[Status and related factors on the drinking behavior among primary and secondary students in China rural middle and western regions in 2019]

Objective: To analyze the daily drinking behavior and related factors of primary and middle school students in the Nutrition Improvement Program for Rural Compulsory Education Students (NIPRCES) pilot regions. Methods: Multi-stage stratified random cluster sampling method was used to select one to three national pilot counties in 22 provinces in central and western China where the NIPRCES was implemented in 2019. According to different feeding patterns, two primary schools and two middle schools were selected as key monitoring schools. One or two classes were selected from grade 3 to grade 9. The student questionnaire was used to collect the basic information and daily drinking behavior. Taking whether the drinking water ≥5 cups every day as the dependent variable, multivariate logistic regression model was used to analyze the related factors of drinking behavior among students. Results: A total of 27 374 students were included. On average, primary and middle school students in the regions where NIPRCES was implemented had 3.9 cups of water every day. Logistic regression model showed that boys (OR=1.230, P<0.001), primary school students (OR=1.379, P<0.001), father worked outside the home (OR=1.169, P<0.001), both parents worked outside the home (OR=1.228, P<0.001), non-resident students (OR=1.142, P<0.001), the school in the village (OR=1.638, P<0.001) or township (OR=1.358, P<0.001), school feeding (OR=1.252, P<0.001), the school building with flush toilets (OR=1.384, P<0.001) and the central regions (OR=1.300, P<0.001) students were more likely to drink ≥5 cups water every day. Conclusion: The water consumption of primary and middle school students in the pilot regions of NIPRCES is low, and their drinking behaviors are affected by many factors.

Traffic-related air pollution and genome-wide DNA methylation: A randomized, crossover trial

BACKGROUND

Traffic-related air pollution (TRAP) has been associated with changes in gene-specific DNA methylation. However, few studies have investigated impact of TRAP exposure on genome-wide DNA methylation in circulating blood of human.

OBJECTIVE

To explore the association between TRAP exposure and genome-wide DNA methylation.

METHODS

We conducted a randomized, crossover exposure trial among 35 healthy adults in Shanghai, China. All subjects were randomly allocated to a traffic-free park or a main road for consecutive 4 h, respectively. Blood genome-wide DNA methylation after each exposure session was measured by the Infinium Methylation EPIC BeadChip (850K). The differentially methylated CpGs loci associated with TRAP exposure were identified using linear mixed-effect model.

RESULTS

The average concentrations of traffic-related air pollutants including black carbon, ultrafine particles, carbon dioxide, and nitrogen dioxide were 2-3 times higher in the road compared to those in the park. Methylation levels of 68 CpG loci were significantly changed (false discovery rate < 0.05) following TRAP exposure, among which 49 were hypermethylated and 19 were hypomethylated. The annotated genes based on the differential CpGs loci were related to pathways in cardiovascular signaling, cytokine signaling, immune response, nervous system signaling, and metabolism.

CONCLUSIONS

We found that TRAP exposure was associated with DNA methylation in dozens of genes concerning cardiometabolic health. This trial for the first-time profiled genome-wide methylation changes induced by TRAP exposure using the 850K assay, providing epigenetic insights in understanding the cardiometabolic effects of TRAP exposure.

Risk factors for the development of hepatocellular carcinoma in Chengdu: a prospective cohort study

OBJECTIVE

To investigate the incidence of hepatocellular carcinoma (HCC) in Chengdu, identify the risk factors for the development of HCC in Chengdu and provide a reference for the prevention of HCC.

PATIENTS AND METHODS

The study population was recruited from Chengdu, Sichuan Province, China. The study group recruited volunteers in Chengdu from 2007 to 2012, conducted a baseline survey, and subsequently conducted long-term follow-up until December 31, 2019. A total of 22,525 study subjects were enrolled, excluding those who reported a previous history of liver disease, malignancy, and HCC within three months of enrollment. Cox proportional risk regression models were used to screen and determine the various risk factors and their hazard ratios (HR) for HCC in Chengdu, as well as to determine whether the association between other risk factors and HCC was modified by gender.

RESULTS

The study population had a median follow-up of 5.35 years, and a total of 142 people developed HCC, with an incidence rate of 0.71%. Analysis of the multifactorial Cox proportional risk regression model showed that age (age 10 years for 1 group, HR= 1.98, 95% CI: 1.86-2.11, p<0.001), current smoking (HR= 1.25, 95% CI: 1.07-1.31, p=0.031), weekly consumption of pickled vegetables (HR= 1.70, 95% CI: 1.49-1.81, p=0.003) and consumption of pickled vegetables daily (HR= 1.36, 95% CI: 1.21-1.42, p=0.021) were risk factors for HCC, and women (HR= 0.39, 95% CI: 0.28-0.55, p=0.002) and the use of air conditioning (10 years for 1 group, HR= 0.79, 95% CI: 0.68-0.83, p=0.002) were protective factors against HCC. Further analysis revealed that the association between length of time using air conditioning and HCC was heterogeneous among men and women (p=0.007) and that there was an interaction between sex and use of air conditioning in the association with HCC development (p<0.001).

CONCLUSIONS

The Chengdu population has a high incidence of HCC and numerous risk factors for HCC. There is a synergistic interaction between sex and length of time using air conditioning in their role in the development of HCC.

[Effect of P62 on the migration and motility of human epidermal cell line HaCaT in high glucose microenvironment and its mechanism]

Objective: To investigate the effect of P62 on the migration and motility of human epidermal cell line HaCaT in high glucose microenvironment and its possible molecular mechanism, so as to explore the mechanism of refractory diabetic foot wound healing. Methods: The method of experimental research was used. HaCaT cells in logarithmic growth phase was taken for experiment. The cells were collected and divided into normal control group (culture solution containing glucose with final molarity of 5.5 mmol/L) and high glucose (culture solution containing glucose with final molarity of 30.0 mmol/L) 24 h group, high glucose 48 h group, and high glucose 72 h group according to the random number table (the same grouping method below). The cells in normal control group were routinely cultured for 72 h, cells in high glucose 72 h group were cultured with high glucose for 72 h, cells in high glucose 48 h group were routinely cultured for 24 h then cultured with high glucose for 48 h, cells in high glucose 24 h group were routinely cultured for 48 h then cultured with high glucose for 24 h. Then the protein expression of P62 was detected by Western blotting. The cells were collected and divided into normal control group and high glucose group. After being correspondingly cultured for 48 h as before, the protein expression of P62 was detected by immunofluorescence method (indicated as green fluorescence). The cells were collected and divided into negative control small interfering RNA (siRNA) group, P62-siRNA-1 group, P62-siRNA-2 group, and P62-siRNA-3 group, and transfected with the corresponding reagents. At post transfection hour (PTH) 72, the protein expression of P62 was detected by Western blotting. The cells were collected and divided into normal glucose+negative control siRNA group, normal glucose+P62-siRNA group, high glucose+negative control siRNA group, and high glucose+P62-siRNA group. After the corresponding treatment, the protein expression of P62 was detected by Western blotting at PTH 72 h, the cell migration rate was detected and calculated at 24 h after scratching by scratch test, with the number of samples being 9; and the range of cell movement was observed and the trajectory velocity was calculated within 3 h under the living cell workstation, with the number of samples being 76, 75, 80, and 79 in normal glucose+negative control siRNA group, normal glucose+P62-siRNA group, high glucose+negative control siRNA group, and high glucose+P62-siRNA group, respectively. The cells were collected and divided into normal glucose+phosphate buffered solution (PBS) group, high glucose+PBS group, and high glucose+N-acetylcysteine (NAC) group. After the corresponding treatment, the protein expression of P62 at 48 h of culture was detected by Western blotting and immunofluorescence method, respectively. Except for scratch test and cell motility experiment, the number of samples was all 3 in the rest experiments. Data were statistically analyzed with one-way analysis of variance and least significant difference test. Results: Compared with the protein expression in normal control group, the protein expressions of P62 of cells in high glucose 24 h group, high glucose 48 h group, and high glucose 72 h group were significantly increased (P<0.01). At 48 h of culture, the green fluorescence of P62 of cells in high glucose group was stronger than that in normal control group. At PTH 72, compared with the protein expression in negative control siRNA group, the protein expressions of P62 of cells in P62-siRNA-1 group, P62-siRNA-2 group, and P62-siRNA-3 group were significantly decreased (P<0.01). At PTH 72, compared with the protein expression in normal glucose+negative control siRNA group, the protein expression of P62 of cells in normal glucose+P62-siRNA group was significantly decreased (P<0.01), while the protein expression of P62 of cells in high glucose+negative control siRNA group was significantly increased (P<0.01); compared with the protein expression in high glucose+negative control siRNA group, the protein expression of P62 of cells in high glucose+P62-siRNA group was significantly decreased (P<0.01). At 24 h after scratching, compared with (55±7)% in normal glucose+negative control siRNA group, the cell migration rate in normal glucose+P62-siRNA group was significantly increased ((72±14)%, P<0.01), while the cell migration rate in high glucose+negative control siRNA group was significantly decreased ((37±7)%, P<0.01); compared with that in high glucose+negative control siRNA group, the cell migration rate in high glucose+P62-siRNA group was significantly increased ((54±10)%, P<0.01). Within 3 h of observation, the cell movement range in high glucose+negative control siRNA group was smaller than that in normal glucose+negative control siRNA group, while the cell movement range in normal glucose+P62-siRNA group was larger than that in normal glucose+negative control siRNA group, and the cell movement range in high glucose+P62-siRNA group was larger than that in high glucose+negative control siRNA group. Compared with that in normal glucose+negative control siRNA group, the cell trajectory speed in normal glucose+P62-siRNA group was significantly increased (P<0.01), while the cell trajectory speed in high glucose+negative control siRNA group was significantly decreased (P<0.01); compared with that in high glucose+negative control siRNA group, the cell trajectory speed in high glucose+P62-siRNA group was significantly increased (P<0.01). At 48 h of culture, compared with that in normal glucose+PBS group, the protein expression of P62 of cells in high glucose+PBS group was significantly increased (P<0.01); compared with that in high glucose+PBS group, the protein expression of P62 of cells in high glucose+NAC group was significantly decreased (P<0.01). At 48 h of culture, the green fluorescence of P62 of cells in high glucose+PBS group was stronger than that in normal glucose+PBS group, while the green fluorescence of P62 of cells in high glucose+NAC group was weaker than that in high glucose+PBS group. Conclusions: In HaCaT cells, high glucose microenvironment can promote the protein expression of P62; knockdown of P62 protein can promote the migration and increase the mobility of HaCaT cells; and the increase of reactive oxygen species in high glucose microenvironment may be the underlying mechanism for the increase of P62 expression.

[Quality of life and risk factors in patients with herpes zoster]

Objective: To evaluate the quality of life and influencing factors of patients with herpes zoster (HZ) seen in hospitals. Methods: Based on Zoster Brief Pain Inventory (ZBPI) and Five-level EuroQol Five-dimensional Questionnaire (EQ-5D-5L), a cross-sectional survey was conducted to evaluate the pain severity and quality of life of 332 HZ cases seen in 22 hospitals of Lu'an City (Anhui Province), Zibo City (Shandong Province) and Tongchuan City (Shaanxi Province) from October to December 2021. The censored least absolute deviations (CLAD) model was used to analyze the related factors affecting the changes of patients' health utility values. Results: The 45.5% of 332 HZ cases were male. The median (Q₁,Q₃) age was 59 (50, 68) years. 59.64% of them assessed by ZBPI had moderate to severe pain in the past 24 hours (worst pain score≥5), and that of PHN cases was 84.8%(39/46). 77.7% (258/332), 77.4% (257/332) and 74.1% (246/332) of all patients reported that pain interfered with sleep, mood and general activities, respectively. Aging [β_40-49y (95%CI)=-0.11 (-0.15, -0.08); β_50-59y (95%CI)=-0.03 (-0.05, 0.00); β_60-69y (95%CI)=-0.09 (-0.12, -0.06); β_70-90y(95%CI)=-0.16 (-0.19, -0.12)], working status (unemployed) [β_farmer (95%CI)=0.15 (0.13, 0.18); β_retirees(95%CI)=0.21 (0.18, 0.24); β_employee (95%CI)=0.13 (0.10, 0.16) ], complications[β_PHN (95%CI)=-0.08 (-0.13, -0.04); β_{other complications} (95%CI)=-0.12 (-0.15, -0.08)], within 30 days after onset [β(95%CI)=-0.01 (-0.03, 0.01)] and treatment [β_{other complications} (95%CI)=-0.09 (-0.11, -0.06)] were related factors for the decline of health utility value (all P values <0.05). Conclusions: More than half of the patients with HZ had moderate to severe pain in the past 24 hours, which had a serious negative impact on the physical and mental health of the patients. Elderly patients, acute patients and patients with complications had lower health utility values and worse health status. We suggest that eligible people be vaccinated with HZ vaccine as soon as possible.

[Associations between internet addiction, screen time and depressive symptoms]

Objective: To understand the associations between internet addiction, screen time (computer/mobile devices use and television watching time) and depressive symptoms in adults. Methods: A total of 6 932 adults aged <60 years from the Tianjin Chronic Low-grade Sgstemic Inflammation and Health (TCLSIH) Cohort of 2013-2019 were surveyed. The information about their computer/mobile devices use and television watching time were collected by using a self-reported questionnaire. The depressive symptoms were assessed using the self-rating depression scale (SDS). The adults surveyed were divided into two groups: non-depressive symptom group (SDS score <45) and depressive symptom group (SDS score ≥45). The associations between internet addiction, screen time and depressive symptoms were estimated using Cox proportional hazard regression models, with adjusting for multiple confounders. Results: After adjusting for confounding factors, the hazard ratios (HRs) of depressive symptom in the adults who had internet addiction before, had light internet addiction and had moderate or severe internet addiction were 0.83 (95%CI: 0.56-1.23) , 1.20 (95%CI: 1.03-1.41) for light and 1.48 (95%CI: 1.16-1.89), respectively, compared with those without internet addiction. The linear trend test results of the association between internet addiction and depressive symptoms was significant (trend P<0.001). Compared with the adults who used computer/mobile devices for <1 hour/day, the HRs of depressive symptoms in those who used computer/mobile devices for >1 hour, >3 hours, >5 hours and >10 hours were 0.59 (95%CI: 0.40-0.88), 0.58 (95%CI: 0.40-0.85), 0.52 (95%CI: 0.36-0.76) and 0.69 (95%CI: 0.45-1.05) respectively, a U-shaped association was found between computer/mobile devices use time and depressive symptoms (trend P<0.001). Compared with the adults who never watch TV, the HR of depressive symptoms was 1.36 (95%CI:1.09-1.69) for those watching TV for ≥3 hours/day in crude model and 1.34 (95%CI: 1.07-1.68) for those watching TV for ≥3 hours/day in adjusted model (trend P<0.001). Conclusion: Our findings suggested that internet addiction and television watching time were associated with an increased risk of depressive symptoms, while computer/mobile device use time was associated with a reduced risk of depressive symptoms.

Overview of particulate air pollution and human health in China: Evidence, challenges, and opportunities

Ambient particulate matter (PM) pollution in China continues to be a major public health challenge. With the release of the new WHO air quality guidelines in 2021, there is an urgent need for China to contemplate a revision of air quality standards (AQS). In the recent decade, there has been an increase in epidemiological studies on PM in China. A comprehensive evaluation of such epidemiological evidence among the Chinese population is central for revision of the AQS in China and in other developing countries with similar air pollution problems. We thus conducted a systematic review on the epidemiological literature of PM published in the recent decade. In summary, we identified the following: (1) short-term and long-term PM exposure increase mortality and morbidity risk without a discernible threshold, suggesting the necessity for continuous improvement in air quality; (2) the magnitude of long-term associations with mortality observed in China are comparable with those in developed countries, whereas the magnitude of short-term associations are appreciably smaller; (3) governmental clean air policies and personalized mitigation measures are potentially effective in protecting public and individual health, but need to be validated using mortality or morbidity outcomes; (4) particles of smaller size range and those originating from fossil fuel combustion appear to show larger relative health risks; and (5) molecular epidemiological studies provide evidence for the biological plausibility and mechanisms underlying the hazardous effects of PM. This updated review may serve as an epidemiological basis for China’s AQS revision and proposes several perspectives in designing future health studies.

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Acute effects of PM are smaller in China compared with developed countries

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Health effects caused by PM depend on particle composition, source, and size

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There are no thresholds for the health effects of PM

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Mechanistic studies support the biological plausibility of PM’s health effects

The efficacy and safety of pirfenidone in the treatment of HPS-related pulmonary fibrosis and Idiopathic pulmonary fibrosis: a systematic review and meta-analysis

OBJECTIVE

The incidence of idiopathic pulmonary fibrosis is increasing year by year in the world, which has a greater impact on the quality of life of patients. In the past, symptomatic treatment was used in clinical practice, but the overall effect is still not good. Multiple clinical studies have demonstrated the efficacy of pirfenidone in the treatment of idiopathic pulmonary fibrosis; however, adverse reactions have been reported. We, therefore, systematically evaluated the effectiveness and safety of pirfenidone in patients with idiopathic pulmonary fibrosis.

PATIENTS AND METHODS

Relevant studies were retrieved from the Embase, PubMed, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature (CBM), Wanfang and Weipu databases between January 1999 and May 2020, including the keywords "pirfenidone" and "idiopathic pulmonary fibrosis", were included in our systematic review. Review Manager 5.4 software was used for data synthesis, and analyses of publication bias and sensitivity.

RESULTS

Our systematic review included 13 studies involving a total of 13247 patients with idiopathic pulmonary fibrosis. Pirfenidone was associated with reduced declines in vital capacity (VC) and forced vital capacity (FVC) from baseline in patients with hermansky-pudlak syndrome (HPS)-related pulmonary fibrosis and to moderate idiopathic pulmonary fibrosis (IPF). Pirfenidone treatment was associated with lower reductions in FVC, lower reductions in 6-minute walking test distance, lower decreases in minimum oxygen saturation during the 6-minute walking test, lower all-cause death, lower relative risk of IPF-related death and increased progression-free survival compared to placebo. Progression-free survival was significantly longer in the pirfenidone group. The incidence of gastrointestinal, skin, nervous system, and liver function-related adverse events was significantly higher in the pirfenidone group compared to the control group.

CONCLUSIONS

Pirfenidone has efficacy in delaying the progression of idiopathic pulmonary fibrosis. Pirfenidone is well-tolerated by the majority of patients; however, mild adverse reactions related to the gastrointestinal tract, skin, nervous system, and liver function are common. Overall, Pirfenidone may be an effective and well-tolerated treatment option for idiopathic pulmonary fibrosis.

Low temperature and temperature decline increase acute aortic dissection risk and burden: A nationwide case crossover analysis at hourly level among 40,270 patients

Background

Acute aortic dissection (AAD) is a life-threatening cardiovascular emergency with high mortality, so identifying modifiable risk factors of AAD is of great public health significance. The associations of non-optimal temperature and temperature variability with AAD onset and the disease burden have not been fully understood.

Methods

We conducted a time-stratified case-crossover study using a nationwide registry dataset from 1,868 hospitals in 313 Chinese cities. Conditional logistic regression and distributed lag models were used to investigate associations of temperature and temperature changes between neighboring days (TCN) with the hourly AAD onset and calculate the attributable fractions. We also evaluated the heterogeneity of the associations.

Findings

A total of 40,270 eligible AAD cases were included. The exposure-response curves for temperature and TCN with AAD onset risk were both inverse and approximately linear. The risks were present on the concurrent hour (for temperature) or day (for TCN) and lasted for almost 1 day. The cumulative relative risks of AAD were 1.027 and 1.026 per 1°C lower temperature and temperature decline between neighboring days, respectively. The associations were significant during the non-heating period, but were not present during the heating period in cities with central heating. 23.13% of AAD cases nationwide were attributable to low temperature and 1.58% were attributable to temperature decline from the previous day.

Interpretation

This is the largest nationwide study demonstrating robust associations of low temperature and temperature decline with AAD onset. We, for the first time, calculated the corresponding disease burden and further showed that central heating may be a modifier for temperature-related AAD risk and burden.

Funding

This work was supported by the National Natural Science Foundation of China (92043301 and 92143301), Shanghai International Science and Technology Partnership Project (No. 21230780200), the Medical Research Council-UK (MR/R013349/1), and the Natural Environment Research Council UK (NE/R009384/1).

[The association of high-sensitivity C-reactive protein with new-onset hypertension in different age groups]

Objective: To investigate the association between high sensitivity C-reactive protein (hsCRP) level and new-onset hypertension in different age groups. Methods: This was a prospective cohort study involving non-hypertensive population in Kailuan Group community who participated in health examination between 2006 and 2007.Follow-up was conducted every 2 years, and the time of new onset of hypertension was used as the endpoint of follow-up. The endtime of follow-up for patients without hypertension was the time of death or the last follow-up (December 31, 2017).According to the baseline hsCRP level, the participants were divided into low-risk group (hsCRP<1.0 mg/L), medium-risk group (hsCRP ≥1.0 and ≤3.0 mg/L), and high-risk group (hsCRP>3.0 mg/L), and further stratified by age. Kaplan-Meier method was used to calculate the cumulative incidence of hypertension in each group. Multivariate Cox regression model was used to analyze the association between hsCRP level and new-onset hypertension. Results: A total of 51 179 participants were included in this study, including 38 606 males (75.43%) with an average age of (48.1±12.2) years. The baseline hsCRP was 0.64 (0.25, 1.60) mg/L. The baseline hsCRP was 0.30 (0.16, 0.59), 1.57 (1.20, 2.10), 5.17 (3.80, 7.10) mg/L respectively in low-, medium- and high-risk groups. During the follow-up of (8.1±2.2) years, a total of 9 523 (18.60%) patients developed hypertension, and the cumulative incidence rates of low-, medium- and high-risk groups were 17.41%, 20.48% and 20.73%, respectively. The cumulative incidence of hypertension in low-, medium- and high-risk groups of<45, 45-54, 55-64, ≥65 years old were 13.53%, 15.82%, 16.76%; 19.27%, 22.84%, 21.62%; 21.55%, 24.19%, 24.88%;20.20%, 22.35%, 19.11%, respectively. Except for people aged ≥65 years, there were significant differences in the cumulative incidence of hypertension in low-, medium- and high-risk groups (all P<0.05).Multivariate Cox regression analysis showed that the risk of new-onset hypertension in the high risk group was 1.11 times higher than that in the low risk group (HR=1.11, 95%CI 1.05-1.18). The risk of new-onset hypertension in the high-risk group was 1.22 times (HR=1.22, 95%CI 1.08-1.38), 1.14 times (HR=1.14, 95%CI 1.04-1.26), 1.16 times (HR=1.16, 95%CI 1.04-1.30), and 1.02 times (HR=1.02, 95%CI 0.86-1.20) of the low-risk group, in the<45, 45-54, 55-64, and ≥65 years old groups, respectively. Conclusion: Higher hsCRP level is a risk factor for new-onset hypertension, and the risk of developing hypertension caused by elevated hsCRP is age-dependent.

[Prevalence and risk factors for pterygium in six rural regions of Yunnan Province]

Objective: To investigate the prevalence and risk factors of pterygium in the rural population aged 40 years and above of 12 ethnic groups in 6 regions of Yunnan Province. Methods: This was a cross-sectional study. According to the method of multistage stratified sampling, samples of the rural population aged 40 years and above were collected from 12 ethnic groups (Han, Yi, Tibetan, Lisu, Bai, Naxi, Zhuang, Miao, Dai, Jingpo, Hani, and Lahu) in six areas (Diqing, Lijiang, Wenshan, Dehong, and Pu'er) of Yunnan Province from March 2019 to November 2019. Anterior segment examination was carried out in the target population with a hand-held slit-lamp, according to which pterygium was diagnosed, while the posterior segment of the eye was assessed by direct ophthalmoscopy. A field questionnaire survey was also conducted. A two-level model was used to study the effects of the location, nationality, sex, age, occupation, outdoor activities, smoking, and alcohol consumption on the prevalence of pterygium, with the ethnic group as the high level and the individual as the low level. Results: Among 9 617 subjects, the total prevalence rate of pterygium was 22.6%, which was adjusted to 19.6% according to the age and gender data of the Statistics Bureau of Yunnan Province. There was significant difference in prevalence of pterygium among six regions after adjusting for age and sex (χ²=146.50, P<0.001). The prevalence of pterygium was the highest in Wenshan (29.4%), followed by Chuxiong (24.4%), Diqing (17.5%), Pu'er (17.5%), Dehong (15.8%), and Lijiang (15.7%) (χ²=146.50, P<0.001). The results of the single factor analysis showed that there was statistically significant difference among different groups of age, gender, nationality, location, history of smoking, drinking, eating habits, sleeping time, continuous use of eye drops, temperature, humidity, altitude, longitude, latitude, and ultraviolet ray (P<0.05). However, the results of the multivariate analysis showed that the main risk factors of pterygium were female(OR=1.357,95%CI:1.173~1.568), advanced age(OR=1.540,95%CI:1.301~1.823), location(OR=1.713,95%CI:1.000~2.667), continuous use of eye drops(OR=1.177,95%CI:1.034~1.340), and more than 40 years of alcohol drinking(OR=1.525, 95%CI: 1.108~2.099), and the protective factor was more than 40 years of smoking(OR=0.723,95%CI:0.544~0.960). Conclusions: The prevalence of pterygium varies greatly among different regions in Yunnan Province. The main factors affecting the prevalence are sex, age, region, smoking history, and drinking history.