Genetic ancestry in lung-function predictions

Pediatric pulmonology year in review 2023: Physiology

Application of the principles of pulmonary physiology and lung development to the care and management of respiratory disease in children is a distinguishing feature of pediatric pulmonology. In 2023, this was evident in numerous publications in Pediatric Pulmonology and other journals. This review will highlight some of the papers in this area.

Implications of Race Adjustment in Lung-Function Equations

BACKGROUND

Adjustment for race is discouraged in lung-function testing, but the implications of adopting race-neutral equations have not been comprehensively quantified.

METHODS

We obtained longitudinal data from 369,077 participants in the National Health and Nutrition Examination Survey, U.K. Biobank, the Multi-Ethnic Study of Atherosclerosis, and the Organ Procurement and Transplantation Network. Using these data, we compared the race-based 2012 Global Lung Function Initiative (GLI-2012) equations with race-neutral equations introduced in 2022 (GLI-Global). Evaluated outcomes included national projections of clinical, occupational, and financial reclassifications; individual lung-allocation scores for transplantation priority; and concordance statistics (C statistics) for clinical prediction tasks.

RESULTS

Among the 249 million persons in the United States between 6 and 79 years of age who are able to produce high-quality spirometric results, the use of GLI-Global equations may reclassify ventilatory impairment for 12.5 million persons, medical impairment ratings for 8.16 million, occupational eligibility for 2.28 million, grading of chronic obstructive pulmonary disease for 2.05 million, and military disability compensation for 413,000. These potential changes differed according to race; for example, classifications of nonobstructive ventilatory impairment may change dramatically, increasing 141% (95% confidence interval [CI], 113 to 169) among Black persons and decreasing 69% (95% CI, 63 to 74) among White persons. Annual disability payments may increase by more than $1 billion among Black veterans and decrease by $0.5 billion among White veterans. GLI-2012 and GLI-Global equations had similar discriminative accuracy with regard to respiratory symptoms, health care utilization, new-onset disease, death from any cause, death related to respiratory disease, and death among persons on a transplant waiting list, with differences in C statistics ranging from -0.008 to 0.011.

CONCLUSIONS

The use of race-based and race-neutral equations generated similarly accurate predictions of respiratory outcomes but assigned different disease classifications, occupational eligibility, and disability compensation for millions of persons, with effects diverging according to race. (Funded by the National Heart Lung and Blood Institute and the National Institute of Environmental Health Sciences.).

FEV1Q: a race-neutral approach to assessing lung function

BACKGROUND

Forced expiratory volume in 1 s quotient (FEV1Q) is a simple approach to spirometry interpretation that compares measured lung function to a lower boundary. This study evaluated how well FEV1Q predicts survival compared with current interpretation methods and whether race impacts FEV1Q.

METHODS

White and Black adults with complete spirometry and mortality data from the National Health and Nutrition Examination Survey (NHANES) III and the United Network for Organ Sharing (UNOS) database for lung transplant referrals were included. FEV1Q was calculated as FEV1 divided by 0.4 L for females or 0.5 L for males. Cumulative distributions of FEV1 were compared across races. Cox proportional hazards models tested mortality risk from FEV1Q adjusting for age, sex, height, smoking, income and among UNOS individuals, referral diagnosis. Harrell's C-statistics were compared between absolute FEV1, FEV1Q, FEV1/height2, FEV1 z-scores and FEV1 % predicted. Analyses were stratified by race.

RESULTS

Among 7182 individuals from NHANES III and 7149 from UNOS, 1907 (27%) and 991 (14%), respectively, were Black. The lower boundary FEV1 values did not differ between Black and White individuals in either population (FEV1 first percentile difference ≤0.01 L; p>0.05). Decreasing FEV1Q was associated with increasing hazard ratio (HR) for mortality (NHANES III HR 1.33 (95% CI 1.28-1.39) and UNOS HR 1.18 (95% CI 1.12-1.23)). The associations were not confounded nor modified by race. Discriminative power was highest for FEV1Q compared with alternative FEV1 approaches in both Black and White individuals.

CONCLUSIONS

FEV1Q is an intuitive and simple race-neutral approach to interpreting FEV1 that predicts survival better than current alternative methods.

Association of Preoperative Lung Function with Complications after Lobectomy Using Race-Neutral and Race-Specific Normative Equations

Rationale: Pulmonary function testing (PFT) is performed to aid patient selection before surgical resection for non-small cell lung cancer (NSCLC). The interpretation of PFT data relies on normative equations, which vary by race, but the relative strength of association of lung function using race-specific or race-neutral normative equations with postoperative pulmonary complications is unknown. Objectives: To compare the strength of association of lung function, using race-neutral or race-specific equations, with surgical complications after lobectomy for NSCLC. Methods: We studied 3,311 patients who underwent lobectomy for NSCLC and underwent preoperative PFT from 2001 to 2021. We used Global Lung Function Initiative equations to generate race-specific and race-neutral normative equations to calculate percentage predicted forced expiratory volume in 1 second (FEV1%). The primary outcome of interest was the occurrence of postoperative pulmonary complications within 30 days of surgery. We used unadjusted and race-adjusted logistic regression models and least absolute shrinkage and selection operator analyses adjusted for relevant comorbidities to measure the association of race-specific and race-neutral FEV1% with pulmonary complications. Results: Thirty-one percent of patients who underwent surgery experienced pulmonary complications. Higher FEV1, whether measured with race-neutral (odds ratio [OR], 0.98 per 1% change in FEV1% [95% confidence interval (CI), 0.98-0.99]; P < 0.001) or race-specific (OR, 0.98 per 1% change in FEV1% [95% CI, 0.98-0.98]; P < 0.001) normative equations, was associated with fewer postoperative pulmonary complications. The area under the receiver operator curve for pulmonary complications was similar for race-adjusted race-neutral (0.60) and race-specific (0.60) models. Using least absolute shrinkage and selection operator regression, higher FEV1% was similarly associated with a lower rate of pulmonary complications in race-neutral (OR, 0.99 per 1% [95% CI, 0.98-0.99]) and race-specific (OR, 0.99 per 1%; 95% CI, 0.98-0.99) models. The marginal effect of race on pulmonary complications was attenuated in all race-specific models compared with all race-neutral models. Conclusions: The choice of race-specific or race-neutral normative PFT equations does not meaningfully affect the association of lung function with pulmonary complications after lobectomy for NSCLC, but the use of race-neutral equations unmasks additional effects of self-identified race on pulmonary complications.

Impact of Spirometry Race-Correction on Preadolescent Black and White Children

BACKGROUND

Race-correction for Black patients is standard practice in spirometry testing. History suggests that these corrections are at least partially a result of racist assumptions regarding lung anatomy among Black individuals, which can potentially lead to less frequent diagnoses of pulmonary diseases in this population.

OBJECTIVE

To evaluate the impact of race-correction in spirometry testing among Black and White preadolescents, and examine the frequency of current asthma symptoms in Black children who were differentially classified depending on whether race-corrected or race-uncorrected reference equations were deployed.

METHODS

Data from Black and White children who completed a clinical examination at age 10 years from a Detroit-based unselected birth cohort were analyzed. Global Lung Initiative 2012 reference equations were applied to spirometry data using both race-corrected and race-uncorrected (ie, population-average) equations. Abnormal results were defined as values less than the fifth percentile. Asthma symptoms were assessed concurrently using the International Study of Asthma and Allergies in Childhood questionnaire, while asthma control was assessed using the Asthma Control Test.

RESULTS

The impact of race-correction on forced expiratory volume in 1 second (FEV1)/forced vital capacity ratio was minimal, but abnormal classification of FEV1 results more than doubled among Black children when race-uncorrected equations were used (7% vs 18.1%) and were almost 8 times greater based on forced vital capacity classification (1.5% vs 11.4%). More than half of Black children differentially classified on FEV1 (whose FEV1 was classified as normal with race-corrected equations but abnormal with race-uncorrected equations) experienced asthma symptoms in the past 12 months (52.6%), which was significantly higher than the percentage of Black children consistently classified as normal (35.5%, P = .049), but similar to that of Black children consistently classified as abnormal using both race-corrected and race-uncorrected equations (62.5%, P = .60). Asthma Control Test scores were not different based on classification.

CONCLUSIONS

Race-correction had an extensive impact on spirometry classification in Black children, and differentially classified children had a higher rate of asthma symptoms than children consistently classified as normal. Spirometry reference equations should be reevaluated to be aligned with current scientific perspectives on the use of race in medicine.

Asthma and Chronic Obstructive Pulmonary Disease

In the United States, asthma and chronic obstructive pulmonary disease (COPD) disproportionately affect African Americans, Puerto Ricans, and other minority groups. Compared with non-Hispanic whites, minorities have been marginalized and more frequently exposed to environmental risk factors such as tobacco smoke and outdoor and indoor pollutants. Such divergent environmental exposures, alone or interacting with heredity, lead to disparities in the prevalence, morbidity, and mortality of asthma and COPD, which are worsened by lack of access to health care. In this article, we review the burden and risk factors for racial or ethnic disparities in asthma and COPD and discuss future directions in this field.

Immunogenetics and pharmacogenetics of allergic asthma in Africa

Asthma is a common chronic condition in children and in an African setting is often highly prevalent in urban areas as compared to rural areas. Asthma is a heritable disease and the genetic risk is often exacerbated by unique localised environmental factors. The Global Initiative for Asthma (GINA) recommendation for the control of asthma includes inhaled corticosteroids (ICS) alone or together with short-acting β₂-agonists (SABA) or long-acting β₂-agonists (LABA). While these drugs can relieve asthma symptoms, there is evidence of reduced efficacy in people of African ancestry. Whether this is due to immunogenetics, genomic variability in drug metabolising genes (pharmacogenetics) or genetics of asthma-related traits is not well defined. Pharmacogenetic evidence of first-line asthma drugs in people of African ancestry is lacking and is further compounded by the lack of representative genetic association studies in the continent. In this review, we will discuss the paucity of data related to the pharmacogenetics of asthma drugs in people of African ancestry, mainly drawing from African American data. We will further discuss how this gap can be bridged to improve asthma health outcomes in Africa.

A Race-neutral Approach to the Interpretation of Lung Function Measurements

Rationale: The use of self-reported race and ethnicity to interpret lung function measurements has historically assumed that the observed differences in lung function between racial and ethnic groups were because of thoracic cavity size differences relative to standing height. Very few studies have considered the influence of environmental and social determinants on pulmonary function. Consequently, the use of race and ethnicity-specific reference equations may further marginalize disadvantaged populations. Objectives: To develop a race-neutral reference equation for spirometry interpretation. Methods: National Health and Nutrition Examination Survey (NHANES) III data (n = 6,984) were reanalyzed with sitting height and the Cormic index to investigate whether body proportions were better predictors of lung function than race and ethnicity. Furthermore, the original GLI (Global Lung Function Initiative) data (n = 74,185) were reanalyzed with inverse-probability weights to create race-neutral GLI global (2022) equations. Measurements and Main Results: The inclusion of sitting height slightly improved the statistical precision of reference equations compared with using standing height alone but did not explain observed differences in spirometry between the NHANES III race and ethnic groups. GLI global (2022) equations, which do not require the selection of race and ethnicity, had a similar fit to the GLI 2012 "other" equations and wider limits of normal. Conclusions: The use of a single global spirometry equation reflects the wide range of lung function observed within and between populations. Given the inherent limitations of any reference equation, the use of GLI global equations to interpret spirometry requires careful consideration of an individual's symptoms and medical history when used to make clinical, employment, and insurance decisions.

Change Management Strategies Towards Dismantling Race-Based Structural Barriers in Radiology

Political momentum for antiracist policies grew out of the collective trauma highlighted during the COVID pandemic. This prompted discussions of root cause analyses for differences in health outcomes among historically underserved populations, including racial and ethnic minorities. Dismantling structural racism in medicine is an ambitious goal that requires widespread buy-in and transdisciplinary collaborations across institutions to establish systematic, rigorous approaches that enable sustainable change. Radiology is at the center of medical care and renewed focus on equity, diversity, and inclusion (EDI) provides an opportune window for radiologists to facilitate an open forum to address racialized medicine to catalyze real and lasting change. The framework of change management can help radiology practices create and maintain this change while minimizing disruption. This article discusses how change management principles can be leveraged by radiology to lead EDI interventions that will encourage honest dialogue, serve as a platform to support institutional EDI efforts, and lead to systemic change.

Ancestry-driven recalibration of tumor mutational burden and disparate clinical outcomes in response to immune checkpoint inhibitors

The immune checkpoint inhibitor (ICI) pembrolizumab is US FDA approved for treatment of solid tumors with high tumor mutational burden (TMB-high; ≥10 variants/Mb). However, the extent to which TMB-high generalizes as an accurate biomarker in diverse patient populations is largely unknown. Using two clinical cohorts, we investigated the interplay between genetic ancestry, TMB, and tumor-only versus tumor-normal paired sequencing in solid tumors. TMB estimates from tumor-only panels substantially overclassified individuals into the clinically important TMB-high group due to germline contamination, and this bias was particularly pronounced in patients with Asian/African ancestry. Among patients with non-small cell lung cancer treated with ICIs, those misclassified as TMB-high from tumor-only panels did not associate with improved outcomes. TMB-high was significantly associated with improved outcomes only in European ancestries and merits validation in non-European ancestry populations. Ancestry-aware tumor-only TMB calibration and ancestry-diverse biomarker studies are critical to ensure that existing disparities are not exacerbated in precision medicine.

Developing CIRdb as a catalog of natural genetic variation in the Canary Islanders

The current inhabitants of the Canary Islands have a unique genetic makeup in the European diversity landscape due to the existence of African footprints from recent admixture events, especially of North African components (> 20%). The underrepresentation of non-Europeans in genetic studies and the sizable North African ancestry, which is nearly absent from all existing catalogs of worldwide genetic diversity, justify the need to develop CIRdb, a population-specific reference catalog of natural genetic variation in the Canary Islanders. Based on array genotyping of the selected unrelated donors and comparisons against available datasets from European, sub-Saharan, and North African populations, we illustrate the intermediate genetic differentiation of Canary Islanders between Europeans and North Africans and the existence of within-population differences that are likely driven by genetic isolation. Here we describe the overall design and the methods that are being implemented to further develop CIRdb. This resource will help to strengthen the implementation of Precision Medicine in this population by contributing to increase the diversity in genetic studies. Among others, this will translate into improved ability to fine map disease genes and simplify the identification of causal variants and estimate the prevalence of unattended Mendelian diseases.

Race- and Ethnicity-Based Spirometry Reference Equations: Are They Accurate for Genetically Admixed Children?

BACKGROUND

Variation in genetic ancestry among genetically admixed racial and ethnic groups may influence the fit of guideline-recommended spirometry reference equations, which rely on self-identified race and ethnicity.

RESEARCH QUESTION

What is the influence of genetic ancestry on the fit of race- and ethnicity-based spirometry reference equations in populations of genetically admixed children?

STUDY DESIGN AND METHODS

Cross-sectional fit of guideline-recommended race- and ethnicity-based spirometry reference equations was evaluated in healthy control participants from case-control studies of asthma. Anthropometry, blood samples, and spirometric measurements were obtained for 599 genetically admixed children 8 to 21 years of age. Genetic ancestry was estimated using genome-wide genotype data. Equation fit, measured as a mean z score, was assessed in self-identified African American (n = 275) and Puerto Rican (n = 324) children as well as genetic ancestry-defined strata of each population.

RESULTS

For African American children, African American-derived equations fit for predicting FEV₁ and FVC in those with an African ancestry more than the median (81.4%-100.0%), whereas composite equations for "other/mixed" populations fit for predicting FEV₁ and FVC in those with African ancestry at or less than the median (30.7%-81.3%). For Puerto Rican children with African ancestry at or less than the median (6.4%-21.3%), White-derived equations fit both FEV₁ and FVC, whereas for those with African ancestry more than the median (21.4%-87.5%), White-derived equations fit the FEV₁ and the composite equations fit the FVC.

INTERPRETATION

Guideline-recommended spirometry reference equations yielded biased estimates of lung function in genetically admixed children with high variation of African ancestry. Spirometry could benefit from reference equations that incorporate genetic ancestry, either for more precise application of the current equations or the derivation and use of new equations.

Higher native Peruvian genetic ancestry proportion is associated with tuberculosis progression risk

We investigated whether ancestry-specific genetic factors affect tuberculosis (TB) progression risk in a cohort of admixed Peruvians. We genotyped 2,105 patients with TB and 1,320 household contacts (HHCs) who were infected with Mycobacterium tuberculosis (M. tb) but did not develop TB and inferred each individual’s proportion of native Peruvian genetic ancestry. Our HHC study design and our data on potential confounders allowed us to demonstrate increased risk independent of socioeconomic factors. A 10% increase in individual-level native Peruvian genetic ancestry proportion corresponded to a 25% increased TB progression risk. This corresponds to a 3-fold increased risk for individuals in the highest decile of native Peruvian genetic ancestry versus the lowest decile, making native Peruvian genetic ancestry comparable in effect to clinical factors such as diabetes. Our results suggest that genetic ancestry is a major contributor to TB progression risk and highlight the value of including diverse populations in host genetic studies.

Our understanding of how genetic differences among human populations may affect susceptibility to infectious diseases is very limited. Asgari et al. show that the proportion of native genetic ancestry in contemporary Peruvians affects the risk of progression from latent to active tuberculosis even after accounting for differences in socio-demographic factors.

Differences in the Spirometry Parameters Between Indigenous and Non-Indigenous Patients with COPD: A Matched Control Study

Background

Comparison of spirometry parameters between Indigenous and non-Indigenous patients with underlying chronic obstructive pulmonary disease (COPD) has been sparsely reported in the past. In this study, differences in the lung function parameters (LFPs), in particular spirometry values for forced vital capacity (FVC), forced expiratory volume in one second (FEV₁) and FEV₁/FVC ratio between Indigenous and non-Indigenous patients with COPD were assessed.

Methods

In this retrospective study, Indigenous and non-Indigenous patients with a diagnosis of COPD between 2012-2020 according to spirometry criteria (ie; post-bronchodilator (BD) FEV₁/FVC < 0.7) were included. A further analysis was undertaken to compare the differences in the spirometry parameters, including lower limit of normal (LLN) values matching for age, sex, height and smoking status between these two diverse ethnic populations.

Results

A total of 240/742 (32%) Indigenous and 873/4579 (19%) non-Indigenous patients were identified to fit the criteria for COPD. Indigenous patients were significantly younger (mean difference 9.9 years), with a greater proportion of females (50% vs 33%), underweight (20% vs 8%) and current smokers (47% vs 32%). Prior to matching, Indigenous patients' post-BD percent predicted values for FVC, FEV₁, and FEV₁/FVC ratio were 17, 17%, and -2 points lower (Hedges G measure of effect size large (0.91), large (0.87), and small (0.25), respectively). Among the matched cohort (111 Indigenous and non-Indigenous), Indigenous patients LFPs remained significantly lower, with a mean difference of 16%, 16%, and -4, respectively (Hedges G large (0.94), large (0.92) and small (0.41), respectively). The differences persisted despite no significant differences in LLN values for these parameters.

Conclusion

Indigenous Australian patients with COPD display a significantly different demographic and clinical profile than non-Indigenous patients. LFPs were significantly lower, which may or may not equate to greater severity of disease in the absence of normative predictive lung function reference values specific to this population.

Society for Maternal-Fetal Medicine Consult Series #62: Best practices in equitable care delivery-Addressing systemic racism and other social determinants of health as causes of obstetrical disparities

The Centers for Disease Control and Prevention define social determinants of health as "the conditions in the places where people live, learn, work, and play" that can affect health outcomes. Systemic racism is a root cause of the power and wealth imbalances that affect social determinants of health, creating disproportionate rates of comorbidities and adverse outcomes in the communities of racial and ethnic minority groups. Focusing primarily on disparities between Black and White individuals born in the United States, this document reviews the effects of social determinants of health and systemic racism on reproductive health outcomes and recommends multilevel approaches to mitigate disparities in obstetrical outcomes.

Deconstructing the Way We Use Pulmonary Function Test Race-Based Adjustments

Race is a social construct. It is used in medical diagnostic algorithms to adjust the readout for spirometry and other diagnostic tests. The authors review historic evidence about the origins of race adjustment in spirometry, and recent attention to the lack of scientific evidence for their continued use. Existing reference values imply that White patients have better lung function than non-White patients. They perpetuate the historical assumptions that human biological functions of the lung should be calculated differently on the basis of racial-skin color without considering the difficulty of using self-identified race. More importantly, they fail to consider the important effects of environmental exposures, socioeconomic differences, health care access, and prenatal factors on lung function. In addition, the use of "race adjustment" implies a White standard to which other non-White values need "adjustment." Because of the spirometric guidelines in place, the current diagnostic prediction adjustment practice may have untoward effects on patients not categorized as "White," including underdiagnosis in asthma and restrictive lung disease, undertreatment with lung transplant, undercompensation in workers compensation cases, and other unintended consequences. Individuals, institutions, national organizations, and policymakers should carefully consider the historic basis, and reconsider the current role of an automated, race-based adjustment in spirometry.

Reconsidering the Utility of Race-Specific Lung Function Prediction Equations

Rationale: African American individuals have worse outcomes in chronic obstructive pulmonary disease (COPD). Objectives: To assess whether race-specific approaches for estimating lung function contribute to racial inequities by failing to recognize pathological decrements and considering them normal. Methods: In a cohort with and at risk for COPD, we assessed whether lung function prediction equations applied in a race-specific versus universal manner better modeled the relationship between FEV1, FVC, and other COPD outcomes, including the COPD Assessment Test, St. George's Respiratory Questionnaire, computed tomography percent emphysema, airway wall thickness, and 6-minute-walk test. We related these outcomes to differences in FEV1 using multiple linear regression and compared predictive performance between fitted models using root mean squared error and Alpaydin's paired F test. Measurements and Main Results: Using race-specific equations, African American individuals were calculated to have better lung function than non-Hispanic White individuals (FEV1, 76.8% vs. 71.8% predicted; P = 0.02). Using universally applied equations, African American individuals were calculated to have worse lung function. Using Hankinson's Non-Hispanic White equation, FEV1 was 64.7% versus 71.8% (P < 0.001). Using the Global Lung Initiative's Other race equation, FEV1 was 70.0% versus 77.9% (P < 0.001). Prediction errors from linear regression were less for universally applied equations compared with race-specific equations when examining FEV1% predicted with the COPD Assessment Test (P < 0.01), St. George's Respiratory Questionnaire (P < 0.01), and airway wall thickness (P < 0.01). Although African American participants had greater adversity (P < 0.001), less adversity was only associated with better FEV1 in non-Hispanic White participants (P for interaction = 0.041). Conclusions: Race-specific equations may underestimate COPD severity in African American individuals.Clinical trial registered with www.clinicaltrials.gov (NCT01969344).

Sex, ancestry, senescence, and aging (SAnSA) are stark drivers of nontuberculous mycobacterial pulmonary disease

Nontuberculous mycobacterial (NTM) pulmonary disease (PD) disproportionately affects otherwise healthy, older, Caucasian females. The reasons behind this are likely multifactorial involving several conspiring factors. A variety of factors are thought to contribute to increased susceptibility to NTM in the older adult including exposure to various environmental conditions and contaminants across the lifespan, genetic risk factors, hormonal changes, and immunodeficiency. Independent of sex and ancestry, respiratory muscle atrophy intensifies with age and an aging immune system can show functional decline of macrophages, poor lung migration and homing of dendritic cells, promotion of aberrant pro-inflammatory responses, acceleration of inflammation related to aging, and increased immunosenescence. The purpose of this review is to synthesize the current body of knowledge regarding the roles of sex, ancestry, senescence, and aging (SAnSA) in NTM acquisition and the possible mechanisms involved in NTM PD, highlighting age-related respiratory and immune system changes. We also summarize molecular tools and biomarkers of these fields and contextualize these into the study of NTM PD. Finally, we discuss the relevance of biomarkers described for senescence and aging and senolytic therapies as potentially new adjunctive strategies to reduce the burden of NTM PD.

Research race-specific reference values and lung function impairment, breathlessness and prognosis: Analysis of NHANES 2007-2012

BACKGROUND

Spirometry reference values differ by race/ethnicity, which is controversial. We evaluated the effect of race-specific references on prevalence of lung function impairment and its relation to breathlessness and mortality in the US population.

METHODS

Population-based analysis of the National Health and Nutrition Examination Survey (NHANES) 2007-2012. Race/ethnicity was analyzed as black, white, or other. Reference values for forced expiratory volume in one second (FEV₁) and forced vital capacity (FVC) were calculated for each person using the Global Lung Initiative (GLI)-2012 equations for (1) white; (2) black; and (3) other/mixed people. Outcomes were prevalence of lung function impairment (< lower limit of normal [LLN]), moderate/severe impairment (< 50%pred); exertional breathlessness; and mortality until 31 December, 2015.

RESULTS

We studied 14,123 people (50% female). Compared to those for white, black reference values identified markedly fewer cases of lung function impairment (FEV₁) both in black people (9.3% vs. 36.9%) and other non-white (1.5% vs. 9.5%); and prevalence of moderate/severe impairment was approximately halved. Outcomes by impairment differed by reference used: white (best), other/mixed (intermediate), and black (worst outcomes). Black people with FEV₁ ≥ LLN_black but < LLN_white had 48% increased rate of breathlessness and almost doubled mortality, compared to blacks ≥ LLN_white. White references identified people with good outcomes similarly in black and white people. Findings were similar for FEV₁ and FVC.

CONCLUSION

Compared to using a common reference (for white) across the population, race-specific spirometry references did not improve prediction of breathlessness and prognosis, and may misclassify lung function as normal despite worse outcomes in black people.

The Impact of an Electronic Health Record Intervention on Spirometry Completion in Patients with Chronic Obstructive Pulmonary Disease

Spirometry is necessary to diagnose chronic obstructive pulmonary disease (COPD), yet a large proportion of patients are diagnosed and treated without having received testing. This study explored whether the effects of interventions using the electronic health record (EHR) to target patients diagnosed with COPD without confirmatory spirometry impacted the incidence rates of spirometry referrals and completions. This retrospective before and after study assessed the impact of provider-facing clinical decision support that identified patients who had a diagnosis of COPD but had not received spirometry. Spirometry referrals, completions, and results were ascertained 1.5 years prior to and 1.5 years after the interventions were initiated. Inhaler prescriptions by class were also tallied. There were 10,949 unique patients with a diagnosis of COPD who were eligible for inclusion. 4,895 patients (44.7%) were excluded because they had completed spirometry prior to the cohort start dates. The pre-intervention cohort consisted of 2,622 patients, while the post-intervention cohort had 3,392. Spirometry referral rates pre-intervention were 20.2% compared to 31.6% post-intervention (p < 0.001). Spirometry completion rates rose from 13.2% pre-intervention to 19.3% afterwards (p < 0.001). 61.7% (585 of 948) had no evidence of airflow obstruction. After excluding patients with a diagnosis of asthma, 25.8% (126 of 488) patients who had no evidence of airflow obstruction had prescriptions for long-acting bronchodilators or inhaled steroids. A concerted EHR intervention modestly increased spirometry referral and completion rates in patients with a diagnosis of COPD without prior spirometry and decreased misclassification of disease.

Exploring the 175-year history of spirometry and the vital lessons it can teach us today

175 years have elapsed since John Hutchinson introduced the world to his version of an apparatus that had been in development for nearly two centuries, the spirometer. Though he was not the first to build a device that sought to measure breathing and quantify the impact of disease and occupation on lung function, Hutchison coined the terms spirometer and vital capacity that are still in use today, securing his place in medical history. As Hutchinson envisioned, spirometry would become crucial to our growing knowledge of respiratory pathophysiology, from Tiffeneau and Pinelli's work on forced expiratory volumes, to Fry and Hyatt's description of the flow-volume curve. In the 20th century, standardization of spirometry further broadened its reach and prognostic potential. Today, spirometry is recognized as essential to respiratory disease diagnosis, management and research. However, controversy exists in some of its applications, uptake in primary care remains sub-optimal and there are concerns related to the way in which race is factored into interpretation. Moving forward, these failings must be addressed, and innovations like Internet-enabled portable spirometers may present novel opportunities. We must also consider the physiologic and practical limitations inherent to spirometry and further investigate complementary technologies such as respiratory oscillometry and other emerging technologies that assess lung function. Through an exploration of the storied history of spirometry, we can better contextualize its current landscape and appreciate the trends that have repeatedly arisen over time. This may help to improve our current use of spirometry and may allow us to anticipate the obstacles confronting emerging pulmonary function technologies.

Race/Ethnicity, Spirometry Reference Equations and Prediction of Incident Clinical Events: The Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study

RATIONALE

Normal values for forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) are currently calculated using cross-sectional reference equations that include terms for race/ethnicity, an approach that may reinforce disparities and is of unclear clinical benefit.

OBJECTIVES

To determine whether race/ethnic-based spirometry reference equations improve the prediction of incident chronic lower respiratory disease (CLRD) events and mortality compared to race/ethnic-neutral equations.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study, a population-based, prospective cohort study of White, Black, Hispanic, and Asian adults, performed standardized spirometry in 2004-06. Predicted values for spirometry were calculated using race/ethnic-based equations following guidelines and, alternatively, race/ethnic-neutral equations without terms for race/ethnicity. Participants were followed for events through 2019.

MEASUREMENTS AND MAIN RESULTS

The mean age of 3,344 participants was 65 years and self-reported race/ethnicity was 36% White, 25% Black, 23% Hispanic, and 17% Asian. There were 181 incident CLRD-related events and 547 deaths over a median of 11.6 years. There was no evidence that percent-predicted FEV1 or FVC calculated by race/ethnic-based equations improved the prediction of CLRD-related events compared to that calculated by race/ethnic-neutral equations (difference in C-statistics -0.005, 95% CI -0.013, 0.003, and -0.008, 95% CI -0.016, -0.0006, respectively). Findings were similar for mortality (difference in C-statistics -0.002, 95% CI -0.008, 0.003, and -0.004, 95% CI -0.009, 0.001, respectively).

CONCLUSIONS

There was no evidence that race/ethnic-based spirometry reference equations improved the prediction of clinical events compared to race/ethnic-neutral equations. The inclusion of race/ethnicity in spirometry reference equations should be reconsidered.

Association Between Preserved Ratio Impaired Spirometry and Clinical Outcomes in US Adults

Importance

Chronic lung diseases are a leading cause of morbidity and mortality. Unlike chronic obstructive pulmonary disease, clinical outcomes associated with proportional reductions in expiratory lung volumes without obstruction, otherwise known as preserved ratio impaired spirometry (PRISm), are poorly understood.

Objective

To examine the prevalence, correlates, and clinical outcomes associated with PRISm in US adults.

Design, Setting, and Participants

The National Heart, Lung, and Blood Institute (NHLBI) Pooled Cohorts Study was a retrospective study with harmonized pooled data from 9 US general population-based cohorts (enrollment, 65 251 participants aged 18 to 102 years of whom 53 701 participants had valid baseline lung function) conducted from 1971-2011 (final follow-up, December 2018).

Exposures

Participants were categorized into mutually exclusive groups by baseline lung function. PRISm was defined as the ratio of forced expiratory volume in the first second to forced vital capacity (FEV1:FVC) greater than or equal to 0.70 and FEV1 less than 80% predicted; obstructive spirometry FEV1:FVC ratio of less than 0.70; and normal spirometry FEV1:FVC ratio greater than or equal to 0.7 and FEV1 greater than or equal to 80% predicted.

Main Outcomes and Measures

Main outcomes were all-cause mortality, respiratory-related mortality, coronary heart disease (CHD)-related mortality, respiratory-related events (hospitalizations and mortality), and CHD-related events (hospitalizations and mortality) classified by adjudication or validated administrative criteria. Absolute risks were adjusted for age and smoking status. Poisson and Cox proportional hazards models comparing PRISm vs normal spirometry were adjusted for age, sex, race and ethnicity, education, body mass index, smoking status, cohort, and comorbidities.

Results

Among all participants (mean [SD] age, 53.2 [15.8] years, 56.4% women, 48.5% never-smokers), 4582 (8.5%) had PRISm. The presence of PRISm relative to normal spirometry was significantly associated with obesity (prevalence, 48.3% vs 31.4%; prevalence ratio [PR], 1.68 [95% CI, 1.55-1.82]), underweight (prevalence, 1.4% vs 1.0%; PR, 2.20 [95% CI, 1.72-2.82]), female sex (prevalence, 60.3% vs 59.0%; PR, 1.07 [95% CI, 1.01-1.13]), and current smoking (prevalence, 25.2% vs 17.5%; PR, 1.33 [95% CI, 1.22-1.45]). PRISm, compared with normal spirometry, was significantly associated with greater all-cause mortality (29.6/1000 person-years vs 18.0/1000 person-years; difference, 11.6/1000 person-years [95% CI, 10.0-13.1]; adjusted hazard ratio [HR], 1.50 [95% CI, 1.42-1.59]), respiratory-related mortality (2.1/1000 person-years vs 1.0/1000 person-years; difference, 1.1/1000 person-years [95% CI, 0.7-1.6]; adjusted HR, 1.95 [95% CI, 1.54-2.48]), CHD-related mortality (5.4/1000 person-years vs 2.6/1000 person-years; difference, 2.7/1000 person-years [95% CI, 2.1-3.4]; adjusted HR, 1.55 [95% CI, 1.36-1.77]), respiratory-related events (12.2/1000 person-years vs 6.0/1000 person-years; difference, 6.2/1000 person-years [95% CI, 4.9-7.5]; adjusted HR, 1.90 [95% CI, 1.69-2.14]), and CHD-related events (11.7/1000 person-years vs 7.0/1000 person-years; difference, 4.7/1000 person-years [95% CI, 3.7-5.8]; adjusted HR, 1.30 [95% CI, 1.18-1.42]).

Conclusions and Relevance

In a large, population-based sample of US adults, baseline PRISm, compared with normal spirometry, was associated with a small but statistically significant increased risk for mortality and adverse cardiovascular and respiratory outcomes. Further research is needed to explore whether this association is causal.

Pharmacogenetic studies of long-acting beta agonist and inhaled corticosteroid responsiveness in randomised controlled trials of individuals of African descent with asthma

BACKGROUND

Pharmacogenetic studies in asthma cohorts, primarily made up of White people of European descent, have identified loci associated with response to inhaled beta agonists and corticosteroids (ICSs). Differences exist in how individuals from different ancestral backgrounds respond to long-acting beta agonist (LABA) and ICSs. Therefore, we sought to understand the pharmacogenetic mechanisms regulating therapeutic responsiveness in individuals of African descent.

METHODS

We did ancestry-based pharmacogenetic studies of children (aged 5-11 years) and adolescents and adults (aged 12-69 years) from the Best African Response to Drug (BARD) trials, in which participants with asthma uncontrolled with low-dose ICS (fluticasone propionate 50 μg in children, 100 μg in adolescents and adults) received different step-up combination therapies. The hierarchal composite outcome of pairwise superior responsiveness in BARD was based on asthma exacerbations, a 31-day difference in annualised asthma-control days, or a 5% difference in percentage predicted FEV1. We did whole-genome admixture mapping of 15 159 ancestral segments within 312 independent regions, stratified by the two age groups. The two co-primary outcome comparisons were the step up from low-dose ICS to the quintuple dose of ICS (5 × ICS: 250 μg twice daily in children and 500 μg twice daily in adolescents and adults) versus double dose (2-2·5 × ICS: 100 μg twice daily in children, 250 μg twice daily in adolescents and adults), and 5 × ICS versus 100 μg fluticasone plus a LABA (salmeterol 50 μg twice daily). We used a genome-wide significance threshold of p<1·6 × 10-4, and tested for replication using independent cohorts of individuals of African descent with asthma.

FINDINGS

We included 249 unrelated children and 267 unrelated adolescents and adults in the BARD pharmacogenetic analysis. In children, we identified a significant admixture mapping peak for superior responsiveness to 5 × ICS versus 100 μg fluticasone plus salmeterol on chromosome 12 (odds ratio [ORlocal African] 3·95, 95% CI 2·02-7·72, p=6·1 × 10-5) fine mapped to a locus adjacent to RNFT2 and NOS1 (rs73399224, ORallele dose 0·17, 95% CI 0·07-0·42, p=8·4 × 10-5). In adolescents and adults, we identified a peak for superior responsiveness to 5 × ICS versus 2·5 × ICS on chromosome 22 (ORlocal African 3·35, 1·98-5·67, p=6·8 × 10-6) containing a locus adjacent to TPST2 (rs5752429, ORallele dose 0·21, 0·09-0·52, p=5·7 × 10-4). We replicated rs5752429 and nominally replicated rs73399224 in independent African American cohorts.

INTERPRETATION

BARD is the first genome-wide pharmacogenetic study of LABA and ICS response in clinical trials of individuals of African descent to detect and replicate genome-wide significant loci. Admixture mapping of the composite BARD trial outcome enabled the identification of novel pharmacogenetic variation accounting for differential therapeutic responses in people of African descent with asthma.

FUNDING

National Institutes of Health, National Heart, Lung, and Blood Institute.

An Overview of Health Disparities in Asthma

Asthma is a heterogeneous disease characterized by inflammation in the respiratory airways which manifests clinically with wheezing, cough, and episodic periods of chest tightness; if left untreated it can lead to permanent obstruction or death. In the US, asthma affects all ages and genders, and individuals from racial and ethnic minority groups are disproportionately burdened by this disease. The financial cost of asthma exceeds $81 billion every year and despite all the resources invested, asthma is responsible for over 3,500 deaths annually in the nation. In this overview, we highlight important factors associated with health disparities in asthma. While they are complex and overlap, we group these factors in five domains: biological, behavioral, socio-cultural, built environment, and health systems. We review the biological domain in detail, which traditionally has been best studied. We also acknowledge that implicit and explicit racism is an important contributor to asthma disparities and responsible for many of the socio-environmental factors that worsen outcomes in this disease.

Prognostic implications of differences in forced vital capacity in black and white US adults: Findings from NHANES III with long-term mortality follow-up

BACKGROUND

Because Forced Vital Capacity (FVC) is reduced in Black relative to White Americans of the same age, sex, and height, standard lung function prediction equations assign a lower "normal" range for Black patients. The prognostic implications of this race correction are uncertain.

METHODS

We analyzed 5,294 White and 3,743 Black participants age 20-80 in NHANES III, a nationally-representative US survey conducted 1988-94, which we linked to the National Death Index to assess mortality through December 31, 2015. We calculated the FVC-percent predicted among Black and White participants, first applying NHANES III White prediction equations to all persons, and then using standard race-specific prediction equations. We used Cox proportional hazard models to calculate the association between race and all-cause mortality without and with adjustment for FVC (using each FVC metric), smoking, socioeconomic factors, and comorbidities.

FINDINGS

Black participants' age- and sex-adjusted mortality was greater than White participants (HR 1.46; 95%CI:1.29, 1.65). With adjustment for FVC in liters (mean 3.7 L for Black participants, 4.3 L for White participants) or FVC percent-predicted using White equations for everyone, Black race was no longer independently predictive of higher mortality (HR∼1.0). When FVC-percent predicted was "corrected" for race, Black individuals again showed increased mortality hazard. Deaths attributed to chronic respiratory disease were infrequent for both Black and White individuals.

INTERPRETATION

Lower FVC in Black people is associated with elevated risk of all-cause mortality, challenging the standard assumption about race-based normal limits. Black-White disparities in FVC may reflect deleterious social/environmental exposures, not innate differences.

FUNDING

No funding.

Addressing Race in Pulmonary Function Testing by Aligning Intent and Evidence With Practice and Perception

The practice of using race or ethnicity in medicine to explain differences between individuals is being called into question because it may contribute to biased medical care and research that perpetuates health disparities and structural racism. A commonly cited example is the use of race or ethnicity in the interpretation of pulmonary function test (PFT) results, yet the perspectives of practicing pulmonologists and physiologists are missing from this discussion. This discussion has global relevance for increasingly multicultural communities in which the range of values that represent normal lung function is uncertain. We review the underlying sources of differences in lung function, including those that may be captured by race or ethnicity, and demonstrate how the current practice of PFT measurement and interpretation is imperfect in its ability to describe accurately the relationship between function and health outcomes. We summarize the arguments against using race-specific equations as well as address concerns about removing race from the interpretation of PFT results. Further, we outline knowledge gaps and critical questions that need to be answered to change the current approach of including race or ethnicity in PFT results interpretation thoughtfully. Finally, we propose changes in interpretation strategies and future research to reduce health disparities.

Pediatric pulmonology year in review 2020: Physiology

Pulmonary physiology is a core element of pediatric pulmonology care and research. This article reviews some of the notable publications in physiology that were published in Pediatric Pulmonology in 2020.

Genetic ancestry differences in pediatric asthma readmission are mediated by socioenvironmental factors

BACKGROUND

Social and financial hardships, combined with disease managment and environmental factors explain approximately 80% of the observed disparity in asthma-related readmissions between Black and White children.

OBJECTIVE

We sought to determine whether asthma-related readmissions differed by degree of African ancestry and the extent to which such an association would also be explained by socioenvironmental risk factors.

METHODS

This study used data from a prospective cohort study of 695 Black and White children aged 1 to 16 years with an asthma-related admission. The primary outcome was a similar readmission within 12 months. Each subject's African ancestry was determined by single nucleotide polymorphisms on a continuous scale ranging from 0 to 1 (0 = no African ancestry; 1 = 100% African ancestry). We also assessed 37 social, environmental, and clinical variables that we clustered into 6 domains (for example, hardship, disease management). Survival and mediation analyses were conducted.

RESULTS

A total of 134 children (19.3%) were readmitted within 12 months. Higher African ancestry was associated with asthma readmission (odds ratio 1.11, 95% confidence interval 1.05-1.18 for every 10% increase in African ancestry) with adjustment for age and gender. The association between African ancestry and readmission was mediated by hardship (sβ = 3.42, P < .001) and disease management (sβ = 0.046, P = .001), accounting for >50% of African ancestry's effect on readmission. African ancestry was no longer significantly associated with readmission (sβ = 0.035, P = .388) after accounting for these mediators.

CONCLUSIONS

African ancestry was strongly associated with readmission, and the association was mediated by family hardship and disease management. These results are consistent with the notion that asthma-related racial disparities are driven by factors like structural racism and social adversity.

Cystic fibrosis patients of minority race and ethnicity less likely eligible for CFTR modulators based on CFTR genotype

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators are disease-modifying medications for cystic fibrosis (CF) and are shown to be efficacious for only specific CFTR mutations. CFTR mutation frequency varies by ancestry, which is different from but related to demographic racial and ethnic group. Eligibility for CFTR modulator therapy has not been previously reported by race and ethnicity.

METHODS

We conducted a cross-sectional study of patients in the 2018 CF Foundation Patient Registry. We analyzed the percentage of patients in each US Census defined racial and ethnic group eligible for CFTR modulators based on CFTR mutations approved by the US FDA and then based on both mutations and FDA approval by age. We compared lung function based on CFTR modulator eligibility and prescription.

FINDINGS

Based on CFTR mutations alone, 92.4% of non-Hispanic White patients, 69.7% of Black/African American patients, 75.6% of Hispanic patients, and 80.5% of other race patients eligible for CFTR modulators. For each CFTR modulator, Black/African American patients were least likely to have eligible mutations, and non-Hispanic White patients were most likely. There was no difference in the disparity between racial and/or ethnic groups with the addition of current FDA approval by age. The lowest pulmonary function in the cohort was seen in non-Hispanic White, Black/African American, and Hispanic patients not eligible for CFTR modulators.

INTERPRETATION

Patients with CF from minority groups are less likely to be eligible for CFTR modulators. Because people with CF who are racial and ethnic minorities have increased disease severity and earlier mortality, this will further contribute to health disparities.

Integrative genomic analysis in African American children with asthma finds three novel loci associated with lung function

Bronchodilator (BD) drugs are commonly prescribed for treatment and management of obstructive lung function present with diseases such as asthma. Administration of BD medication can partially or fully restore lung function as measured by pulmonary function tests. The genetics of baseline lung function measures taken before BD medication have been extensively studied, and the genetics of the BD response itself have received some attention. However, few studies have focused on the genetics of post-BD lung function. To address this gap, we analyzed lung function phenotypes in 1103 subjects from the Study of African Americans, Asthma, Genes, and Environment, a pediatric asthma case-control cohort, using an integrative genomic analysis approach that combined genotype, locus-specific genetic ancestry, and functional annotation information. We integrated genome-wide association study (GWAS) results with an admixture mapping scan of three pulmonary function tests (forced expiratory volume in 1 s [FEV1 ], forced vital capacity [FVC], and FEV1 /FVC) taken before and after albuterol BD administration on the same subjects, yielding six traits. We identified 18 GWAS loci, and five additional loci from admixture mapping, spanning several known and novel lung function candidate genes. Most loci identified via admixture mapping exhibited wide variation in minor allele frequency across genotyped global populations. Functional fine-mapping revealed an enrichment of epigenetic annotations from peripheral blood mononuclear cells, fetal lung tissue, and lung fibroblasts. Our results point to three novel potential genetic drivers of pre- and post-BD lung function: ADAMTS1, RAD54B, and EGLN3.

Examining the Potential Impact of Race Multiplier Utilization in Estimated Glomerular Filtration Rate Calculation on African-American Care Outcomes

BACKGROUND

Advancing health equity entails reducing disparities in care. African-American patients with chronic kidney disease (CKD) have poorer outcomes, including dialysis access placement and transplantation. Estimated glomerular filtration rate (eGFR) equations, which assign higher eGFR values to African-American patients, may be a mechanism for inequitable outcomes. Electronic health record-based registries enable population-based examination of care across racial groups.

OBJECTIVE

To examine the impact of the race multiplier for African-Americans in the CKD-EPI eGFR equation on CKD classification and care delivery.

DESIGN

Cross-sectional study SETTING: Two large academic medical centers and affiliated community primary care and specialty practices.

PARTICIPANTS

A total of 56,845 patients in the Partners HealthCare System CKD registry in June 2019, among whom 2225 (3.9%) were African-American.

MEASUREMENTS

Exposures included race, age, sex, comorbidities, and eGFR. Outcomes were transplant referral and dialysis access placement.

RESULTS

Of 2225 African-American patients, 743 (33.4%) would hypothetically be reclassified to a more severe CKD stage if the race multiplier were removed from the CKD-EPI equation. Similarly, 167 of 687 (24.3%) would be reclassified from stage 3B to stage 4. Finally, 64 of 2069 patients (3.1%) would be reassigned from eGFR > 20 ml/min/1.73 m2 to eGFR ≤ 20 ml/min/1.73 m2, meeting the criterion for accumulating kidney transplant priority. Zero of 64 African-American patients with an eGFR ≤ 20 ml/min/1.73 m2 after the race multiplier was removed were referred, evaluated, or waitlisted for kidney transplant, compared to 19.2% of African-American patients with eGFR ≤ 20 ml/min/1.73 m2 with the default CKD-EPI equation.

LIMITATIONS

Single healthcare system in the Northeastern United States and relatively small African-American patient cohort may limit generalizability.

CONCLUSIONS

Our study reveals a meaningful impact of race-adjusted eGFR on the care provided to the African-American CKD patient population.

Black Older Adults in the Age of Biomarkers, Physical Functioning, and Genomics: Heterogeneity, Community Engagement, and Bioethics

There are persistent disparities in all-cause mortality between Blacks and Whites in the United States. Black Americans also carry the greatest burden of morbidity from different diseases of aging including heart disease, stroke, hypertension, type 2 diabetes, and certain types of cancer. Health disparities research, and particularly race/ethnic comparison studies of physical health and aging, have consistently positioned Black health in frameworks of disadvantage, suggesting that regardless of the outcome, Black people are in worse states of health and well-being relative to Whites. Yet, extensive evidence suggests that there is significant within-group variability in the aging process among Black older adults. The use of biological, physical performance, and genomic data in survey settings offer new tools and insights to interrogate heterogeneity in Black health. This chapter examines indicators of biological, physical performance, and genetic markers of aging among a national sample of Black Americans ages 54+ years with the aim of addressing two questions about heterogeneity among Black older adults: (a) How do these measures vary by age and gender among Black older adults? (b) Which indicators predict health and mortality among Black older adults? The results indicate that biological, physical performance, and genomic measures of health, generally, have more variation than simple yes or no measures of a disease, condition, or diagnosis among Black older adults, providing counternarratives to the disadvantage frameworks that dominate characterizations of Black health and aging. However, bioethical challenges limit the utility of biomarkers, physical performance, and genomics measures for Black populations.

Higher serum vitamin D levels are associated with decreased odds of obstructive lung disease in the general population: an NHANES analysis (2007-2008 to 2009-2010)

Background

Obstructive lung disease is a significant cause of morbidity and healthcare burden within the USA. A growing body of evidence has suggested that vitamin D levels can influence the course or incidence of obstructive lung disease. However, there is an insufficient previous investigation of this association.

Study design and methods

We used the National Health and Nutrition Examination Survey (NHANES) cycles 2007–2008 and 2009–2010 spirometry results of individuals aged 40 years and older to assess the association between serum 25-hydroxyvitamin D levels and obstructive lung disease, as defined by the American Thoracic Society using the lower limit of normal. We used stage multivariate survey-logistic regression.

Results

The final model included age, gender, body mass index, pack-years smoking history, season, income-to-poverty ratio and race/ethnicity. In the primary analysis using vitamin D as a continuous variable, there was no association between vitamin D levels and obstructive lung disease. We noted a trend between ‘other Hispanic’ self-identified race and serum vitamin D levels wherein higher levels were associated with higher odds of obstructive lung disease in this ethnicity, but not among other racial or ethnic groups (OR (95% CI)=1.40 (0.98 to 1.99), p=0.06). In a secondary analysis, when vitamin D was measured as a categorical variable, there was a significant association between the highest levels of serum vitamin D levels and lesser odds of obstructive lung disease (OR (95% CI)=0.77 [0.61 to 0.98], p=0.04).

Conclusions

Higher serum vitamin D levels among adults are associated with decreased odds of obstructive lung disease in the general population. Results among non-Mexican Hispanic participants highlight the need for further research in minority populations. More work is needed to address the course and incidence of lung disease in the USA.

Lung function parameters among Australian Aboriginal 'apparently healthy' adults: an Australian Caucasian and Global Lung Function Initiative (GLI-2012) various ethnic norms comparative study

Background: There is sparse literature evidence evaluating the applicability of the GLI-2012 spirometric norms for Australian Aboriginal adults.Methods: Lung function parameters (LFPs) were compared between Australian Aboriginal and Australian Caucasians, and the fit of Australian Aboriginals LFPs with various ethnic GLI equations was tested.Results: Of 1350 and 5634 Pulmonary function tests (PFTs) in Australian Aboriginal and Australian Caucasian adults, 153 and 208 PFTs matched for anthropometrics and normal chest radiology, respectively. Absolute FVC and FEV₁ values were 20% lower in Australian Aboriginals compared to Australian Caucasians. Differences remained significant after accounting for age, sex, height, weight and smoking status in multivariate regression (FVC -0.84 L (-0.98, -0.71), FEV₁ - 0.72 L (-0.84, -0.59), but with nearly preserved FEV₁/FVC. GLI-2012 transformation resulted in z-scores significantly below zero for each of FVC, FEV₁ and FEV₁/FVC with z-scores ranging from -4.52 (-4.87, -4.16) for North East Asian FVC transformation for males, to -0.34 (-0.73, 0.05) for Black FVC transformation for females.Conclusions: Australian Aboriginal adults had 20% lower values for FVC and FEV₁ but nearly preserved absolute FEV₁/FVC in comparison to Australian Caucasians. The GLI-2012 spirometric norms do not appear to fit for Australian Aboriginal adults regardless of which ethnicity options selected, including 'others/mixed'.

Whole-Genome Sequencing Identifies Novel Functional Loci Associated with Lung Function in Puerto Rican Youth

Rationale: Puerto Ricans have the highest childhood asthma prevalence in the United States (23.6%); however, the etiology is uncertain.Objectives: In this study, we sought to uncover the genetic architecture of lung function in Puerto Rican youth with and without asthma who were recruited from the island (n = 836).Methods: We used admixture-mapping and whole-genome sequencing data to discover genomic regions associated with lung function. Functional roles of the prioritized candidate SNPs were examined with chromatin immunoprecipitation sequencing, RNA sequencing, and expression quantitative trait loci data.Measurements and Main Results: We discovered a genomic region at 1q32 that was significantly associated with a 0.12-L decrease in the lung volume of exhaled air (95% confidence interval, -0.17 to -0.07; P = 6.62 × 10-8) with each allele of African ancestry. Within this region, two SNPs were expression quantitative trait loci of TMEM9 in nasal airway epithelial cells and MROH3P in esophagus mucosa. The minor alleles of these SNPs were associated with significantly decreased lung function and decreased TMEM9 gene expression. Another admixture-mapping peak was observed on chromosome 5q35.1, indicating that each Native American ancestry allele was associated with a 0.15-L increase in lung function (95% confidence interval, 0.08-0.21; P = 5.03 × 10-6). The region-based association tests identified four suggestive windows that harbored candidate rare variants associated with lung function.Conclusions: We identified common and rare genetic variants that may play a critical role in lung function among Puerto Rican youth. We independently validated an inflammatory pathway that could potentially be used to develop more targeted treatments and interventions for patients with asthma.