Disparities in Hypertension Prevalence, Awareness, Treatment and Control between Bouyei and Han: Results from a Bi-Ethnic Health Survey in Developing Regions from South China.

Hypertension is highly prevalent in low-income population. This study aims to investigate ethnic disparities in hypertension and identify modifiable factors related to its occurrence and control in developing regions in South China. Blood pressure was measured in the Bouyei and Han populations during a community-based health survey in Guizhou, 2012. A multistage stratified sampling method was adopted to recruit Bouyei and Han aged from 20 to 80 years. Taking mixed effects into consideration, multilevel logistic models with random intercept were used for data analysis. The prevalence rates of hypertension were 35.3% for the Bouyei and 33.7% for the Han. Among the hypertensive participants, 30.1% of the Bouyei and 40.2% of the Han were aware of their hypertensive conditions, 19.7% of the Bouyei and 31.1% of the Han were receiving treatment, and only 3.6% of the Bouyei and 9.9% of the Han had their blood pressure under control. Age-sex standardized rates of awareness, treatment, and control were consistently lower in the Bouyei than the Han. Such ethnic disparities were more evident in the elderly population. Avoidance of excessive alcohol consumption and better education were favorable lifestyle for reduction in risk of hypertension. Moderate physical activity improved control of hypertension in Bouyei patients under treatment. Conclusively, hypertension awareness, treatment, and control were substantially lower in Bouyei than Han, particularly in the elderly population. Such ethnic disparities indicate that elderly Bouyei population should be targeted for tailored interventions in the future.

Prevalence of Obesity and Related Factors among Bouyei and Han Peoples in Guizhou Province, Southwest China.

OBJECTIVE: To investigate the prevalence of general and abdominal obesity and associated factors in Bouyei and Han peoples. DESIGN: A cross-sectional study was carried out in Guizhou province, southwest China in 2012, with multi-stage sampling to enroll 4551 participants aged 20 to 80 years. General and abdominal obesity were defined by World Health Organization (WHO) for Chinese. A design-based analysis was performed to evaluate prevalence of obesity and its related factors. RESULTS: Bouyei people had a significantly lower prevalence of general obesity (4.8% vs. 10.9%, p < 0.05) and abdominal obesity (13.6% vs. 26.8%, p < 0.05) than that in Han people. Prevalence of obesity increased with age until middle-age period and declined thereafter. Men aged 40-49 years group and women aged 50-59 years group have the highest prevalence of general obesity. Prevalence of abdominal obesity was higher than that of general obesity. Middle-age, Higher income, Han people were significantly associated with an increased risk of General/abdominal obesity. CONCLUSIONS: Bouyei people had a lower prevalence of general and abdominal obesity than the Han people. Etiological studies should be conducted to determine underlying genetic factors and dietary factors.

[Prevalence and associated risk factors of diabetes among ethnic Han residents in Guizhou].

OBJECTIVE: To understand the fast plasma glucose (FPG) level and the epidemiologic characteristics of diabetes in ethnic Han residents of Guizhou province. METHODS: The survey was conducted among the ethnic Han residents aged 20-80 years, who were selected through multi stage cluster sampling in Guizhou. Basic laboratory test, physical examination were performed for each subject. RESULTS: A total of 2 967 subjects were surveyed. The average FPG level was 5.21 mmol/L for urban residents and 5.03 mmol/L for rural residents, (P<0.001) and the average FPG level was higher in males than in females (5.23 mmol/L vs. 5.09 mmol/L, P=0.003). The FPG level increased with age (P<0.001). In urban residents, the standardized prevalence of diabetes was 6.01% (crude prevalence: 7.45%), higher in males than in females (P<0.001) and increased with age. In rural residents, the standardized prevalence of diabetes was 3.47% (crude prevalence: 3.77%) and increased with age, but there was no sex specific difference in diabetes prevalence. The awareness rate of self diabetes status was 56.59%, the treatment rate was 84.47% and the plasma glucose control rate was 41.38%. Multiple logistic regression analysis indicated that risk factors for diabetes included being male, older than 40 years, family history of diabetes, frequent physical exercise, hypertension, high triglycerid level. CONCLUSION: The prevalence of diabetes was high in ethnic Han residents in Guizhou, the differences in diabetes prevalence between urban area and rural area was statistical significant. More than half of the patients' FPG level had not been under control after treatment. The awareness rate of self diabetes status, the treatment rate and the control rate of diabetes should be improved.

Contributions of major smoking-related diseases to reduction in life expectancy associated with smoking in Chinese adults: a cross-sectional study.

BACKGROUND: Cigarette smoking is a prominent risk factor for a wide range of diseases. The current study aimed to evaluate the impact of smoking on deaths from major smoking-related diseases (neoplasms, vascular diseases and respiratory diseases) in Chinese adults by estimating the potential gains in life expectancy (LE) that would accrue from eliminating deaths from these diseases, and to determine the contribution of each disease to the reduction in LE associated with smoking. METHODS: Two cohorts of Chinese smokers and non-smokers were constructed from a retrospective national mortality survey that had been conducted in 1989-1991 and included one million all-cause deaths among adults during 1986-1988 in 103 geographical regions. For each cohort, potential gains in LE by eliminating deaths from each major smoking-related disease were estimated. The contributions of each disease to smoking-associated reduction in LE were assessed using the LE decomposition approach. RESULTS: Among the major smoking-related diseases, it was estimated that elimination of vascular diseases would provide the greatest potential gain in LE (years), regardless of smoking status. The gains for smokers versus non-smokers in populations of urban men, urban women, rural men and rural women aged 35 years were 3.5 vs. 4.3, 3.8 vs. 4.1, 2.4 vs. 3.0, and 2.6 vs. 2.9 years, respectively. Respiratory diseases contributed most to smoking-associated LE reductions in urban women, rural men and rural women of 43.6%, 46.4%, and 62.9%, respectively. In urban men, neoplasms contributed most to smoking-associated LE reduction, their contribution being estimated as 45.8%. CONCLUSIONS: Respiratory disease has the greatest influence on the LE reduction associated with smoking. Thus, smoking prevention could significantly reduce deaths from respiratory disease and improve LE.

[A study on indicator system for early-warning on hemorrhagic fever with renal syndrome epidemic].

OBJECTIVE: To establish an early-warning indicator system on outbreak of hemorrhagic fever with renal syndrome by Delphi method seeking expert advices. METHODS: Firstly, the literature review and the experts meeting method were used to formulate the initiator frame work and indicators. A two-round consultation was used to filter indicators, discuss the boundary of indicators and determine the weighting coefficient among 25 experts from 14 provinces, municipalities and autonomous regions. The relative weightiless of indicators was determined by the weight coefficients method. RESULTS: The experts' average length of service in prevention and control of hemorrhagic fever with renal syndrome was (23.80 ± 11.70) years. The positivity coefficients of the two-round experts were 100% and 72%. Kendall's coefficients of the two-round consultation were 0.50 (χ(2)(R) = 148.95, P < 0.01) and 0.54 (χ(2)(R) = 212.63, P < 0.01) and opinions among experts became consistent and the consultation had achieved the need of forecast. Four first-class indicators (host animals, risk population, social environment and case-related indicators) and 14 second-class indicators were filtered to develop the indicators system. The weight coefficients of the first-class indicators were 0.28, 0.23, 0.23 and 0.26. CONCLUSION: The early-warning index system of hemorrhagic fever with renal syndrome has been established and it could provide a reference for the forest and warning of HFRS outbreak.

Case-spouse control design in practice: an experience in estimating smoking and chronic obstructive pulmonary disease deaths in Chinese adults.

BACKGROUND/PURPOSE: We assessed the effect of smoking on death from chronic obstructive pulmonary disease (COPD) in China by employing a large population-based, case-spouse control study design using data from a nationwide survey of mortality. METHODS: During 1989-1991, a nationwide retrospective survey of mortality was conducted in China. For approximately 1,000,000 adults dying from all causes during 1986-1988, their surviving spouses or other informants provided detailed information about their own as well as the deceased person's smoking history. For this study, 183,393 individuals who died of COPD at age > or = 40 years were taken as cases, while 272,984 sex-matched surviving spouses of subjects who died from any cause were taken as controls. RESULTS: COPD death rates for smokers were more than twice as high as those of non-smokers, with a dose-response risk pattern, despite the fact that COPD death rates varied widely by region and age. Tobacco accounted for 41.4% of COPD deaths in men, but only 13.5% of those in women, who had a lower rate of smoking. CONCLUSION: A case-spouse control study, as an alternative design, is valid and feasible in utilizing information from population-based, retrospective mortality survey data for an analytical epidemiological study of disease etiology.

Smoking-attributable deaths and potential years of life lost from a large, representative study in China.

OBJECTIVES: To provide a more accurate estimate of early smoking-attributable mortality and potential years of life lost using data from a representative study of 103 study areas in China. METHODS: Two datasets were employed as follows. Firstly, retrospective national mortality survey data, which included a population of 67 million in 103 study areas, and about 1 million adults who died in 1986-1988; secondly, nationally representative case-control comparative data was extracted from the survey data to measure the effect of smoking on age trends in smoking-attributable mortality. Potential years of life lost, and sex differences in life expectancy in smokers and non-smokers in the total population aged 35 and over were also estimated. RESULTS: Tobacco caused 11.2% (16.0% of men and 3.7% of women) of total deaths in 1987, and more than two-thirds of these excess deaths occurred between the ages of 50 and 74 years, but only less than 5% excess deaths occurred at ages under 50. Although life expectancies varied with region or sex differences, the years of life lost attributable to smoking was almost the same. Smokers at age 35 lost about 3 years of life expectancy in comparison with never smokers. The study also confirmed that more than 50% of the sex difference in life expectancy was accounted for by smoking. CONCLUSION: Fully understanding the consequences of smoking in relation to mortality can clarify its effects on the health and longevity of the entire population.

Comparative study of control selection in a national population-based case-control study: Estimating risk of smoking on cancer deaths in Chinese men.

PURPOSE: To assess the validation of a novel control selection design by comparing the consistency between the new design and a routine design in a large case-control study that was incorporated into a nationwide mortality survey in China. METHODS: A nationwide mortality study was conducted during 1989-1991. Surviving spouses or other relatives of all adults who died during 1986-1988 provided detailed information about their own as well as the deceased person's smoking history. In this study, 130,079 males who died of various smoking-related cancers at age 35 or over were taken as cases, while 103,248 male surviving spouses (same age range with cases) of women who died during the same period and 49,331 males who died from causes other than those related to smoking were used as control group 1 and control group 2, respectively. Consistency in the results when comparing cases with each of the control groups was assessed. RESULTS: Consistency in the results was observed in the analyses using different control groups although cancer deaths varied with region and age. Equivalence could be ascertained using a 15% criterion in most cancer deaths which had high death rates in urban areas, but they were uncertain for most cancers in rural areas irrespective of whether the hypothesis testing showed significant differences or not. CONCLUSIONS: Sex-matched living spouse control design as an alternative control selection for a case-control study is valid and feasible, and the basic principles of the equivalence study are also supported by epidemiological survey data.

[Study on the relations between smoking and the risk of age-specific lung cancer deaths in urban and rural areas of China].

OBJECTIVE: To study the association between smoking and lung cancer mortality of residents living in the urban and rural areas of China. METHODS: Using the national census data on causes of death and case-control studies, stratified analysis was conducted by parameters as geography and age, to calculate the risk ratios, excess risks, average years lost for life expectancy by smoking in males and females in 103 cities/counties in China. RESULTS: Smoking increased the risks for lung cancer death in all ages older than 35 years of age, in urban and rural areas, through data analysis on 52 193 cases died from lung cancer in 1986 - 1988 and 307 934 matched controls in China. The risk ratio was 3.0 (95%CI: 2.9 - 3.1) with 53.0% excess for lung cancer deaths in the male smokers. The years lost for life expectancy were 18.5 in urban, and 17.7 in rural male smokers aged 35 to 69 years. Similarly, the risk ratio was 3.0 (95%CI: 2.9 - 3.1), with 26.0% excess for lung cancer deaths in female smokers. The life-expectancy lost was 13.0 and 20.4 for female smokers aged 35 to 69 years in urban and rural areas, respectively. CONCLUSION: In both urban and rural areas, risk on lung cancer deaths caused by smoking in all males and females aged at 35 years and older had been significantly increased. Control of smoking prevalence should play a vital role in the prevention of the lung cancer death risks in China.

Age-related effects of smoking on lung cancer mortality: a nationwide case-control comparison in 103 population centers in China.

PURPOSE: To examine age-related effects of smoking on lung cancer mortality in a large population-based case-control study that was incorporated into a nationwide retrospective survey of mortality in China. METHODS: Two data sets were pooled for this analysis: national mortality survey data and data from a nationwide case-control comparison. These pooled data were used to calculate age-specific lung cancer death rates by smoking status and expected years of lost life expectancy for each smoking-associated death. RESULTS: There was a significant excess of deaths (54% of urban deaths, 51% of rural deaths) at 35 to 69 years of age among male smokers and the average loss of life expectancy per smoking-associated death at these ages was 18.3 years. For women ages 35 to 69 years of age, 29% and 11% excess lung cancer mortality was observed in urban and rural smokers, respectively, with an average loss of life expectancy per smoking-associated death of 21.3 years. CONCLUSIONS: Tobacco smoking was associated with a large number of deaths from lung cancer. Utilizing information from a population-based retrospective mortality survey for conducting an analytic epidemiological study of main determinants of disease is feasible and can generate important results.

[Association of Taq I T/C and Fok I C/T polymorphisms of vitamin D receptor gene with outcome of hepatitis B virus infection].

OBJECTIVE: To determine whether Taq I T/C and Fok I C/T polymorphisms of vitamin D Receptor (VDR) gene was associated with the outcomes of hepatitis B virus (HBV) infection. METHODS: A total of 212 HBV self-limited infection individuals, 244 asymptomatic HBsAg carriers and 391 chronic hepatitis B (HB) patients were recruited to conduct a case-control study. VDR-Taq I T/C and VDR-Fok I C/T polymorphisms were examined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: The frequency of VDR-Fok I allele C in the chronic HB patients was 45.8%, significantly higher than 38.2% of the self-limited infection individuals (chi(2) = 6.43, P = 0.01). The frequencies of VDR-Fok I genotypes TT, TC, and CC in HB patients were 30.7%, 47.1%, and 22.2% respectively, and 41.0% (TT), 41.5% (TC), and 17.5% (CC) in the self-limited infection individuals. There was a statistically significant difference between HB patients and self-limited infection individuals (chi(2) = 6.76, P = 0.03). The results of univariate analysis showed that the subjects carrying VDR-Fok I CC/TC genotype had 1.57-fold elevated risk for developing chronic HB when they were infected HBV (OR = 1.57, P = 0.01). A multiple logistic regression analysis revealed that VDR-Fok I CC/CT was independently associated with chronic HB after adjusting both potential confounding effects of gender (OR = 1.70, P = 0.021). The statistically significant association between TaqI T/C polymorphism and outcome of HBV infection was not demonstrated in the study. The frequency of haplotype TC of VDR-TaqI and Fok I in HB patients was 2.3080%, significantly higher than 0.5391% of the self-limited infection individuals (chi(2) = 6.08, P = 0.01). However, the frequency of haplotype TT in the HB patients was 1.5283%, significantly lower than 3.7061% of the self-limited infection individuals (chi(2) = 5.65, P = 0.02) and 3.4820% of the HBV carriers (chi(2) = 5.12, P = 0.02). CONCLUSION: VDR gene polymorphism is probably an influence factor on the genetic susceptibility of HBV infection.

[Study on association between vitamin D receptor gene polymorphisms and the outcomes of HBV infection].

OBJECTIVE: To explore whether the vitamin D receptor gene (VDR) polymorphisms are associated with the outcomes of hepatitis B virus (HBV) infection in Chinese Han population. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect the polymorphisms of Fok I locus in exon 2 and Taq I locus in exon 9 of VDR gene. One hundred and eighty-four chronic hepatitis B patients and 205 asymptomatic HBV carriers were recruited to make the comparison of frequencies of genotype and haplotype of the VDR gene between the patients and the carriers. RESULTS: The univariate analysis showed a significant difference in Fok I polymorphism between chronic hepatitis B patients group and asymptomatic HBV carriers group. The FF genotype frequency in chronic hepatitis B patients group was 44.6%,higher than 31.7% in asymptomatic HBV carriers group (P<0.05). After adjusting the confounders by multiple logistic regression analysis, the result still showed a significant difference in Fok I site polymorphism between chronic hepatitis B patients group and asymptomatic HBV carriers group (OR=1.95, P<0.05). The FT haplotype frequency in chronic hepatitis B patients group was higher than that in asymptomatic HBV carriers group (OR=1.45, P<0.05). The fT haplotype frequency in chronic hepatitis B patients group was lower than that in asymptomatic HBV carriers group (OR=0.72, P<0.05). CONCLUSION: VDR gene polymorphism may be an influence factor of genetic susceptibility to HBV infection.

[Relationship between smoking and risk of esophageal cancer in 103 areas in China: a large-scale case-control study incorporated into a nationwide survey of mortality].

OBJECTIVE: To examine the relationship between smoking and risk of esophageal cancer (EC), and present a theoretical framework of control selection in population-based case-control study which was incorporated into a nationwide retrospective survey of mortality in China. METHODS: A large-scale population-based case-control study was incorporated into the nationwide retrospective survey of mortality conducted 1989 - 1991 in 24 urban cities selected by non-random sampling and 79 rural counties selected from 3000 counties included in the 1973 - 1975 cancer distribution survey by random sampling during. A questionnaire survey was conducted by home visit to investigate the death causes and smoking history of 19 734 deceased male adults who died of esophageal cancer during 1986 - 1988 at the age >or= 35. Two control groups were set up to undergo questionnaire survey by home visit to investigate the smoking history of the deceased persons and the informants. Control group I included the surviving spouses or other informants of 31 989 male adults who died of non-malignant digestive diseases during 1986 - 1988 at the age >or= 35, and control group II included 104 846 male spouses of the deceased female adults who died of different causes during 1986 - 1989 at the age >or= 35. The relative risks and population smoking attributable risks for EC were calculated using non-conditional logistic model, and the results were compared for consistency between the analyses using two different control groups. RESULTS: The EC absolute death rates were higher in the smokers than in the non-smokers in all urban and rural area groups. The total EC absolute death rate per 1000 among the non-smokers vs. smokers was 0.37:0.65 in the urban areas, 0.99:1.29 in the inland rural areas, and 1.09:1.62 in the coastal rural areas in the control group I, and there was a similar trend in the control group II. There was a significant dose-response relation between the period of smoking and the death risk of EC and between the daily cigarette consumption and the death risk of EC. The risk ratios, for example, for cigarette per day < 10, 10-, and 20- in the urban men were 1.42, 1.82, 2.22 in the control group I (trend test P < 0.01), and 1.57, 1.95, and 3.18 in the control group II (trend test P < 0.01). CONCLUSION: Smoking is an important risk factor for mortality from EC in China. Investigating the surviving spouses of the deceased patients is a creative, effective, and feasible trial, with the prerequisite of whole population-based survey, in study of the main types of death and the relevant risk factors.

Smoking and mortality from esophageal cancer in China: a large case-control study of 19,734 male esophageal cancer deaths and 104,846 living spouse controls.

An innovative population-based case-control study was conducted in a national mortality survey to assess the hazards of tobacco use on esophageal cancer among Chinese men. Cases were 19,734 males aged 35 years or older, who died of esophageal cancer during 1986-1988. Controls were 104,846 male living spouses of the same age when their wife died (of any cause) during the same period in the same county or city. The absolute esophageal cancer death rates were higher in smokers than those in nonsmokers in all geographical groups. The relative risks for esophageal cancer were 1.88 (95% CI: 1.73-2.05) and 1.39 (95% CI: 1.28-1.50) in urban and rural men, respectively, after adjustment for other relevant covariates including age group (5 years) and locality. When the calculation was restricted to men aged 35-69, the risk ratios for current cigarette smokers increased significantly with increasing number of cigarettes smoked daily and duration of smoking. Tobacco use, in any form, is an important risk factor for esophageal cancer in Chinese men. Selecting living spouses as controls is a unique and useful approach in the design of case-control studies of cigarette smoking.

The relationship between nonresponse to hepatitis B vaccine and HLA genotype/haplotype.

OBJECTIVE: To study the relationship between the nonresponse to hepatitis B vaccine and HLA genotype/heplotype in Chinese population and provide the evidence for explaining the genetic mechanism of this nonresponse. METHODS: Our research focused on the relationship between nonresponse to Hepatitis B vaccine and HLA-DRB1, DRB3, DRB4, DRB5 and DQB1 genotype/haplotype in Chinese population, collected from a community in Guangxi Zhuang Autonomous Region. The group specific amplification was employed to characterize 107 individuals' genotype and haplotype of HLA clusters. Different models statistics such as relative risk test, correlation test and linkage disequilibrium analysis were used to analyze the data. RESULTS: The results showed that there is a linkage disequilibrium between nonresponse to Hepatitis B vaccine and HLA haplotype DR4, 1122 (DRB1 * 0401- 22, 1122)-DR53 (DRB4 * 0101101, 0102/3)-DQB4 (DQB1 * 04). CONCLUSION: In Chinese population, nonresponse to hepatitis B vaccine is highly associated with special HLA haplotye.

Long-term effectiveness of infancy low-dose hepatitis B vaccine immunization in Zhuang minority area in China.

AIM:To observe the long-term effectiveness of low-dose immunization strategy and risk factors of HBsAg carriers in immunized children of Zhuang minorities of Longan County in the 9th year after infancy immunization.METHODS:Two epidemiologic methods,a cross-sectional follow-up study and a case-control study,were used for the evaluation of the serological effect and the determination of the risk factors. Hepatitis B virus markers were detected with radioimmunoassay.RESULTS:The protective anti-HBs-positive rate was 43.8% in 1183 children aged 1-9 years,who were immunized with three doses of 10&mgr;g hepatitis B vaccine in infancy according to 0, 1 and 6 months schedul.It declined from 87.9% in the first year to 37.1% in the 9th year after vaccination.The HbsAg-positive rate was 1.6%, not increasing with age during 9 years after the infant immunization program. Compared with 14.0% of HbsAg-positive rate of the baseline survey in 1985, the effectiveness of hepatitis B vaccine immunization was 88.6%. Of 36 immunized children with positive HBsAg, 89.1% were likely attributable to HBsAg positivity of their mothers.CONCLUSION:The long-term effectiveness of infancy low-dose hepatitis B vaccine immunization is high,and the booster is not needed 9 years after the vaccination in the Zhuang minority area where hepatitis B is highly endemic.A high-dose immunization strategy should be recommended in order to further decrease the current HbsAg-positive rate.

Survey of coverage, strategy and cost of hepatitis B vaccination in rural and urban areas of China.

AIM:In order to understand the coverage, immunization strategy and cost of hepatitis B (HB) vaccination of China in recent years.METHODS:A two-stage household random sampling method was used in the survey.RESULTS:The survey carried out at 112 Disease Surveillance Points (DSPs) of 25 provinces, autonomous regions and municipalities of China in 1996, showed that the coverage rates of HB vaccination among neonates were 96.9% in the urban DSPs and 50.8% in the rural DSPs in 1993-1994,while in students aged 7-9 years, they were 85.8% and 31.5% in 1994, respective-ly. Up to 1994, 97.5% of the urban DSPs and 73.9% of the rural DSPs on a neonate vaccination against HB program were included in EPI. About 93% of the urban DSPs and 44% of the rural DSPs did HBsAg and HBeAg screening for all or part of pregnant women. The neonates received the regimen of high-dose HB vaccine in combination with hepatitis B immune globin (HBIG) if their mothers were HBsAg and/or HBeAg positive in pregnancy,otherwise they received the low-dose vaccine (10&mgr;gX3). Part of DSPs had a lower neonate coverage due to unreasonable allocation of the vaccines (used for adults not at risk) or higher cost or insufficient supply of the vaccines. It is necessary to evaluate the quality of serological lab test to HBVMs in the maternal prescreening.CONCLUSION:Remarkable achievements have been made according to the national planning and policy of HB immunization in China.