Deep inspirations attenuate postprandial airway inflammation in college-aged adults with elevated baseline exhaled nitric oxide: A pilot study

Airway inflammation (assessed by exhaled nitric oxide (eNO)) increases after a single high-fat meal (HFM), yet this response may be modified by airway stretch and baseline eNO level.Purpose: The purpose of this study was to investigate whether deep inspirations (DIs) would attenuate airway inflammation post-HFM and whether this is modulated by baseline eNO level.Methods: A total of sixteen healthy college-aged participants completed a randomized cross-over study with 8 lower eNO (14.8 ± 2.0 ppb: 3 M/5F; age: 22.0 ± 2.2 yrs) and 8 higher eNO (29.3 ± 11.6 ppb 5 M/3F; age: 22.5 ± 2.6 yrs) participants. All participants completed a control (CON) condition (no DIs pre-HFM) and DI condition (60 DI's to total lung capacity immediately pre-HFM) after an overnight fast. The primary outcome was eNO. Participants had 20 minutes to consume the HFM (1 g fat/1 kg body weight) and eNO was performed at 2- and 4- hours post-HFM. To determine whether baseline eNO levels impacted the effect of DI's, a median split was performed on their baseline eNO level.Results: There was a significant increase in eNO as a main effect of time (p < 0.001). However when analyzing the potential effect of baseline eNO, there was no significant increase in eNO post-HFM in the higher eNO group in the DI condition (p = 0.54). DIs modified the eNO response to a HFM in the group with a higher baseline eNO value.Conclusions: These data display a possible bronchoprotective protect of DIs against postprandial airway inflammation in participants with higher initial eNO level.

Older women exhibit greater airway 8-isoprostane responses to strenuous exercise compared with older men and younger controls

Development of late-onset respiratory diseases is associated with elevated 8-isoprostane, a marker of oxidative stress, in the airways. However, sex differences exist in development of these diseases. Using an exhaustive exercise bout as a physiological stressor may elucidate whether there is a sex difference with aging in pre- to postexercise airway 8-isoprostane generation. The purpose of this study was to determine whether older women exhibit a greater airway 8-isoprostane response to exhaustive exercise compared with older men and younger controls. Thirty-six individuals completed the study (12 postmenopausal older women (OW) and 12 age-matched older men (OM), 65 ± 4 years of age; and 12 younger controls (YC), 21 ± 2 years of age). Baseline measurements included exhaled breath condensate (EBC) for assessment of airway 8-isoprostane and standard pulmonary function tests (PFTs) to assess forced expiratory volume in 1-s (FEV₁), forced vital capacity (FVC), FEV₁/FVC, and forced expiratory flow at 25%-75% of FVC. Subjects then performed a peak oxygen uptake test to exhaustion on a cycle ergometer. Immediately postexercise, PFTs and EBC were performed. The generation of airway 8-isoprostane from pre- to postexercise was greater in OW compared with OM and YC (p < 0.01), increasing ∼74% ± 77% in OW, while decreasing in OM (∼12% ± 50%) and YC (∼20.9% ± 30%). The OW exhibited a greater airway 8-isoprostane response to exhaustive exercise compared with OM and YC, which may suggest that sex differences in oxidative stress generation following exhaustive exercise may provide a mechanistic rationale for sex differences in late-onset respiratory diseases.

Does chronic physical activity level modify the airway inflammatory response to an acute bout of exercise in the postprandial period?

Recent studies have confirmed that a single high-fat meal (HFM) leads to increased airway inflammation. However, exercise is a natural anti-inflammatory and may modify postprandial airway inflammation. The postprandial airway inflammatory response is likely to be modified by chronic physical activity (PA) level. This study investigated whether chronic PA modifies the airway inflammatory response to an acute bout of exercise in the postprandial period in both insufficiently active and active subjects. Thirty-nine nonasthmatic subjects (20 active, 13 males/7 females) who exceeded PA guidelines (≥150 min moderate-vigorous PA/week) and 19 insufficiently active (6 males/13 females) underwent an incremental treadmill test to exhaustion to determine peak oxygen uptake. Subjects were then randomized to a condition (COND), either remaining sedentary (CON) or exercising (EX) post-HFM. Exercise was performed at the heart rate corresponding to 60% peak oxygen uptake on a treadmill for 1 h post-HFM (63% fat, 10 kcal/kg body weight). Blood lipids and exhaled nitric oxide (eNO: marker of airway inflammation) were measured at baseline and 2 h and 4 h post-HFM. Sputum differential cell counts were performed at baseline and 4 h post-HFM. The mean eNO response for all groups increased at 2 h post-HFM (∼6%) and returned to baseline by 4 h (p = 0.03). There was a time × COND interaction (p = 0.04), where EX had a greater eNO response at 4 h compared with CON. Sputum neutrophils increased at 4 h post-HFM (p < 0.05). These findings suggest that airway inflammation occurs after an HFM when exercise is performed in the postprandial period, regardless of habitual activity level.

Household Air Pollution Exposure and Influence of Lifestyle on Respiratory Health and Lung Function in Belizean Adults and Children: A Field Study

Household air pollution (HAP) contributes to the global burden of disease. Our primary purpose was to determine whether HAP exposure was associated with reduced lung function and respiratory and non-respiratory symptoms in Belizean adults and children. Our secondary purpose was to investigate whether lifestyle (physical activity (PA) and fruit and vegetable consumption (FV)) is associated with reported symptoms. Belizean adults (n = 67, 19 Male) and children (n = 23, 6 Male) from San Ignacio Belize and surrounding areas participated in this cross-sectional study. Data collection took place at free walk-in clinics. Investigators performed initial screenings and administered questionnaires on (1) sources of HAP exposure; (2) reported respiratory and non-respiratory symptoms and (3) validated lifestyle questionnaires. Participants then performed pulmonary function tests (PFTs) and exhaled breath carbon monoxide (CO). There were no significant associations between HAP exposure and pulmonary function in adults. Increased exhaled CO was associated with a significantly lower forced expiratory volume in 1-s divided by forced vital capacity (FEV₁/FVC) in children. Exposed adults experienced headaches, burning eyes, wheezing and phlegm production more frequently than unexposed adults. Adults who met PA guidelines were less likely to experience tightness and pressure in the chest compared to those not meeting guidelines. In conclusion, adults exposed to HAP experienced greater respiratory and non-respiratory symptoms, which may be attenuated by lifestyle modifications.