Effect of Pod e-Cigarettes vs Cigarettes on Carcinogen Exposure Among African American and Latinx Smokers: A Randomized Clinical Trial.

Importance: Fourth-generation nicotine salt pod system (NSPS) electronic cigarettes (e-cigarettes) are the leading class of e-cigarettes. They contain high nicotine concentrations, which may facilitate switching among smokers, but could also lead to increased exposure to nicotine and biomarkers of potential harm. African American and Latinx smokers experience significant tobacco-related health disparities. The potential of NSPS e-cigarettes to reduce smoking-related harm among these groups is unknown. Objective: To compare the harm reduction potential of NSPS e-cigarette vs combustible cigarettes. Design, Setting, and Participants: This unblinded randomized clinical trial compared 6 weeks of e-cigarette use vs cigarettes as usual from to 2018 to 2019 among smokers in the San Diego, California, and Kansas City, Missouri, areas. Participants included African American and Latinx adult combustible cigarette smokers who smoked at least 5 cigarettes/d on at least 25 of the past 30 days for at least 6 months and were interested in switching to e-cigarettes. Data were analyzed from September 18, 2019, to September 4, 2020. Interventions: 6 weeks of e-cigarette use in a choice of pod flavors (5% nicotine) along with brief education, training, and action planning to completely switch to e-cigarettes from combustible cigarettes. The control group smoked combustible cigarettes as usual. Main Outcomes and Measures: The primary outcome was reduction in urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) concentration at week 6. Secondary outcomes were change in urinary cotinine, expired carbon monoxide (CO), respiratory symptoms, lung function, blood pressure, past 7-day consumption of combustible cigarettes, and switching rates (e-cigarette group only) at weeks 2 and 6. Results: This study included 186 participants, including 92 African American participants and 94 Latinx participants. The mean (SD) age was 43.3 (12.5) years, and 75 (40.3%) were women. Participants smoked a mean (SD) of 12.1 (7.2) cigarettes/d on 6.8 (0.6) d/wk at baseline. A total of 125 participants were randomized to the e-cigarette group and 61 were randomized to the control group. At baseline, median (interquartile range) NNAL was 124 (45-197) pg/mL in the e-cigarette group and 88 (58-197) pg/mL in the control group. At week 6, the e-cigarette group had significantly greater reductions in NNAL (relative risk [RR], 0.36 [95% CI, 0.23-0.54]; P < .001), CO (RR, 0.53 [95% CI, 0.42-0.68]; P < .001), respiratory symptoms (RR, 0.63 [95% CI, 0.47-0.85]; P = .002), and number of cigarettes smoked in the past 7 days among those still smoking (RR, 0.30 [95% CI, 0.20-0.43]; P < .001) than the control group and maintained their cotinine levels (RR, 0.80 [95% CI, 0.58-1.10]; P = .17). Lung function and diastolic and systolic blood pressure remained unchanged and did not differ between groups. For participants randomized to receive e-cigarettes, 32 participants (28.1%) were exclusively using e-cigarettes at week 6, while 66 participants (57.9%) were dual using and 16 participants (14%) resumed exclusively using cigarettes. Conclusions and Relevance: These findings suggest that e-cigarettes may be an inclusive harm reduction strategy for African American and Latinx smokers. Trial Registration: ClinicalTrials.gov Identifier: NCT03511001.

Longitudinal assessment of lung function in children with sickle cell disease.

OBJECTIVES: To prospectively assess longitudinal lung function in children with sickle cell disease (SCD). WORKING HYPOTHESIS: Lung function in SCD children deteriorates with increasing age and the decline is more marked in younger children who have recently suffered ACS episodes. STUDY DESIGN: Two prospective longitudinal studies. PATIENT-SUBJECT SELECTION: Two cohorts of SCD children and age and ethnic matched controls were recruited. Cohort One (47 SCD and 26 controls) had a median age of 8.8 years and follow up of 2 years and Cohort Two (45 SCD and 26 controls) a median age of 10.2 years and follow up of 10 years. METHODOLOGY: Forced expiratory volume in one second (FEV1 ), vital capacity (VC), forced expiratory flow between 25% and 75% of VC (FEF 25-75 ), total lung capacity (TLC) and residual volume (RV) were measured on two occasions. RESULTS: In both groups of SCD children, lung function declined significantly, but in neither control group. ACS episodes were more frequent during the follow up period in Cohort One than Cohort Two (P < 0.0001). The rate of decline was greater in Cohort One than Cohort Two for FEV1 (P = 0.008), VC (P = 0.001), FEF25-75 (P = 0.030), TLC (P = 0.004), and RV (P = 0.043). In Cohort Two restrictive abnormalities were more common at follow up (P = 0.006). CONCLUSIONS: Lung function deteriorated with increasing age in SCD children and the rate of decline was greater in younger children in whom ACS episodes were more common. Pediatr Pulmonol. 2016;51:717-723. © 2015 Wiley Periodicals, Inc.

Assessment of Small Airways with Computed Tomography: Mosaic Attenuation or Lung Density?

BACKGROUND: Computed tomography (CT) assessment of air trapping has been considered useful as a measure of small airway disease. Mean lung density (MLD) and the percentage of the lung field occupied by low attenuation area (LAA%) can be evaluated automatically, and their expiratory/inspiratory (E/I) ratios correlate with asthma severity and spirometry parameters. However, mosaic attenuation, another indicator of air trapping, has been assessed visually, and its functional relevance remains controversial. OBJECTIVES: This retrospective study was conducted to correlate mosaic attenuation, which was assessed visually and automatically, and the E/I ratios of MLD and LAA% (defined as areas <-960 Hounsfield units) with clinical and physiological variables, including impulse oscillometry (IOS) indices. MATERIAL AND METHODS: In 36 nonsmoking patients with stable asthma, the lungs were scanned at full inspiration and full expiration. Mosaic attenuation was measured visually and automatically, by counting areas with CT values higher than the surrounding areas. MLD and LAA% were measured using our validated method. Spirometry, IOS, exhaled NO and the sputum eosinophil count were evaluated. RESULTS: The automatic results and visual scores of mosaic attenuation correlated well on expiratory scans (r = 0.894) and to a lesser degree on inspiratory scans (r = 0.629; p < 0.0001 for both). However, only the E/I ratios of MLD and LAA% correlated with forced expiratory volume in 1 s/forced vital capacity of spirometry and the IOS indices of resistance from 5 to 20 Hz and the integrated area of low-frequency reactance. CONCLUSIONS: Our automatic method for analysis of mosaic attenuation is likely useful, but the results themselves may not be reflecting small airway involvement of asthma, unlike the E/I ratios of MLD and LAA%.

Understanding the contribution of native tracheobronchial structure to lung function: CT assessment of airway morphology in never smokers.

BACKGROUND: Computed tomographic (CT) airway lumen narrowing is associated with lower lung function. Although volumetric CT measures of airways (wall volume [WV] and lumen volume [LV]) compared to cross sectional measures can more accurately reflect bronchial morphology, data of their use in never smokers is scarce. We hypothesize that native tracheobronchial tree morphology as assessed by volumetric CT metrics play a significant role in determining lung function in normal subjects. We aimed to assess the relationships between airway size, the projected branching generation number (BGN) to reach airways of <2mm lumen diameter -the site for airflow obstruction in smokers- and measures of lung function including forced expiratory volume in 1 second (FEV1) and forced expiratory flow between 25% and 75% of vital capacity (FEF 25-75). METHODS: We assessed WV and LV of segmental and subsegmental airways from six bronchial paths as well as lung volume on CT scans from 106 never smokers. We calculated the lumen area ratio of the subsegmental to segmental airways and estimated the projected BGN to reach a <2mm-lumen-diameter airway assuming a dichotomized tracheobronchial tree model. Regression analysis was used to assess the relationships between airway size, BGN, FEF 25-75, and FEV1. RESULTS: We found that in models adjusted for demographics, LV and WV of segmental and subsegmental airways were directly related to FEV1 (P <0.05 for all the models). In adjusted models for age, sex, race, LV and lung volume or height, the projected BGN was directly associated with FEF 25-75 and FEV1 (P = 0.001) where subjects with lower FEV1 had fewer calculated branch generations between the subsegmental bronchus and small airways. There was no association between airway lumen area ratio and lung volume. CONCLUSION: We conclude that in never smokers, those with smaller central airways had lower airflow and those with lower airflow had less parallel airway pathways independent of lung size. These findings suggest that variability in the structure of the tracheobronchial tree may influence the risk of developing clinically relevant smoking related airway obstruction.

Assessment of spirometry and impulse oscillometry in relation to asthma control.

INTRODUCTION: Guidelines advocate the use of spirometry to assess pulmonary function in asthmatic patients. Commonly used measures include forced expiratory volume in 1 s (FEV1), forced expiratory ratio (FEV1/FVC), and forced mid-expiratory flow between 25 and 75 % of forced vital capacity (FEF25-75). Impulse oscillometry (IOS) is an effort-independent test performed during tidal breathing. IOS may be used to assess the total and central airway resistance at 5 Hz (R5) and 20 Hz (R20), respectively, and hence derive the peripheral airway resistance from the difference (R5-R20). We compared spirometry and IOS as tests of global airway function (i.e., FEV1, FEV1/FVC, R5) and putative measures of small airways function (i.e., FEF25-75, R5-R20) and their relationship to oral steroid and short-acting beta-agonist (SABA) use as surrogates for long-term asthma control. METHODS: Spirometry and IOS measurements from physician-diagnosed asthmatics were linked to a health informatics database for oral steroid and SABA use 1 year prior to the index measurements. RESULTS: Four hundred forty-two patients had both spirometry and IOS, mean FEV1 = 86 % predicted, 94 % on ICS, median dose 800 µg/day. IOS and spirometry measures were equally predictive of impaired asthma control for both oral steroid and SABA use. For oral steroid use, the adjusted odds ratio, OR (95 % CI) is as follows: FEV1 < 80 %: 1.56(0.99-2.47), p = 0.056; FEV1/FVC < 0.70: 1.67(1.03-2.69), p = 0.037; FEF25-75 < 60 %: 1.84(1.18-2.86), p = 0.007; R5 > 150 %: 1.91(1.25-2.95), p = 0.003; and R5-R20 > 0.1 kPa L(-1) s 1.73(1.12-2.66), p = 0.013. For SABA use, the adjusted OR (95 % CI) is as follows: FEV1 < 80 %: 2.22(1.43-3.44), p < 0.001; FEV1/FVC < 0.70: 2.26(1.44-3.57), p < 0.001; FEF25-75 < 60 %: 2.51(1.65-3.82), p < 0.001; R5 > 150 %: 1.76(1.18-2.63), p = 0.006; and R5-R20 > 0.1 kPa L(-1) s: 2.94(1.94-4.46), p < 0.001. CONCLUSION: Spirometry or IOS measurements were equally useful as potential markers of asthma control in persistent asthmatic patients.

Visual analogue scale assessment of nasal obstruction might define patients candidates to spirometry.

BACKGROUND: Asthma may be frequently associated with allergic rhinitis. Bronchial obstruction is a characteristic of asthma and spirometry is a cardinal step in asthma diagnosis. However, spirometry is rarely suitable in medical office. Visual Analogue Scales (VAS) is frequently used in common practice. OBJECTIVE: This study aimed at evaluating the suitability of the use of VAS assessment of nasal obstruction to define patients with allergic rhinitis candidates for spirometry. METHODS: 1728 patients with allergic rhinitis were consecutively evaluated. Clinical examination, skin prick test, VAS assessment, and spirometry were performed in all patients. RESULTS: 7.9% of patients had impaired FEV1 values and 24.5% had impaired FEF25-75 values. A VAS value < 3.3 might identify with good reliability patients with impaired FEF25-75 values, such as having initial bronchial airflow limitation. CONCLUSIONS: This study, performed in a large cohort of subjects, highlights the close link between upper and lower airways and shows the possible suitability of the use of nasal obstruction VAS assessment to define patients with allergic rhinitis candidates for spirometry.

Assessment of airway inflammation using sputum, BAL, and endobronchial biopsies in current and ex-smokers with established COPD.

RATIONALE: Smoking effects on physiological and gross pathology in chronic obstructive pulmonary disease (COPD) are relatively well described. However, there is little known in COPD about the detailed interrelationships between lung function and inflammatory profiles in different airway compartments from the same individual and whether airway inflammation in these different compartments differs in ex- and current smokers with established COPD. OBJECTIVES: We compared sputum, bronchoalveolar (BAL), and airway wall inflammatory profiles in current versus ex-smokers and related this to smoking intensity and lung function in 17 current and 17 ex-smokers with mild to moderate COPD. RESULTS: Current smokers had more sputum mast cells (% differential and absolute numbers), whereas ex-smokers had increased sputum neutrophils. In BAL, there was a significant increase in eosinophils in current smokers, but ex-smokers had significantly increased neutrophils, lymphocytes, and epithelial cells. There were no cell profile differences observed in airway biopsies between current and ex-smokers and there were no correlations between the individual inflammatory cell populations in any of the airway compartments. In current smokers only, smoking intensity was negatively correlated with lung function, and associated with a reduction in overall cellularity of both sputum and BAL. CONCLUSION: Airway inflammation persists in ex-smokers with COPD, but differs from COPD current smokers. The impact of smoking appears to vary in different airway compartments and any direct relationships between cellularity and lung function tended to be negative, ie, worse lung function indicated the presence of fewer cells.

Effect of exposure to traffic on lung development from 10 to 18 years of age: a cohort study.

BACKGROUND: Whether local exposure to major roadways adversely affects lung-function growth during the period of rapid lung development that takes place between 10 and 18 years of age is unknown. This study investigated the association between residential exposure to traffic and 8-year lung-function growth. METHODS: In this prospective study, 3677 children (mean age 10 years [SD 0.44]) participated from 12 southern California communities that represent a wide range in regional air quality. Children were followed up for 8 years, with yearly lung-function measurements recorded. For each child, we identified several indicators of residential exposure to traffic from large roads. Regression analysis was used to establish whether 8-year growth in lung function was associated with local traffic exposure, and whether local traffic effects were independent of regional air quality. FINDINGS: Children who lived within 500 m of a freeway (motorway) had substantial deficits in 8-year growth of forced expiratory volume in 1 s (FEV(1), -81 mL, p=0.01 [95% CI -143 to -18]) and maximum midexpiratory flow rate (MMEF, -127 mL/s, p=0.03 [-243 to -11), compared with children who lived at least 1500 m from a freeway. Joint models showed that both local exposure to freeways and regional air pollution had detrimental, and independent, effects on lung-function growth. Pronounced deficits in attained lung function at age 18 years were recorded for those living within 500 m of a freeway, with mean percent-predicted 97.0% for FEV1 (p=0.013, relative to >1500 m [95% CI 94.6-99.4]) and 93.4% for MMEF (p=0.006 [95% CI 89.1-97.7]). INTERPRETATION: Local exposure to traffic on a freeway has adverse effects on children's lung development, which are independent of regional air quality, and which could result in important deficits in attained lung function in later life.

Assessment of mid flow rate measurements in patients undergoing methacholine challenge.

The objective of this study is to assess the FEF(25-75) and FEF(25-75)/FVC in relation to the FEV1 in patients who have had a methacholine inhalation challenge study for a variety of clinical indications. The study is a retrospective review of methacholine challenge results at the university medical center. One hundred twenty-one consecutive patients who had a methacholine challenge performed for clinical indications were included in the study with no intervention. Methacholine was administered in successively increasing twofold concentrations in doses from 0.62 mg to a final concentration of 10 mg. A 20% drop in FEV1 compared to the prechallenge value was considered a positive test. We considered > or = 25% decrease in FEF(25-75) as a significant change. The > or = 25% decrease in FEF(25-75) occurred sooner than the 20% drop in FEV1 with a positive response occurring at least one full dose sooner in 23 of the 55 subjects. Thirty two subjects reacted at the same dose. The dose at which the FEF(25-75) decreased by > or = 25% was significantly different from the corresponding dose causing a 20% decrease in FEV1. The FEF(25-75) decreases more per mg methacholine. There were no subjects in whom there was > or = 20% decrease in FEV1 without a > or = 25% decrease in FEF(25-75). The mean FEF(25-75)/FVC after diluent inhalation = 0.87 +/- 0.27 standard deviation with a range of 0.23 to 1.67. The doses at which the FEF(25-75)/FVC decreased by > or = 20% and by > or = 30% was significantly lower than the corresponding doses causing a 20% decrease in FEV1. FEF(25-75) and the FEF(25-75)/FVC are more sensitive but less specific than the FEV1 as indicators of a positive response to a methacholine challenge. The FEF(25-75)/FVC does not provide additional information to that provided by the FEF(25-75).

Assessment of pulmonary function in patients before and after laparoscopic and open esophagogastric surgery.

BACKGROUND: Laparoscopy is a technique used in various surgical procedures. Few studies in the literature compare stress between laparoscopic and open surgery used for esophagogastric surgical procedures. Pulmonary function is known to be significantly affected in open surgeries, increasing postoperative morbidity and mortality. The current study aimed to assess pulmonary function in patients before and after open and laparoscopic esophagogastric surgery. METHODS: For this study, 75 patients were divided into two groups: 50 patients undergoing laparoscopy and 25 patients undergoing open surgery. The following parameters were determined by spirometry before and after surgery: forced expiratory volume in the first second (FEV(1)), forced vital capacity (FVC), and forced expiratory flow in the midexpiratory phase (FEF(25-75%)). RESULTS: A decrease in FEV(1,) FVC, and FEF((25-75%)) was observed in the two groups on postoperative days 2, 3, and 4, as compared with the preoperative period. Likewise, FEV(1) and FVC showed a significant reduction on postoperative days 2, 3, and 4 in the patients who underwent to open surgery, but only on the day 2 in those who underwent to laparoscopic surgery. A significant decrease in FEF((25-75%)) was observed only on postoperative day 2 in the group that underwent open surgery. Significant differences in FEV(1) between the groups were observed on postoperative days 2, 3, and 4. No significant difference in FVC was noted between the groups, and a difference in FEF((25-75%)) was observed only on postoperative day 4. CONCLUSIONS: Postoperative pulmonary dysfunction was more important for the patients undergoing open surgery than for those undergoing laparoscopic surgery.

Forced expiratory maneuvers in very young children. Assessment of flow limitation.

The application of negative expiratory pressure (NEP) to the airway opening during forced expiratory maneuvers has recently been described as a noninvasive method to assess whether flow limitation is achieved in adults. This methodology has great potential for extending the measurement of forced expiratory maneuvers to young children who may not produce maximal efforts as reproducibly as adults. We used NEP to assess flow limitation in 10 children between 3 and 5 yr of age. NEP was well tolerated by all subjects. With the application of NEP, there was not a step increase in flow, a finding consistent with flow limitation for the subjects. In addition to visual inspection, we proposed a method to quantify the change in flow during a short NEP. The flow-volume curves obtained with and without NEP were visually the same, other than the flow transients produced by NEP. The calculated values of FVC and FEF25-75 were not significantly different when measured from flow- volume curves with and without NEP. There was a statistically significant increase in FEV1 with NEP; however, the group mean increase in FEV1 was less than 2%. We conclude that NEP may be a useful technique to determine whether flow limitation has been achieved in young children performing forced expiratory maneuvers.

Prospective evaluation of resting energy expenditure, nutritional status, pulmonary function, and genotype in children with cystic fibrosis.

Growth failure and malnutrition are common clinical features in cystic fibrosis (CF), but the relationships among resting energy expenditure (REE), pulmonary function, and nutritional status, are poorly understood. To better understand these relationships, REE, growth, nutritional status, and pulmonary function were measured prospectively in 25 prepubertal children with CF and 26 prepubertal control subjects of similar age and gender over a 3-y period. All subjects with CF had pancreatic insufficiency and mild pulmonary disease. REE was elevated for the CF children compared with control subjects throughout the study. This increased REE was not associated with declining pulmonary function. Longitudinal analyses revealed different patterns of change over time in boys and girls, such that REE significantly increased in the girls with CF and pulmonary function decreased in the boys. Boys with CF experienced a decline in weight Z score and percent ideal body weight, whereas the girls with CF experienced a decline in height Z score. Pulmonary function was not associated with REE, but nutritional status (percent ideal body weight) and genotype (delta F508 homozygotes versus others) were predictive of changes in pulmonary function over time. Fat free mass and height were found to be the best predictors of REE, and after accounting for these important body size and composition variables, differences in REE between boys and girls and CF and control groups increased over time. These findings identify the importance of investigating gender differences in the course of disease and considering REE as an early indicator of disease severity independent of pulmonary function.

Assessment of respiratory limitation in activities of daily life among retired workers.

Epidemiologic studies of occupational lung diseases generally compare symptoms and pulmonary function between groups with differing exposure risks. However, the functional consequences (e.g., on activities of daily life) of statistically significant group differences in either symptoms or pulmonary function are rarely addressed. An understanding of this is important for both the scientific investigators and users of these public health investigations. To address this issue, we developed a 15-item questionnaire to assess breathing-related limitations in activities of daily life, and applied this in a study of 112 retired workers. For each subject, we calculated a limitation score as the number of items associated with breathing difficulty divided by the total number of applicable items. Results from this questionnaire were compared to respiratory symptoms, the Sickness Impact Profile (SIP), lung function test results, 6-min walking distance, and participants' assessment of breathing effort after the walk. The limitation score was significantly higher in subjects reporting dyspnea (22% versus 4%, p < 0.01) or occasional wheeze (27% versus 6%, p < 0.01), and correlated negatively with FEV1, MMEF, and FEV1/FVC (R2 = -0.47, -0.36, and -0.45, respectively, p < 0.0001) and breathing effort after the 6-min walk (R2 = 0.31, p < 0.01). Breathing related limitation in daily activities was also associated with a general health related limitation in household maintenance and ambulation in the SIP (p < 0.01). For each questionnaire item, we compared the responses among subjects with a normal FEV1 to those of subjects with an abnormal FEV1 (below the lower 95% confidence limit).(ABSTRACT TRUNCATED AT 250 WORDS)

Twice-daily peak expiratory flow rate monitoring for the assessment of childhood asthma.

The reliability of the home recording of peak expiratory flow rate (PEFR) in 31 newly diagnosed school-aged asthmatic children was monitored. The patients recorded their PEFR values in the morning and at bedtime and filled in their diary cards for 14 days. The mean amplitude of PEFR variation between the highest and lowest daily recordings varied from 1.9 to 34.4% (mean 6.7%) of the daily mean. Seven children, six of whom belonging to the most seriously affected half in the group had two or more daily PEFR variations of 15% or higher, but only two of them had their mean amplitude of variation at that limit or more. When the whole group was considered, however, no significant correlation was found between the mean amplitude of PEFR variation and the symptom score, the medication needed, baseline FEV1/FVC, or the methacholine threshold. The findings indicate that twice-daily PEFR monitoring may help the physician detect some troublesome cases of childhood asthma, but it is of limited value for diagnostic purposes or when assessing the degree of severity of asthma in routine clinical work.

The importance of spirometry in the assessment of childhood asthma.

OBJECTIVE: To assess the pulmonary function of children with asthma at the time of a routine follow-up visit when they were judged to be clinically well. DESIGN: Pulmonary function tests were performed on children with a previous diagnosis of asthma. None had had any symptoms for at least 6 weeks. All had normal Wright peak flow rates and normal findings at physical examination. SETTING: General pediatric and pediatric pulmonary clinic at a municipal hospital in the Bronx, NY. PATIENTS: Sixty-five children with asthma who fit the above criteria. All were able to perform spirometry adequately. Their mean (+/- SD) age was 11 +/- 3 years, and their median age was 10 years. SELECTION PROCEDURES: All clinic patients were screened as possible participants. The 65 patients were deemed eligible, and were willing and able to perform spirometry. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The group's mean (+/- SD) forced expiratory volume in 1 second/forced vital capacity ratio was 80% +/- 8%, and their mean mid-maximal expiratory flow was 66% +/- 23% of the predicted value. Of the 65 patients, 11 (17%) had forced expiratory volume in 1 second/forced vital capacity ratios of less than 72%, and 35 (54%) had a mid-maximal expiratory flow of less than 65% of the predicted value. CONCLUSION: Failure to perform spirometry in children with asthma results in underdiagnosis of airflow obstruction. This may result in obstruction persisting into adulthood and/or progression to hyperinflation.

Relationship of pulmonary function to radiographic interstitial fibrosis in 2,611 long-term asbestos insulators. An assessment of the International Labour Office profusion score.

Radiographic evidence of interstitial fibrosis (IF) secondary to asbestos inhalation (using the International Labour Office [ILO] profusion of small irregular opacities) was compared with FVC as an independent indicator of IF. In addition, spirometric indices of airflow (FEV1/FVC and FET25-75%) were correlated with the radiographic profusion score. A study of 2,611 long-term insulators was well designed for these analyses since all subjects were from the same trade, there were sufficient (n = 515) nonsmokers to assess the effects of asbestos exposure in the absence of smoking, most (60%, n = 1,557) of the workers had parenchymal abnormalities (scores greater than or equal to 1/0), and there was a greater prevalence of high scores than in other published series (347 workers or 13.3% had scores greater than or equal to 2/1). Looking at all subjects, the FVC decreased as profusion score increased. The FVC was abnormal (88.0% of predicted) even when the profusion score was clearly normal (0/0). The FVC was lower at any score in smokers and in workers with pleural thickening (more so with diffuse thickening). There was, however, no difference in FVC between intermediate scores 0/1 versus 1/0 and 1/2 versus 2/1. Airflow increased with greater profusion, tending to overcome a decrease seen at lesser profusion scores. These results provide a greater understanding of the relationships among profusion scores, smoking, pleural diseases, and pulmonary function.

Familial factors related to lung function in children aged 6-10 years. Results from the PAARC epidemiologic study.

Familial factors related to lung function between six and 10 years of age have been studied among 1,160 children whose both parents were examined in 1975 in the French PAARC (Pollution Atmosphérique et Affections Respiratoires Chroniques) Cooperative Study. The three indices FVC (forced vital capacity), FEV1 (forced expiratory volume in one second), and FEF25-75 (forced expiratory flow between 25 and 75 per cent of the vital capacity) were studied after adjustment for sex, town, age, and height (and weight for children's FVC and FEV1). Maternal (but not paternal) smoking was associated with a significant decrease in FEV1 and FEF25-75, but not in FVC. Familial resemblance was observed for all indices between children and parents and between siblings. None of the environmental factors considered (i.e., parental smoking or education) or body habitus explained the familial resemblance observed. Conversely, after taking into account the aggregation between siblings, associations between children's lung function and parental characteristics (smoking, lung function) remained significant. Parental-children correlations exhibited an increasing temporal trend with increasing age of the children. All but one correlation for FVC, FEV1, and FEF25-75 residuals of children with mothers' residuals were higher in the oldest age group compared with the youngest age group at the 0.10 level. Furthermore, correlations between siblings of opposite sex were significantly lower than correlations between siblings of like sex, especially for FEV1/FVC and FEF25-75/FVC. Results suggest that different growth patterns between boys and girls may be a critical factor in the study of lung function familial resemblance.

Vascular ring: clinical and physiological assessment of pulmonary function following surgical correction.

Twelve children were evaluated 7.1 years (mean) after surgical repair of a vascular ring causing tracheal compression. Nine patients complained of persistent respiratory symptoms, mostly cough, dyspnea, and/or wheezing. Functional evaluation revealed abnormal spirometry and/or lung volumes in seven subjects. Analysis of maximal expiratory-inspiratory flow-volume loops suggested the presence of residual upper airway obstruction in three patients and peripheral airway obstruction in three others. Eleven patients demonstrated bronchial hyperreactivity to histamine.