Development and external validation of the DOAT and DOATS scores: simple decision support tools to identify disease progression among nonelderly patients with mild/moderate COVID-19.

BACKGROUND: During the fifth wave of the coronavirus disease 2019 (COVID-19) pandemic in Japan, which took place between June and September 2021, a significant number of COVID-19 cases with deterioration occurred in unvaccinated individuals < 65 years old. However, the risk factors for COVID-19 deterioration in this specific population have not yet been determined. This study developed a prediction method to identify COVID-19 patients < 65 years old who are at a high risk of deterioration. METHODS: This retrospective study analyzed data from 1,675 patients < 65 years old who were admitted to acute care institutions in Fukushima with mild-to-moderate-1 COVID-19 based on the Japanese disease severity criteria prior to the fifth wave. For validation, 324 similar patients were enrolled from 3 hospitals in Yamagata. Logistic regression analyses using cluster-robust variance estimation were used to determine predictors of disease deterioration, followed by creation of risk prediction scores. Disease deterioration was defined as the initiation of medication for COVID-19, oxygen inhalation, or mechanical ventilation starting one day or later after admission. RESULTS: The patients whose condition deteriorated (8.6%) tended to be older, male, have histories of smoking, and have high body temperatures, low oxygen saturation values, and comorbidities, such as diabetes/obesity and hypertension. Stepwise variable selection using logistic regression to predict COVID-19 deterioration retained comorbidities of diabetes/obesity (DO), age (A), body temperature (T), and oxygen saturation (S). Two predictive scores were created based on the optimism-corrected regression coefficients: the DOATS score, including all of the above risk factors, and the DOAT score, which was the DOATS score without oxygen saturation. In the original cohort, the areas under the receiver operating characteristic curve (AUROCs) of the DOATS and DOAT scores were 0.81 (95% confidence interval [CI] 0.77-0.85) and 0.80 (95% CI 0.76-0.84), respectively. In the validation cohort, the AUROCs for each score were both 0.76 (95% CI 0.69-0.83), and the calibration slopes were both 0.80. A decision curve analysis confirmed the clinical practicability of both scores in the validation cohort. CONCLUSIONS: We established two prediction scores that can quickly evaluate the risk of COVID-19 deterioration in mild/moderate patients < 65 years old.

[Case of Lung Cancer with High-Grade Fetal Lung Adenocarcinoma Components Treated with Chemotherapy].

A woman in her 70s presented to our hospital with complaints of cough and dyspnea. Computed tomography(CT) images showed a large amount of left pleural effusion, pleural tumors, and mediastinal lymphadenopathy. Left thoracic drainage was performed, and high-grade fetal lung adenocarcinoma was suspected upon pleural effusion-cell block immunostaining. Pathological evaluation of the CT-guided biopsy specimen provided a diagnosis of carcinoma with high-grade fetal lung adenocarcinoma. Although the tumor progressed rapidly, chemotherapy with atezolizumab/bevacizumab/carboplatin/ paclitaxel was highly effective. However, subsequent maintenance therapy with atezolizumab/bevacizumab led to disease progression.

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.

Hyperhomocysteinaemia predicts the decline in pulmonary function in healthy male smokers.

Hyperhomocysteinaemia is associated with chronic obstructive pulmonary disease. However, the relationship between plasma homocysteine levels and spirometric measures has not been investigated in a general population. We aimed to determine whether homocysteine levels are predictive for a rapid decline in lung function among healthy current smokers. Blood sampling and spirometry were performed on subjects participating in a community-based annual health check in Takahata, Japan, from 2004 to 2006 (n=3257). Spirometry was re-evaluated in 147 male current smokers in 2009. On initial assessment, forced vital capacity (FVC) % predicted and forced expiratory volume in 1 s (FEV1) % predicted correlated inversely with homocysteine levels and were predictive for homocysteine levels, independent of various clinical factors. Homocysteine levels were higher in subjects with restrictive, obstructive or mixed ventilatory disorders. In addition, homocysteine levels were higher in subjects with mixed ventilatory disorders, compared with restrictive or obstructive disorders. On follow-up, subjects showing a decline in FEV1 had higher homocysteine levels than those who did not. Logistic regression analysis indicated that homocysteine levels were predictive for a decline in FEV1. FVC % pred and FEV1 % pred were significantly associated with homocysteine levels, and hyperhomocysteinaemia predicted the annual rate of decline in FEV1 among male smokers.

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

BACKGROUND: Metabolic syndrome (Mets) is reportedly associated with chronic obstructive pulmonary disease (COPD). However, the relationship between abdominal circumference (AC) and decline in FEV(1) has not been elucidated. We aimed to investigate this relationship among male current smokers. METHODS: Spirometry was performed on subjects (n = 3,257) ≥ 40 years of age, who participated in a community-based annual health check in Takahata, Japan, from 2004 through 2006 (visit 1). Spirometry was re-evaluated, and AC was assessed in 147 of the male current smokers in 2009 (visit 2). The diagnosis of Mets was based on the criteria used in the Hisayama Study. RESULTS: No significant relationships were observed between AC and spirometric parameters such as % predicted forced vital capacity (FVC), % predicted forced expiratory volume in 1 s (FEV(1)) and FEV(1)/FVC. However, decline in FEV(1) was significantly correlated with AC. Multivariate logistic regression analysis showed that AC was a significant discriminating factor for decline in FEV(1), independently of age, Brinkman index and change in body mass index from visit 1 to visit 2. At visit 2, there was a greater prevalence of decline in FEV(1) among subjects with Mets (n=17) than among those without Mets. Although there were no differences in % predicted FVC, % predicted FEV(1) or FEV(1)/FVC between subjects with or without Mets, the rate of decline in FEV(1) was significantly greater in subjects with Mets than in those without. CONCLUSIONS: This retrospective analysis suggested that measuring AC may be useful for discriminating male smokers who show a decline in FEV(1).

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.

Soluble endothelial selectin in acute lung injury complicated by severe pneumonia.

BACKGROUND: Pneumonia is still one of the most frequent causes of death in the elderly. Complication of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by pneumonia makes patients very ill due to severe respiratory failure. Biomarkers that can discriminate the presence of complicating ALI/ARDS are required for early detection. The aim of this research was to investigate whether soluble endothelial selectin (sES) could be a biomarker for ALI. METHODS: Serum sES levels were measured in 27 pneumonia patients, who were enrolled between April 2006 and September 2007. Among these patients, six had ALI or a condition that was clinically comparable to ALI (cALI). All patients who were enrolled were successfully treated and survived. RESULTS: Circulating sES levels were elevated in pneumonia patients with ALI/cALI, and sES levels decreased following treatment of their pneumonia. Univariate and multivariate logistic regression analyses showed that sES was the only significant factor for identifying complicating ALI/cALI, independently of C-reactive protein (CRP) and lactate dehydrogenase (LDH). By receiver operating characteristic (ROC) curve analysis, the cut-off value for sES was 40.1 ng/mL, with a sensitivity of 0.8 and a specificity of 0.8. CONCLUSION: sES may be a useful biomarker for discriminating complicating ALI/cALI in patients with severe pneumonia.

The relationship between serum uric acid and spirometric values in participants in a health check: the Takahata study.

BACKGROUND: Tissue hypoxia induces the degradation of adenosine triphosphate, resulting in the production of uric acid (UA). Patients with chronic obstructive pulmonary disease (COPD) have been reported to have high serum levels of UA (sUA), compared with control subjects. However, the relationship between sUA levels and spirometric measures has not been investigated in detail in a general population. METHODS: Subjects aged 40 years or older (n = 2,917), who had participated in a community-based annual health check in Takahata, Japan, in 2004 and 2005, were enrolled in the study. These subjects performed spirometry, their blood pressure was measured, and a blood sample was taken. RESULTS: sUA levels were significantly higher in males than in females. Percent predicted forced vital capacity [FVC %predicted] (r = -0.13) and forced expiratory volume in 1 s [FEV(1) %predicted] (r = -0.118) were inversely correlated with sUA levels in females but not in males. Univariate regression analysis indicated that age, body mass index (BMI), ethanol intake, mean blood pressure (BP), and serum creatinine (sCr) were significantly associated with sUA levels in males. In females, age, BMI, mean BP, hemoglobin A1c, sCr, FVC %predicted, and FEV(1) %predicted were significantly associated with sUA levels. Multiple linear regression analysis showed that for both genders, FVC %predicted and FEV(1) %predicted were predictive for sUA levels, independently of the other clinical parameters. Subjects with lung restriction had higher sUA levels than subjects without lung restriction. In addition, subjects with moderate and severe airflow limitation had higher sUA levels than subjects without airflow limitation or those with mild airflow limitation. CONCLUSION: FVC %predicted and FEV(1) %predicted were significantly associated with sUA levels in a general population.

Impairment of pulmonary function is an independent risk factor for atrial fibrillation: the Takahata study.

BACKGROUND: Chronic pulmonary disorders, such as chronic obstructive pulmonary disease (COPD) and fibrosing lung diseases, and atrial fibrillation (AF), are prevalent in elderly people. The impact of cardiac co-morbidities in the elderly, where pulmonary function is impaired, cannot be ignored as they influence mortality. The relationship between the prevalence of AF and pulmonary function is unclear. The aim of this study was to evaluate this relationship in participants in a health check. METHODS: Subjects aged 40 or older (n = 2,917) who participated in a community-based annual health check in Takahata, Japan, from 2004 through to 2005, were enrolled in the study. We performed blood pressure measurements, blood sampling, electrocardiograms, and spirometry on these subjects. RESULTS: The mean FEV(1) % predicted and FVC % predicted in AF subjects was significantly lower than in non-AF subjects. The prevalence of AF was higher in those subjects with airflow limitation or lung restriction than in those without. Furthermore, AF prevalence was higher in those subjects with severe airflow obstruction (FEV(1) %predicted < 50) than in those who had mild or moderate airflow obstruction (FEV(1) %predicted ≥ 50), although there was no difference between the prevalence of AF in subjects with 70≤ FVC %predicted <80 lung restriction and those with FVC %predicted <70. Multiple logistic regression analysis revealed that FEV(1) %predicted and FVC %predicted are independent risk factors for AF (independent of age, gender, left ventricular hypertrophy, and serum levels of B-type natriuretic peptide). CONCLUSION: Impaired pulmonary function is an independent risk factor for AF in the Japanese general population.

[A case of lung adenocarcinoma exhibiting Garcin syndrome].

We report a rare case of lung adenocarcinoma exhibiting Garcin syndrome due to skull base metastasis. A diagnosis of lung adenocarcinoma and intraperitoneal lymph node metastases was given to a 50-year-old man after pathological examination of a superclavicular lymph node biopsy. After systemic chemotherapy with cisplatin plus docetaxel, he had left hearing loss and vertigo. Since auditory nerve damage might occur due to cisplatin, the chemotherapy regimen was changed. However, facial paralysis occurred and his auditory nerve disorder progressed to deafness. He was diagnosed with Garcin syndrome due to the skull base and spinal cord metastases by brain and spine MRI, and cytological examination of the spinal fluid. After intrathecal administration of methotrexate and cranial irradiation, the progression of facial paralysis and auditory nerve disorder were halted. It is important to consider Garcin syndrome as a possible complication in lung cancer patients who have central nervous system symptoms.

The role of macrophage transcription factor MafB in atherosclerotic plaque stability.

BACKGROUND AND AIMS: Macrophage differentiation is associated with the development of atherosclerosis and plaque vulnerability and is regulated by transcription factor MafB. We previously reported that MafB attenuates macrophage apoptosis, which is associated with atherosclerotic plaque instability. The aim of this study was to elucidate the role of MafB in the progression of atherosclerotic plaque. METHODS: We generated macrophage-specific dominant-negative (DN) MafB transgenic mice and intercrossed DN-MafB mice with apolipoprotein E (ApoE) knockout (KO) mice. RESULTS: There was no significant difference in advanced atherosclerotic lesion area between DN-MafB/ApoE KO mice and littermate control ApoE KO mice 9 weeks after high-cholesterol diet. However, DN-MafB/ApoE KO mice showed significantly larger necrotic cores and lower collagen content in atherosclerotic plaques than ApoE KO mice. Although there was no difference in intraplaque macrophage infiltration and efferocytosis, DN-MafB/ApoE KO mice showed significantly more apoptotic macrophages at the plaque edges than did ApoE KO mice. Real-time PCR analysis revealed that peritoneal macrophages of DN-MafB/ApoE KO mice had a greater increase in matrix metalloproteinase-9 and mRNA expression of inflammatory/M1 macrophage markers (tissue necrosis factor-α, interleukin-6, CD11c, and p47phox) after lipopolysaccharide stimulation than those of ApoE KO mice. CONCLUSION: Macrophage-specific inhibition of MafB may destabilize atherosclerotic plaques in advanced lesions.

Low arterial blood oxygenation is associated with calcification of the coronary arteries in patients with chronic obstructive pulmonary disease.

BACKGROUND: Cigarette smoking is a well-known major cause of both chronic obstructive pulmonary disease (COPD) and atherosclerosis. However, few studies have investigated the correlation between COPD and coronary atherosclerosis. METHODS: We recruited 54 patients with stable COPD (51 men, 3 women) but without angina symptoms. Arterial blood gas analyses were performed, pulmonary function was assessed, and calcification of the coronary arteries was evaluated by computed tomography (CT). RESULTS: Calcification of the coronary arteries was noted in 25 patients. There were no significant differences in age, body mass index, respiratory function, and levels of low-density lipoprotein cholesterol, hemoglobin A1c, glucose, or C-reactive protein between patients with or without calcification of the coronary arteries. Arterial blood oxygenation was significantly lower in patients with calcification of the coronary arteries. On both univariate and multivariate analyses, low arterial blood oxygenation was an independent risk factor for calcification of the coronary arteries. CONCLUSIONS: In patients with COPD, low arterial blood oxygenation was strongly associated with calcification of the coronary arteries and may be a significant predictor of cardiovascular disease.

Inhibition of elastase-pulmonary emphysema in dominant-negative MafB transgenic mice.

Alveolar macrophages (AMs) play important roles in the pathogenesis of chronic obstructive pulmonary disease (COPD). We previously demonstrated upregulation of the transcription factor MafB in AMs of mice exposed to cigarette smoke. The aim of this study was to elucidate the roles of MafB in the development of pulmonary emphysema. Porcine pancreatic elastase was administered to wild-type (WT) and dominant-negative (DN)-MafB transgenic (Tg) mice in which MafB activity was suppressed only in macrophages. We measured the mean linear intercept and conducted cell differential analysis of bronchoalveolar lavage (BAL) cells, surface marker analysis using flow cytometry, and immunohistochemical staining using antibodies to matrix metalloproteinase (MMP)-9 and MMP-12. Airspace enlargement of the lungs was suppressed significantly in elastase-treated DN-MafB Tg mice compared with treated WT mice. AMs with projected pseudopods were decreased in DN-MafB Tg mice. The number of cells intermediately positive for F4/80 and weakly or intermediately positive for CD11b, which are considered cell subsets of matured AMs, decreased in the BAL of DN-MafB Tg mice. Furthermore, MMP-9 and -12 were significantly downregulated in BAL cells of DN-MafB Tg mice. Because MMPs exacerbate emphysema, MafB may be involved in pulmonary emphysema development through altered maturation of macrophages and MMP expression.

Relationship between Serum Level of Lymphatic Vessel Endothelial Hyaluronan Receptor-1 and Prognosis in Patients with Lung Cancer.

BACKGROUND: Lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) is a hyaluronic acid receptor that is selectively expressed in the endothelia of lymphatic capillaries. The density of lymphatic vessels expressing LYVE-1 on immunohistochemistry negatively correlates with prognosis of patients with non-small-cell lung cancer. However, the relationship between LYVE-1 serum levels and lung cancer staging is unknown. METHODS: We collected blood samples from 58 lung cancer patients before treatment and measured LYVE-1 serum levels using an enzyme-linked immunosorbent assay. RESULTS: Mean serum LYVE-1 levels were 1,420 pg/mL. Serum LYVE-1 levels correlated positively with serum albumin levels, but inversely with primary tumor size, leukocyte counts, and platelet counts by Pearson's product-moment correlation coefficient. A high cancer staging, occurrence of lymph-node metastases, and occurrence of distant metastases were significantly associated with low LYVE-1 levels. Moreover, multiple logistic regression analyses revealed that LYVE-1 levels were predictive of the presence of lymph node and distant metastases, independently of the other factors. Kaplan-Meier analysis showed that the survival of patients with serum LYVE-1 ≤1,553 pg/mL was significantly poorer than that of patients with serum LYVE-1 >1,553 pg/mL. This survival difference relative to LYVE-1 levels remained statistically significant after adjusting for age and gender by the Cox proportional-hazard analysis. CONCLUSION: Serum LYVE-1 is significantly low in lung cancer patients with metastasis, compared with those without. Measuring LYVE-1 levels in lung cancer patients may be useful for evaluating lung cancer progression.

Reduced number and morphofunctional change of alveolar macrophages in MafB gene-targeted mice.

Alveolar macrophages (AMs) play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). We previously demonstrated that the transcription factor, MafB, increased in the AMs of mice exposed to cigarette smoke, and in those of human patients with COPD. The aim of this study was to evaluate the role of MafB in AMs using newly established transgenic (TG) mice that specifically express dominant negative (DN) MafB in macrophages under the control of macrophage scavenger receptor (MSR) enhancer-promoter. We performed cell differential analyses in bronchoalveolar lavage cells, morphological analyses with electron microscopy, and flow cytometry-based analyses of surface markers and a phagocytic capacity assay in macrophages. AM number in the TG mice was significantly decreased compared with wild-type (WT) mice. Morphologically, the high electron density area in the nucleus increased, the shape of pseudopods on the AMs was altered, and actin filament was less localized in the pseudopods of AMs of TG mice, compared with WT mice. The expression of surface markers, F4/80 and CD11b, on peritoneal macrophages in TG mice was reduced compared with WT mice, while those on AMs remained unchanged. Phagocytic capacity was decreased in AMs from TG mice, compared with WT mice. In conclusion, MafB regulates the phenotype of macrophages with respect to the number of alveolar macrophages, the nuclear compartment, cellular shape, surface marker expression, and phagocytic function. MSR-DN MafB TG mice may present a useful model to clarify the precise role of MafB in macrophages.

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.

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.

FEV6 and FEV1/FEV6 in Japanese participants of the community-based annual health check: the Takahata study.

BACKGROUND: Forced expiratory volume in 6 seconds (FEV(6)) is becoming a substitute of forced vital capacity (FVC). However, the Japanese predictive equation for FEV(6) has not been established, and the validity for the use of FEV(1)/FEV(6) for diagnosing airflow limitation in Japanese has not been confirmed. METHODS: Subjects aged 40 or older, who had participated in a community-based health check in Takahata, Japan, from 2004 through 2005, were enrolled. The smoking histories of these subjects were investigated using a self-reporting questionnaire. FVC, FEV(1), and FEV(6) were measured using spirometric machines. Predictive equations of FEV(6) were obtained from never-smoking subjects without history of pulmonary diseases by multiple linear regression assay. RESULTS: FEV(6) and FEV(1)/FEV(6) were significantly correlated with FVC (r=0.998, p<0.001) and FEV(1)/FVC (r=0.989, p<0.001), respectively. The cutoff values of percent predicted (%) FEV(6) and FEV(1)/FEV(6) for discrimination of having the restrictive lung disorder determined by %FVC <0.8 and having the airflow limitation determined by FEV(1)/FVC <0.7 were 0.80 and 0.72, respectively (%FEV(6): sensitivity=0.995, specificity=0.983, positive predictive value =0.832, negative predictive value =1.000; FEV(1)/FEV(6): sensitivity=0.942; specificity=0.971; PPV=0.787; NPV=0.993). When the 5th percentile the lower limit of normal values was used as criterion for discrimination of having airflow limitation, sensitivity, specificity, PPV, and NPV of FEV(1)/FEV(6) were 0.932, 0.985, 0.808, and 0.995, respectively. CONCLUSION: The results of the present study suggest that %FEV(6) and FEV(1)/FEV(6) are excellent substitutes for %FVC and FEV(1)/FVC, respectively. We confirmed the validity of the use of FEV(6) and FEV(1)/FEV(6) for identifying pulmonary diseases in Japanese individuals.

Impact of cigarette smoking on maximal expiratory flows in a general population: the Takahata study.

BACKGROUND: Maximal expiratory flows (MEFs) depend on the elastic recoil pressure in the alveoli, airway resistance and bronchial collapsibility. MEFs at lower levels of vital capacity [MEFs at x% FVC (MEF(x))] would indicate the patency of peripheral airways. In Japan, a ratio of MEF(50) to MEF(25) (MEF(50)/MEF(25)) greater than 4.0 is used as an index of injury to the small airways in subjects without airflow limitation. However, to date there have been no epidemiological investigations relating to this index. The aim of this study was to evaluate the impact of cigarette smoking on MEFs in a general population, and to assess the validity of using this index to evaluate injury to the small airways. METHODS: Subjects aged 40 years or older (n=2,917), who had participated in a community-based annual health-check in Takahata, Japan, were enrolled in the study. MEF(75), MEF(50) and MEF(25) were measured in these subjects. RESULTS: In smokers, as compared with never-smokers, the percentage predicted MEFs (%MEFs) decreased according to the aging of the population, except in the case of %MEF(25) in females. In males, but not in females, %MEFs decreased significantly with an increase in cigarette consumption. In both genders, MEF(50)/MEF(25) was slightly, but significantly, elevated with aging of the population. In addition, 36.5% of subjects who participated in this health-check had MEF(50)/MEF(25) values greater than 4.0. No difference in MEF(50)/MEF(25) was observed between smokers and never-smokers. CONCLUSION: Cigarette smoking enhanced the age-related decline in MEFs. Since many healthy subjects aged 40 years or older have MEF(50)/MEF(25) values greater than 4.0, the use of this criterion may over-estimate the presence of small airway disease.