The impact of asthma control on salivary cortisol level in adult asthmatics

Multi-ancestry genome-wide association study reveals novel genetic signals for lung function decline

Rationale

Accelerated decline in lung function contributes to the development of chronic respiratory disease. Despite evidence for a genetic component, few genetic associations with lung function decline have been identified.

Objectives

To evaluate genome-wide associations and putative downstream functionality of genetic variants with lung function decline in diverse general population cohorts.

Methods

We conducted genome-wide association study (GWAS) analyses of decline in the forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and their ratio (FEV1/FVC) in participants across six cohorts in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the UK Biobank. Genotypes were imputed to TOPMed (CHARGE cohorts) or Haplotype Reference Consortium (HRC) (UK Biobank) reference panels, and GWAS analyses used generalized estimating equation models with robust standard error. Models were stratified by cohort, ancestry, and sex, and adjusted for important lung function confounders and genotype principal components. Results were combined in cross-ancestry and ancestry-specific meta-analyses. Selected top variants were tested for replication in two independent COPD-enriched cohorts.

Measurements and Main Results

Our discovery analyses included 52,056 self-reported White (N=44,988), Black (N=5,788), Hispanic (N=550), and Chinese American (N=730) participants with a mean of 2.3 spirometry measurements and 8.6 years of follow-up. Functional mapping of GWAS meta-analysis results identified 361 distinct genome-wide significant (p<5E-08) variants in one or more of the FEV1, FVC, and FEV1/FVC decline phenotypes, which overlapped with previously reported genetic signals for several related pulmonary traits. Of these, 8 variants, or 20.5% of the variant set available for replication testing, were nominally associated (p<0.05) with at least one decline phenotype in COPD-enriched cohorts (White [N=4,778] and Black [N=1,118]). Using the GWAS results, gene-level analysis implicated 38 genes, including eight (XIRP2, GRIN2D, SATB1, MARCHF4, SIPA1L2, ANO5, H2BC10, and FAF2) with consistent associations across ancestries or decline phenotypes. Annotation class analysis revealed significant enrichment of several regulatory processes for corticosteroid biosynthesis and metabolism. Drug repurposing analysis identified 43 approved compounds targeting eight of the implicated 38 genes.

Conclusions

Our multi-ancestry GWAS meta-analyses identified numerous genetic loci associated with lung function decline. These findings contribute knowledge to the genetic architecture of lung function decline, provide evidence for a role of endogenous corticosteroids in the etiology of lung function decline, and identify drug targets that merit further study for potential repurposing to slow lung function decline and treat lung disease.

Impact of CYP3A5 Polymorphisms on Pediatric Asthma Outcomes

Genetic variation among inhaled corticosteroid (ICS)-metabolizing enzymes may affect asthma control, but evidence is limited. This study tested the hypothesis that single-nucleotide polymorphisms (SNPs) in Cytochrome P450 3A5 (CYP3A5) would affect asthma outcomes. Patients aged 2-18 years with persistent asthma were recruited to use the electronic AsthmaTracker (e-AT), a self-monitoring tool that records weekly asthma control, medication use, and asthma outcomes. A subset of patients provided saliva samples for SNP analysis and participated in a pharmacokinetic study. Multivariable regression analysis adjusted for age, sex, race, and ethnicity was used to evaluate the impact of CYP3A5 SNPs on asthma outcomes, including asthma control (measured using the asthma symptom tracker, a modified version of the asthma control test or ACT), exacerbations, and hospital admissions. Plasma corticosteroid and cortisol concentrations post-ICS dosing were also assayed using liquid chromatography-tandem mass spectrometry. Of the 751 patients using the e-AT, 166 (22.1%) provided saliva samples and 16 completed the PK study. The e-AT cohort was 65.1% male, and 89.6% White, 6.0% Native Hawaiian, 1.2% Black, 1.2% Native American, 1.8% of unknown race, and 15.7% Hispanic/Latino; the median age was 8.35 (IQR: 5.51-11.3) years. CYP3A5*3/*3 frequency was 75.8% in White subjects, 50% in Native Hawaiians and 76.9% in Hispanic/Latino subjects. Compared with CYP3A5*3/*3, the CYP3A5*1/*x genotype was associated with reduced weekly asthma control (OR: 0.98; 95% CI: 0.97-0.98; p < 0.001), increased exacerbations (OR: 6.43; 95% CI: 4.56-9.07; p < 0.001), and increased asthma hospitalizations (OR: 1.66; 95% CI: 1.43-1.93; p < 0.001); analysis of 3/*3, *1/*1 and *1/*3 separately showed an allelic copy effect. Finally, PK analysis post-ICS dosing suggested muted changes in cortisol concentrations for patients with the CYP3A5*3/*3 genotype, as opposed to an effect on ICS PK. Detection of CYP3A5*3/3, CYPA35*1/*3, and CYP3A5*1/*1 could impact inhaled steroid treatment strategies for asthma in the future.

Stress as a possible cause of a high incidence of hypertension and diabetes and a low incidence of asthma in the Iraqi population

Hypertension and diabetes represent a significant public health burden worldwide and are significant risk factors for heart disease and stroke. Nevertheless, Iraqi people, in particular, experience higher levels of stress due to political instability and economic issues. The study aimed to investigate the prevalence of common morbidities among Iraqi patients and the possible relationship with exposure to stress. The data was collected from patients (n=500) who attended the health center in Najaf, Iraq, between 25 August 2021 and 30 September 2021. The prevalence of hypertension, diabetes, and asthma among Iraqi people was determined along with patients' awareness and control of these conditions. In addition, patients were asked about their experiences with stress, including the type of stress they encountered. Our findings revealed that nearly 47% of patients involved in this study had hypertension, with the highest percentage in patients over 40. Moreover, the incidence of diabetes was 12%, with the highest incidence in the age group of 40-59. The incidence of asthma was lower in all groups. Data analysis concerning exposure to stress demonstrated that about 60% of patients suffer from a stressful life. We found that the incidence of hypertension and diabetes was high while the incidence of asthma was low. This study also reveals that a considerable number of people were unaware of their hypertension and diabetes. Exposure to daily life stress among Iraqi people may play a role in the observed incidence of these morbidities.

Metabolomic profiling reveals extensive adrenal suppression due to inhaled corticosteroid therapy in asthma

The application of large-scale metabolomic profiling provides new opportunities for realizing the potential of omics-based precision medicine for asthma. By leveraging data from over 14,000 individuals in four distinct cohorts, this study identifies and independently replicates 17 steroid metabolites whose levels were significantly reduced in individuals with prevalent asthma. Although steroid levels were reduced among all asthma cases regardless of medication use, the largest reductions were associated with inhaled corticosteroid (ICS) treatment, as confirmed in a 4-year low-dose ICS clinical trial. Effects of ICS treatment on steroid levels were dose dependent; however, significant reductions also occurred with low-dose ICS treatment. Using information from electronic medical records, we found that cortisol levels were substantially reduced throughout the entire 24-hour daily period in patients with asthma who were treated with ICS compared to those who were untreated and to patients without asthma. Moreover, patients with asthma who were treated with ICS showed significant increases in fatigue and anemia as compared to those without ICS treatment. Adrenal suppression in patients with asthma treated with ICS might, therefore, represent a larger public health problem than previously recognized. Regular cortisol monitoring of patients with asthma treated with ICS is needed to provide the optimal balance between minimizing adverse effects of adrenal suppression while capitalizing on the established benefits of ICS treatment.

Wearable aptamer-field-effect transistor sensing system for noninvasive cortisol monitoring

Wearable technologies for personalized monitoring require sensors that track biomarkers often present at low levels. Cortisol—a key stress biomarker—is present in sweat at low nanomolar concentrations. Previous wearable sensing systems are limited to analytes in the micromolar-millimolar ranges. To overcome this and other limitations, we developed a flexible field-effect transistor (FET) biosensor array that exploits a previously unreported cortisol aptamer coupled to nanometer-thin-film In₂O₃ FETs. Cortisol levels were determined via molecular recognition by aptamers where binding was transduced to electrical signals on FETs. The physiological relevance of cortisol as a stress biomarker was demonstrated by tracking salivary cortisol levels in participants in a Trier Social Stress Test and establishing correlations between cortisol in diurnal saliva and sweat samples. These correlations motivated the development and on-body validation of an aptamer-FET array–based smartwatch equipped with a custom, multichannel, self-referencing, and autonomous source measurement unit enabling seamless, real-time cortisol sweat sensing.

Challenges to Identity Integration Indirectly Link Experiences of Heterosexist and Racist Discrimination to Lower Waking Salivary Cortisol in Sexually Diverse Latinx Emerging Adults

Heterosexist and racist discrimination may adversely impact neurobiological processes implicated in the physical and psychosocial well-being of sexually diverse Latinx people. Yet, little is known about how experiences of both heterosexist and racist discrimination are associated with adrenocortical and psychological functioning in groups of people with multiply marginalized social group identities. Through the application of the intersectionality, minority stress, and allostatic load frameworks, it was hypothesized that experiences of heterosexist and racist discrimination would be associated with disruptions to diurnal salivary cortisol patterns and challenges to identity integration. A group of sexually diverse (self-identified lesbian, gay, bisexual, and queer) Latinx emerging adults (N = 51; ages 18-29, M = 24.06 years; SD = 2.73) provided saliva samples and completed a series of questionnaires during a four-day testing protocol. Heterosexist and racist discrimination were both positively associated with challenges to identity integration. Challenges to identity integration, in turn, were associated with lower intercepts of diurnal cortisol slopes, and heterosexist and racist discrimination were indirectly associated with lower cortisol intercepts via challenges to identity integration. These findings suggest that experiences of heterosexist and racist discrimination may interconnect by challenging sexual and ethnic/racial identity integration and disrupting adaptive adrenocortical regulation among sexually diverse Latinx emerging adults.

Association of asthma and sleep insufficiency among South Korean adolescents: analysis of web-based self-reported data from the Korean youth risk behavior web-based survey

Objectives: Weekend oversleep or catch-up sleep is common among adolescents, but relatively few data are available with regard to its effects on asthma. Our aim was to investigate whether weekend oversleep is associated with ever having asthma among Korean adolescents. Methods: We analyzed web-based self-reported data from the Korean Youth Risk Behavior Web-based Survey in 25,927 physician-diagnosed adolescent asthma cases and 266,160 non-asthma cases. Self-report questionnaires were used to assess socioeconomic status, health behaviors, psychological factors and sleep patterns. Multiple logistic regression after adjusting for factors was used to determine the association between sleep and asthma. Results: The asthma group slept less (≤5 hours: 23.9% vs. 22.8%) had a later weekend bedtime (≥1:00 AM: 58.1% vs. 57.8%), and an earlier weekend wake time (≤7:00 AM: 18.1% vs. 17.0%) compared to the non-asthma group. After multiple logistic regression, a sleep duration ≤5 hours (odds ratio (OR), 1.09; 95% confidence interval (CI), 1.04-1.14) and weekend "early bird" (weekend wake time ≤7:00 AM: OR, 1.03; 95% CI, 1.00-1.07) were significantly associated with an increased frequency of asthma. Long weekend catch-up sleep (weekend sleep duration minus weekday sleep duration ≥2 hours) was significantly associated with a decreased frequency of asthma (OR, 0.98; 95% CI, 0.94-0.99). Conclusion: Long weekend catch-up sleep, as an indicator of insufficient weekday sleep, is associated with a decreased frequency of asthma in Korean adolescents.