Background: Cigarette smoking is the principal environmental risk factor for developing COPD, and nicotine dependence strongly influences smoking behavior. This study was performed to elucidate the relationship between nicotine dependence, genetic susceptibility to nicotine dependence, and volumetric CT findings in smokers. Methods: Current smokers with COPD (GOLD stage ≥ 2) or normal spirometry were analyzed from the COPDGene Study, a prospective observational study. Nicotine dependence was determined by the Fagerstrom test for nicotine dependence (FTND). Volumetric CT acquisitions measuring the percent of emphysema on inspiratory CT (% of lung <-950 HU) and gas trapping on expiratory CT (% of lung <-856 HU) were obtained. Genotypes for two SNPs in the CHRNA3/5 region (rs8034191, rs1051730) previously associated with nicotine dependence and COPD were analyzed for association to COPD and nicotine dependence phenotypes. Results: Among 842 currently smoking subjects (335 COPD cases and 507 controls), 329 subjects (39.1%) showed high nicotine dependence. Subjects with high nicotine dependence had greater cumulative and current amounts of smoking. However, emphysema severity was negatively correlated with the FTND score in controls (ρ = -0.19, p < .0001) as well as in COPD cases (ρ = -0.18, p = 0.0008). Lower FTND score, male gender, lower body mass index, and lower FEV1 were independent risk factors for emphysema severity in COPD cases. Both CHRNA3/5 SNPs were associated with FTND in current smokers. An association of genetic variants in CHRNA3/5 with severity of emphysema was only found in former smokers, but not in current smokers. Conclusions: Nicotine dependence was a negative predictor for emphysema on CT in COPD and control smokers. Increased inflammation in more highly addicted current smokers could influence the CT lung density distribution, which may influence genetic association studies of emphysema phenotypes. Trial registration: ClinicalTrials (NCT): NCT00608764
Tuberculosis is associated with hypercoagulation; however, there are few reports of cases thromboembolism and tuberculosis at the same time in the real world. The purpose of this study was to report the incidence and clinical course of thromboembolism in patients diagnosed with tuberculosis. We retrospectively analyzed the data of patients who were diagnosed with both tuberculosis and thromboembolism including pulmonary thromboembolism (PTE) or deep vein thrombosis (DVT) at Seoul National University Boramae Medical Center from January 2000 through March 2015. Among the 7905 tuberculosis patients, 49 (0.6%) exhibited PTE, DVT, or both at or after the time of tuberculosis diagnosis. All patients treated for tuberculosis started with isoniazid, ethambutol, rifampicin, and pyrazinamide. Eight patients were switched to treatment with second-line medication because of resistance or adverse events. About half of the patients (n = 21, 44.7%) had thrombosis at the time of tuberculosis diagnosis. Of 48 patients treated for thromboembolism, 36 received warfarin. A total of 20 patients improved symptom caused by thrombosis, and 10 patients were confirmed cure by image study such as computed tomography or doppler ultrasonography. Eight patients who were treated with warfarin had persistent thrombosis. Five patients (10.2%) experienced major bleeding that required hospitalization. All of these bleeding events were associated with warfarin therapy. Careful attention to PTE/DVT is needed at the time of diagnosis of tuberculosis and during anti-tuberculosis therapy. Warfarin therapy administered with anti-tuberculosis medication requires frequent monitoring to prevent major bleeding.