Association of Nonobstructive Chronic Bronchitis With Respiratory Health Outcomes in Adults.

Importance: Chronic bronchitis has been associated with cigarette smoking as well as with e-cigarette use among young adults, but the association of chronic bronchitis in persons without airflow obstruction or clinical asthma, described as nonobstructive chronic bronchitis, with respiratory health outcomes remains uncertain. Objective: To assess whether nonobstructive chronic bronchitis is associated with adverse respiratory health outcomes in adult ever smokers and never smokers. Design, Setting, and Participants: This prospective cohort study included 22 325 adults without initial airflow obstruction (defined as the ratio of forced expiratory volume in the first second [FEV1] to forced vital capacity [FVC] of <0.70) or clinical asthma at baseline. The National Heart, Lung, and Blood Institute (NHLBI) Pooled Cohorts Study harmonized and pooled data from 9 US general population-based cohorts. Thus present study is based on data from 5 of these cohorts. Participants were enrolled from August 1971 through May 2007 and were followed up through December 2018. Exposures: Nonobstructive chronic bronchitis was defined by questionnaire at baseline as both cough and phlegm for at least 3 months for at least 2 consecutive years. Main Outcomes and Measures: Lung function was measured by prebronchodilator spirometry. Hospitalizations and deaths due to chronic lower respiratory disease and respiratory disease-related mortality were defined by events adjudication and administrative criteria. Models were stratified by smoking status and adjusted for anthropometric, sociodemographic, and smoking-related factors. The comparison group was participants without nonobstructive chronic bronchitis. Results: Among 22 325 adults included in the analysis, mean (SD) age was 53.0 (16.3) years (range, 18.0-95.0 years), 58.2% were female, 65.9% were non-Hispanic white, and 49.6% were ever smokers. Among 11 082 ever smokers with 99 869 person-years of follow-up, participants with nonobstructive chronic bronchitis (300 [2.7%]) had accelerated decreases in FEV1 (4.1 mL/y; 95% CI, 2.1-6.1 mL/y) and FVC (4.7 mL/y; 95% CI, 2.2-7.2 mL/y), increased risks of chronic lower respiratory disease-related hospitalization or mortality (hazard ratio [HR], 2.2; 95% CI, 1.7-2.7), and greater respiratory disease-related (HR, 2.0; 95% CI, 1.1-3.8) and all-cause mortality (HR, 1.5; 95% CI, 1.3-1.8) compared with ever smokers without nonobstructive chronic bronchitis. Among 11 243 never smokers with 120 004 person-years of follow-up, participants with nonobstructive chronic bronchitis (151 [1.3%]) had greater rates of chronic lower respiratory disease-related hospitalization or mortality (HR, 3.1; 95% CI, 2.1-4.5) compared with never smokers without nonobstructive chronic bronchitis. Nonobstructive chronic bronchitis was not associated with FEV1:FVC decline or incident airflow obstruction. The presence of at least 1 of the component symptoms of nonobstructive chronic bronchitis (ie, chronic cough or phlegm), which was common in both ever smokers (11.0%) and never smokers (6.7%), was associated with adverse respiratory health outcomes. Conclusions and Relevance: The findings suggest that nonobstructive chronic bronchitis is associated with adverse respiratory health outcomes, particularly in ever smokers, and may be a high-risk phenotype suitable for risk stratification and targeted therapies.

Lung function decline in former smokers and low-intensity current smokers: a secondary data analysis of the NHLBI Pooled Cohorts Study.

BACKGROUND: Former smokers now outnumber current smokers in many developed countries, and current smokers are smoking fewer cigarettes per day. Some data suggest that lung function decline normalises with smoking cessation; however, mechanistic studies suggest that lung function decline could continue. We hypothesised that former smokers and low-intensity current smokers have accelerated lung function decline compared with never-smokers, including among those without prevalent lung disease. METHODS: We used data on six US population-based cohorts included in the NHLBI Pooled Cohort Study. We restricted the sample to participants with valid spirometry at two or more exams. Two cohorts recruited younger adults (≥17 years), two recruited middle-aged and older adults (≥45 years), and two recruited only elderly adults (≥65 years) with examinations done between 1983 and 2014. FEV1 decline in sustained former smokers and current smokers was compared to that of never-smokers by use of mixed models adjusted for sociodemographic and anthropometric factors. Differential FEV1 decline was also evaluated according to duration of smoking cessation and cumulative (number of pack-years) and current (number of cigarettes per day) cigarette consumption. FINDINGS: 25 352 participants (ages 17-93 years) completed 70 228 valid spirometry exams. Over a median follow-up of 7 years (IQR 3-20), FEV1 decline at the median age (57 years) was 31·01 mL per year (95% CI 30·66-31·37) in sustained never-smokers, 34·97 mL per year (34·36-35·57) in former smokers, and 39·92 mL per year (38·92-40·92) in current smokers. With adjustment, former smokers showed an accelerated FEV1 decline of 1·82 mL per year (95% CI 1·24-2·40) compared to never-smokers, which was approximately 20% of the effect estimate for current smokers (9·21 mL per year; 95% CI 8·35-10·08). Compared to never-smokers, accelerated FEV1 decline was observed in former smokers for decades after smoking cessation and in current smokers with low cumulative cigarette consumption (<10 pack-years). With respect to current cigarette consumption, the effect estimate for FEV1 decline in current smokers consuming less than five cigarettes per day (7·65 mL per year; 95% CI 6·21-9·09) was 68% of that in current smokers consuming 30 or more cigarettes per day (11·24 mL per year; 9·86-12·62), and around five times greater than in former smokers (1·57 mL per year; 1·00-2·14). Among participants without prevalent lung disease, associations were attenuated but were consistent with the main results. INTERPRETATION: Former smokers and low-intensity current smokers have accelerated lung function decline compared with never-smokers. These results suggest that all levels of smoking exposure are likely to be associated with lasting and progressive lung damage. FUNDING: National Institutes of Health, National Heart Lung and Blood Institute, and US Environmental Protection Agency.

Soy isoflavones reduce asthma exacerbation in asthmatic patients with high PAI-1-producing genotypes.

BACKGROUND: The 4G4G genotype of plasminogen activator inhibitor 1 (PAI-1) is associated with increased plasma PAI-1 levels and poor asthma control. Previous studies suggest that soy isoflavones can reduce PAI-1 levels. OBJECTIVE: We sought to investigate PAI-1 genotype-specific differences of the soy isoflavone response in asthma outcomes. METHODS: A PAI-1 functional polymorphism (rs1799768, 4G5G) was characterized in subjects with poorly controlled asthma enrolled in a randomized clinical trial of soy isoflavones (n = 265). Genotype-specific treatment responses on asthma outcomes were compared between soy isoflavones and placebo. Normal human bronchial epithelial cells were cultured with or without TGF-ß1, genistein, or both, and PAI-1 levels were measured. RESULTS: The 4G4G/4G5G genotype was associated with a greater risk for allergy-related worsened asthma symptoms and eczema at baseline compared with the 5G5G genotype. There was a significant interaction between the genotype and soy isoflavone intervention on oral corticosteroid use for asthma exacerbation (P = .005). In a subgroup analysis soy isoflavones significantly reduced the use of oral corticosteroids (number of events/person-year) by 4-fold compared with placebo in the 4G4G/4G5G genotype (0.2 vs 0.8; relative risk, 0.28; P < .001) but not in the 5G5G genotype. Soy isoflavones reduced plasma PAI-1 levels compared with placebo. Genistein treatment reduced TGF-ß1-induced PAI-1 production in normal human bronchial epithelial cells. CONCLUSIONS: This study demonstrates that soy isoflavone treatment provides a significant benefit in reducing the number of severe asthma exacerbations in asthmatic patients with the high PAI-1-producing genotype. PAI-1 polymorphisms can be used as a genetic biomarker for soy isoflavone-responsive patients with asthma.

Omega-3 Fatty Acids and Genome-Wide Interaction Analyses Reveal DPP10-Pulmonary Function Association.

RATIONALE: Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have anti-inflammatory properties that could benefit adults with comprised pulmonary health. OBJECTIVE: To investigate n-3 PUFA associations with spirometric measures of pulmonary function tests (PFTs) and determine underlying genetic susceptibility. METHODS: Associations of n-3 PUFA biomarkers (α-linolenic acid, eicosapentaenoic acid, docosapentaenoic acid [DPA], and docosahexaenoic acid [DHA]) were evaluated with PFTs (FEV1, FVC, and FEV1/FVC) in meta-analyses across seven cohorts from the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium (N = 16,134 of European or African ancestry). PFT-associated n-3 PUFAs were carried forward to genome-wide interaction analyses in the four largest cohorts (N = 11,962) and replicated in one cohort (N = 1,687). Cohort-specific results were combined using joint 2 degree-of-freedom (2df) meta-analyses of SNP associations and their interactions with n-3 PUFAs. RESULTS: DPA and DHA were positively associated with FEV1 and FVC (P < 0.025), with evidence for effect modification by smoking and by sex. Genome-wide analyses identified a novel association of rs11693320-an intronic DPP10 SNP-with FVC when incorporating an interaction with DHA, and the finding was replicated (P2df = 9.4 × 10-9 across discovery and replication cohorts). The rs11693320-A allele (frequency, ∼80%) was associated with lower FVC (PSNP = 2.1 × 10-9; ßSNP = -161.0 ml), and the association was attenuated by higher DHA levels (PSNP×DHA interaction = 2.1 × 10-7; ßSNP×DHA interaction = 36.2 ml). CONCLUSIONS: We corroborated beneficial effects of n-3 PUFAs on pulmonary function. By modeling genome-wide n-3 PUFA interactions, we identified a novel DPP10 SNP association with FVC that was not detectable in much larger studies ignoring this interaction.

Meta-analysis across Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium provides evidence for an association of serum vitamin D with pulmonary function.

The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)-pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D-pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (P race difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (P race difference=0·56). Among EA, the 25(OH)D-FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.

Harmonization of Respiratory Data From 9 US Population-Based Cohorts: The NHLBI Pooled Cohorts Study.

Chronic lower respiratory diseases (CLRDs) are the fourth leading cause of death in the United States. To support investigations into CLRD risk determinants and new approaches to primary prevention, we aimed to harmonize and pool respiratory data from US general population-based cohorts. Data were obtained from prospective cohorts that performed prebronchodilator spirometry and were harmonized following 2005 ATS/ERS standards. In cohorts conducting follow-up for noncardiovascular events, CLRD events were defined as hospitalizations/deaths adjudicated as CLRD-related or assigned relevant administrative codes. Coding and variable names were applied uniformly. The pooled sample included 65,251 adults in 9 cohorts followed-up for CLRD-related mortality over 653,380 person-years during 1983-2016. Average baseline age was 52 years; 56% were female; 49% were never-smokers; and racial/ethnic composition was 44% white, 22% black, 28% Hispanic/Latino, and 5% American Indian. Over 96% had complete data on smoking, clinical CLRD diagnoses, and dyspnea. After excluding invalid spirometry examinations (13%), there were 105,696 valid examinations (median, 2 per participant). Of 29,351 participants followed for CLRD hospitalizations, median follow-up was 14 years; only 5% were lost to follow-up at 10 years. The NHLBI Pooled Cohorts Study provides a harmonization standard applied to a large, US population-based sample that may be used to advance epidemiologic research on CLRD.

Respiratory Symptoms in Young Adults and Future Lung Disease. The CARDIA Lung Study.

RATIONALE: There are limited data on factors in young adulthood that predict future lung disease. OBJECTIVES: To determine the relationship between respiratory symptoms, loss of lung health, and incident respiratory disease in a population-based study of young adults. METHODS: We examined prospective data from 2,749 participants in the CARDIA (Coronary Artery Risk Development in Young Adults) study who completed respiratory symptom questionnaires at baseline and 2 years later and repeated spirometry measurements over 30 years. MEASUREMENTS AND MAIN RESULTS: Cough or phlegm, episodes of bronchitis, wheeze, shortness of breath, and chest illnesses at both baseline and Year 2 were the main predictor variables in models assessing decline in FEV1 and FVC from Year 5 to Year 30, incident obstructive and restrictive lung physiology, and visual emphysema on thoracic computed tomography scan. After adjustment for covariates, including body mass index, asthma, and smoking, report of any symptom was associated with -2.71 ml/yr excess decline in FEV1 (P < 0.001) and -2.18 in FVC (P < 0.001) as well as greater odds of incident (prebronchodilator) obstructive (odds ratio [OR], 1.63; 95% confidence interval [CI], 1.24-2.14) and restrictive (OR, 1.40; 95% CI, 1.09-1.80) physiology. Cough-related symptoms (OR, 1.56; 95% CI, 1.13-2.16) were associated with greater odds of future emphysema. CONCLUSIONS: Persistent respiratory symptoms in young adults are associated with accelerated decline in lung function, incident obstructive and restrictive physiology, and greater odds of future radiographic emphysema.

A Longitudinal Cohort Study of Aspirin Use and Progression of Emphysema-like Lung Characteristics on CT Imaging: The MESA Lung Study.

BACKGROUND: Platelet activation reduces pulmonary microvascular blood flow and contributes to inflammation; these factors have been implicated in the pathogenesis of COPD and emphysema. We hypothesized that regular use of aspirin, a platelet inhibitor, would be associated with a slower progression of emphysema-like lung characteristics on CT imaging and a slower decline in lung function. METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) enrolled participants 45 to 84 years of age without clinical cardiovascular disease from 2000 to 2002. The MESA Lung Study assessed the percentage of emphysema-like lung below -950 Hounsfield units ("percent emphysema") on cardiac (2000-2007) and full-lung CT scans (2010-2012). Regular aspirin use was defined as 3 or more days per week. Mixed-effect models adjusted for demographics, anthropometric features, smoking, hypertension, angiotensin-converting enzyme inhibitor or angiotensin II-receptor blocker use, C-reactive protein levels, sphingomyelin levels, and scanner factors. RESULTS: At baseline, the 4,257 participants' mean (± SD) age was 61 ± 10 years, 54% were ever smokers, and 22% used aspirin regularly. On average, percent emphysema increased 0.60 percentage points over 10 years (95% CI, 0.35-0.94). Progression of percent emphysema was slower among regular aspirin users compared with patients who did not use aspirin (fully adjusted model: -0.34% /10 years, 95% CI, -0.60 to -0.08; P = .01). Results were similar in ever smokers and with doses of 81 and 300 to 325 mg and were of greater magnitude among those with airflow limitation. No association was found between aspirin use and change in lung function. CONCLUSIONS: Regular aspirin use was associated with a more than 50% reduction in the rate of emphysema progression over 10 years. Further study of aspirin and platelets in emphysema may be warranted.

Spirometry Reference Equations from the HCHS/SOL (Hispanic Community Health Study/Study of Latinos).

RATIONALE: Accurate reference values for spirometry are important because the results are used for diagnosing common chronic lung diseases such as asthma and chronic obstructive pulmonary disease, estimating physiologic impairment, and predicting all-cause mortality. Reference equations have been established for Mexican Americans but not for others with Hispanic/Latino backgrounds. OBJECTIVES: To develop spirometry reference equations for adult Hispanic/Latino background groups in the United States. METHODS: The HCHS/SOL (Hispanic Community Health Study/Study of Latinos) recruited a population-based probability sample of 16,415 Hispanics/Latinos aged 18-74 years living in the Bronx, Chicago, Miami, and San Diego. Participants self-identified as being of Puerto Rican, Cuban, Dominican, Mexican, or Central or South American background. Spirometry was performed using standardized methods with central quality control monitoring. Spirometric measures from a subset of 6,425 never-smoking participants without respiratory symptoms or disease were modeled as a function of sex, age, height, and Hispanic/Latino background to produce background-specific reference equations for the predicted value and lower limit of normal. MEASUREMENTS AND MAIN RESULTS: Dominican and Puerto Rican Americans had substantially lower predicted and lower limit of normal values for FVC and FEV1 than those in other Hispanic/Latino background groups and also than Mexican American values from NHANES III (Third National Health and Nutrition Examination Survey). CONCLUSIONS: For patients of Dominican and Puerto Rican background who present with pulmonary symptoms in clinical practice, use of background-specific spirometry reference equations may provide more appropriate predicted and lower limit of normal values, enabling more accurate diagnoses of abnormality and physiologic impairment.

Pulmonary Disease and Age at Immigration among Hispanics. Results from the Hispanic Community Health Study/Study of Latinos.

RATIONALE: Asthma has been reported to be more prevalent among Hispanics of Puerto Rican heritage than among other Hispanics and among Hispanics born in the United States or who immigrated as children than among those who came as adults; however, direct comparisons across Hispanic groups are lacking. OBJECTIVES: To test whether asthma is more prevalent among Hispanics of Puerto Rican heritage than among other Hispanic groups, whether asthma is associated with age of immigration, and whether chronic obstructive pulmonary disease varies by heritage in a large, population-based cohort of Hispanics in the United States. METHODS: The Hispanic Community Health Study/Study of Latinos researchers recruited a population-based probability sample of 16,415 Hispanics/Latinos, 18-74 years of age, in New York City, Chicago, Miami, and San Diego. Participants self-reported Puerto Rican, Cuban, Dominican, Mexican, Central American, or South American heritage; birthplace; and, if relevant, age at immigration. A respiratory questionnaire and standardized spirometry were performed with post-bronchodilator measures for those with airflow limitation. MEASUREMENTS AND MAIN RESULTS: The prevalence of physician-diagnosed asthma among Puerto Ricans (36.5%; 95% confidence interval, 33.6-39.5%) was higher than among other Hispanics (odds ratio, 3.9; 95% confidence interval, 3.3-4.6). Hispanics who were born in the mainland United States or had immigrated as children had a higher asthma prevalence than those who had immigrated as adults (19.6, 19.4, and 14.1%, respectively; P < 0.001). Current asthma, bronchodilator responsiveness, and wheeze followed similar patterns. Chronic obstructive pulmonary disease prevalence was higher among Puerto Ricans (14.1%) and Cubans (9.8%) than among other Hispanics (<6.0%), but it did not vary across Hispanic heritages after adjustment for smoking and prior asthma (P = 0.22), by country of birth, or by age at immigration. CONCLUSIONS: Asthma was more prevalent among Puerto Ricans, other Hispanics born in the United States, and those who had immigrated as children than among other Hispanics. In contrast, the higher prevalence of chronic obstructive pulmonary disease among Puerto Ricans and Cubans was largely reflective of differential smoking patterns and asthma.

Ability of Reduced Lung Function to Predict Development of Atrial Fibrillation in Persons Aged 45 to 84 Years (from the Multi-Ethnic Study of Atherosclerosis-Lung Study).

Atrial fibrillation (AF) occurs frequently in patients with chronic obstructive pulmonary disease. Epidemiologic studies have found inconsistent associations between lung function and AF, and none have studied pulmonary emphysema, which overlaps only partially with chronic obstructive pulmonary disease in the general population. The aim of this study was to assess the relation among lung function measured by spirometry, the percentage of emphysema-like lung on computed tomography, and incident AF. The Multi-Ethnic Study of Atherosclerosis (MESA) is a multicenter cohort study following 6,814 subjects free of clinical cardiovascular disease, including AF, at baseline. Spirometry was performed in a subset of 3,965 participants. Percentage emphysema was defined on baseline computed tomographic scans as lung regions <950 Hounsfield units. Incident AF was identified from hospital discharge diagnosis and Medicare claims data. Cox proportional hazards models were used to assess independent associations of lung volumes and percentage emphysema with AF. A total of 3,811 participants with valid spirometric results were included in this study. The mean age was 64.5 ± 9.8 years, and 49.4% were men. AF developed in 149 subjects (3.8%) over a mean follow-up period of 4.1 years after spirometry. Lower levels of forced expiratory volume at 1 second and forced vital capacity were associated with a higher risk for AF (hazard ratios 1.21 and 1.19 per 500 ml, respectively, p <0.001) after adjustment for demographic and cardiovascular risk factors. Percentage emphysema was not significantly related to AF. In conclusion, in a multiethnic community-based sample of subjects free of cardiovascular disease at baseline, functional airflow limitation was related to a higher risk for AF.

Adult-onset asthma becomes the dominant phenotype among women by age 40 years. the longitudinal CARDIA study.

RATIONALE: Although asthma is usually considered to originate in childhood, adult-onset disease is being increasingly reported. OBJECTIVES: To contrast the proportion and natural history of adult-onset versus pediatric-onset asthma in a community-based cohort. We hypothesized that asthma in women is predominantly of adult onset rather than of pediatric onset. METHODS: This study used data from the Coronary Artery Risk Development in Young Adults (CARDIA) cohort in the United States over a 25-year period. Adult- and pediatric-onset asthma phenotypes were studied, as defined by age at onset of 18 years or older. Subjects with asthma were categorized by sex, obesity, atopy, smoking, and race by mean age/examination year, using a three-way analysis of covariance model. Natural history of disease was examined using probabilities derived from a Markov chain model. MEASUREMENTS AND MAIN RESULTS: Asthma of adult onset became the dominant (i.e., exceeded 50%) phenotype in women by age 40 years. The age by which adult-onset asthma became the dominant phenotype was further lowered for obese, nonatopic, ever-smoking, or white women. The prevalence trend with increasing time for adult-onset disease was greater among subjects with nonatopic than atopic asthma among both sexes. Furthermore, adult-onset asthma had remarkable sex-related differences in risk factors. In both sexes, the quiescent state for adult-onset asthma was less frequent and also "less stable" over time than for pediatric-onset asthma. CONCLUSIONS: Using a large national cohort, this study challenges the dictum that most asthma in adults originates in childhood. Studies of the differences between pediatric- and adult-onset asthma may provide greater insight into the phenotypic heterogeneity of asthma.

Replication and fine mapping of asthma-associated loci in individuals of African ancestry.

Asthma originates from genetic and environmental factors with about half the risk of disease attributable to heritable causes. Genome-wide association studies, mostly in populations of European ancestry, have identified numerous asthma-associated single nucleotide polymorphisms (SNPs). Studies in populations with diverse ancestries allow both for identification of robust associations that replicate across ethnic groups and for improved resolution of associated loci due to different patterns of linkage disequilibrium between ethnic groups. Here we report on an analysis of 745 African-American subjects with asthma and 3,238 African-American control subjects from the Candidate Gene Association Resource (CARe) Consortium, including analysis of SNPs imputed using 1,000 Genomes reference panels and adjustment for local ancestry. We show strong evidence that variation near RAD50/IL13, implicated in studies of European ancestry individuals, replicates in individuals largely of African ancestry. Fine mapping in African ancestry populations also refined the variants of interest for this association. We also provide strong or nominal evidence of replication at loci near ORMDL3/GSDMB, IL1RL1/IL18R1, and 10p14, all previously associated with asthma in European or Japanese populations, but not at the PYHIN1 locus previously reported in studies of African-American samples. These results improve the understanding of asthma genetics and further demonstrate the utility of genetic studies in populations other than those of largely European ancestry.

Genetic ancestry-smoking interactions and lung function in African Americans: a cohort study.

BACKGROUND: Smoking tobacco reduces lung function. African Americans have both lower lung function and decreased metabolism of tobacco smoke compared to European Americans. African ancestry is also associated with lower pulmonary function in African Americans. We aimed to determine whether African ancestry modifies the association between smoking and lung function and its rate of decline in African Americans. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated a prospective ongoing cohort of 1,281 African Americans participating in the Health, Aging, and Body Composition (Health ABC) Study initiated in 1997. We also examined an ongoing prospective cohort initiated in 1985 of 1,223 African Americans in the Coronary Artery Disease in Young Adults (CARDIA) Study. Pulmonary function and tobacco smoking exposure were measured at baseline and repeatedly over the follow-up period. Individual genetic ancestry proportions were estimated using ancestry informative markers selected to distinguish European and West African ancestry. African Americans with a high proportion of African ancestry had lower baseline forced expiratory volume in one second (FEV1) per pack-year of smoking (-5.7 ml FEV1/ smoking pack-year) compared with smokers with lower African ancestry (-4.6 ml in FEV1/ smoking pack-year) (interaction P value  = 0.17). Longitudinal analyses revealed a suggestive interaction between smoking, and African ancestry on the rate of FEV(1) decline in Health ABC and independently replicated in CARDIA. CONCLUSIONS/SIGNIFICANCE: African American individuals with a high proportion of African ancestry are at greater risk for losing lung function while smoking.

Low serum adiponectin predicts future risk for asthma in women.

RATIONALE: Our previous cross-sectional study showed that serum adiponectin is inversely associated with asthma among women. However, it is not known if serum adiponectin predicts future development of asthma or if asthma affects subsequent serum adiponectin concentrations among women. OBJECTIVES: To determine longitudinal association between serum adiponectin and incident asthma among women. METHODS: We used data from examinations at Years 10, 15, and 20 of the Coronary Artery Risk Development in Young Adults (CARDIA) cohort. In our primary analysis, the association of CARDIA Year 15 serum adiponectin concentration with Year 20 incident asthma was evaluated. In our secondary analysis, the converse direction, that is, the association of CARDIA Year 10 prevalent asthma with Year 15 serum adiponectin, was evaluated, using logistic regression techniques. MEASUREMENTS AND MAIN RESULTS: Our primary analysis included 1,450 women, mostly premenopausal. Multivariable analyses demonstrated that the lowest tertile of Year 15 serum adiponectin concentration (<7 mg/L) predicted significantly higher risk for incident asthma at Year 20 among women (odds ratio, 2.07; 95% confidence interval, 1.05, 4.10), and particularly among current smokers (interaction P = 0.051). Further, low serum adiponectin was more important than body mass index in predicting the risk for incident asthma among women. We also showed that the converse relationship was not true; that is, Year 10 prevalent asthma did not predict Year 15 serum adiponectin concentrations in women. CONCLUSIONS: Serum adiponectin affects future risk for asthma in women and not vice versa. Measures that raise systemic adiponectin concentrations may lead to newer ways to prevent asthma among women, particularly among those who smoke.

Reduced lung diffusion capacity in type 2 diabetes is independent of heart failure.

In a case-control analysis comparing 303 patients with diabetes and 303 without (matched on age, race, sex and height), diabetics had reduced lung diffusion (DLCO) independent of smoking, obesity, clinical heart failure, asymptomatic left ventricular systolic and diastolic dysfunction: DLCO (mean±SE: 15.5±0.9 vs. 16.4 ±0.9, p=0.01).

Rate of decline of forced vital capacity predicts future arterial hypertension: the Coronary Artery Risk Development in Young Adults Study.

Lung function studies in middle-aged subjects predict cardiovascular disease mortality. We studied whether greater loss of forced vital capacity (FVC) early in life predicted incident hypertension. The sample was 3205 black and white men and women in the Coronary Artery Risk Development in Young Adults Study examined between 1985 and 1986 (Coronary Artery Risk Development in Young Adults year 0, ages 18-30 years) and 2005-2006 and who were not hypertensive by year 10. FVC was assessed at years 0, 2, 5, 10, and 20. Proportional hazard ratios and linear regression models predicted incident hypertension at years 15 or 20 (n=508) from the change in FVC (FVC at year 10 - peak FVC, where peak FVC was estimated as the maximum across years 0, 2, 5, and 10). Covariates included demographics, center, systolic blood pressure, FVC maximum, smoking, physical activity, asthma, and body mass index. Unadjusted cumulative incident hypertension was 25% in the lowest FVC loss quartile (Q1; median loss: 370 mL) compared with 12% cumulative incident hypertension in those who achieved peak FVC at year 10 (Q4). Minimally adjusted hazard ratio for Q1 versus Q4 was 2.21 (95% CI: 1.73-2.83), and this association remained significant in the fully adjusted model (1.37; 95% CI: 1.05-1.80). Decline in FVC from average age at peak (29.4 years) to 35 years old predicted incident hypertension between average ages 35 and 45 years. The findings may represent a common pathway that may link low normal FVC to cardiovascular disease morbidity and mortality.

Serum carotenoid concentrations predict lung function evolution in young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

BACKGROUND: A higher dietary intake of carotenoid-rich foods and higher circulating concentrations of carotenoids have been associated with better lung function in cross-sectional studies; however, the longitudinal association between carotenoids and lung function has shown conflicting results. OBJECTIVE: We examined the longitudinal association between serum carotenoids (ß-cryptoxanthin, α-carotene, ß-carotene, lutein/zeaxanthin, and lycopene) and the evolution of lung function. DESIGN: We evaluated our hypothesis in the Coronary Artery Risk Development in Young Adults (CARDIA) prospective cohort study. Spirometry testing was conducted at year 0 (1985-1986) and at follow-up in years 2, 5, 10, and 20; serum carotenoids were assayed at years 0 and 15, and diet was assessed at years 0 and 20. RESULTS: Year 0 sum of provitamin A carotenoids and ß-cryptoxanthin concentrations were associated with maximum forced vital capacity (FVC) (P ≤ 0.01) and forced expiratory volume in 1 s (FEV(1)) (P ≤ 0.05) (maximum across years 0-10) in linear regression models adjusted for age, race, height, study center, amount of physical activity, smoking status, and BMI. Year 0 lutein/zeaxanthin and lycopene were not associated with maximum lung function. Baseline concentrations of lutein/zeaxanthin, lycopene, sum of the 3 provitamin A carotenoids, ß-carotene, and ß-cryptoxanthin were each inversely associated with a decline from maximum FVC and FEV(1) (P ≤ 0.04). The sum of provitamin A carotenoids and lycopene remained significant after adjustment for dietary intake related to serum carotenoids (P ≤ 0.03). The 15-y change in provitamin A carotenoid and lutein/zeaxanthin concentrations was associated with a slower decline from maximum FVC and FEV(1) (P ≤ 0.04). CONCLUSION: These findings support an association between serum carotenoid concentrations and a decline in lung function.

Socioeconomic status is positively associated with percent emphysema on CT scan: The MESA lung study.

RATIONALE AND OBJECTIVES: Higher socioeconomic status (SES) has been associated with lower respiratory mortality and better lung function, but whether a similar gradient exists for computed tomography (CT) measures of subclinical emphysema is unknown. MATERIALS AND METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) recruited African-American, Chinese, Hispanic, and white participants, ages 45 to 84 years, without clinical cardiovascular disease, from six US sites between 2000 and 2002. The MESA Lung Study assessed percent emphysema, defined based on the proportion of pixels below an attenuation threshold of 910 HU from lung windows of cardiac CT scans. Generalized linear models were adjusted for demographic characteristics, height, body mass index, history of respiratory illness, occupational and residential exposures, tobacco use, and CT scanner type. RESULTS: Among 3706 participants with a mean age of 61 (±10), the median value for percent emphysema was 18 (interquartile range = 20). Compared with those who did not complete high school, participants with a graduate degree had a higher percent emphysema (difference of 4; P < .001). Income and wealth were also positively associated with percent emphysema. In contrast, higher SES was associated with better lung function. Descriptive and subgroup analyses were used to explore potential explanations for divergent results, including the possibility that suboptimal inspiration during CT scanning would decrease percent emphysema, making the lungs appear healthier when effort is relatively poor. CONCLUSION: Although SES indicators were positively associated with subclinical emphysema detectable on CT scan, this unexpected association may highlight potential bias because of effort dependence of both CT measures and spirometry.

Systemic inflammation in young adults is associated with abnormal lung function in middle age.

BACKGROUND: Systemic inflammation is associated with reduced lung function in both healthy individuals and those with chronic obstructive pulmonary disease (COPD). Whether systemic inflammation in healthy young adults is associated with future impairment in lung health is uncertain. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated the association between plasma fibrinogen and C-reactive protein (CRP) in young adults and lung function in the Coronary Artery Risk Development in Young Adults cohort study. Higher year 7 fibrinogen was associated with greater loss of forced vital capacity (FVC) between years 5 and 20 (439 mL in quartile 4 vs. 398 mL in quartile 1, P<0.001) and forced expiratory volume in 1 second (FEV(1)) (487 mL in quartile 4 vs. 446 mL in quartile 1, P<0.001) independent of cigarette smoking, body habitus, baseline lung function and demographic factors. Higher year 7 CRP was also associated with both greater loss of FVC (455 mL in quartile 4 vs. 390 mL in quartile 1, P<0.001) and FEV(1) (491 mL in quartile 4 vs. 442 mL in quartile 1, P = 0.001). Higher year 7 fibrinogen and CRP were associated with abnormal FVC at year 20 (odds ratio (OR) per standard deviation 1.51 (95% confidence interval (CI): 1.30-1.75) for fibrinogen and 1.35 (95% CI: 1.14-1.59) for CRP). Higher year 5 fibrinogen was additionally associated with abnormal FEV(1). A positive interaction was observed between pack-years cigarette smoking and year 7 CRP for the COPD endpoint, and among participants with greater than 10 pack-years of cigarette exposure, year 7 CRP was associated with greater odds of COPD at year 20 (OR per standard deviation 1.53 (95% CI: 1.08-2.16). CONCLUSION/SIGNIFICANCE: Systemic inflammation in young adults is associated with abnormal lung function in middle age. In particular, elevated CRP may identify vulnerability to COPD among individuals who smoke. TRIAL REGISTRATION: ClinicalTrials.gov NCT00005130.