FEV1 and FVC as robust risk factors for cardiovascular disease and mortality: Insights from a large population study

INTRODUCTION

Data is limited on influence of forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) in a large adult population, including individuals with normal spirometry at baseline.

METHODS

Using the UK Biobank cohort, a multivariable Cox regression analysis was conducted on 406,424 individuals to examine the association between FEV1 and FVC, categorized into three groups based on their percentage of predicted values (%pred) (≥80, 60-80 and < 60), and overall mortality, cardiovascular mortality, myocardial infarction, stroke, and heart failure over approximately 12.5 years. Moreover, a subgroup analysis was conducted on 295,459 individuals who had normal spirometry.

RESULTS

Reduced FEV1 and FVC %pred values were associated with an elevated risk across all studied outcomes. Individuals with the lowest FEV1 and FVC %pred values (<60 %) exhibited HR of 1.83 (95 % CI 1.74-1.93) and 1.98 (95 % CI 1.76-2.22) for overall mortality, and 1.96 (95 % CI 1.83-2.1) and 2.26 (95 % CI 1.94-2.63) for cardiovascular mortality. Moreover, a graded association was observed between lower FEV1 and FVC %pred, even among never smokers and individuals with normal spirometry at baseline.

DISCUSSION

Reduced FEV1 and FVC represent robust risk factors for cardiovascular disease and mortality. The fact that the increased risk was evident also at FEV1 and FVC levels exceeding 80 %pred challenges the contemporary classification of lung function categories and the notion that the entire FEV1- and FVC-range above 80 % of predicted represents a normal lung function.

Association between chronic psychoactive substances use and systemic inflammation: A systematic review and meta-analysis

This systematic review and meta-analysis assess the change in inflammation biomarkers level among chronic psychoactive substance users. To meet the required inclusion criteria, all studies had to describe human participants with an age ≥18y., experiencing chronic psychostimulant (nicotine, amphetamine, cocaine), sedative (benzodiazepine, opioids) and/or cannabinoid use. The comparison group was defined as healthy participants. Studies where included if they reported at least one of the pro/inflammatory biomarkers. Study bias was examined by Funnel plots and heterogeneity by computing the I² statistics. Only 21 eligible studies were selected based on 26,216 study participants. A small and significant effect size of 0.18 mg/l (95 % CI:0.10-0.27) was detected in favour of chronic smokers (z = 4.33;P < 0.0001). There was evidence of publication bias for studies measuring IL-6 and IL-10 association with cocaine and IL-6 in association with cannabis. In summary, except for chronic tobacco users, there was no evidence of association between other chronic substances abuse and inflammatory levels. More studies are needed to inform policy and decision makers about the utility of anti-inflammatory based targeted intervention programmes.

COPD beyond proximal bronchial obstruction: phenotyping and related tools at the bedside

Chronic obstructive pulmonary disease (COPD) is characterised by nonreversible proximal bronchial obstruction leading to major respiratory disability. However, patient phenotypes better capture the heterogeneously reported complaints and symptoms of COPD. Recent studies provided evidence that classical bronchial obstruction does not properly reflect respiratory disability, and symptoms now form the new paradigm for assessment of disease severity and guidance of therapeutic strategies. The aim of this review was to explore pathways addressing COPD pathogenesis beyond proximal bronchial obstruction and to highlight innovative and promising tools for phenotyping and bedside assessment. Distal small airways imaging allows quantitative characterisation of emphysema and functional air trapping. Micro-computed tomography and parametric response mapping suggest small airways disease precedes emphysema destruction. Small airways can be assessed functionally using nitrogen washout, probing ventilation at conductive or acinar levels, and forced oscillation technique. These tests may better correlate with respiratory symptoms and may well capture bronchodilation effects beyond proximal obstruction.Knowledge of inflammation-based processes has not provided well-identified targets so far, and eosinophils probably play a minor role. Adaptative immunity or specific small airways secretory protein may provide new therapeutic targets. Pulmonary vasculature is involved in emphysema through capillary loss, microvascular lesions or hypoxia-induced remodelling, thereby impacting respiratory disability.

Endothelial dysfunction is associated with impaired lung function in two independent community cohorts

BACKGROUND

Prior studies investigating the association between endothelial dysfunction and impaired lung function have been small and inconsistent. The primary aim was to investigate the association between endothelial function and lung function in two community-based cohorts.

METHODS

We used a discovery/replication approach to study the association between endothelial function and lung function in the Prospective investigation of Obesity, Energy and Metabolism (POEM, discovery cohort, n = 490, mean age 50.3 ± 0.2 years) and the Prospective Study of the Vasculature in Uppsala Seniors (PIVUS, replication cohort, n = 892, mean age 70.2 ± 0.15 years). Spirometry and three different measures of endothelial function were performed including both the invasive forearm technique (endothelium-dependent and endothelium-independent vasodilation [EDV and EIDV, respectively] and noninvasive flow mediated dilation [FMD]).

RESULTS

An age and sex adjusted association between lower EDV and lower FEV₁ was found in POEM and replicated in PIVUS. After merging the two cohorts, 1 standard deviation decrease in EDV was associated with 1.57% lower FEV₁ after additional adjustment for smoking status, body mass index, exercise level, and C-reactive protein (95% confidence intervals 0.63-2.51, p = 0.001). The association was slightly lower albeit still statistically significant after excluding participants without cardiovascular disease and chronic respiratory disease and appeared stronger among previous/current smokers vs. non-smokers and in men vs. women (p for interaction = 0.2 and 0.02 respectively).

CONCLUSIONS

Our findings suggest that even individuals with sub-clinical impairments of lung function in the community have concomitant endothelial dysfunction.

Airway and Pulmonary β2-Adrenergic Vasodilatory Function in Current Smokers and Never Smokers

BACKGROUND

Cigarette smoking has been associated with diminished vasodilatory function in the airway circulation. It is possible that cigarette smoking similarly affects the pulmonary circulation before resting pulmonary circulatory abnormalities become manifested. The aim of this study was to compare the acute effect of inhaled albuterol on airway and pulmonary hemodynamic function as an index of β₂-adrenoceptor-mediated vasodilation in smokers and never smokers.

METHODS

In 30 adults, airway and pulmonary vascular function was assessed before and 15 min after albuterol inhalation (270 μg). From mean systemic arterial pressure, cardiac output, airway blood flow, and mean pulmonary arterial pressure, airway vascular resistance (AVR) and pulmonary vascular resistance (PVR) were derived.

RESULTS

Albuterol induced a substantial drop in mean (± SE) PVR (-67.2% ± 5%), with no difference between groups. In contrast, the albuterol-induced decrease in AVR was significantly greater in never smokers than in smokers (-28.6% ± 3% vs -3.1% ± 6%; P < .02).

CONCLUSIONS

These results are consistent with a dysfunction in a β₂-adrenergic signaling pathway mediating vasorelaxation in the airway circulation of current smokers. The vasodilatory deficit in the airway circulation but not in the pulmonary circulation could be related to local differences in the impact of cigarette smoke on the vascular endothelium.

Are healthy smokers really healthy?

Cigarette smoke contains more than 4500 chemicals which have toxic, mutagenic and carcinogenic effects. Strong evidences have shown that current smokers take a significantly higher risk of cardiovascular diseases, chronic obstructive pulmonary disease (COPD) and lung cancer than nonsmokers. However, less attention has been paid to the smoking induced abnormalities in the individuals defined as healthy smokers who are normal with spirometry, radiographic images, routine physical exam and categorized as healthy control group in many researches. Actually, ‘healthy smokers’ are not healthy. This narrative review focuses on the smoking related pathophysiologic changes mainly in the respiratory system of healthy smokers, including inflammation and immune changes, genetic alterations, structural changes and pulmonary dysfunction.