Asthma, corticosteroid use and schizophrenia: A nationwide population-based study in Taiwan

Multimorbidity and the Etiology of Schizophrenia

PURPOSE OF REVIEW

A global study of multimorbidity in schizophrenia, especially of the association with physical conditions, might offer much needed etiological insights.

RECENT FINDINGS

Our review suggests that life-style factors and medication related to schizophrenia are only part of the explanation of the increase in risk for cardiovascular, metabolic, pulmonary disorders, and some cancers. Positive associations with autoimmune disorders (with the exception of rheumatoid arthritis) and epilepsy are promising avenues of research but to date have not been fully exploited. The same holds for the negative comorbidity seen for rheumatoid arthritis and some cancers (e.g., prostate). As a whole, our review suggests that most of the explored conditions have a different prevalence in schizophrenia than in the general population. Several hypotheses emerged from this review such as the role of immune and genetic factors, of sex hormones, and of more general variability factors.

Prevalence and 3-year incidence of physical illnesses after schizophrenia diagnosis: Comparison with general population

AIM

People with schizophrenia are at a greater risk of poor physical health than the general population. This study investigated the annual incidence of physical illnesses after a new schizophrenia diagnosis, which has rarely been investigated in the literature.

METHODS

The authors collected data from Taiwan's National Health Insurance Research Database from January 1, 1996, to December 31, 2013, and enrolled 1910 patients with newly diagnosed schizophrenia cases aged 10-40 years and 7640 age- and sex-matched controls from the general population. They estimated the 1-year prevalence and annual incidence rate ratio (IRR) of specified physical diseases across 3 years in the schizophrenia group compared with the controls.

RESULTS

Several physical illnesses were prevalent within 1 year of schizophrenia diagnosis. Regarding incident physical illnesses, patients had a moderate to strong risk of numerous physical illnesses (IRR > 3.0: ischemic heart disease, cerebrovascular disease, diabetes mellitus, and cancer; IRR 1.8-3.0: other forms of heart disease, vein and lymphatic diseases, pneumonia, chronic hepatic disease, and ulcer disease) within the first year after schizophrenia diagnosis. The IRRs of most physical illnesses declined over 3 years, except for that of cerebrovascular disease, which significantly increased (IRR > 3.0) over the 3 years after schizophrenia diagnosis. Cerebrovascular disease had a significant incidence risk (IRR > 3) persistently across the 3 years.

CONCLUSION

Various comorbid physical illnesses can occur in the early stages of schizophrenia. Clinicians should consider these vulnerabilities to physical illnesses during the evaluation of patients with newly diagnosed schizophrenia by attempting to prevent, screen for, and manage them.

Increased Risk of Hypothyroidism in People with Asthma: Evidence from a Real-World Population-Based Study

Background: Non-T2 asthma and hypothyroidism share several inflammatory mechanisms in common. However, large-scale, real-world studies evaluating the association between asthma and hypothyroidism are lacking. The objective of this study was to evaluate the risk for asthma patients of developing hypothyroidism. Methods: In the retrospective cohort study, people with asthma were recruited from the Longitudinal Health Insurance Database in Taiwan. After excluding ineligible patients with a previous history of hypothyroidism, 1:1 propensity matching was conducted to select a non-asthma control group. Based on the multivariate Cox regression model, the adjusted hazard ratio of asthma patients developing hypothyroidism was calculated. Results: In total, 95,321 asthma patients were selected as the asthma group and the same amount of people without asthma were selected as the control group. The incidence levels of new-onset hypothyroidism in asthma and non-asthma groups were 8.13 and 6.83 per 100,000 people per year, respectively. Compared with the non-asthma group, the adjusted hazard ratio of the asthma group developing hypothyroidism was 1.217 (95% confidence interval, 1.091–1.357). Conclusions: We found having asthma to be associated with an increased risk of hypothyroidism. Clinicians should be concerned regarding the endocrinological and inflammatory interaction between the two diseases while caring for people with asthma.

Investigating the causal relationship between allergic disease and mental health

BACKGROUND

Observational studies have reported an association between allergic disease and mental health, but a causal relationship has not been established. Here, we use Mendelian randomization (MR) to investigate a possible causal relationship between atopic disease and mental health phenotypes.

METHODS

The observational relationship between allergic disease and mental health was investigated in UK Biobank. The direction of causality was investigated with bidirectional two-sample MR using summary-level data from published genome-wide association studies. A genetic instrument was derived from associated variants for a broad allergic disease phenotype to test for causal relationships with various mental health outcomes. We also investigated whether these relationships were specific to atopic dermatitis (AD), asthma or hayfever. Given the multiple testing burden, we applied a Bonferroni correction to use an individual test p-value threshold of .0016 (32 tests).

RESULTS

We found strong evidence of an observational association between the broad allergic disease phenotype and depression (OR_self-report =1.45, 95% CI: 1.41-1.50, p = 3.6 × 10^-130 ), anxiety (OR=1.25, 95% CI: 1.18-1.33, p = 6.5 × 10^-13 ), bipolar disorder (OR_self-report =1.29, 95% CI: 1.12-1.47, p = 2.8 × 10^-4 ) and neuroticism (β = 0.38, 95% CI: 0.36-0.41, p = 6.8 × 10^-166 ). Similar associations were found between asthma, AD, hayfever individually with the mental health phenotypes, although the associations between AD and hayfever with bipolar disorder were weaker. There was little evidence of causality in either direction (all p-values>.02).

CONCLUSION

Using MR, we were unable to replicate most of the phenotypic associations between allergic disease and mental health. Any causal effects we detected were considerably attenuated compared with the phenotypic association. This suggests that most comorbidity observed clinically is unlikely to be causal.

The Association Between Asthma and Narcolepsy: A Nationwide Case-Control Study in Taiwan

PURPOSE

Asthma, which is caused by inflammation of the airways, affects the sensitivity of nerve endings. Narcolepsy is a chronic sleep disorder that may be caused by autoimmunity. Recent studies have reported a positive association between narcolepsy and asthma. We aimed to examine the association between asthma and narcolepsy and determine the effects of therapeutic corticosteroid or bronchodilator use.

MATERIALS AND METHODS

We conducted a nationwide population-based, nested case-control study using Taiwan's National Health Insurance Research Database (NHIRD) between 2000 and 2013. Subjects with narcolepsy (ICD-9-CM code 347) were enrolled, with 1:3 estimated propensity score-matched controls based on sex, age, and index year. The association between narcolepsy and asthma was assessed using multiple logistic regression analyses. The covariates included sex, age, monthly insurance premiums, geographical area of residence, urbanization level of residence, level of care, and presence of diseases related to immune response and central nervous system. The effects of corticosteroid and bronchodilator use were also analyzed.

RESULTS

Overall, 2008 subjects were identified from the NHIRD (502 patients with narcolepsy and 1506 controls). The participants with narcolepsy had almost three times the level of previous asthma diagnosis than controls. Compared to those without asthma, patients with asthma had an adjusted odds ratio (OR) of 3.181 for narcolepsy comorbidity (95% confidence interval [CI]: 2.048-4.941, p<0.001). The use of inhaled corticosteroids was associated with a lower risk of narcolepsy comorbidity, with an adjusted OR of 0.465 (95% CI, 0.250-0.634; p<0.001), in patients with asthma when compared to those without treatment.

CONCLUSION

This study demonstrated a significantly higher level of previous asthma diagnosis in patients with narcolepsy. The use of inhaled corticosteroids was associated with a lower risk of narcolepsy comorbidity in asthma patients, compared to those without treatment.

Common issues among asthma, epilepsy, and schizophrenia: from inflammation to Ca2+/cAMP signalling

BACKGROUND

A large amount of evidence has described that asthma may be associated with a high epilepsy risk, and epilepsy may be linked with a high asthma risk, especially among children and individuals in their 30s. Curiously, asthma has also been associated with an increased risk for schizophrenia. Most interestingly, a bidirectional link between schizophrenia and epilepsy has also been established, and has been of interest for many years.

OBJECTIVE

Bearing in mind the experience of our group in the field of Ca2+/cAMP signalling pathways, this article discussed, beyond inflammation, the role of these signalling pathways in this link among epilepsy, asthma, and schizophrenia.

METHODS

Publications involving these signalling pathways, asthma, epilepsy, and schizophrenia (alone or combined) were collected by searching PubMed and EMBASE.

RESULTS AND CONCLUSION

There is a clear relationship between Ca2+ signalling, e.g. increased Ca2+ signals, and inflammatory responses. In addition to Ca2+, cAMP regulates pro- and anti-inflammatory responses. Then, beyond inflammation, the comprehension of the link among epilepsy, asthma and schizophrenia could improve the drug therapy.

A link among schizophrenia, diabetes, and asthma: Role of Ca2+/cAMP signaling

Asthma has been associated with an increased risk for developing schizophrenia. In addition, schizophrenia has been associated with an increased risk for developing type 2 diabetes mellitus, resulting in an elevated cardiovascular risk and in a limited life expectancy. It is well discussed that dysregulations related to Ca²⁺ signaling could link these diseases, in addition to cAMP signaling pathways. Thus, revealing this interplay among schizophrenia, diabetes, and asthma may provide novel insights into the pathogenesis of these diseases. Publications involving Ca²⁺ and cAMP signaling pathways, schizophrenia, diabetes, and asthma (alone or combined) were collected by searching PubMed and EMBASE. Both Ca²⁺ and cAMP signaling pathways (Ca²⁺/cAMP signaling) control the release of neurotransmitters and hormones, in addition to airway smooth muscle contractility, then dysregulations of these cellular processes may be involved in these diseases. Taking into consideration, the experience of our group in this field, this narrative review debated the involvement of Ca²⁺/cAMP signaling in this link among schizophrenia, diabetes, and asthma, including its pharmacological implications.

Physical Illnesses Before Diagnosed as Schizophrenia: A Nationwide Case-Control Study

Some physical illnesses are potentially associated with the development of schizophrenia. However, few studies have investigated these associations. Here, we examined physical illnesses and medical utilization patterns existing before patients received a diagnosis of schizophrenia. We enrolled a large representative cohort of the general population in Taiwan (N = 1 000 000) and identified 1969 young patients with a new diagnosis of schizophrenia from January 1, 2000 to December 31, 2013. We conducted a nested case-control study based on risk-set sampling. Each case was age-matched and sex-matched with 4 controls selected from the general population. The case and control groups were compared on the basis of various clinical characteristics. Conditional logistic regression was used to estimate the magnitude of risk associated with newly diagnosed schizophrenia. Within the 1 year before the schizophrenia diagnosis, the cases were most likely to visit the psychiatry department, followed by internal medicine and family medicine departments. According to multivariate analysis, compared with the controls, the cases had substantially higher risk of physical conditions in the prodromal phase, including hypertension (adjusted risk ratio [aRR] = 1.93, P = .001), other forms of heart disease (aRR = 2.07, P < .001), cerebrovascular diseases (aRR = 2.96, P = .001), chronic obstructive pulmonary disease (aRR = 1.50, P = .005), asthma (aRR = 1.76, P = .003), and irritable bowel syndrome (aRR = 2.00, P < .001). A wide range of psychiatric diseases and concomitant use of medications were significantly associated with schizophrenia development. In conclusion, several physical illnesses were identified to be associated with schizophrenia development, indicating that people with these illnesses could be vulnerable to schizophrenia.

Identification of psychiatric patients with high mortality and low medical utilization: a population-based propensity score-matched analysis

Background

The decreased life expectancy and care costs of mental disorders could be enormous. However, research that compares mortality and utilization concurrently across the major category of mental disorders is absent. This study investigated all-cause mortality and medical utilization among patients with and without mental disorders, with an emphasis on identifying the psychiatric category of high mortality and low medical utilization.

Methods

A total of 570,250 individuals identified from the 2002–2013 Taiwan National Health Insurance Reearch Database consistuted 285,125 psychiatric patients and 285,125 non-psychiatric peers through 1:1 dual propensity score matching (PSM). The expenditure survival ratio (ESR) was proposed to indicate potential utilization shortage. The category of mental disorders and 13 covariates were analyzed using the Cox proportional hazard model and general linear model (GLM) through SAS 9.4.

Results

PSM analyses indicated that mortality and total medical expenditures per capita were both significantly higher in psychiatric patients than those in non-psychiatric patients (all P <.0.0001). Patients with substance use disorders were reported having the youngest ages at diagnosis and at death, with the highest 25.64 of potential years of life loss (YPLL) and relevant 2904.89 of ESR. Adjusted Cox model and GLM results indicated that, compared with anxiety disorders, affective disorders and substance use disorders were significantly associated with higher mortality (HR = 1.246 and 1.064, respectively; all P < 0.05); schizophrenia was significantly associated with higher total medical expenditures per capita (P < 0.0001). Thirteen additional factors were significantly associated with mortality or utilization (all P < 0.05).

Conclusion

Substance use disorders are the category of highest YPLL but notably in insufficient utilization. Health care utilization in patients with substance use disorders should be augmented timely after the diagnosis, especially toward home and community care. The factors related to mortality and utilization identified by this study merit clinical attention.

Role of Infection, Autoimmunity, Atopic Disorders, and the Immune System in Schizophrenia: Evidence from Epidemiological and Genetic Studies

An immunologic component to schizophrenia has been increasingly recognized, where infections and chronic inflammatory diseases as atopic disorders and autoimmune diseases could be involved in the pathogenesis of schizophrenia. Psychotic symptoms can be directly triggered by infections reaching the CNS, or be secondary to systemic inflammation indirectly affecting the brain through immune components, such as brain-reactive antibodies and cytokines. Large-scale epidemiological studies have consistently displayed that infections, autoimmune diseases, and atopic disorders are associated with increased risk of schizophrenia and that schizophrenia is associated with increased levels of immune markers at diagnosis. However, since there is also an increased risk of immune-related diseases after the diagnosis with schizophrenia and in family members of individuals with schizophrenia, parts of the association could also be due to heritable factors. Shared genetic factor might account for some of this increased prevalence of immune-related diseases among individuals with schizophrenia, and indeed the most pronounced genetic association with schizophrenia lies within the HLA region, which is one of the most important regions for the immune system. However, genetic studies have shown that the common genetic variants associated with schizophrenia do not seem to increase the susceptibility for acquiring infections. Nonetheless, shared genes with the susceptibility for acquiring infections not captured by the polygenic risk score for schizophrenia could still influence the association.

Risk of acute exacerbation between acetaminophen and ibuprofen in children with asthma

Background

Antipyretics are widely prescribed in pediatric practice. Some reports have mentioned that acetaminophen and non-steroid anti-inflammatory drugs may negatively affect asthma control by causing asthma exacerbation (AE). However, many confounding factors can also influence the risks. We assessed the impact of using acetaminophen or ibuprofen on AE in asthmatic children, especially those with strong risk factors.

Methods

We used the 2010 Taiwan National Health Insurance Research Database and identified 983 children with persistent asthma aged 1-5 years old; among them, 591 used acetaminophen alone and 392 used ibuprofen alone in 2010. Then, we analyzed the risk of AE over 52 weeks in the patients with and without severe AE in the previous year.

Results

The ibuprofen group had a higher risk of an emergency room (ER) visit or hospitalization for AE (odds ratio (OR) = 2.10, 95% confidence interval (CI) [1.17-3.76], P = 0.01). Among asthmatic children who had severe AE in the previous year, the risk of AE was higher in the ibuprofen group than in the acetaminophen group (OR = 3.28, 95% CI [1.30-8.29], P = 0.01), where as among those who did not, the risks of AE were similar between the acetaminophen and ibuprofen groups (OR = 1.52, 95% CI [0.71-3.25], P = 0.28).

Conclusions

Among young asthmatic children, use of ibuprofen was associated with a higher risk of AE than acetaminophen, if they had severe AE with ER visit or hospitalization in the previous year. Pediatricians should use antipyretics among children with asthma after a full evaluation of the risk.

Clinical Trials and Therapeutic Rationale for Drug Repurposing in Schizophrenia

There is a paucity of efficacious novel drugs to address high rates of treatment resistance and refractory symptoms in schizophrenia. The identification of novel therapeutic indications for approved drugs-drug repurposing-has the potential to expedite clinical trials and reduce the costly risk of failure which currently limits central nervous system drug discovery efforts. In the present Review we discuss the historical role of drug repurposing in schizophrenia drug discovery and review the main classes of repurposing candidates currently in clinical trials for schizophrenia in terms of their therapeutic rationale, mechanisms of action, and preliminary results from clinical trials. Subsequently we outline the challenges and limitations which face the clinical repurposing pipeline and how novel technologies might serve to address these.

The relationship between asthma and depression in a community-based sample

OBJECTIVE

Asthma is an increasingly prevalent disease that is associated with substantial physical and financial burdens. Additionally, asthma is linked to psychiatric disorders. This study examines the relationship between asthma diagnosis, current depressive symptoms, and lifetime psychiatric disorder history in a large, community-based sample.

METHODS

We analyzed data from 2168 participants in the Dallas Heart Study, a large, diverse, community-based sample of people designed to be representative of the Dallas County population. Logistic regressions analyzing the relationship between asthma diagnosis and history of a psychiatric disorder, as well as between asthma diagnosis and the Quick Inventory of Depressive Symptomatology (QIDS) scores were performed, controlling for demographic data.

RESULTS

13.4% of the sample had an asthma diagnosis. Asthma diagnosis was significantly associated with a history of nervous, emotional, or mental health disorder diagnosis [OR 1.810 (95% CI 1.280-2.559) p = 0.001], and with QIDS scores consistent with moderate or greater current depressive symptom severity [OR 1.586 (95%CI 1.106-2.274) p = 0.012]. The relationships were not moderated by age, gender, race, smoking status, or Body Mass Index.

CONCLUSIONS

A diagnosis of asthma may be associated with current clinically significant levels of depressive symptoms and a lifetime psychiatric disorder. The current report adds to the existing literature in this area by assessing both current and lifetime symptoms and by using a large and diverse population. The findings highlight the clinical importance of considering the possibility of psychiatric illness in asthma patients and suggest further research in this area is needed.

Effect of increasing temperature on daily hospital admissions for schizophrenia in Hefei, China: a time-series analysis

OBJECTIVE

To investigate the relationship between ambient temperature and hospital admissions for schizophrenia in Hefei, China.

STUDY DESIGN

An ecological design was used to explore the effect of ambient temperature on hospital admissions for schizophrenia.

METHODS

Daily data on hospital admissions for schizophrenia and meteorological data for the warm season (May-October) in 2005-2014 were obtained from Anhui Mental Health Centre and Hefei Bureau of Meteorology, respectively. Poisson generalised linear regression model combined with a distributed lag non-linear model was used to analyse the effects of temperature on admissions for schizophrenia. Stratified analyses according to individual characteristics, such as age and sex, were also conducted.

RESULTS

A significant relationship was found between ambient temperature and admissions for schizophrenia. High temperature appeared to have a delayed effect on admissions for schizophrenia, and a temperature of 28°C (75th percentile) at lag 0-4 days was associated with a 7% (95% confidence interval: 4-11%) increase in admissions for schizophrenia. Stratified analyses showed that male patients, patients aged 21-60 years and married patients were more vulnerable to high temperature, and the temperature effects for those groups occurred at a lag of 1 day.

CONCLUSION

High temperature poses significant risks for schizophrenia in subtropical regions. Future preventive measures for reducing the occurrence of schizophrenia should be considered for susceptible populations.

Increased Risk of Psychiatric Disorders in Allergic Diseases: A Nationwide, Population-Based, Cohort Study

BACKGROUND/OBJECTIVE

Allergic diseases, such as bronchial asthma, allergic rhinitis, atopic dermatitis, and psychiatric disorders, are major health issues. There have been reports that allergic diseases were associated with depression or anxiety disorders. This study aimed to investigate the association between these allergic diseases and the risk of developing overall psychiatric disorders in patients from Taiwan.

METHODS

This cohort study used the database of the Taiwan National Health Insurance Program. A total of 186,588 enrolled patients, with 46,647 study subjects who had suffered from allergic diseases, and 139,941 controls matched for sex and age, from the Longitudinal Health Insurance Dataset of 2000-2015, were selected from a sub-dataset of the National Health Insurance Research Database. Fine and Gray's competing risk model analysis was used to explore the hazard ratio (HR), and 95% confidence interval, for the risk of allergic diseases being associated with the risk of developing psychiatric disorders during the 15 years of follow-up.

RESULTS

Of the study subjects, 5,038 (10.8%) developed psychiatric disorders when compared to 9,376 (6.7%) in the control group, with significant difference (p < 0.001). Fine and Gray's competing risk model analysis revealed that the adjusted HR was 1.659 (95% CI = 1.602-1.717, p < 0.001). In this study, we found that the groups of atopic dermatitis alone and the allergic rhinitis + atopic dermatitis were associated with a lower risk of psychiatric disorders, but all the other four groups, such as bronchial asthma alone, allergic rhinitis alone, bronchial asthma + allergic rhinitis, bronchial asthma + atopic dermatitis, and the combination of all these three allergic diseases, were associated with a higher risk of psychiatric disorders.

CONCLUSION

Allergic diseases are therefore associated with a 1.66-fold increased hazard of psychiatric disorders in Taiwan.