Reduced lung function predicts increased fatality in future cardiac events. A population-based study

By deflating the lungs pulmonologists help the cardiologists. A literature review

In this review, we present the effects of lung hyperinflation on the cardiovascular system (CVS) and the beneficial outcomes of different deflation treatment modalities. We discuss the effects of long-acting bronchodilator drugs, medical and surgical lung volume reduction on the performance of the CVS. Although there is a small number of studies investigating lung deflation and the CVS, the short-term improvement in heart function was clearly demonstrated. However, more studies, with longer duration, are needed to verify these significant beneficial effects of deflation of the lungs on the CVS. Dynamic hyperinflation during exercise could be a research model to investigate further the effects of lung hyperinflation and/or deflation on the CVS.

The relationship between preserved ratio impaired spirometry and mortality in the myocardial infarction survivors: a population-based cohort study

INTRODUCTION

Preserved ratio impaired spirometry (PRISm) is a subtype of pulmonary function abnormality which is characterized by a proportional reduction in non-obstructive expiratory lung volume. Currently, no studies have shown a relationship between PRISm and mortality in myocardial infarction (MI) survivors.

METHODS

We used cohort data from U.S. adults who attended the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2012. According to the ratio of forced expiratory volume in the first second (FEV1) to forced vital capacity (FVC), we divided lung function into normal spirometry (FEV1/ FVC) ≥ 70%, FEV1 ≥ 80%), PRISm (FEV1/FVC ≥ 70%, FEV1 < 80%) and obstructive spirometry (FEV1/FVC < 70%). Cox regression was used to estimate the correlation between lung functions and mortality among MI patients. Kaplan-Meier survival curves compared the prognosis of MI with three different lung functions. We further verify the stability of the results by sensitivity analysis.

RESULTS

411 subjects were included in our research. The mean follow-up time for the study was 105 months. Compared with normal spirometry, PRISm was significantly correlated with a greater relative risk for all-cause mortality (adjust HR 3.41, 95% confidence interval [95%CI]: 1.76-6.60, P < 0.001) and cardiovascular mortality (adjust HR 13.9, 95%CI: 2.60-74.6, P = 0.002). PRISm remains more correlated with all-cause mortality (adjust HR 2.73, 95%CI: 1.28-5.83, P = 0.009) relative to obstructive spirometry. The results are basically stable after sensitivity analysis. Kaplan-Meier survival curves showed that patients with PRISm tended to have the lowest survival during the follow-up period.

CONCLUSION

PRISm is an independent risk factor for all-cause and cardiovascular mortality in MI survivors. The presence of PRISm was associated with a significantly higher risk of all-cause mortality compared with obstructive spirometry.

Reduced peak expiratory flow predicts increased risk of cardiovascular disease: A 10-year prospective cohort study in Eastern China

BACKGROUND

The correlation between impaired lung function and cardiovascular diseases (CVD) has attracted more and more attention. We aimed to assess the longitudinal association between decreased peak expiratory flow (PEF) and cardiovascular risk among Eastern Chinese general population.

METHODS

In total, 6295 participants aged>30 years and free of CVD at baseline were followed for up to 10 years in Eastern China. The adjusted hazard ratios (HRs) for CVD and mortality associated with decreased PEF were analyzed.

RESULTS

Among all participants, 421 CVD incident events were reported during 10-year follow-up, and a total of 272 participants died during the follow-up period, 94 of them from CVD. The HRs in the lowest group of PEF (PEF ≤218.33 L/min) were 1.31 (95% confidence interval [CI]:1.01 to 1.68) for high CVD incidence (172 vs 116), 2.43 (95% CI:1.72 to 3.42) for all-cause mortality (156 vs 48), and 3.94 (95% CI:1.96 to 7.92) for CVD mortality (59 vs 10) when compared with the highest group (PEF ≥321.68 L/min).

CONCLUSION

The decreased PEF was associated with increased CVD incidence, CVD and all-cause mortality in Eastern Chinese general population.

Low lung function, sudden cardiac death and non-fatal coronary events in the general population

BACKGROUND

Many of those who suffer from a first acute coronary event (CE) die suddenly during the day of the event, most of them die outside hospital. Poor lung function is a strong predictor of future cardiac events; however, it is unknown whether the pattern of lung function impairment differs for the prediction of sudden cardiac death (SCD) versus non-fatal CEs. We examined measures of lung function in relation to future SCD and non-fatal CE in a population-based study.

METHODS

Baseline spirometry was assessed in 28 584 middle-aged subjects, without previous history of CE, from the Malmö Preventive Project. The cohort was followed prospectively for incidence of SCD (death on the day of a first CE, inside or outside hospital) or non-fatal CE (survived the first day). A modified version of the Lunn McNeil's competing risk method for Cox regression was used to run models for both SCD and non-fatal CE simultaneously.

RESULTS

A 1-SD reduction in forced expiratory volume in 1 s (FEV₁) was more strongly associated with SCD than non-fatal CE even after full adjustment (FEV₁: HR for SCD: 1.23 (1.15 to 1.31), HR for non-fatal CE 1.08 (1.04 to 1.13), p value for equal associations=0.002). Similar associations were found for forced vital capacity (FVC) but not FEV₁/FVC. The results remained significant even in life-long never smokers (FEV₁: HR for SCD: 1.34 (1.15 to 1.55), HR for non-fatal CE: 1.11 (1.02 to 1.21), p value for equal associations=0.038). Similar associations were seen when % predicted values of lung function measures were used.

CONCLUSIONS

Low FEV₁ is associated with both SCD and non-fatal CE, but consistently more strongly associated with future SCD. Measurement with spirometry in early life could aid in the risk stratification of future SCD. The results support the use of spirometry for a global assessment of cardiovascular risk.

Low lung function and the risk of incident chronic kidney disease in the Malmö Preventive Project cohort

BACKGROUND

Although the prevalence of kidney disease is higher in those with reduced lung function, the longitudinal relationship between low lung function and future risk of chronic kidney disease (CKD) has not been widely explored.

METHODS

Baseline lung function was assessed in 20,700 men and 7325 women from 1974 to 1992. Mean age was 43.4 (±6.6) and 47.5 (±7.9) for men and women respectively. Sex-specific quartiles of FEV1 and FVC (L) were created (Q4: highest, reference) and the cohort was also divided by the FEV1/FVC ratio (≥ or < 0.70). Cox proportional hazards regression was used to determine the risk of incident CKD events (inpatient or outpatient hospital diagnosis of CKD) in relation to baseline lung function after adjustment for various confounding factors.

RESULTS

Over 41 years of follow-up there were 710 and 165 incident CKD events (main diagnosis) in men and women respectively. Low FEV1 was strongly associated with future risk of CKD in men (Q1 vs Q4 adjusted HR: 1.46 (CI:1.14-1.89), p-trend 0.002). Similar findings were observed for FVC in men (1.51 (CI:1.16-1.95), p-trend 0.001). The adjusted risks were not found to be significant in women, for either FEV1 or FVC. FEV1/FVC < 0.70 was not associated with increased incidence of CKD in men or women.

CONCLUSION

Low FEV1 and FVC levels at baseline are a risk factor for the development of future incident CKD in men. Monitoring kidney function in those with reduced vital capacity in early life could help with identifying those at increased risk of future CKD.

Association of lung function with cardiovascular risk: a cohort study

BACKGROUND

The potential effects of pulmonary dysfunction on cardiovascular diseases (CVD) are receiving attention. We aimed to investigate and quantify the cross-sectional and longitudinal associations between lung function and overall cardiovascular risk among Chinese general population.

METHODS

We studied 4019 participants from the Wuhan-Zhuhai cohort, with a follow-up of 3 years. A multivariable risk algorithm generated from the Framingham study was used to calculate individuals' overall cardiovascular risk i.e. 10-Year CVD Risk, which was further classified into 2 categories: low (< 10%) and high (≥10%) CVD risk. General linear model and logistic regression model were separately used to assess the associations of lung function with continuous and dichotomous 10-Year CVD Risk.

RESULTS

Cross-sectionally, each 5% decrease in FEV₁/FVC was associated with a 0.47% increase in 10-Year CVD Risk (P < 0.001). The adjusted odds ratio (OR) (95% confidence interval [CI]) for the prevalence of high CVD risk (10-Year CVD Risk≥10%) was 1.12 (1.07, 1.17) corresponding to each 5% decrease in FEV₁/FVC. The OR (95% CI) for high CVD risk in the lowest group of FEV₁/FVC (< 70% i.e. chronic obstructive pulmonary disease [COPD]) was 2.37 (1.43, 3.91) when compared with the highest group. Longitudinally, the adjusted risk ratio (RR) (95% CI) for the incidence of high CVD risk was 1.14 (1.03, 1.25) with each 5% decrease in baseline FEV₁/FVC. Compared with the highest group of FEV₁/FVC, the RR (95% CI) for high CVD risk in the lowest group (COPD) was 4.06 (1.46, 11.26). Analyses of 10-Year CVD Risk with FVC or FEV₁ showed similar trends and significant associations (all P < 0.05).

CONCLUSION

Reduced lung function was cross-sectionally and longitudinally associated with increased cardiovascular risk in Chinese general population.

Measures of low lung function and the prediction of incident COPD events and acute coronary events

BACKGROUND

Although reduced lung function is associated with both COPD and coronary events (CE), the pattern of lung function impairment could be different for the two outcomes. We examined different measures of lung function in relation to incident COPD events and CE in a population-based cohort.

METHODS

Baseline spirometry and lung clearance index (LCI) were assessed in 672 men aged 55 years. Outcomes included incident COPD events and CE (hospitalisation or mortality). Cox regression was used to obtain HRs per 1-standard deviation (SD) decrement in baseline lung function. The Lunn-McNeil competing risks approach was used to assess if differences in risks for incident COPD events and CE were significant.

RESULTS

Over 44 years follow-up there were 85 incident COPD events and 266 incident CE. Low FEV₁ and FEV₁/VC and high LCI showed significantly stronger relationships with COPD events than CE (adjusted HRs per 1SD decrement and p-value for equal associations: FEV₁; HR_COPD: 2.11 (1.66-2.68), HR_CE: 1.30 (1.13-1.49) p < 0.001, FEV₁/VC; HR_COPD 1.95 (1.60-2.36), HR_CE 1.11 (0.98-1.26) p < 0.0001, LCI; HR_COPD: 1.58 (1.26-1.98), HR_CE: 1.14 (1.00-1.31) p = 0.015. Low VC was significantly associated with both COPD and CE, but HRs were not significantly different between the outcomes (p-value for equal associations = 0.706).

CONCLUSIONS

Low FEV₁ and FEV₁/VC and high LCI at baseline show significantly stronger relationships with future COPD events than CE. Low VC at baseline is similarly associated with future COPD events and CE. This indicates differences but also an important similarity in the "lung function profile" for developing incident COPD events or incident CE later in life.

Lung function impairment is not associated with the severity of acute coronary syndrome but is associated with a shorter stay in the coronary care unit

Background

Previous population-based studies have suggested that lung function impairment (LFI) could be associated with an increase in the mortality of cardiovascular events.

Methods

We evaluated the association between LFI and the severity and short-term prognosis of acute coronary syndrome (ACS). LFI was established through presence of a forced expiratory volume in one second (FEV1) and/or a forced vital capacity (FVC) less than 80% of predicted.

Results

Seventy-one LFI subjects (61.45±10.70 years, 83.10% males) and 247 non-LFI subjects (58.98±11.18 years, 80.57% males) with ACS were included. Subjects with LFI exhibited a higher prevalence of systemic hypertension (57.75% vs. 40.89%, P=0.02) and tobacco exposure (28.50±26.67 vs. 18.21±19.83 pack-years, P=0.007). No significant differences between groups were found regarding the severity of ACS (ejection fraction, Killip class, number of affected vessels, and peak plasma troponin). However, in comparison to non-LFI subjects, a significantly shorter length of stay in the coronary care unit (CCU) was observed in the LFI group (1.83±1.10 vs. 2.24±1.21 days, P=0.01) and this was even shorter in subjects with obstructive LFI (1.62±1.17 days, P=0.009). When considering obstructive sleep apnea (OSA), an interaction with length of stay was found, revealing that OSA subjects with obstructive LFI had the shortest length of stay in the CCU (0.60±0.89 days, P=0.05) also in comparison to non-LFI.

Conclusions

This study indicates a possible association between LFI and a shorter length of stay in the CCU but does not show a significant association with ACS severity.

Pulmonary function and adverse cardiovascular outcomes: Can cardiac function explain the link?

BACKGROUND

The complex interaction between pulmonary function, cardiac function and adverse cardiovascular events has only been partially described. We sought to describe the association between pulmonary function with left heart structure and function, all-cause mortality and incident cardiovascular hospitalization.

METHODS

This study is a retrospective analysis of patients evaluated in a single tertiary care medical center. We used multivariable linear regression analyses to examine the relationship between FVC and FEV1 with left ventricular ejection fraction (LVEF), left ventricular internal dimension in systole and diastole (LVIDS, LVIDD) and left atrial diameter, adjusting for baseline characteristics, right ventricular function and lung hyperinflation. We also used Cox proportional hazards models to examine the relationship between FVC and FEV1 with all-cause mortality and cardiac hospitalization.

RESULTS

A total of 1807 patients were included in this analysis with a median age of 61 years and 50% were female. Decreased FVC and FEV1 were both associated with decreased LVEF. In individuals with FVC less than 2.75 L, decreased FVC was associated with increased all-cause mortality after adjusting for left and right heart echocardiographic variables (hazard ratio [HR] 0.49, 95% CI 0.29, 0.82, respectively). Decreased FVC was associated with increased cardiac hospitalization after adjusting for left heart size (HR 0.80, 95% CI 0.67, 0.96), even in patients with normal LVEF (HR 0.75, 95% CI 0.57, 0.97).

CONCLUSION

In a tertiary care center reduced pulmonary function was associated with adverse cardiovascular events, a relationship that is not fully explained by left heart remodeling or right heart dysfunction.

Ischemic heart disease among subjects with and without chronic obstructive pulmonary disease--ECG-findings in a population-based cohort study

Background

Cardiovascular comorbidity in COPD is common and contributes to increased mortality. A few population-based studies indicate that ischemic electrocardiogram (ECG)-changes are more prevalent in COPD, while others do not. The aim of the present study was to estimate the presence of ischemic heart disease (IHD) in a population-based COPD-cohort in comparison with subjects without COPD.

Methods

All subjects with obstructive lung function (COPD, n = 993) were identified together with age- and sex-matched controls (non-COPD, n = 993) from population-based cohorts examined in 2002–04. In 2005, data from structured interview, spirometry and ECG were collected from 1625 subjects. COPD was classified into GOLD 1–4 after post-bronchodilator spirometry. Ischemic ECG-changes, based on Minnesota-coding, were classified according to the Whitehall criteria into probable and possible IHD.

Results

Self-reported IHD was equally common in COPD and non-COPD, and so were probable and possible ischemic ECG-changes according to Whitehall. After excluding subjects with restrictive spirometric pattern from the non-COPD-group, similar comparison with regard to presence of IHD performed between those with COPD and those with normal lung-function did neither show any differences. There was a significant association between self-reported IHD (p = 0.007) as well as probable ischemic ECG-changes (p = 0.042), and increasing GOLD stage. In COPD there was a significant association between level of FEV₁ percent of predicted and self-reported as well as probable ischemic ECG-changes, and this association persisted for self-reported IHD also after adjustment for sex and age.

Conclusion

In this population-based study, self-reported IHD and probable ischemic ECG-changes were associated with COPD disease severity assessed by spirometry.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-015-0149-1) contains supplementary material, which is available to authorized users.

The Swedish CArdioPulmonary BioImage Study: objectives and design

Cardiopulmonary diseases are major causes of death worldwide, but currently recommended strategies for diagnosis and prevention may be outdated because of recent changes in risk factor patterns. The Swedish CArdioPulmonarybioImage Study (SCAPIS) combines the use of new imaging technologies, advances in large-scale 'omics' and epidemiological analyses to extensively characterize a Swedish cohort of 30 000 men and women aged between 50 and 64 years. The information obtained will be used to improve risk prediction of cardiopulmonary diseases and optimize the ability to study disease mechanisms. A comprehensive pilot study in 1111 individuals, which was completed in 2012, demonstrated the feasibility and financial and ethical consequences of SCAPIS. Recruitment to the national, multicentre study has recently started.

Secreted phosphoprotein 1 is a determinant of lung function development in mice

Secreted phosphoprotein 1 (Spp1) is located within quantitative trait loci associated with lung function that was previously identified by contrasting C3H/HeJ and JF1/Msf mouse strains that have extremely divergent lung function. JF1/Msf mice with diminished lung function had reduced lung SPP1 transcript and protein during the peak stage of alveologenesis (postnatal day [P]14-P28) as compared with C3H/HeJ mice. In addition to a previously identified genetic variant that altered runt-related transcription factor 2 (RUNX2) binding in the Spp1 promoter, we identified another promoter variant in a putative RUNX2 binding site that increased the DNA protein binding. SPP1 induced dose-dependent mouse lung epithelial-15 cell proliferation. Spp1((-/-)) mice have decreased specific total lung capacity/body weight, higher specific compliance, and increased mean airspace chord length (Lm) compared with Spp1((+/+)) mice. Microarray analysis revealed enriched gene ontogeny categories, with numerous genes associated with lung development and/or respiratory disease. Insulin-like growth factor 1, Hedgehog-interacting protein, wingless-related mouse mammary tumor virus integration site 5A, and NOTCH1 transcripts decreased in the lung of P14 Spp1((-/-)) mice as determined by quantitative RT-PCR analysis. SPP1 promotes pneumocyte growth, and mice lacking SPP1 have smaller, more compliant lungs with enlarged airspace (i.e., increased Lm). Microarray analysis suggests a dysregulation of key lung developmental transcripts in gene-targeted Spp1((-/-)) mice, particularly during the peak phase of alveologenesis. In addition to its known roles in lung disease, this study supports SPP1 as a determinant of lung development in mice.

Peak flow rate and death due to coronary heart disease: 30-year results from the Northwick Park Heart cohort study

Objective

Numerous studies have reported that chronic obstructive pulmonary disease or impaired lung function are associated with later coronary heart disease (CHD). However, it is unclear if lung function is an independent risk factor, as many of these studies have included only limited measures of other factors associated with CHD.

Methods

In total 2167 men of all ages in the first Northwick Park Heart Study were followed for a median of 30 years. Cox regression models were used to assess the relationship between peak flow rate (PFR) and CHD mortality adjusted for potential confounders measured at baseline. Analyses allowed for missing data, and secondary analyses for repeat measures on some men and competing risks of CHD death.

Results

There were 254 CHD deaths with some evidence of an association between PFR and CHD mortality. The adjusted HRs (95% CIs) from the lowest to the highest of four PFR quartiles were 1.53 (1.04 to 2.25), <430 L/min; 1.43 (0.99 to 2.08), 430 – <490 L/min; and 1.31 (0.93 to 1.86), 490 – <550 L/min; compared with the reference group of ≥550 L/min (trend test p=0.025). Other associations with CHD mortality were observed for systolic blood pressure (p<0.0001), body mass index (p=0.0002), smoking status (p=0.015), blood cholesterol (p=0.005), plasma fibrinogen (p=0.001) and high-risk ECG (p=0.021). There were no strong associations for factors V and VIII or platelet count.

Conclusions

After allowing for a range of other risk factors associated with CHD, there was only limited evidence of a relation between PFR and CHD mortality.

Reduced forced expiratory volume is associated with increased incidence of atrial fibrillation: the Malmo Preventive Project

AIMS

Reduced forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) have been associated with increased incidence of cardiovascular diseases. However, whether reduced lung function is also a risk factor for incidence of atrial fibrillation (AF) is still unclear. We aimed to determine whether lung function predicted AF in the Malmö Preventive Project, a large population-based cohort with a long follow-up.

METHODS AND RESULTS

The study population consisted of 7674 women and 21 070 men, mean age 44.6 years. The cohort was followed on average for 24.8 years, during which time 2669 patients were hospitalized due to AF. The incidence of AF in relationship to quartiles of FEV1 and FVC and per litre decrease at baseline was determined using a Cox proportional hazards model adjusted for age, height, weight, current smoking status, systolic blood pressure, erythrocyte sedimentation rate, and fasting blood glucose. Forced expiratory volume in one second was inversely related to incidence of AF (per litre reduction in FEV1) hazard ratio (HR): 1.39 [95% confidence interval (CI): 1.16-1.68; P = 0.001] for women, and HR: 1.20 (95% CI: 1.13-1.29; P < 0.0001) for men. Forced vital capacity was also inversely related to incidence of AF (per litre reduction in FVC) HR: 1.20 (95% CI: 1.03-1.41; P = 0.020) for women, and HR: 1.08 (95% CI: 1.02-1.14; P = 0.01) for men. This relationship was consistent in non-smokers as well as smokers, and among individuals younger than the median age of 45.8 years or normotensive subjects.

CONCLUSION

Impaired lung function is an independent predictor of AF. This may explain some risk of AF that is currently unaccounted for.

Lung function predicts mortality: 10-year follow-up after lung cancer screening among asbestos-exposed workers

PURPOSE

To assess the predictive value of lung function impairment on mortality among asbestos-exposed workers.

METHODS

A total of 590 workers originally screened for occupational lung disease including spirometry and pulmonary diffusing capacity measurements were followed up for mortality data (ICD-10 classification). The mean follow-up time was 10.5 years. Associations of different lung function parameters with mortality from all causes and from cardiovascular (I00-I99) and non-malignant respiratory diseases (J00-J99) were analysed. Factor analysis was used to create obstructive and restrictive factors.

RESULTS

A total of 191 deaths were found altogether. Most measured lung function variables were associated with increased mortality when studied separately. Both decreased forced expiratory flow in one second (hazard ratio/measurement unit = 0.977, 95 % CI 0.969-0.988, p < 0.001) and impaired diffusing capacity (0.973, 0.965-0.981, p < 0.001) were independently associated with mortality from all causes, as well as from cardiovascular and non-malignant respiratory diseases. Both obstructive factor alone and the sum of obstructive and restrictive factors were associated with all studied mortality categories. The restrictive factor alone was associated with all-cause and respiratory mortality.

CONCLUSIONS

Deteriorated lung function predicts deaths. The reasons for impaired lung function should be medically explored to enable restoring measures aiming thus to prevent premature deaths.

c-Kit is essential for alveolar maintenance and protection from emphysema-like disease in mice

RATIONALE

Previously, we demonstrated a candidate region for susceptibility to airspace enlargement on mouse chromosome 5. However, the specific candidate genes within this region accounting for emphysema-like changes remain unrecognized. c-Kit is a receptor tyrosine kinase within this candidate gene region that has previously been recognized to contribute to the survival, proliferation, and differentiation of hematopoietic stem cells. Increases in the percentage of cells expressing c-Kit have previously been associated with protection against injury-induced emphysema.

OBJECTIVES

Determine whether genetic variants of c-Kit are associated with spontaneous airspace enlargement.

METHODS

Perform single-nucleotide polymorphism association studies in the mouse strains at the extremes of airspace enlargement phenotype for variants in c-Kit tyrosine kinase. Characterize mice bearing functional variants of c-Kit compared with wild-type controls for the development of spontaneous airspace enlargement. Epithelial cell proliferation was measured in culture.

MEASUREMENTS AND MAIN RESULTS

Upstream regulatory single-nucleotide polymorphisms in the divergent mouse strains were associated with the lung compliance difference observed between the extreme strains. c-Kit mutant mice (Kit(W-sh)/(W-sh)), when compared with genetic controls, developed altered lung histology, increased total lung capacity, increased residual volume, and increased lung compliance that persist into adulthood. c-Kit inhibition with imatinib attenuated in vitro proliferation of cells expressing epithelial cell adhesion molecule.

CONCLUSIONS

Our findings indicate that c-Kit sustains and/or maintains normal alveolar architecture in the lungs of mice. In vitro data suggest that c-Kit can regulate epithelial cell clonal expansion. The precise mechanisms that c-Kit contributes to the development of airspace enlargement and increased lung compliance remain unclear and warrants further investigation.

Lung function and risk of type 2 diabetes and fatal and nonfatal major coronary heart disease events: possible associations with inflammation

OBJECTIVE

We prospectively examined the relationship between lung function and risk of type-2 diabetes and fatal and nonfatal coronary heart disease (CHD) events and investigated the hypothesis that inflammation may underlie these associations.

RESEARCH DESIGN AND METHODS

A prospective study of 4,434 men aged 40-59 years with no history of cardiovascular disease (CHD or stroke) or diabetes drawn from general practices in 24 British towns and followed up for 20 years.

RESULTS

There were 680 major CHD events (276 fatal, 404 nonfatal) and 256 incident type 2 diabetes during the 20 years follow-up. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV(1)) but not FEV(1)-to-FVC ratio were significantly and inversely associated with incident type 2 diabetes and fatal CHD events (not nonfatal events) after adjustment for age, potential confounders, and metabolic risk factors. The adjusted relative risk (RR) for type 2 diabetes (Quartile 1 vs. Quartile 4) were 1.59 (1.07-2.56) and 1.74 (1.16-2.61) for FVC and FEV(1), respectively (P = 0.03 and P = 0.04 for trend). The corresponding RR for fatal CHD were 1.48 (1.00-2.21) and 1.81 (1.19-2.76) (P = 0.002 and P = 0.0003 for trend). Lung function was significantly and inversely associated with C-reactive protein and interleukin-6; the inverse associations with type 2 diabetes for FVC and FEV(1) were attenuated after further adjustment for these factors (P = 0.14 and P = 0.11 for trend) but remained significant for fatal CHD (P = 0.03 and P = 0.01, respectively).

CONCLUSIONS

Restrictive rather than obstructive impairment of lung function is associated with incident type 2 diabetes (and fatal CHD) with both associations partially explained by traditional and metabolic risk factors and inflammation.

Chronic obstructive pulmonary disease as an independent risk factor for cardiovascular morbidity

RATIONALE

Recent studies described association between chronic obstructive pulmonary disease (COPD) and increased risk of cardiovascular diseases (CVD). In their analysis none of these studies accounted for sociodemographic factors, health behaviors, and patient comorbidities simultaneously.

OBJECTIVE

To study whether COPD diagnosis is an independent risk factor for CVD.

METHODS

Subjects aged 40 years and older (N = 18,342) from the sample adult file of the 2002 National Health Interview Survey (NHIS) were included in the analysis. Chi-squared tests and odds ratios (OR) were utilized to compare the data. Multiple logistic regression was employed to analyze the association between COPD and CVD with simultaneous control for sociodemographic factors (age, gender, race, marital status, education, income), health behaviors (tobacco use, alcohol consumption, physical activity), and patient comorbidities (diabetes, hypertension, high cholesterol, and obesity). The analysis employed NHIS sampling weights to generate data representative of the entire US population.

RESULTS

The COPD population had increased prevalence of CVD (56.5% vs 25.6%; P < 0.0001). Adjusted logistic regression showed that COPD patients (N = 958) were at higher risk of having coronary heart disease (OR = 2.0, 95% CI: 1.5-2.5), angina (OR = 2.1, 95% CI: 1.6-2.7), myocardial infarction (OR = 2.2, 95% CI: 1.7-2.8), stroke (OR = 1.5, 95% CI: 1.1-2.1), congestive heart failure (OR = 3.9, 95% CI: 2.8-5.5), poor circulation in lower extremities (OR = 2.5, 95% CI: 2.0-3.0), and arrhythmia (OR = 2.4, 95% CI: 2.0-2.8). Overall, the presence of COPD increased the odds of having CVD by a factor of 2.7 (95% CI: 2.3-3.2).

CONCLUSIONS

These findings support the conclusion that COPD is an independent risk factor for CVD.

BP variability and cardiovascular autonomic function in relation to forced expiratory volume: a population-based study

BACKGROUND

Cardiovascular autonomic dysfunction is associated with increased incidence of cardiovascular diseases. This population-based study explored whether low FEV(1) or low vital capacity (VC) is associated with autonomic dysfunction, as measured by spontaneous heart rate variability (HRV) and systolic BP variability (SBPV).

METHODS

SBPV and HRV were recorded during 5 min of controlled breathing in men and women who were 70 years of age. FEV(1) and VC were recorded in 901 subjects. Of them, information on HRV and SBPV was available in 820 and 736 subjects, respectively. Measures of autonomic function, that is, SBPV in the low-frequency (LF) and high-frequency (HF) domains, HRV, and baroreceptor sensitivity (BRS), were studied in sex-specific quartiles of FEV(1) and VC.

RESULTS

Low FEV(1) was associated with high SBPV in the HF domain. The mean SBPV-HFs were 5.2, 4.5, 4.1, and 3.8 mm Hg, respectively, in subjects with FEV(1) in the first (low), second, third, and fourth quartile (p < 0.001 [for trend]). This relationship persisted after adjustments for potential confounding factors. Low VC was significantly associated with high SBPV-HF in the crude analysis but not after adjustment for confounding factors. Neither FEV(1) nor VC showed any significant relationship with BRS, HRV, or SBPV in the LF domain.

CONCLUSION

In this population-based study, low FEV(1) was associated with high SBPV in the HF domain. It is suggested that high beat-to-beat variability in BP could contribute to the increased cardiovascular risk in subjects with moderately reduced FEV(1).