Forced expiratory time: a composite of airway narrowing and airway closure.

Forced expiratory time (FET) is a spirometrically derived variable thought to reflect lung function, but its physiological basis remains poorly understood. We developed a mathematical theory of FET assuming a linear forced expiratory flow-volume profile that terminates when expiratory flow falls below a defined detection threshold. FET is predicted to correlate negatively with both FEV and FVC if variations in the rate of lung emptying (relative to normal) among individuals in a population exceed variations in the amount of lung emptying.

BMI but not central obesity predisposes to airway closure during bronchoconstriction.

Background And Objective: Obesity produces restrictive effects on lung function. We previously reported that obese patients with asthma exhibit a propensity towards small airway closure during methacholine challenge which improved with weight loss. We hypothesized that increased abdominal adiposity, a key contributor to the restrictive effects of obesity on the lung, mediates this response.

Is aging a "comorbidity" of asthma?

The aging population is growing at an unparalleled rate. Asthma is common in the elderly (age over 65 years) and can be more severe with little chance for remission. Asthma in older individuals is often under-diagnosed, misdiagnosed and frequently under-treated.

The Effects of Aging on Lung Structure and Function.

Growth of the segment of the population older than 65 years has led to intensified interest in understanding the biology of aging. This article is focused on age-related alterations in lung structure that produce predictable changes in physiologic function, both at rest and during exercise. Increased insight into the physiology of the healthy aging lung should ultimately lead to improved methods of lung function assessment in the elderly (defined as those older than 65 years) as well as better understanding of the manifestations and possibly even the treatment of geriatric lung disease.

Inhaled steroids reduce pain and sVCAM levels in individuals with sickle cell disease: A triple-blind, randomized trial.

Clinical and preclinical data demonstrate that altered pulmonary physiology (including increased inflammation, increased blood flow, airway resistance, and hyper-reactivity) is an intrinsic component of Sickle Cell Disease (SCD) and may contribute to excess SCD morbidity and mortality. Inhaled corticosteroids (ICS), a safe and effective therapy for pulmonary inflammation in asthma, may ameliorate the altered pulmonary physiologic milieu in SCD. With this single-center, longitudinal, randomized, triple-blind, placebo controlled trial we studied the efficacy and feasibility of ICS in 54 nonasthmatic individuals with SCD.

Asthma phenotypes and endotypes: a personalized approach to treatment.

Purpose Of Review: Asthma is quite common and is better described as a syndrome with a heterogeneous presentation than as a single disease. Although most individuals can be effectively managed using a guideline-directed approach to care, those with the most severe illness may benefit from a more targeted therapy. The review describes our current understanding of how asthma phenotypes (observable characteristics) and endotypes (specific biologic mechanisms) can be employed to gain insight into asthma pathobiology and personalized therapy.

"Sarcoid like" granulomatous pulmonary disease in World Trade Center disaster responders.

Background: More than 20,000 responders have been examined through the World Trade Center (WTC) Medical Monitoring and Treatment Program since September 11, 2001. Studies on WTC firefighters have shown elevated rates of sarcoidosis. The main objective of this study was to report the incidence of "sarcoid like" granulomatous pulmonary disease in other WTC responders.

Four-year calibration stability of the EasyOne portable spirometer.

Background: Clinical practice guidelines recommend daily spirometer calibration checks and weekly linearity checks. The long-term stability of the volume and flow accuracy of a specific model of spirometer should be carefully characterized before modification of the frequency of calibration checks is considered for that model of spirometer.

Methods: The EasyOne ultrasonic flow-sensing spirometer was chosen for use by the clinical centers at the 2002 inception of the World Trade Center Worker and Volunteer Medical Screening Program.

Quality of spirometry performed by 13,599 participants in the World Trade Center Worker and Volunteer Medical Screening Program.

Objective: To determine the ability of spirometry technicians in the World Trade Center Worker and Volunteer Medical Screening Program to meet American Thoracic Society spirometry quality goals.

Methods: Spirometry technicians were trained centrally and performed spirometry sessions at 6 sites in the greater New York City area. We reviewed and graded the spirometry results for quality every month.

Longitudinal assessment of spirometry in the World Trade Center medical monitoring program.

Background: Multiple studies have demonstrated an initial high prevalence of spirometric abnormalities following World Trade Center (WTC) disaster exposure. We assessed prevalence of spirometric abnormalities and changes in spirometry between baseline and first follow-up evaluation in participants in the WTC Worker and Volunteer Medical Monitoring Program. We also determined the predictors of spirometric change between the two examinations.

The bronchoprotective effect of deep inspiration is flow rate dependent.

Background And Study Objective: Deep inspiration (DI) protects against methacholine-induced bronchoconstriction in healthy subjects. We hypothesized that this bronchoprotective effect of DI depends upon the inspiratory flow rate.

Design: Prospective, controlled study.

Effect of obesity on clinical presentation and response to treatment in asthma.

Obesity is a risk factor for being diagnosed with asthma, but there is conflicting evidence on whether obesity is a risk factor for lung function abnormalities characteristic of asthma. We studied a cohort of 488 subjects, 47% of whom were obese. Obese and non-obese subjects with asthma had similar airflow limitation and bronchodilator responsiveness, but obese participants had increased sleep disturbance and gastroesophageal reflux disease, higher cytokine levels, and a trend towards increased exacerbations when treated with theophylline.

Nocturnal asthma: mechanisms and management.

Nocturnal asthma, defined as an exacerbation of asthma at night, is associated with increases in symptoms and need for medication, increased airway responsiveness and worsening of lung function. Nighttime worsening of asthma has been recognized since the 5th century A.D.