American journal of respiratory and critical care medicine
-
Am. J. Respir. Crit. Care Med. · Jul 2019
Childhood Body Composition Trajectories and Adolescent Lung Function: Findings from the ALSPAC Study.
Rationale: Body composition changes throughout life may explain the inconsistent associations reported between body mass index and lung function in children. Objectives: To assess the associations of body weight and composition trajectories from 7 to 15 years with lung function at 15 years and lung function growth between 8 and 15 years. Methods: Sex-specific body mass index, lean body mass index, and fat mass index trajectories were developed using Group-Based Trajectory Modeling on data collected at least twice between 7 and 15 years from 6,964 children (49% boys) in the UK Avon Longitudinal Study of Parents and Children birth cohort. ⋯ Higher lean body mass index trajectories were associated with higher levels and growth rates of FVC, FEV1, and forced expiratory flow, midexpiratory phase in both sexes (e.g., boys in the highest lean body mass index trajectory had on average a 0.62 L [95% confidence interval, 0.44-0.79; P trend < 0.0001] higher FVC at 15 yr than boys in the lowest trajectory). Increasing fat mass index trajectories were associated with lower levels and growth rates of FEV1 and forced expiratory flow, midexpiratory phase only in boys and lower levels of FEV1/FVC in both sexes. Conclusions: Higher lean body mass during childhood and adolescence is consistently associated with higher lung function at 15 years in both sexes, whereas higher fat mass is associated with lower levels of only some lung function parameters.
-
Am. J. Respir. Crit. Care Med. · Jul 2019
Airway Bacterial Load and Inhaled Antibiotic Response in Bronchiectasis.
Rationale: The principal underlying inhaled antibiotic treatment in bronchiectasis is that airway bacterial load drives inflammation, and therefore antibiotic treatment will reduce symptoms. Objectives: To determine the relationship between bacterial load and clinical outcomes, assess the stability of bacterial load over time, and test the hypothesis that response to inhaled antibiotics would be predicted by baseline bacterial load. Methods: We performed three studies. ⋯ The proportion of patients who achieved an increase above the minimum clinically important difference was higher in the aztreonam group at Week 4 (63% vs. 37%; P = 0.01) and at Week 12 (62% vs. 38%; P = 0.01) only in high bacterial load patients. Conclusions: Improvement of quality of life with inhaled aztreonam was only evident in patients with high bacterial load. Bacterial load may be a useful biomarker of severity of disease and treatment response.
-
Am. J. Respir. Crit. Care Med. · Jul 2019
Protein Phosphatase 2A Reduces Cigarette Smoke-Induced Cathepsin S and Loss of Lung Function.
Rationale: CTSS (cathepsin S) is a cysteine protease that is observed at higher concentrations in BAL fluid and plasma of subjects with chronic obstructive pulmonary disease (COPD). Objectives: To investigate whether CTSS is involved in the pathogenesis of cigarette smoke-induced COPD and determine whether targeting upstream signaling could prevent the disease. Methods: CTSS expression was investigated in animal and human tissue and cell models of COPD. ⋯ Enhancement of PP2A activity prevented chronic smoke-induced COPD in mice. Conclusions: Our study indicates that the decrease in PP2A activity that occurs in COPD contributes to elevated CTSS expression in the lungs and results in impaired lung function. Enhancing PP2A activity represents a feasible therapeutic approach to reduce CTSS activity and counter smoke-induced lung disease.