The effect of the menstrual cycle on the diurnal cortisol rhythm was investigated in 15 normally cyclic healthy women during reproductive life. Salivary cortisol was measured by radioimmunoassay in samples collected every 2 h for 24 h during the four phases of the menstrual cycle: menstrual phase, late follicular/peri-ovulation phase, early to mid luteal phase and late luteal phase, respectively. Distinct diurnal rhythms of free cortisol were found throughout the menstrual cycle by using a nonlinear periodic regression model. The model was characterized by an asymmetrically peaked diurnal cycle and ultradian harmonics. There was a trend to higher troughs and significantly shorter peak-width in phase II and phase IV compared to phase I. The ultradian amplitude in phase IV was significantly lower compared with phase I and showed a trend of decrease compared with phase II. The results suggest that the daily cortisol secretion is modulated by the phase of the menstrual cycle.
Adult ; Circadian Rhythm ; Female ; Humans ; Hydrocortisone ; secretion ; Luteal Phase ; Menstrual Cycle ; Radioimmunoassay ; Salvia ; metabolism

COPD refers to a group of chronic respiratory diseases which seriously influence the people's health and life quality. The national COPD surveillance in China has been implemented since 2014 with the goal of monitoring the prevalence and trend of COPD and related risk factors in China. The paper summarizes the item and method of national COPD surveillance in China.
Aged ; China/epidemiology* ; Chronic Disease/psychology* ; Female ; Humans ; Male ; Middle Aged ; Population Surveillance/methods* ; Prevalence ; Pulmonary Disease, Chronic Obstructive/psychology* ; Quality of Life ; Risk Factors

Objective: Smoking is the most important risk factor for COPD. Understanding the smoking rate, current smoking rate, average age to start smoking and average daily consumption of cigarettes among people aged ≥40 years in China can provide scientific evidence for the effective control and prevention of COPD. Methods: Data were from COPD surveillance in China (2014 to 2015) which covered 31 provinces, autonomous regions and municipalities. A total of 75 107 adults aged ≥40 years selected through multi-stage stratified cluster sampling from 125 surveillance sites (county/district) were surveyed by electronic questionnaire during face to face interviews. The smoking rate and other smoking index were estimated by using weighting complex sampling design. Results: The smoking rate and current smoking rate were 40.0% (95%CI: 38.5%-42.0%) and 31.0% (95%CI: 29.7%-32.0%), respectively, among the Chinese aged ≥40 years in 2014. The smoking rate and current smoking rate in males (74.1% and 57.6%) were much higher than those in females (5.4% and 4.0%). And the two rates were significantly higher in rural area (41.2% and 32.4%) than in urban area (38.8% and 29.5%). The mean age of smokers to start smoking was 20.1 (95%CI: 19.7-20.5) years. The younger the smokers were, the earlier their average age to start smoking was (The ages to start smoking for smokers aged 40-, 50-, 60-, ≥70 years were 18.3, 19.2, 20.9 and 23.1 years, respectively). Average daily cigarette consumption of current daily smokers was 18.9 (95%CI: 18.1-19.7) cigarettes, and the daily cigarette consumption was higher in males (19.3 cigarettes) than in females (12.5 cigarettes). Conclusion: The smoking rate in males aged ≥40 years is high in China. Compared with urban area, the smoking rate in rural area is higher, posing a big challenge for COPD control and prevention.
Adult ; Aged ; Asian People/statistics & numerical data* ; China/epidemiology* ; Female ; Humans ; Male ; Prevalence ; Risk Factors ; Smoking/psychology* ; Smoking Cessation ; Surveys and Questionnaires ; Young Adult

Objective: To describe and analyze the passive smoking exposure level in adults aged ≥40 years in China. Methods: A total of 75 107 adults from 125 sites of COPD surveillance points in China were surveyed by electronic questionnaire during face to face interviews. After comprehensive weighting of the samples, the passive smoking exposure level was analyzed. Results: The passive smoking exposure rate of the adults aged ≥40 years was 44.9% (95%CI: 42.3%-47.5%). The exposure rate was highest in those aged from 40 to 49 years (51.0%, 95%CI: 47.9%-54.1%) in term of age groups, in those with senior high school education level and above (48.6%, 95%CI: 44.9%-52.2%) in term of education level, and in office workers (57.7%, 95%CI: 51.8%-63.7%) in term of occupation. The adults reporting passive smoking exposure every days in a week accounted for 27.7% (95%CI: 25.5%-29.8%), and those reporting household passive smoking exposure accounted for 28.3% (95%CI: 26.2%-30.5%). Logistic regression analysis showed that the passive smoking exposure level was different in different age groups and occupation groups. Conclusion: The passive smoking exposure level is still high in adults in China. Age and occupation are the influencing factors of passive smoking exposure level.
Adult ; Aged ; Asian People/statistics & numerical data* ; China/epidemiology* ; Environmental Exposure ; Family Characteristics ; Female ; Humans ; Male ; Middle Aged ; Population Surveillance/methods* ; Smoking/epidemiology* ; Surveys and Questionnaires ; Tobacco Smoke Pollution/statistics & numerical data*

Objective: To understand the current status of dust and/or harmful gas exposure in adults aged ≥40 years and corresponding protection in China, and provide evidence for strengthening the occupational protection against dust and harmful gas exposure. Methods: The data were obtained from 2014-2015 COPD surveillance in China. A total of 75 107 adults aged ≥40 years selected through multi-stage stratified cluster sampling from 125 surveillance points in 31 provinces (autonomous regions and municipalities) were surveyed in face to face interviews. Occupational exposure was defined as occupational exposure to dust and/or harmful gas for more than 1 year. The weighted percentages of exposure were estimated by using complex sampling design. Results: Among eligible 71 061 participants, the exposure rate of dust and/or harmful gas was 46.3%. The exposure rate in rural area (51.7%) was significantly higher than that in urban area (40.3%), and the exposure rate in the western area was higher than those in the eastern and central areas (P<0.001). Among the groups with different education level, the exposure rate in those with education level of primary school and below was highest (49.7%, P<0.001). The exposure protection rate was 26.7%, and the exposure protection rate was highest in the eastern area (29.9%), followed by that in the central area (27.0%) and that in the western area (22.9%) The exposure protection rate in urban area was significantly higher than that in rural area, and the exposure protection rate was lowest in those with education level of primary school and below. The regular exposure protection was taken by only 50.7% of the adults surveyed. Conclusion: The exposure rate of dust and/or harmful gas is high in China, while the exposure protection rate is very low. Health education, occupational protection and supervision should be strengthened among those with low education level, and those living in rural area and in the western area.
Adult ; China/epidemiology* ; Dust ; Female ; Gases/toxicity* ; Humans ; Male ; Middle Aged ; Occupational Diseases/epidemiology* ; Occupational Exposure/statistics & numerical data* ; Residence Characteristics ; Rural Population ; Surveys and Questionnaires ; Urban Population

Objective: To analyze the status and distribution characteristics of household polluting fuel use in China. Methods: The data were collected from the adults aged ≥40 years who were recruited through multi-stage stratified cluster sampling in 2014-2015 COPD surveillance conducted in 31 provinces (autonomous regions and municipalities) in China. A total of 75 107 adults aged ≥40 years in 125 surveillance points were surveyed in face to face interview. Polluting fuels included biomass fuels (wood, dung, crop residues and charcoal), coal (including coal dust and lignite) and kerosene. The weighted percentage of family using polluting fuels, combustion method for cooking or heating and ventilation installation with 95%CI were estimated by complex sampling design. Results: According to the survey results from 75 075 adults, the percentage of family using polluting fuels for cooking or heating was 59.9% (95%CI: 54.2%-65.7%), the percentage in rural areas was significantly higher than that in urban areas (P<0.001). As for different polluting fuels, the percentage of using only biomass fuels for cooking or heating was 25.9% (95%CI:20.5%-31.3%), the percentage of using only coal (including kerosene) was 18.9% (95%CI: 13.2%-24.7%), and the percentage of using both biomass fuels and coal was 15.1% (95%CI: 10.8%-19.4%). Among seven geographic areas in China, the percentages of using biomass fuels ranged from 53.8% in southern China to 23.0% in northern China (P=0.039), the percentages of using coal (including kerosene) ranged from 59.5% in northwestern China to 22.3% in southern China (P=0.001). Among the families using polluting fuels, the percentages of mainly using traditional open fires and stoves were 21.3% (95%CI: 16.9%-25.8%) and 31.5% (95%CI: 25.8%-37.2%), respectively; the percentage of having ventilation installation was72.7% (95%CI: 66.9%-78.5%). Conclusions: Household polluting fuel use is common in China, but differs with area, traditional fuel combustion method is widely used, the coverage of ventilation installation need to be improved. In order to promote COPD prevention and control, it is necessary to develop strategies on fuels and fuel combustion method improvement to reduce indoor air pollution resulted from household fuel combustion.
Adult ; Aged ; Air Pollution, Indoor/prevention & control* ; Biomass ; China/epidemiology* ; Coal/adverse effects* ; Cooking ; Environmental Pollutants/adverse effects* ; Family Characteristics ; Female ; Heating/methods* ; Humans ; Male ; Middle Aged ; Wood

Objective: To understand the prevalence of biomass fuel exposure in women aged ≥40 years in China during 2014-2015, and provide evidence for the prevention and control of bio-fuel exposure. Methods: All participants were selected from a national representative cross-sectional survey during 2014-2015 in the mainland of China. A multi-stage stratified cluster sampling strategy was used. A total of 37 795 women aged ≥40 years received a face-to-face questionnaire survey at 125 surveillance points in 31 provinces. The level of biomass fuel exposure was analyzed after complex sample weighting to represent the overall Chinese women aged ≥40 years. Results: A total of 37 777 women were included in the analysis. With complex weighting, the rate of biomass fuel exposure in Chinese women aged ≥40 years was 35.8% (95%CI: 29.6%-42.1%), the exposure rate was higher in rural women than in urban women (P<0.001). The biomass fuel exposure rate was highest in northeastern and lowest in northern areas of China (χ(2)=17.03, P=0.009). The estimated biomass fuel exposure rate decreased with the increase of educational level (P<0.001). Conclusion: The prevalence of biomass fuel exposure is high in women aged ≥40 years in China, especially in those in rural areas. The exposure level differs with age and area. Appropriate measures should be taken to reduce the level of biomass fuel exposure in Chinese women.
Adult ; Aged ; Air Pollutants/toxicity* ; Air Pollution, Indoor/statistics & numerical data* ; Asian People ; Biomass ; China/epidemiology* ; Cooking/methods* ; Cross-Sectional Studies ; Female ; Fossil Fuels/toxicity* ; Humans ; Inhalation Exposure/statistics & numerical data* ; Middle Aged ; Prevalence ; Risk Factors ; Rural Population ; Surveys and Questionnaires

Objective: To understand the distribution and characteristics of people aged ≥40 years who are at high risk of COPD in China and provide evidence for COPD prevention and control. Methods: The survey was conducted among the subjects selected through multi-stage stratified cluster sampling from 31 provinces (autonomous regions and municipalities) in China for 2014-2015 national chronic obstructive pulmonary disease surveillance. A total of 75 107 people aged ≥40 years in 125 surveillance points were surveyed in face to face interviews. Subjects who met at least one of the following conditions, including chronic respiratory symptoms, exposure to risk factors, medical history of respiratory diseases, and family history, were defined as population at high risk. The weighted proportion of the population at high risk of COPD and 95%CI were estimated by using complex sampling design. Results: Among eligible 74 296 subjects, the proportion of population at high risk of COPD was 89.5% (95%CI: 87.8%-91.2%). The proportion significantly increased with age (P<0.001). The proportion of the population at high risk was significantly higher in men than in women (P<0.001), and in rural area than in urban area (P<0.001). The highest proportion of population at high risk was observed in men in rural area in western China. The proportion of population at high risk of COPD who met at least two conditions was 32.0% (95%CI:29.7%-34.2%), the proportion of those who met at least three conditions was 7.4% (95%CI: 6.6%- 8.3%), and the proportion of those who met all the conditions was 1.5% (95%CI: 1.2%-1.8%). Among population at high risk of COPD, those who only had exposure to one risk factor accounted for 61.7% (95%CI: 59.8%-63.7%). Conclusion: About 90% of people aged ≥40 years in China are at high risk for COPD. It is necessary to conduct population-based screening for COPD and take comprehensive measures to reduce prevalence of risk factors.
Adult ; Asian People/statistics & numerical data* ; China/epidemiology* ; Female ; Humans ; Male ; Prevalence ; Pulmonary Disease, Chronic Obstructive/ethnology* ; Risk Factors ; Rural Population ; Surveys and Questionnaires ; Urban Population

Objective: To understand the awareness of knowledge about COPD and related factors in residents aged ≥40 years in China. Methods: Through multi-stage stratified cluster sampling, residents aged ≥40 years were selected from 125 sites of COPD surveillance (2014-2015) in 31 provinces of China for a face to face questionnaire survey. The demographic characteristics and awareness rate of knowledge about COPD among 75 082 subjects were described as frequency and percentage. The awareness rate of knowledge about COPD and its 95% confidence interval (CI) among the residents aged ≥40 years were estimated with complicated sampling weights. Meanwhile, the knowledge awareness related factors were screened in complicated sampling data. Results: The awareness rate of COPD was 9.2%. The awareness rate of pulmonary function test was 3.6% and the awareness rate of COPD-related knowledge was 5.8%. All of the awareness rates were associated with gender, age, education level and occupation. Besides, the awareness rate of pulmonary function test and COPD-related knowledge were related with living area. Compared with females, the ORs of the three awareness rates among males were 0.88, 0.81 and 0.78. Compared with the residents aged ≥70 years, the ORs of the three awareness rates among those aged 60-69 years were 1.28, 1.08 and 1.51. Compared with the residents with education level of primary school or below, the ORs of the three awareness rates among those with college degree or above were 2.28, 3.43 and 3.14. The OR of the awareness rate of pulmonary function test among the residents in the eastern area was 1.77 compared with those in the central area. The ORs of the awareness rate of COPD-related knowledge among the residents in the eastern and western areas were 1.95 and 2.16 compared with those in the central area(all above P<0.05). Among COPD symptoms, the awareness rate of dyspnea was highest (67.9%), and among the risk factors for COPD, the awareness rate of smoking was highest (81.3%). The source of awareness of COPD for most residents was television program (38.2%). Conclusion: The awareness rate of knowledge about COPD was low in residents aged ≥40 years in China in 2014. It is necessary to strengthen the health education about COPD to improve the prevention and control of the disease.
Adult ; Aged ; Awareness ; China/epidemiology* ; Dyspnea/epidemiology* ; Educational Status ; Female ; Health Knowledge, Attitudes, Practice ; Humans ; Male ; Middle Aged ; Pulmonary Disease, Chronic Obstructive/epidemiology* ; Respiratory Function Tests ; Risk Factors ; Smoking/epidemiology* ; Surveys and Questionnaires

Objective: To understand the performance of spirometry examination in adults aged ≥40 years and provide evidence for the improvement of comprehensive prevention and control of COPD and the evaluation on the effects of current prevention and control measures. Methods: The study subjects were those included in national COPD surveillance in China during 2014-2015. The surveillance used a multi-stage, stratified cluster sampling strategy and a total of 125 surveillance points in 31 provinces were covered. A total of 75 107 adults aged ≥40 years received a questionnaire survey in face to face interviews to collect the information about their acceptance of spirometry examination in previous years. The estimated rate (95%CI) of spirometry examination was calculated based on complex sampling weight design. Results: A total of 74 591 subjects were included in the analyses. The estimated rate of spirometry examination was 4.5% (95%CI: 3.7%-5.2%), and it was significantly higher in men than in women (P<0.001), in urban population than in rural population (P<0.001). The rate of spirometry examination increased with the increase of education level (P<0.001). The rate of spirometry examination was highest in retirees (10.8%, 95%CI: 8.2%-13.3%), and lowest in those working in the industry of agriculture, forestry, animal husbandry, fishery and water conservancy (2.4%, 95%CI: 2.0%-2.9%). The rate of spirometry examination was high in those with previous chronic respiratory diseases and respiratory symptoms, i.e. 13.4% (95%CI: 10.5%-16.4%) and 15.0% (95%CI: 10.5%-19.4%) respectively. The rate of spirometry examination in former smokers was 7.4% (95%CI: 6.0%-8.8%), slightly higher than those in current smokers and never smokers, 4.7% (95%CI: 3.9%-5.5%) and 3.9% (95%CI: 3.0%-4.7%), respectively. In different population groups, the rate of spirometry examination was lowest in rural population who had received no formal education (1.8%, 95%CI: 1.2%-2.3%) and highest in urban population with respiratory symptoms (20.2%, 95%CI: 12.6%-27.8%). Conclusion: The rate of spirometry examination is extremely low in adults aged ≥40 years in China, therefore effective measures should be taken to increase the rate of spirometry examination in adults in China.
Adult ; China/epidemiology* ; Cross-Sectional Studies ; Female ; Humans ; Male ; Prevalence ; Pulmonary Disease, Chronic Obstructive/physiopathology* ; Rural Population ; Spirometry ; Surveys and Questionnaires ; Urban Population