With many epidemiologic studies made to establish the prevalence of sleep-disordered breathing (SDB) and obstructive sleep apnea syndrome (OSAS) in Western countries, no such data have been reported in Korea. The purpose of this study was to examine the prevalence of SDB and OSAS, and their related factors in Korean adults aged 40-69 years. Among the total of 5,020 participants at the baseline examination of the Korean Health and Genome Study, a random sample of 457 men and women was studied with employment of overnight full polysomnography to determine the prevalence of SDB and OSAS. The prevalence of SDB (apnea-hypopnea index > or = 5) was 27% and 16% in men and women, respectively. When OSAS was defined by an apnea-hypopnea index > or = 5 plus excessive daytime sleepiness, its prevalence was 4.5% in men and 3.2% in women. Logistic regression analyses showed that sex, body mass index, and hypertension were closely associated with the risk of SDB. Our findings show that SDB is a common problem in the Korean adult population. Understanding and treatment of SDB may be essential in terms of intervention to reduce the risk of related medical problems.

Five lipoxygenase (5-LO) is the first committed enzyme in the metabolic pathway leading to the synthesis of the leukotrienes. We examined genomic DNA isolated from 25 normal subjects and 31 patients with asthma (6 of whom had aspirin-sensitive asthma) for mutations in the known transcription factor binding regions and

Neutrophils are considered to play a central role in ventilator-induced lung injury (VILI). However, the pulmonary consequences of neutrophil accumulation have not been fully elucidated. Matrix metalloproteinase-9 (MMP-9) had been postulated to participate in neutrophil transmigration. The purpose of this study was to investigate the role of MMP-9 in the neutrophilic inflammation of VILI. Male Sprague-Dawley rats were divided into three groups: 1) low tidal volume (LVT), 7 ml/kg of tidal volume (VT); 2) high tidal volume (HVT), 30 ml/kg of VT; and 3) HVT with MMP inhibitor (HVT+MMPI). As a MMPI, CMT-3 was administered daily from 3 days before mechanical ventilation. Degree of VILI was assessed by wet-to-dry weight ratio and acute lung injury (ALI) scores. Neutrophilic inflammation was determined from the neutrophil count in the lung tissue and myeloperoxidase (MPO) activity in the bronchoalveolar lavage fluid (BALF). MMP-9 expression and activity were examined by immunohistochemical staining and gelatinase zymography, respectively. The wet-to-dry weight ratio, ALI score, neutrophil infiltration, and MPO activity were increased significantly in the HVT group. However, in the HVT+MMPI group, pretreatment with MMPI decreased significantly the degree of VILI, as well as neutrophil infiltration and MPO activity. These changes correlated significantly with MMP-9 immunoreactivity and MMP-9 activity. Most outcomes were significantly worse in the HVT+MMPI group compared with the LVT group. In conclusion, VILI mediated by neutrophilic inflammation is closely related to MMP-9 expression and activity. The inhibition of MMP-9 protects against the development of VILI through the downregulation of neutrophil-mediated inflammation.

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Adipose stem cells (ASCs) are detectable in the parenchyma and large airways of lungs after systemic administration, and ameliorate inflammatory infiltration and cell death in animal models of emphysema. We evaluated whether ASC treatment could attenuate lung fibrosis induced by repetitive intratracheal bleomycin administration. Male 8-week-old C57BL/6J mice (control group, bleomycin-only group, and bleomycin-plus-ASC group) were used. Eight biweekly doses of bleomycin were injected intratracheally via an intubation procedure at a dose of 0.04 units in a total volume of 100 μL of sterile saline. During the latter 2 months of the 4-month bleomycin exposure, human ASCs (3 × 10(5) cells) were administered repeatedly via intraperitoneal injection at the same time as bleomycin. Lung tissues were evaluated for histology, collagen content, TUNEL staining, and TGF-β levels. Bronchoalveolar lavage (BAL) was performed for cell counting. Administrations of ASCs ameliorated the deleterious effects of repetitive intratracheal instillation of bleomycin, namely hyperplasia of Club cells (Clara cells) and cuboidal alveolar epithelial cells, infiltration of the perialveolar ducts by inflammatory cells, septal thickening, enlarged alveoli, and extensive fibrosis. Addition of ASC led to suppression of bleomycin-induced epithelial cell apoptosis and expression of TGF-β. These results suggest a useful therapeutic effect of ASCs on pulmonary fibrosis induced by repetitive bleomycin administration. Further studies will be required to evaluate the efficacy of ASC therapy for the treatment of idiopathic pulmonary fibrosis.

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Habitual snoring is associated with cardiovascular morbidity and mortality, and metabolic abnormalities such as impaired glucose homeostasis. Many studies were performed in obese Western populations. The purpose of this study was to examine the association of habitual snoring with glucose and insulin metabolism in nonobese Korean men who were free of diabetes and hypertension. A total of 2,719 men ages 40-69 years from the Korean Health and Genome Study participated in this study. Information of snoring frequency was obtained by a questionnaire and glucose and insulin levels during oral glucose tolerance test were measured. Repeated measures analysis of variance detected significant differences in the changing patterns of glucose and insulin levels at 1 hour and 2 hours between habitual snorers and nonhabitual snorers, whereas there were no significant differences in fasting blood glucose and insulin levels. Multivariate logistic regression analyses revealed that habitual snoring was independently associated with elevated 1-hour and 2-hour glucose levels and a 2-hour insulin level, respectively. The present data suggest that habitual snoring may affect glucose-insulin metabolism, independent of diabetes and hypertension, even in nonobese Korean middle-age men. Further prospective studies are needed to examine the causal relationship between habitual snoring and insulin resistance or glucose intolerance.

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