The incidence and prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) have been increasing worldwide. The risk of NTM-PD may be higher in undernourished populations. We tried to elucidate the impact of body mass index (BMI) and its change on development of NTM-PD in this study.We performed a retrospective cohort study including South Koreans age >40 years who underwent biennial National Health Insurance System (NHIS) health checkups in both 2005 and 2009 or 2006 and 2010. We monitored eligible individuals from the study initiation date (NHIS health checkup date on 2009 or 2010) until the diagnosis of NTM-PD or December 31, 2017. Enrolled individuals were classified based on BMI at initiation date. We compared NTM-PD incidence per 100 000 person-years by BMI group as well as by BMI change by calculating hazard ratio (HR).A total of 5 670 229 individuals were included in the final analysis. Compared with the BMI <18.5 kg·m−2 group, the incidence of NTM-PD gradually decreased with increased BMI: adjusted HR (aHR) 0.38 (95% confidence interval [CI] 0.35–0.42) for BMI 18.5–22.9, 0.17 (0.15–0.19) for BMI 23–24.9, 0.1 (0.09–0.11) for BMI 25–29.9, and 0.01 (0.07–0.13) for BMI ≥30. A BMI decrease of ≥1 kg/m2 over 4 years increased the incidence of NTM-PD (aHR 1.08, 95% CI 1.01–1.16) whereas a BMI increase of ≥1 decreased the NTM-PD incidence (0.77, 95% CI 0.71–0.83).In conclusion, BMI was inversely related to development of NTM-PD and weight loss increased the risk of NTM-PD.

Na(+) cotransporters have a substantial role in neuronal damage during brain hypoxia. We proposed these cotransporters have beneficial roles in oxygen-sensing mechanisms that increase periarteriolar nitric oxide (NO) concentration ([NO]) during mild to moderate oxygen deprivation. Our prior studies have shown that cerebral neuronal NO synthase (nNOS) is essential for [NO] responses to decreased oxygen tension and that endothelial NO synthase (eNOS) is of little consequence. In this study, we explored the mechanisms of three specific cotransporters known to play a role in the hypoxic state: KB-R7943 for blockade of the Na(+)/Ca(2+) exchanger, bumetanide for the Na(+)-K(+)-2Cl(-) cotransporter, and amiloride for Na(+)/H(+) cotransporters. In vivo measurements of arteriolar diameter and [NO] at normal and locally reduced oxygen tension in the rat parietal cortex provided the functional analysis. As previously found for intestinal arterioles, bumetanide-sensitive cotransporters are primarily responsible for sensing reduced oxygen because the increased [NO] and dilation were suppressed. The Na(+)/Ca(2+) exchanger facilitated increased NO formation because blockade also suppressed [NO] and dilatory responses to decreased oxygen. Amiloride-sensitive Na(+)/H(+) cotransporters did not significantly contribute to the microvascular regulation. To confirm that nNOS rather than eNOS was primarily responsible for NO generation, eNOS was suppressed with the fusion protein cavtratin for the caveolae domain of eNOS. Although the resting [NO] decreased and arterioles constricted as eNOS was suppressed, most of the increased NO and dilatory response to oxygen were preserved because nNOS was functional. Therefore, nNOS activation secondary to Na(+)-K(+)-2Cl(-) cotransporter and Na(+)/Ca(2+) exchanger functions are key to cerebral vascular oxygen responses.

BackgroundRecent studies that assessed the relevance of the blood eosinophil count as a biomarker in patients with COPD may have overestimated it because they included patients with asthma–COPD overlap syndrome (ACOS). We investigated the clinical implications of the blood eosinophil count in patients with non-ACOS COPD.Patients and methodsFrom a Korean COPD Subtype Study (KOCOSS) cohort, we selected patients with non-ACOS COPD after excluding ACOS patients according to Spanish criteria. Clinical characteristics and the incidence of moderate-to-severe exacerbation were compared among the four groups stratified according to the quartiles of blood eosinophil percent and count.ResultsOf the KOCOSS cohort of 1,132 patients with COPD, 467 non-ACOS COPD patients (41.2%) with data of blood eosinophil count remained after excluding those with ACOS based on the Spanish definition. There was no difference in clinical characteristics among groups classified according to the quartiles of eosinophil percent and count. On multivariate logistic regression, eosinophil quartiles in percent and absolute count were not associated with the incidence of moderate-to-severe acute exacerbations of COPD (AECOPD). The eosinophil count did not affect the risk of AECOPD or forced expiratory volume in 1 second (FEV1) changes according to exposure to inhaled corticosteroid (ICS). However, by increasing the cutoff value for the eosinophil count from 200/μL to 600/μL, the odds ratio for risk of exacerbation increased serially from 0.82 to 2.96 on trend analysis.ConclusionIn patients with non-ACOS COPD, the blood eosinophil count and percent were not associated with FEV1 changes, quality of life (QoL), AECOPD frequency, or response to ICS. The clinical implication of the blood eosinophil count should not be overestimated in patients with non-ACOS COPD.

Background We aimed to investigate inhaler device handling in elderly patients. Furthermore, we compared inhaler devices with respect to misuse and error correction. Methods Inhaler use technique was assessed using standardized checklists at the first and 3-months follow-up visits after retraining. The primary outcome was differences in the acceptable use ratio among inhaler devices. Secondary outcomes included differences in error correction, most common step of misuse, and factors affecting the accuracy of inhaler use. Results A total of 251 patients (mean age, 76.4) were included and the handling of 320 devices was assessed in the study. All patients had been trained before, but only 24.7% of them used inhalers correctly.

ObjectiveHealthcare workers (HCWs) are one of the target groups for systematic testing and treatment of latent tuberculosis infection (LTBI) in a setting of low TB incidence. We performed this study to describe the testing of HCWs for LTBI and analyse the acceptance and completion of treatment of LTBI.MethodsThis retrospective cohort study was conducted in four university-affiliated hospitals between January 1 and December 31, 2018. HCWs with positive interferon-gamma release assay (IGRA) during LTBI screening were analysed. We assessed the acceptance and completion of LTBI treatment.ResultsOverall, 893 HCWs were IGRA positive. Among them, 609 HCWs visited the clinic for evaluation of LTBI. Of 609 HCWs who were evaluated, 302 (49.6%) were offered treatment for LTBI. The proportion of acceptance for treatment was 64.5% (195 of 302 HCWs). The treatment course was completed by 143 of 195 HCWs (73.3%). Three months of isoniazid and rifampin (3HR) was used in 137 HCWs (70.3%) and 4 months of rifampin (4R) in 58 (29.7%). 72 HCWs (36.9%) experienced at least one adverse drug events, but there was no different characteristics between completer and non-completer.ConclusionThe acceptance and completion of LTBI treatment were unsatisfactory. Subjective perspective regarding obstacles to treatment of LTBI needs to be explored to increase compliance to LTBI treatment.