Objective: To explore the association between time to first cigarette (TTFC) and expiratory airflow limitation, so as to provide a reference for the prevention and control of pulmonary function decline. Methods: Based on the baseline survey of the China Multi-Ethnic Cohort (CMEC), the demographic, lifestyle behavior, smoking behavior, and TTFC data of permanent residents aged 30 to 79 years in Chengdu City were collected from 2018 to 2019. The TTFC was divided into ≤5, 6-30, 31-60, and >60 minutes. Expiratory airflow limitation was determined when the proportion of the measured peak expiratory flow to the predicted value was less than 80%. The association between TTFC and expiratory airflow limitation was analyzed using a multivariable logistic regression model, and subgroup analyses were conducted according to smoking cessation, age of starting smoking, smoking duration, average daily smoking volume, and the habit of deep inhalation into the lungs. Results: A total of 6 766 residents were investigated, among whom 6 402 were males, accounting for 94.62%. The median age was 52 (interquartile range, 19) years. A total of 2 468 residents were detected with expiratory airflow limitation, with a detection rate of 36.48%. Multivariable logistic regression analysis showed that after adjusting for demographics, lifestyle behavior, smoking cessation, age of starting smoking, smoking duration, average daily smoking volume, and the habit of deep inhalation into the lungs, TTFC ≤5 minutes (OR=1.203, 95%CI: 1.035-1.397) and 6-30 minutes (OR=1.174, 95%CI: 1.002-1.374) were associated with an increased risk of expiratory airflow limitation. Subgroup analyses showed that there was no interaction between smoking behavior and TTFC on the risk of expiratory airflow limitation (all P>0.05). Conclusion A shorter TTFC is associated with an increased risk of expiratory airflow limitation among residents aged 30 to 79 years, and the association is not affected by snoking behaviors such as smoking cessation, age of starting smoking, smoking duration and average daily smoking volume.

Objective: To investigate the prevalence and influencing factors of dyslipidemia among residents in Chengdu City, so as to provide insights into improving the prevention and control of dyslipidemia. Methods: Based on the baseline survey of the Natural Population Cohort Study in Southwest China, residents aged 30 to 79 years was selected from 34 towns (communities) in 5 counties (districts) of Chengdu City using the multi-stage stratified cluster random sampling method in 2018. Demographic information and lifestyle behaviors were collected through questionnaires. Blood pressure, fasting blood glucose, serum uric acid, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were collected through physical examination and laboratory tests. A multivariable logistic regression model was used to identify the factors affecting dyslipidamia. Results: A total of 21 113 participants were surveyed, including 9 331 males (44.20%) and 11 782 females (55.80%), and had a mean age of (50.80±12.32) years. The prevalence rate of dyslipidemia was 35.64%, and the prevalence rates of high TG, low-HDL-C, high TC and high LDL-C were 17.25%, 11.88%, 10.11% and 7.35%, respectively. Multivariable logistic regression analysis identified gender (male, OR=1.584, 95%CI: 1.463-1.716), age (50 to 79 years old, OR：1.221-1.444, 95%CI: 1.079-1.632), residence (urban, OR=1.123, 95%CI: 1.052-1.198), marital status (not married, OR=1.246, 95%CI: 1.128-1.376), educational level (high school and above, OR=0.914, 95%CI: 0.849-0.983), current smoking (OR=1.220, 95%CI: 1.121-1.327), drinking (1 to 2 d/week, OR=1.525, 95%CI: 1.368-1.700; 3 to 5 d/week, OR=1.857, 95%CI: 1.575-2.191; almost every day, OR=1.512, 95%CI: 1.269-1.801), sedentary time in leisure time (>2 h/d, OR=1.123, 95%CI: 1.046-1.206), central obesity (OR=2.212, 95%CI: 1.986-2.265), hypertension (OR=1.489, 95%CI: 1.388-1.598), diabetes (OR=1.998, 95%CI: 1.833-2.157) and hyperuricemia (OR=2.012, 95%CI: 1.848-2.192) as factors affecting dyslipidemia. Conclusion The prevalence of dyslipidemia among residents in Chengdu City was mainly associated with smoking, drinking, sedentary time, central obesity, hypertension, diabetes and hyperuricemia.

Objective To detect the mutations of COL7A1 gene in three cases of dystrophic epidermolysis bullosa pruriginosa (DEBP). Methods Clinical data were collected from 3 patients with DEBP. Skin lesions were obtained from these patients and subjected to transmission electron microscopy. DNA was extracted from the peripheral blood of the 3 patients, their 16 relatives, and 150 unrelated normal human controls, and PCR was performed to amplify all the exons and flanking sequences of COL7A1 gene followed by sequencing.Results The patient 1 and 2 had family history, whereas the case 3 was sporadic. Transmission electron microscopy showed tissue cleavage beneath lamina densa in case 1 and slightly decreased anchoring fibrils in some areas of the lesions in case 1 and 3. Three heterozygous mutations of COL7A1 gene, i.e., c. G6734T, c.G6859A and c. G5318T, which leaded to three amino acid mutations, i.e., p. G2245V, p. G1773V and p. G2287R, were found in patient 1, 2 and 3 respectively. Of them, p. G2245V and p. G1773V were novel mutations. The mutations strictly cosegregated with the phenotype in the patients of family 1 and 2. No mutation was detected in the unaffected parents of patient 3 or the 150 unrelated healthy controls. Conclusions The p. G2245V, p. G2287Rand p. G1773V mutations of COL7A1 gene may be responsible for the phenotype of DEBP in the three cases,and of them, p. G2245V and p. G1773V have never been reported.