Retrospective analysis of the relationship between decline in FEV(1) and abdominal circumference in male smokers: the Takahata study

Relationship between metabolic syndrome and pulmonary function in workers with respiratory dust exposure in Iran

AIMS

we designed a study to investigate the relationship between metabolic syndrome (MetS) and lung function in workers with dust exposure based on five years of longitudinal study data.

METHODS

In this historical cohort study that conducted in iron ore mine, non-smoker male workers who exposed to dust, were enrolled. MetS was determined according to the National Cholesterol Education Program Adult Treatment Panel III. New spirometry parameters and spirometry from 5 years ago, were compared.

RESULTS

In this study 192 workers were identified without MetS and 77 with MetS. The mean of all lung parameters was lower in subjects with MetS, but it was not statistically significant. The median decline in FEV1 and FVC in 5 years was greater in subjects with MetS but were only significant for a decline in FEV1 (P-Value = 0.04). Linear regression analysis showed a significant relationship between a decline in FEV1 and waist circumference (P-Value = 0.001) when adjusted for age, BMI, physical activity level.

CONCLUSION

In this study, a significant association between mean decline in FEV1 in 5 years and MetS in dust-exposed workers was demonstrated. Decline in FEV1 in 5 years was significantly associated with a Waist circumference as one of the components of MetS.

Effect of Body Mass Index on Lung Function in Chinese Patients with Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study

Objective

The aim of this study was to explain “obesity paradox” in chronic obstructive pulmonary disease (COPD) by evaluating the effect of body mass index (BMI) on lung function in Chinese patients with COPD.

Methods

A total of 1644 patients diagnosed with COPD were recruited from four Chinese tertiary hospitals and were divided into four groups including underweight, normal weight, overweight and obese according to BMI classification standard. The medical data of these patients were collected and used for the multiple linear regression analyses.

Results

After adjustment for age, sex, educational level, economic status, smoking status, alcohol consumption, duration of COPD history, events of acute exacerbation in previous year, hypertension, diabetes mellitus, cardiovascular disease, cerebrovascular disease and osteoporosis, BMI had a curvilinear correlation with the forced expiratory volume in the first second (FEV₁) in patients with Global Initiative for Obstructive Lung Disease (GOLD) 1–2 grade (first-order coefficient β, 0.09; 95% CI, 0.03–0.16; second-order coefficient β, −0.002; 95% CI, −0.003–-0.001; P<0.01). However, BMI had a positive correlation with FEV₁ in patients with GOLD 3–4 grade (β, 0.01; 95% CI, 0.008–0.017; P<0.01) when BMI was used as a quantitative variable. When BMI was used as a qualitative variable, only FEV₁ in overweight group with GOLD 1–2 grade was significantly higher than that of normal weight group (P<0.01). Interestingly, both overweight and obese groups had higher FEV₁ in GOLD 3–4 grade compared with normal weight group (β, 0.06; 95% CI, 0.02–0.11; β, 0.11; 95% CI, 0.04–0.18; P<0.01). The effect of BMI on predicted percentage of FEV₁ (FEV₁%) was similar to that of FEV₁ in different GOLD grades.

Conclusion

Obesity only had a protective effect on lung function in COPD patients with GOLD 3–4 grade rather than GOLD 1–2 grade.

Trial Registry

ClinicalTrials.gov, No.: NCT 03182309, URL: www.clinicaltrials.gov.

Waist Circumference and Spirometric Measurements in Chronic Obstructive Pulmonary Disease

OBJECTIVES

The aim of this study was to evaluate whether the waist circumference of patients with chronic obstructive pulmonary disease (COPD), had an impact on lung function.

METHODS

There were 180 patients with COPD recruited into this prospective cross-sectional study. The age, weight, body mass index and waist circumference (WC) were measured. Spirometry parameters including forced vital capacity (FVC), and forced expiratory volume in the first second (FEV1), were measured and FEV1/FVC calculated.

RESULTS

The mean FEV1/FVC in both normal weight and overweight patients, did not statistically significantly correlate with WC. The COPD assessment test, positively correlated with WC ( p = 0.031). A positive correlation with body mass index ( p < 0.001), smoking ( p = 0.027), and global initiative for chronic obstructive lung disease score ( p = 0.009), were observed to positively associate with WC. WC, age, C-reactive protein, duration of disease, and gender (male), were observed to be statistically significant risk factors for the severity of COPD.

CONCLUSION

WC was not observed to impact upon lung function in this study but it was a predictive factor for COPD severity in patients.

Impact of reduced pulmonary function in the Japanese general population: Lessons from the Yamagata-Takahata study

Regional epidemiological studies for respiratory diseases have been rarely performed in Japan, because spirometry is not regularly conducted in the standard annual health checks. The Yamagata-Takahata Study is an epidemiological study utilizing regional characteristics based on the 21st Century Centers of Excellence (COE) Program and the Global COE Program. Spirometric examination and other specific measurements via blood sampling were performed for the study participants in annual health check-ups held in Takahata, a town in Yamagata Prefecture. The Yamagata-Takahata Study revealed the impact of cigarette smoking habit on pulmonary function, the impact of reduced pulmonary function on mortality, and the situation regarding COPD comorbidities in Japan. Additionally, the study identified biomarkers of decline in pulmonary function among active smokers, and the risk factors for respiratory mortality in Japan. In this review, we summarize the findings of the Yamagata-Takahata study regarding the association between lower pulmonary function and the clinical characteristics of a Japanese general population.

Impact of cigarette smoking on decline in forced expiratory volume in 1s relative to severity of airflow obstruction in a Japanese general population: The Yamagata-Takahata study

BACKGROUND

Few studies are available regarding the annual decline of forced expiratory volume in 1s (FEV1) in chronic obstructive pulmonary disease patients with mild airflow obstruction. This study sought to clarify to what extent cigarette-smoking individuals with mild airflow obstruction lose pulmonary function annually.

METHODS

From 2004 to 2006, pulmonary function tests were performed on people >40 years of age, during the annual health checkup held in Takahata, Yamagata, Japan (initial study population, n=3253). In 2011, pulmonary function tests were performed again on participants who agreed to undergo reexamination (follow-up study population, n=838).

RESULTS

Smokers have decreased pulmonary function in terms of percent forced vital capacity (FVC), %FEV1, and FEV1/FVC; the stages of airflow obstruction were also more severe in smokers than never-smokers. The annual decline in FEV1 was significantly greater in smokers than in never-smokers. The median annual decline in FEV1 was most significant in individuals with mild airflow obstruction. The annual decline in FEV1 was greater in smokers with mild airflow obstruction than in smokers with moderate airflow obstruction. In analyzing the decline in %FEV1, the annual change in smokers with mild airflow obstruction was greater than that in smokers with normal spirometric values.

CONCLUSION

The annual decline in FEV1 was most significant in smokers with mild airflow obstruction in a Japanese general population. This highlights the importance of early detection of chronic obstructive pulmonary disease patients among the general population in order to prevent disease progression in undiagnosed patients.

Prevalence of diabetes mellitus in individuals with airflow obstruction in a Japanese general population: The Yamagata-Takahata Study

BACKGROUND

Diabetes has been reported as a comorbidity of chronic obstructive pulmonary disease (COPD) in Western countries, but it has not been demonstrated in epidemiological reports in Japan. The purpose of this study was to clarify whether the relationship between airflow obstruction and diabetes can be confirmed in a Japanese general population.

METHODS

From 2004 to 2006, blood sampling and pulmonary function tests were performed on 3045 people over the age of 40 years in annual health check-ups held in Takahata, Yamagata Prefecture, Japan. Pulmonary function was re-evaluated in 2009 and 2011.

RESULTS

The prevalence of diabetes did not differ between subjects with and without airflow obstruction. Furthermore, although body mass index decreased, no increase in the prevalence of diabetes was observed with the progression of airflow obstruction. The annual changes in forced expiration volume in 1s (FEV1) did not differ depending on the presence or absence of diabetes in the study population.

CONCLUSION

There was no difference in the prevalence of diabetes between subjects with airflow obstruction and those without. As patients with COPD in Japan are thinner than in the West, diabetes may not be a common comorbidity in Japanese patients with COPD.

Rapid decline in lung function is temporally associated with greater metabolically active adiposity in a longitudinal study of healthy adults

RATIONALE

Adiposity is associated with low lung function, but the longitudinal relationship between lung function and adiposity is inadequately studied.

OBJECTIVE

To examine the bidirectional longitudinal associations between rapid decline in lung function and adiposity phenotypes in healthy adults.

METHODS

This secondary analysis used a 25-year longitudinal dataset from the Coronary Artery Risk Development in Young Adults (CARDIA) study that enrolled 5115 participants.

MEASUREMENTS

In the first analysis, metabolic syndrome at or before CARDIA year (Y) 10 (Y10) was the predictor, and subsequent rapid decline in forced vital capacity (FVC) or forced expiratory volume in 1 s (FEV1) between Y10 and Y20 was the outcome. In the second analysis, rapid decline was the predictor, and incident metabolic syndrome at Y20 and/or Y25 was the outcome. In the third analysis, rapid decline was the predictor, and subsequent CT-assessed regional fat depots at Y25 were the outcome.

RESULTS

Metabolic syndrome at or before Y10 is temporally associated with rapid decline in FVC between Y10 and Y20 (adjusted p=0.04), but this association was explained by body mass index (BMI) at Y10. Rapid decline in FVC or FEV1 is temporally associated with greater incident metabolic syndrome at Y20 and/or Y25 (adjusted OR 2.10 (1.69, 2.61); p<0.001, and 1.56 (1.26, 1.94); p<0.001, respectively) and greater CT-assessed intrathoracic visceral adiposity at Y25 (adjusted standardised β 0.09; p<0.001 for both analyses). These associations were not explained by BMI levels prior to the outcome measurement.

CONCLUSIONS

Healthy adults with rapid decline in lung function are at risk for developing metabolic syndrome and for disproportionate accumulation of intrathoracic visceral fat. Metabolic abnormalities may be an early extrapulmonary manifestation of lung impairment that may be preventable by improving lung health.

Adiposity markers and lung function in smokers: a cross-sectional study in a Mediterranean population

Background

The aim of this study was to assess the association of key adiposity markers with lung function in smokers without respiratory disease in a Mediterranean population.

Methods

We performed a cross-sectional study with baseline data from a representative sample of the ESPITAP study in Spain. Participants were 738 smokers (52.3% men) without respiratory disease, aged 35 to 70, selected from 12 primary health care centres. We assessed weight, height, body mass index (BMI), waist circumference (WC) and waist-to-height ratio (WHtR). The pulmonary functional parameters were forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC ratio.

Results

In this cohort of smokers, 22.2% of individuals had central obesity. FVC% was inversely associated with all anthropometric measures (BMI, WC and WHtR) in the overall population and in men; in women, only BMI was associated with FVC%. FEV1% was inversely associated to BMI and WC in the overall population, and to all anthropometric measures in men. Furthermore, both BMI and obesity were positively associated with FEV1/FVC ratio overall and when stratified by sex; this suggests a restrictive pattern explained by the altered ventilator mechanics experienced by people with obesity.

Conclusion

In a Mediterranean population of smokers without respiratory symptoms, abdominal obesity, evaluated not only by BMI and WC but also WHtR, is inversely associated with lung function. Fat distribution appears more strongly related to pulmonary function parameters in men than in women. In smokers with high values for WC, WHtR and BMI, assessment of lung function is recommended.

Trial registration

Current Controlled Trials NCT01194596. Registered 2 September 2010.

Reference values of MostGraph measures for middle-aged and elderly Japanese individuals who participated in annual health checkups

BACKGROUND

The forced oscillation technique (FOT) can measure respiratory system resistance and reactance under tidal volume respiration. MostGraph is a device that incorporates the FOT and enables the immediate, three-dimensional visualization of resistance and reactance parameters. The aim of this study was to establish MostGraph reference values for middle-aged and elderly Japanese individuals.

METHODS

From 2004 to 2006, 3253 subjects living in Takahata, Yamagata underwent spirometry. Of these, 872 again underwent spirometry in 2011, and 784 (368 men, ages 46-89 years; 416 women, ages 47-90 years) underwent FOT examinations using MostGraph-01.

RESULTS

In this study population, 19.0% of the men and 91.5% of the women were life-long never smokers. Abnormal spirometric findings were observed in 30.2% of the men and 14.6% of the women. Although the respiratory system resistance and reactance parameters obtained using MostGraph were not distributed normally, normal distribution was achieved via natural logarithm (R5, R20, Fres, and ALX), square root (R5-R20), or exponential (X5) transformation. Furthermore, the transformed values were converted back to the actual values after determining the values representing one and two standard deviations from the mean.

CONCLUSION

Respiratory system resistance and reactance reference values were determined using MostGraph in middle-aged and elderly Japanese individuals who participated in annual health checkups.

Association between plasma adiponectin levels and decline in forced expiratory volume in 1 s in a general Japanese population: the Takahata study

BACKGROUND

Adiponectin is an anti-inflammatory and cardio-protective cytokine. However, several studies have demonstrated that plasma adiponectin levels were inversely associated with pulmonary function in patients with chronic obstructive pulmonary disease, suggesting a proinflammatory or pulmonary-destructive role. It is still unclear whether adiponectin is a potent biomarker predicting declines in pulmonary function. The aim of this study was to investigate the association between adiponectin and pulmonary function among Japanese individuals who participated in an annual health check-up.

METHODS

Spirometry and blood sampling, including measurements of plasma adiponectin, were performed for 3,253 subjects aged 40 years or older who participated in a community-based annual health check-up in Takahata, Japan from 2004 to 2006. In 2011, spirometry was re-performed, and the data from 872 subjects (405 men and 467 women) were available for a longitudinal analysis.

RESULTS

Plasma adiponectin levels were found to be significantly associated with age, body mass index (BMI), and alanine aminotransferase (ALT), triglycerides (TG), and high-density lipoprotein-cholesterol (HDL-c) levels among both men and women in the study population. Plasma adiponectin levels were found to be associated with lifetime cigarette consumption (Brinkman index, BI) in men only. Plasma adiponectin levels were inversely correlated with forced expiratory volume in 1 s (FEV1) per forced vital capacity in both men and women. In addition, the annual change in FEV1 was inversely associated with plasma adiponectin levels in both genders. A multiple linear regression analysis revealed that this association was independent of other confounding factors such as age, BMI, BI, ALT, TG, and HDL-c.

CONCLUSIONS

The results of the present study suggest that adiponectin levels are predictive of declines in FEV1 in the general population.

A lower level of forced expiratory volume in 1 second is a risk factor for all-cause and cardiovascular mortality in a Japanese population: the Takahata study

Chronic obstructive pulmonary disease is a known risk factor for cardiovascular death in Western countries. Because Japan has a low cardiovascular death rate, the association between a lower level of forced expiratory volume in 1 s (FEV1) and mortality in Japan's general population is unknown. To clarify this, we conducted a community-based longitudinal study. This study included 3253 subjects, who received spirometry from 2004 to 2006 in Takahata, with a 7-year follow-up. The causes of death were assessed on the basis of the death certificate. In 338 subjects, airflow obstruction was observed by spirometry. A total of 127 subjects died. Cardiovascular death was the second highest cause of death in this population. The pulmonary functions of the deceased subjects were significantly lower than those of the subjects who were alive at the end of follow-up. The relative risk of death by all causes, respiratory failure, lung cancer, and cardiovascular disease was significantly increased with airflow obstruction. The Kaplan-Meier analysis showed that all-cause and cardiovascular mortality significantly increased with a worsening severity of airflow obstruction. After adjusting for possible factors that could influence prognosis, a Cox proportional hazard model analysis revealed that a lower level of FEV1 was an independent risk factor for all-cause and cardiovascular mortality (per 10% increase; hazard ratio [HR], 0.89; 95% confidence interval [CI], 0.82-0.98; and HR, 0.72; 95% CI, 0.61-0.86, respectively). In conclusion, airflow obstruction is an independent risk factor for all-cause and cardiovascular death in the Japanese general population. Spirometry might be a useful test to evaluate the risk of cardiovascular death and detect the risk of respiratory death by lung cancer or respiratory failure in healthy Japanese individuals.

Relationships between values of antibodies to several connective tissue disease autoantigens and pulmonary function in a Japanese general population: the Takahata study

BACKGROUND

Accumulating evidence suggests the involvement of an autoimmune mechanism in the pathogenesis of respiratory dysfunction. The aim of this study was to investigate the relationship between pulmonary function and serum antibodies to several connective tissue disease autoantigens (ACTDA) levels, which has not been investigated in a general population.

METHODS

Blood sampling and spirometry were performed for subjects (n = 3,257) aged ≥40 years who participated in a community-based annual health check in Takahata, Japan, from 2004 to 2006. ACTDA was measured by enzyme immunoassay, and subjects with ACTDA values ≥20 were defined as positive.

RESULTS

In males, there were significant inverse relationships between logarithmically transformed ACTDA values and spirometric parameters, including % predicted values for forced expiratory volume in 1 s (FEV1) and maximal midexpiratory flow (MMF) as well as FEV1/forced vital capacity (FVC). Multiple linear regression analysis revealed that except for the relationship between ACTDA and FEV1/FVC, these relationships were still significant after adjustment for Brinkman index (a measure of inhaled cigarette consumption). The prevalence of positive ACTDA was greater in male never-smokers with mixed ventilation disorders and relatively severe airflow obstruction (% predicted FEV1 below the median value).

CONCLUSIONS

Autoimmunity may be involved in the mechanism of impaired pulmonary function in the general population.

Elevated serum iron is a potent biomarker for spirometric resistance to cigarette smoke among Japanese males: the Takahata study

Chronic obstructive pulmonary disease is a common disability among elderly subjects with a heavy cigarette smoking habit. In contrast to the population that is susceptible to smoking, in whom pulmonary function worsens with the length of exposure to cigarette smoke, there are elderly individuals whose pulmonary function is not impaired. However, to date, the characteristics of this resistant smoking population have not been investigated. We aimed to identify a biomarker in individuals in whom lung health is maintained despite smoking. Blood sampling and spirometry were performed on 3,257 subjects who participated in a community-based annual health check in Takahata, Japan, from 2004 to 2006. We selected 117 elderly smokers (age ≥70, Brinkman index ≥600, smoking years ≥30). The 'smoking resistant' group met the following criteria: FEV1/FVC ≥0.7, and FEV1%predicted ≥80. Spirometry was re-evaluated in 147 male, current smokers in 2009. Baseline serum iron (sFe) levels were higher in the smoke resistant group compared with the non-resistant group. In those with low sFe levels, FEV1/FVC was reduced in male subjects. These spirometric measures were positively associated with sFe levels in men. Multiple linear regression analysis revealed that sFe levels were predictive for spirometric values, independent of other clinical factors. In addition, sFe levels were predictive for a decline in FEV1.Serum iron levels may be a biomarker for the spirometric susceptibility of individuals to cigarette smoke.

Relationship between plasma fibrinogen levels and pulmonary function in the japanese population: the Takahata study

BACKGROUND

Plasma fibrinogen is considered a biomarker of respiratory disease, owing to the relationship between plasma fibrinogen and pulmonary function established in Western populations. However, such a relationship has not yet been confirmed in an Asian population. We assessed this relationship in the general Japanese population.

METHODS

Totally, 3,257 men and women aged ≥40 years who participated in a community-based annual health checkup in Takahata, Japan, from 2004 to 2006, underwent spirometry, and their plasma fibrinogen levels were determined.

RESULTS

We found an inverse relationship between spirometric measures (percent predicted forced vital capacity [%FVC] and forced expiratory volume in 1s [%FEV1], and FEV1/FVC) and plasma fibrinogen levels in men, but not in women. The plasma fibrinogen levels were significantly higher in subjects with restrictive, obstructive, and mixed ventilatory disorders than in those with normal spirometry results. Multiple linear regression analysis revealed that in men, plasma fibrinogen levels were predictive for %FVC and %FEV1 (independent of age, body mass index, and cigarette smoking) but not for FEV1/FVC.

CONCLUSIONS

Plasma fibrinogen was significantly associated with pulmonary function in Japanese men, and as such, plasma fibrinogen might be a potent biomarker for pulmonary dysfunction in men.