% in bipolar disorder, 5.1% in schizophrenia and 3.3 and 3.8% in the controls, respectively. Only bipolar disorder was associated with increased mortality in univariate analyses. This association remained significant after adjustment for sociodemographic characteristics and comorbidities but not after adjustment for trauma severity. Self-administered injuries were associated with increased mortality independent of the presence of a psychiatric diagnosis.

CONCLUSIONS

Patients with bipolar disorder are at higher risk of 30-day mortality, probably through increased trauma severity. A self-administered injury is predictive of a poor survival prognosis regardless of psychiatric diagnosis.

The Skeletal-Protecting Action and Mechanisms of Action for Mood-Stabilizing Drug Lithium Chloride: Current Evidence and Future Potential Research Areas

Lithium, the lightest natural-occurring alkali metal with an atomic number of three, stabilizes the mood to prevent episodes of acute manic and depression. Multiple lines of evidence point to lithium as an anti-suicidal, anti-viral, anti-cancer, immunomodulatory, neuroprotective and osteoprotective agent. This review article provides a comprehensive review of studies investigating the bone-enhancing effects of lithium and its possible underlying molecular mechanisms. Most of the animal experimental studies reported the beneficial effects of lithium in defective bones but not in healthy bones. In humans, the effects of lithium on bones remain heterogeneous. Mechanistically, lithium promotes osteoblastic activities by activating canonical Wingless (Wnt)/beta (β)-catenin, phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) and bone morphogenetic protein-2 (BMP-2) transduction pathways but suppresses osteoclastic activities by inhibiting the receptor activator of nuclear factor-kappa B (RANK)/receptor activator of nuclear factor-kappa B ligand (RANKL)/osteoprotegerin (OPG) system, nuclear factor-kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and calcium signaling cascades. In conclusion, lithium confers protection to the skeleton but its clinical utility awaits further validation from human clinical trials.

Schizophrenia, Bipolar Disorder, and Alzheimer's Disease are not Causal Factors of Bone Mineral Density: A Mendelian Randomization Analysis

Until recently, it remains unclear whether schizophrenia, bipolar disorder (BD), and Alzheimer's disease (AD) is associated with bone mineral density (BMD). We aimed to investigate the causal effects of schizophrenia, BD and AD on BMD with Mendelian randomization (MR) analysis. Single-nucleotide polymorphisms (SNPs) strongly associated with these three neuropsychiatric diseases as instrumental variables were selected from genome-wide association studies in the MR Base database. We analyzed the effects of these SNPs on the femoral neck BMD (FN-BMD), lumbar spine BMD (LS-BMD) and forearm BMD (FA-BMD), and evaluated the heterogeneities and pleiotropy of these genetic variants. We also evaluated the potential confounding factors in the association between these three neuropsychiatric diseases and the BMD level. It was found that none of these genetic variants were significantly associated with BMD or confounding factors. Using these genetic variants, we did not find statistically significant causal effects of per unit increase in the log-odds of having schizophrenia, BD or AD with FN-BMD, LS-BMD and FA-BMD changes (e.g. schizophrenia and FN-BMD, MR-Egger OR 0.9673, 95% CI 0.8382 to 1.1163, p = 0.6519). The MR results also revealed that directional pleiotropy was unlikely to bias the causality (e.g., schizophrenia and FN-BMD, intercept = 0.0023, p = 0.6887), and no evidence of heterogeneity was found between the genetic variants (e.g., schizophrenia and FN-BMD, MR-Egger Q = 46.1502, I² = 0.0899, p = 0.3047). Our MR study did not support causal effects of increased risk of schizophrenia, BD and AD status with BMD level.

Longitudinal outcomes in pediatric- and adult-onset bipolar patients compared to healthy and schizophrenia controls

OBJECTIVES

Comparing outcomes of bipolar disorder (BD) with schizophrenia (SCZ) and psychiatrically healthy controls (PHC), contrasting pediatric-onset with adult-onset disorders.

METHODS

A nationwide cohort study, including patients with an incident diagnosis of BD or SCZ registered in the Danish National Patient Registry and corresponding PHCs. Outcomes were (a) duration of hospitalization, (b) psychiatric admissions, (c) psychiatric outpatient contacts, (d) bone-fracture-related healthcare contacts, (e) self-harm-related healthcare contacts (including suicide and non-suicidal self-injuries), and (f) criminal charges. Incidence rate ratios (IRRs), adjusted for age at first psychiatric contact, substance abuse and parental psychiatric illness, were calculated, comparing pediatric-onset BD (5-17 years) and adult-onset BD (18-39 years) with age- and sex-matched SCZ patients and PHC.

RESULTS

Pediatric-onset BD (n = 349) performed better than 1:1-matched pediatric-onset SCZ (n = 349) on all six outcomes (IRR = 0.30 for self-harm-related contacts (P < 0.001) to IRR = 0.86 for criminal charges (P = 0.05). Similar, but less pronounced results were observed comparing 1:1-matched adult-onset BD (n = 5515) with adult-onset SCZ (n = 5515) IRR = 0.58 for psychiatric outpatient contact (P < 0.001) to IRR = 0.93 for criminal charges (P < 0.001), except for more bone-fracture-related contacts in adult-onset BD (IRR = 1.13, P < 0.01). Comparing pediatric-onset BD (n = 365) to 1:3-matched PHC (n = 1095), only self-harm-related contacts differed significantly (IRR = 2.80, P < 0.001). Conversely, comparing adult-onset BD (n = 6005) with 1:3-matched PHC (n = 18 015), self-harm-related contacts (IRR = 16.68, P < 0.001), bone fractures (IRR = 1.74, P < 0.001), and criminal charges (IRR = 2.03, P < 0.001) were more common in BD.

CONCLUSION

BD was associated with poorer outcomes than PHC, but better outcomes than SCZ. Furthermore, outcomes were more favorable in pediatric-onset BD when indirectly contrasted to adult-onset BD.

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.

Lithium use and risk of fracture: a systematic review and meta-analysis of observational studies

This systematic review and meta-analysis summarized the results from nine eligible observational studies. Lithium use was significantly associated with a decrease risk of fractures.

INTRODUCTION

The association between lithium use and risk of fracture is uncertain. To date, there have been no meta-analyses that have studied the association between the two. We conducted a systematic review and meta-analysis to examine the effect of lithium medication on the risk of fracture.

METHODS

A comprehensive literature search was performed in PubMed, Embase, and MEDLINE to include eligible observational studies. Three reviewers conducted the literature search, study selection, study appraisal, and data abstraction independently. Random effects models were used to obtain the overall estimate for meta-analysis. Cochran's Q and Higgins' I² were used to assess heterogeneity. A funnel plot and Egger's regression test were employed to assess publication bias.

RESULTS

Of the 3819 studies that were identified by our search strategy, eight were eligible for the systematic review, while seven of them qualified for the meta-analysis. In studies that reported risk ratio (RR) of fracture as an outcome (five studies [n = 1,134,722]), lithium use was associated with a 20% decrease in risk of fracture (RR = 0.80; 95% CI, 0.73-0.87; p < 0.01). A decreased risk of fracture associated with lithium was also observed in studies that adjusted for previous fractures (RR = 0.81; 95% CI, 0.73-0.89; p < 0.01). The decreased risk of fracture associated with lithium use remained consistent in all the analyses with different inclusion criteria. Neither significant heterogeneity nor significant publication bias was observed.

CONCLUSION

The present systematic review and meta-analysis demonstrated that lithium use was associated with a significant decreased risk of fracture.

Elucidating the Mechanism(s) Underlying Antipsychotic and Antidepressant-Mediated Fractures

Mood spectrum disorders and medications used to treat these disorders, such as atypical antipsychotic drugs (AA), are associated with metabolic and endocrine side effects including obesity, dyslipidemia, hyperglycemia and increased risk of fractures. Antidepressant medications, including selective serotonin reuptake inhibitors (SSRI), have also been reported to increase fracture risk in some patients. The pharmacology underlying the increased risk of fractures is currently unknown. Possible mechanisms include alternations in dopaminergic and/or serotonergic signaling pathways. As these medications distribute to the bone marrow as well as to the brain, it is possible that drug-induced fractures are due to both centrally mediated effects as well as direct effects on bone turnover. Given the growing patient population that is prescribed these medications for both on- and off-label indications, understanding the level of risk and the mechanisms underlying drug-induced fractures is important for informing both prescribing and patient monitoring practices.