Circulating biomarkers of airflow limitation across the life span.

BACKGROUND: Airflow limitation is a hallmark of chronic obstructive pulmonary disease, which can develop through different lung function trajectories across the life span. There is a need for longitudinal studies aimed at identifying circulating biomarkers of airflow limitation across different stages of life. OBJECTIVES: This study sought to identify a signature of serum proteins associated with airflow limitation and evaluate their relation to lung function longitudinally in adults and children. METHODS: This study used data from 3 adult cohorts (TESAOD [Tucson Epidemiological Study of Airway Obstructive Disease], SAPALDIA [Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults], LSC [Lovelace Smoker Cohort]) and 1 birth cohort (TCRS [Tucson Children's Respiratory Study]) (N = 1940). In TESAOD, among 46 circulating proteins, we identified those associated with FEV1/forced vital capacity (FVC) percent (%) predicted levels and generated a score based on the sum of their z-scores. Cross-sectional analyses were used to test the score for association with concomitant lung function. Longitudinal analyses were used to test the score for association with subsequent lung function growth in childhood and decline in adult life. RESULTS: After false discovery rate adjustment, serum levels of 5 proteins (HP, carcinoembryonic antigen, ICAM1, CRP, TIMP1) were associated with percent predicted levels of FEV1/FVC and FEV1 in TESAOD. In cross-sectional multivariate analyses the 5-biomarker score was associated with FEV1 % predicted in all adult cohorts (meta-analyzed FEV1 decrease for 1-SD score increase: -2.9%; 95% CI: -3.9%, -1.9%; P = 2.4 × 10-16). In multivariate longitudinal analyses, the biomarker score at 6 years of age was inversely associated with FEV1 and FEV1/FVC levels attained by young adult life (P = .02 and .005, respectively). In adults, persistently high levels of the biomarker score were associated with subsequent accelerated decline of FEV1 and FEV1/FVC (P = .01 and .001). CONCLUSIONS: A signature of 5 circulating biomarkers of airflow limitation was associated with both impaired lung function growth in childhood and accelerated lung function decline in adult life, indicating that these proteins may be involved in multiple lung function trajectories leading to chronic obstructive pulmonary disease.

The relation of circulating YKL-40 to levels and decline of lung function in adult life.

BACKGROUND: YKL-40 is a chitinase-like protein that, in cross-sectional clinical studies, has been associated with severe asthma and COPD in smokers. AIM: To determine the longitudinal relation of circulating YKL-40 to levels and decline of lung function in the general population. METHODS: We used longitudinal data from up to 13 surveys from the population-based TESAOD study which was conducted in Tucson, Arizona between 1972 and 1996. In cross-sectional analyses, we also used data from 3 Spanish centers of the multicenter ECRHS study (ECRHS-Sp). Serum YKL-40 was measured at baseline in TESAOD and in survey 2 in ECRHS-Sp using ELISAs. Multivariate linear regression was used to test associations of serum YKL-40 to concomitant lung function. In TESAOD, random coefficients models were used to test associations of serum YKL-40 to subsequent decline of lung function. RESULTS: Data on YKL-40 and lung function were available from 1088 TESAOD and 854 ECRHS-Sp adult participants (59% and 51% females; respectively). In adjusted multivariate meta-analyses, being in the highest YKL-40 quartile was associated cross-sectionally with significant deficits in FEV1 and FVC %predicted. In adjusted longitudinal analyses, TESAOD participants in the top YKL-40 quartile had an FEV1 decline that was 5 ml/yr (p = 0.05) faster than subjects in the third quartile, 5 ml/yr (p = 0.02) faster than subjects in the second quartile, and 10 ml/yr (p < 0.001) faster than subjects in the lowest YKL-40 quartile. These longitudinal effects were particularly strong in smokers and absent in never smokers. After adjusting for covariates, as compared with the other three quartiles combined, the top YKL-40 quartile was associated with a 9 ml/yr (p = 0.001) faster FEV1 decline among smokers, while no significant effects were found among never smokers (2 ml/yr, p = 0.35). CONCLUSIONS: Circulating YKL-40 is associated with levels and decline of lung function in the general population and may be a biomarker of susceptibility to the long-term effects of cigarette smoking.

Evaluating intense rehabilitative therapies with and without acupuncture for children with cerebral palsy: a randomized controlled trial.

OBJECTIVE: To compare the outcomes of conventional therapies (physical, occupational, and hydrotherapies) plus acupuncture with those without acupuncture when administered intensely in the management of children with spastic cerebral palsy (CP). DESIGN: Evaluation-blind, prospective randomized controlled trial. SETTING: Therapies and video-recorded assessments at a children's hospital in Beijing, China, and blind scoring and data analyses at a university in the United States. PARTICIPANTS: Children (N=75), 12 to 72 months of age, with spastic CP. INTERVENTIONS: Intensely administered (5 times per week for 12wk) physical therapy, occupational therapy, and hydrotherapy either with acupuncture (group 1) or without acupuncture (group 2). To satisfy standard of care, group 2 subsequently received acupuncture (weeks 16-28). MAIN OUTCOME MEASURES: The Gross Motor Function Measure (GMFM)-66 and the Pediatric Evaluation of Disability Inventory (PEDI) assessments at 0, 4, 8, 12, 16, and 28 weeks. RESULTS: At the end of 12 weeks, there was no statistically significant difference between the 2 groups, but when group 2 received acupuncture (16-28wk) there was a shift toward improvement in the GMFM-66 and the PEDI-Functional Skills Self-Care and Mobility domain. When groups were combined, statistically significant improvements after intense therapies occurred from baseline to 12 weeks for each outcome measure at each Gross Motor Function Classification System (GMFCS) level. After adjusting for expected normative maturational gains based on age, the GMFM gains for children with GMFCS II level was statistically significant (P<.05) with a mean gain of 6.5 versus a predicted gain of 3.4. CONCLUSIONS: Intense early administered rehabilitation improves function in children with spastic CP. The contribution from acupuncture was unclear. Children's response varied widely, suggesting the importance of defining clinical profiles that identify which children might benefit most. Further research should explore how this approach might apply in the U.S.

Morbidity and mortality associated with the restrictive spirometric pattern: a longitudinal study.

BACKGROUND: Recent studies have suggested that a restrictive pattern assessed with a single spirometric test is associated with increased morbidity and mortality. This study was undertaken to determine demographic, clinical and mortality profiles of subjects with either a recurrent or an inconsistent restrictive spirometric pattern assessed prospectively. METHODS: Data from 2048 adult participants in the population-based TESAOD study were analysed. Normal (forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) ratio >or=70% and FVC >or=80% predicted), restrictive (FEV(1)/FVC >or=70% and FVC <80% predicted) and obstructive (FEV(1)/FVC <70%) patterns were assessed at the enrollment survey in 1972 and in 11 subsequent follow-up surveys up to 1996. Demographic and clinical characteristics were measured at enrollment and vital status and cause of death were assessed at January 2005. RESULTS: Overall, 12% of participants had a restrictive spirometric pattern at enrollment. They were less likely to be male, to smoke and to have asthma, and had lower IgE levels than subjects in the obstructive group. Among subjects with a restrictive pattern at enrollment, 38% developed an obstructive pattern during follow-up. The remaining 62% had either a recurrent (restrictive pattern >or=50% of follow-up surveys) or inconsistent (restrictive pattern <50% of follow-up surveys) longitudinal restrictive pattern. The recurrent and inconsistent restrictive groups had increased mortality risk for all-cause (adjusted HR 1.7 (95% CI 1.3 to 2.3) and 1.9 (95% CI 1.4 to 2.6), respectively), heart disease (2.0 (95% CI 1.3 to 3.1) and 2.7 (95% CI 1.7 to 4.3)), stroke (2.4 (95% CI 0.9 to 6.3) and 3.5 (95% CI 1.2 to 9.8)) and diabetes (8.0 (95% CI 2.9 to 21.8) and 6.0 (95% CI 1.9 to 19.2)). CONCLUSIONS: The restrictive spirometric pattern identifies a pulmonary condition that is distinguishable from obstructive lung disease and is associated with an increased risk of life-threatening comorbidities.

The course of persistent airflow limitation in subjects with and without asthma.

RATIONALE: Most patients who develop persistent airflow limitation do so either as a manifestation of chronic obstructive pulmonary disease that is largely related to smoking or as a consequence of persistent asthma. We sought to compare the natural course of lung function associated with persistent airflow limitation in subjects with and without asthma from early to late adult life. METHODS: We studied 2552 participants aged 25 or more who had multiple questionnaire and lung function data from the long-term prospective population-based Tucson Epidemiological Study of Airway Obstructive Disease. Persistent airflow limitation was defined as FEV(1)/FVC ratio consistently < 70% in all completed surveys subsequent to the first survey with airflow limitation. Participants were divided into nine groups based on the combination of their physician-confirmed asthma status (never, onset < or = 25 years, or onset > 25 years) and the presence of airflow limitation during the study follow-up (never, inconsistent, or persistent). RESULTS: Among subjects with an asthma onset < or = 25 years, blood eosinophilia increased significantly the odds of developing persistent airflow limitation (adjusted ORs: 3.7, 1.4-9.5), whereas cigarette smoking was the strongest risk factor for persistent airflow limitation among non-asthmatics and among subjects with asthma onset after age 25 years. Among subjects with persistent airflow limitation, the natural course of lung function differed between subjects with asthma onset < or = 25 years and non-asthmatics, with the former having lower FEV(1) levels at age 25 (predicted value for a 175-cm tall male of 3400 versus 4090 ml, respectively; p<0.001) and the latter having greater FEV(1) loss between age 25 and 75 (1590 versus 2140 ml; p=0.003). CONCLUSION: In subjects who have asthma onset before 25 years of age and persistent airflow limitation in adult life, the bulk of the FEV(1) deficit is already established before age 25 years.

Normative psychomotor vigilance task performance in children ages 6 to 11--the Tucson Children's Assessment of Sleep Apnea (TuCASA).

Although the psychomotor vigilance task (PVT) is commonly used in sleep and other research settings, normative data for PVT performance in children have not been published. This report presents normal PVT performance measures among children without a sleep disorder participating in the Tucson Children's Assessment of Sleep Apnea (TuCASA) study. TuCASA is a community-based, prospective study of sleep-disordered breathing in Caucasian and Hispanic children ages 6 to 11 years. A standard 10-min PVT trial was completed by 360 participants-48% female and 36% Hispanic; mean age 8.9 years. Detailed analyses were performed for 162 children with respiratory disturbance indices <1 and no parent-reported sleep problems. Mean and median reaction times (RT) decreased with increasing age (p trend < 0.001). Children ages 6 and 11 had median RTs of 544.24 and 325.70 ms, respectively. Standard deviations in RTs also decreased with increasing age (p trend = 0.001), as did lapses (p trend < 0.001), but no trend was apparent in total errors. There were statistically significant (p = 0.006) differences in the performance of boys and girls. Gender differences were greatest at age 6, where boys had shorter RTs, and decreased with age until performance was approximately equal by age 11. No ethnic differences were detected. Children's PVT performance improves with age and differs by gender. These differences should be considered when the PVT is utilized in pediatric populations.