Objective To investigate the association between different smoking statuses and survival and emphysema in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Methods This retrospective study included patients admitted from October 2014 to September 2017. Demographic, clinical, laboratory, imaging, impulse oscillometry, and traditional pulmonary function data were collected. The relationship between smoking and EI was analyzed via binary logistic regression after adjusting for other factors. Survival was analyzed using the Kaplan–Meier method and the log rank test. Results The patients with AECOPD (357 cases) were identified (and stratified into three groups: never smoked (NS; n=83), former smokers (FS, n=118), and current smokers (CS; n=156). Compared with CS, NS were older and predominantly female. No differences were observed in respiratory symptoms and acute exacerbation between CS and NS. NS had higher resistance and reaction in the central and peripheral airways, while CS exhibited more severe diffuse dysfunction. CS demonstrated more severe and extensive emphysema. Smoking was an independent risk factor for emphysema after adjusting for age, forced expiratory volume in the first second over predicted value, BMI, leukocyte count, and carbon monoxide transfer coefficient. No difference in 5-year survival rates between NS and CS was established. Conclusion CS has the worst pulmonary function, suggesting a more important destruction of the lung parenchyma, while AECOPD without smoking risk factors mostly affects the airways. Impulse oscillometry can be used for imaging airway-dominant AECOPD. There was no difference in the 5-year survival rate.

In terms of airway wall area and emphysema index, patients with chronic bronchitis with PRISm were essentially no different than those with chronic bronchitis without abnormal spirometry, whereas for symptoms, they are more like GOLD 1 and 2 patients. Our findings show that it is not yet clear whether it constitutes an intermediate stage of chronic bronchitis with normal lung function that progression to early COPD.

Objective: To evaluate the association between calcium-sensing receptor (CaSR) Arg990Gly (rs1042636, A > G), Ala986Ser (rs1801725, G > T) polymorphisms, and urolithiasis risk. Methods: Polymorphisms mentioned above were genotyped in a hospital-based case-control study of 615 patients diagnosed with nephrolithiasis and 315 kidney stone-free controls in a Chinese population using the SNaPshot method. Results: The results indicated a significantly increased risk associated with CaSR Arg990Gly GG genotypes (OR 1.64, 95% CI 1.08-2.50) compared with the AA genotype. The CaSR Arg990Gly G carriers (AG/GG) had an adjusted OR (95% CI) of 1.45 (1.04-2.03, p = 0.021) compared with the wild genotype in the dominant model. In the stratified analyses, the risk remained for the subgroup of patients with age >48, never smokers and patients with hypertension and calcium oxalate stones (OR 1.78, 95% CI 1.02-3.09; OR 1.54, 95% CI 1.03-2.30; OR 2.83, 95% CI 1.32-6.07; OR 1.60, 95% CI 1.12-2.28, respectively). Conclusion: Our results provide evidences that the CaSR Arg990Gly polymorphism is associated with the risk of nephrolithiasis development in a Chinese population.

BackgroundChronic obstructive pulmonary disease (COPD) with carbon dioxide retention is associated with a worsening clinical condition and the beginning of pulmonary ventilation decompensation. This study aimed to identify the factors associated with carbon dioxide retention.MethodsThis was a retrospective study of consecutive patients with COPD (meeting the Global Initiative for Chronic Obstructive Lung Disease diagnostic criteria) hospitalized at The Ninth Hospital of Xi’an Affiliated Hospital of Xi’an Jiaotong University between October 2014 and September 2017. The baseline demographic, clinical, laboratory, pulmonary function, and imaging data were compared between the 86 cases with carbon dioxide retention and the 144 cases without carbon dioxide retention.ResultsCompared with the non-carbon dioxide retention group, the group with carbon dioxide retention had a higher number of hospitalizations in the previous 12 months (p = 0.013), higher modified Medical Research Council (mMRC) dyspnea scores (p = 0.034), lower arterial oxygen pressure (p = 0.018), worse pulmonary function (forced expiratory volume in one second/forced vital capacity [FEV1/FVC; p < 0.001], FEV1%pred [p < 0.001], Z5%pred [p = 0.004], R5%pred [p = 0.008], R5-R20 [p = 0.009], X5 [p = 0.022], and Ax [p = 0.011]), more severe lung damage (such as increased lung volume [p = 0.011], more emphysema range [p = 0.007], and lower mean lung density [p = 0.043]). FEV1 < 1 L (odds ratio [OR] = 4.011, 95% confidence interval [CI]: 2.216–7.262) and emphysema index (EI) > 20% (OR = 1.926, 95% CI: 1.080–3.432) were independently associated with carbon dioxide retention in COPD.ConclusionCompared with the non-carbon dioxide retention group, the group with carbon dioxide retention had different clinical, pulmonary function, and imaging features. FEV1 < 1 L and EI > 20% were independently associated with carbon dioxide retention in AECOPD.Trial registrationChiCTR-OCH-14004904. Registered 25 June 2014.Electronic supplementary materialThe online version of this article (10.1186/s12890-018-0691-8) contains supplementary material, which is available to authorized users.