Yichong Li

Prevalence and Control of Diabetes in Chinese Adults

IMPORTANCEnNoncommunicable chronic diseases have become the leading causes of mortality and disease burden worldwide.nnnOBJECTIVEnTo investigate the prevalence of diabetes and glycemic control in the Chinese adult population.nnnDESIGN, SETTING, AND PARTICIPANTSnUsing a complex, multistage, probability sampling design, we conducted a cross-sectional survey in a nationally representative sample of 98,658 Chinese adults in 2010.nnnMAIN OUTCOMES AND MEASURESnPlasma glucose and hemoglobin A1c levels were measured after at least a 10-hour overnight fast among all study participants, and a 2-hour oral glucose tolerance test was conducted among participants without a self-reported history of diagnosed diabetes. Diabetes and prediabetes were defined according to the 2010 American Diabetes Association criteria; whereas, a hemoglobin A1c level of <7.0% was considered adequate glycemic control.nnnRESULTSnThe overall prevalence of diabetes was estimated to be 11.6% (95% CI, 11.3%-11.8%) in the Chinese adult population. The prevalence among men was 12.1% (95% CI, 11.7%-12.5%) and among women was 11.0% (95% CI, 10.7%-11.4%). The prevalence of previously diagnosed diabetes was estimated to be 3.5% (95% CI, 3.4%-3.6%) in the Chinese population: 3.6% (95% CI, 3.4%-3.8%) in men and 3.4% (95% CI, 3.2%-3.5%) in women. The prevalence of undiagnosed diabetes was 8.1% (95% CI, 7.9%-8.3%) in the Chinese population: 8.5% (95% CI, 8.2%-8.8%) in men and 7.7% (95% CI, 7.4%-8.0%) in women. In addition, the prevalence of prediabetes was estimated to be 50.1% (95% CI, 49.7%-50.6%) in Chinese adults: 52.1% (95% CI, 51.5%-52.7%) in men and 48.1% (95% CI, 47.6%-48.7%) in women. The prevalence of diabetes was higher in older age groups, in urban residents, and in persons living in economically developed regions. Among patients with diabetes, only 25.8% (95% CI, 24.9%-26.8%) received treatment for diabetes, and only 39.7% (95% CI, 37.6%-41.8%) of those treated had adequate glycemic control.nnnCONCLUSIONS AND RELEVANCEnThe estimated prevalence of diabetes among a representative sample of Chinese adults was 11.6% and the prevalence of prediabetes was 50.1%. Projections based on sample weighting suggest this may represent up to 113.9 million Chinese adults with diabetes and 493.4 million with prediabetes. These findings indicate the importance of diabetes as a public health problem in China.

Cause-specific mortality for 240 causes in China during 1990–2013: a systematic subnational analysis for the Global Burden of Disease Study 2013

BACKGROUNDnChina has experienced a remarkable epidemiological and demographic transition during the past three decades. Far less is known about this transition at the subnational level. Timely and accurate assessment of the provincial burden of disease is needed for evidence-based priority setting at the local level in China.nnnMETHODSnFollowing the methods of the Global Burden of Disease Study 2013 (GBD 2013), we have systematically analysed all available demographic and epidemiological data sources for China at the provincial level. We developed methods to aggregate county-level surveillance data to inform provincial-level analysis, and we used local data to develop specific garbage code redistribution procedures for China. We assessed levels of and trends in all-cause mortality, causes of death, and years of life lost (YLL) in all 33 province-level administrative units in mainland China, all of which we refer to as provinces, for the years between 1990 and 2013.nnnFINDINGSnAll provinces in mainland China have made substantial strides to improve life expectancy at birth between 1990 and 2013. Increases ranged from 4.0 years in Hebei province to 14.2 years in Tibet. Improvements in female life expectancy exceeded those in male life expectancy in all provinces except Shanghai, Macao, and Hong Kong. We saw significant heterogeneity among provinces in life expectancy at birth and probability of death at ages 0-14, 15-49, and 50-74 years. Such heterogeneity is also present in cause of death structures between sexes and provinces. From 1990 to 2013, leading causes of YLLs changed substantially. In 1990, 16 of 33 provinces had lower respiratory infections or preterm birth complications as the leading causes of YLLs. 15 provinces had cerebrovascular disease and two (Hong Kong and Macao) had ischaemic heart disease. By 2013, 27 provinces had cerebrovascular disease as the leading cause, five had ischaemic heart disease, and one had lung cancer (Hong Kong). Road injuries have become a top ten cause of death in all provinces in mainland China. The most common non-communicable diseases, including ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and cancers (liver, stomach, and lung), contributed much more to YLLs in 2013 compared with 1990.nnnINTERPRETATIONnRapid transitions are occurring across China, but the leading health problems and the challenges imposed on the health system by epidemiological and demographic change differ between groups of Chinese provinces. Localised health policies need to be implemented to tackle the diverse challenges faced by local health-care systems.nnnFUNDINGnChina National Science & Technology Pillar Program 2013 (2013BAI04B02) and Bill & Melinda Gates Foundation.

Prevalence and Ethnic Pattern of Diabetes and Prediabetes in China in 2013

Importance Previous studies have shown increasing prevalence of diabetes in China, which now has the world’s largest diabetes epidemic. Objectives To estimate the recent prevalence and to investigate the ethnic variation of diabetes and prediabetes in the Chinese adult population. Design, Setting, and Participants A nationally representative cross-sectional survey in 2013 in mainland China, which consisted of 170u2009287 participants. Exposures Fasting plasma glucose and hemoglobin A1c levels were measured for all participants. A 2-hour oral glucose tolerance test was conducted for all participants without diagnosed diabetes. Main Outcomes and Measures Primary outcomes were total diabetes and prediabetes defined according to the 2010 American Diabetes Association criteria. Awareness and treatment were also evaluated. Hemoglobin A1c concentration of less than 7.0% among treated diabetes patients was considered adequate glycemic control. Minority ethnic groups in China with at least 1000 participants (Tibetan, Zhuang, Manchu, Uyghur, and Muslim) were compared with Han participants. Results Among the Chinese adult population, the estimated standardized prevalence of total diagnosed and undiagnosed diabetes was 10.9% (95% CI, 10.4%-11.5%); that of diagnosed diabetes, 4.0% (95% CI, 3.6%-4.3%); and that of prediabetes, 35.7% (95% CI, 34.1%-37.4%). Among persons with diabetes, 36.5% (95% CI, 34.3%-38.6%) were aware of their diagnosis and 32.2% (95% CI, 30.1%-34.2%) were treated; 49.2% (95% CI, 46.9%-51.5%) of patients treated had adequate glycemic control. Tibetan and Muslim Chinese had significantly lower crude prevalence of diabetes than Han participants (14.7% [95% CI, 14.6%-14.9%] for Han, 4.3% [95% CI, 3.5%-5.0%] for Tibetan, and 10.6% [95% CI, 9.3%-11.9%] for Muslim; Pu2009<u2009.001 for Tibetan and Muslim compared with Han). In the multivariable logistic models, the adjusted odds ratios compared with Han participants were 0.42 (95% CI, 0.35-0.50) for diabetes and 0.77 (95% CI, 0.71-0.84) for prediabetes for Tibetan Chinese and 0.73 (95% CI, 0.63-0.85) for diabetes and 0.78 (95% CI, 0.71-0.86) for prediabetes in Muslim Chinese. Conclusions and Relevance Among adults in China, the estimated overall prevalence of diabetes was 10.9%, and that for prediabetes was 35.7%. Differences from previous estimates for 2010 may be due to an alternate method of measuring hemoglobin A1c.

Prevalence, Incidence, and Mortality of Stroke in China: Results from a Nationwide Population-Based Survey of 480 687 Adults.

Background: China bears the biggest stroke burden in the world. However, little is known about the current prevalence, incidence, and mortality of stroke at the national level, and the trend in the past 30 years. Methods: In 2013, a nationally representative door-to-door survey was conducted in 155 urban and rural centers in 31 provinces in China, totaling 480u2009687 adults aged ≥20 years. All stroke survivors were considered as prevalent stroke cases at the prevalent time (August 31, 2013). First-ever strokes that occurred during 1 year preceding the survey point-prevalent time were considered as incident cases. According to computed tomography/MRI/autopsy findings, strokes were categorized into ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, and stroke of undetermined type. Results: Of 480u2009687 participants, 7672 were diagnosed with a prevalent stroke (1596.0/100u2009000 people) and 1643 with incident strokes (345.1/100u2009000 person-years). The age-standardized prevalence, incidence, and mortality rates were 1114.8/100u2009000 people, 246.8 and 114.8/100u2009000 person-years, respectively. Pathological type of stroke was documented by computed tomography/MRI brain scanning in 90% of prevalent and 83% of incident stroke cases. Among incident and prevalent strokes, ischemic stroke constituted 69.6% and 77.8%, intracerebral hemorrhage 23.8% and 15.8%, subarachnoid hemorrhage 4.4% and 4.4%, and undetermined type 2.1% and 2.0%, respectively. Age-specific stroke prevalence in men aged ≥40 years was significantly greater than the prevalence in women (P<0.001). The most prevalent risk factors among stroke survivors were hypertension (88%), smoking (48%), and alcohol use (44%). Stroke prevalence estimates in 2013 were statistically greater than those reported in China 3 decades ago, especially among rural residents (P=0.017). The highest annual incidence and mortality of stroke was in Northeast (365 and 159/100u2009000 person-years), then Central areas (326 and 154/100u2009000 person-years), and the lowest incidence was in Southwest China (154/100u2009000 person-years), and the lowest mortality was in South China (65/100u2009000 person-years) (P<0.002). Conclusions: Stroke burden in China has increased over the past 30 years, and remains particularly high in rural areas. There is a north-to-south gradient in stroke in China, with the greatest stroke burden observed in the northern and central regions.

Drinking behaviour among men and women in China: the 2007 China Chronic Disease and Risk Factor Surveillance.

AIMnTo obtain information on drinking behaviour and to examine the associations between frequency of drinking, usual daily drinking quantity and binge drinking behaviour among Chinese residents aged 15-69 years.nnnDESIGNnA multi-stage clustering sampling method was used to select a nationally representative sample and data were collected as part of the China Chronic Disease and Risk Factor Surveillance by face-to-face interview.nnnSETTINGnRespondents were selected randomly from 160 counties/districts scattered over 31 provinces/autonomous regions/municipalities between August and October, 2007.nnnPARTICIPANTSnWeighted analyses included 49,527 Chinese residents (aged 15-69 years).nnnMEASUREMENTSnPrevalence of current drinking and usual daily quantity, median number of annual binge drinking episodes, proportions of excessive drinking, frequent drinking and binge drinking among current drinkers were the main measurements.nnnRESULTSnThe prevalence of male, female and total current drinking was 55.6%, 15.0% and 35.7%, respectively. On average, male drinkers consumed 47.8 g alcohol per drinking day, whereas females consumed 19.1 g. The median numbers of annual binge drinking episodes were 5.6 for male drinkers and 2.4 for females. Among the current drinkers, proportions of excessive drinking, frequent dinking and binge drinking were 62.7%, 26.3%, 57.3% for men and 51.0%, 7.8%, 26.6% for women, respectively. Logistic regressions showed that binge drinking was associated strongly with drinking frequency and drinking quantity increased with drinking frequency for both genders.nnnCONCLUSIONSnExcessive drinking, frequent drinking and binge drinking behaviour have reached epidemic proportions among current drinkers in China, and culturally appropriate public health strategies to reduce hazardous drinking behaviour are needed.

The associations between ambient air pollution and adult respiratory mortality in 32 major Chinese cities, 2006-2010

BACKGROUNDnChina has experienced increasingly severe levels of air pollution in the past decades, yet studies on the health effects of air pollution in China at a national study level, remain limited. This study assess the sub-chronic effect of ambient air pollution on respiratory mortality in the 32 largest Chinese cities.nnnMETHODSnWe employ two-way fixed effects panel data analysis and monthly air pollution and mortality panel data. We estimate associations between monthly respiratory mortality and air pollution; pollution is defined as particulate matter with aerodynamic diameter <10μm. We adjust for city characteristics, seasonality (monthly effects), and weather conditions (precipitation and temperature). We examine the associations between monthly injury mortality and air pollution to check for robustness.nnnRESULTSnThe results show positive and statistically significant associations of air pollution with respiratory mortality. During the study period (2006-2010) a 10μg/m(3) increase in monthly PM10 concentration is associated with a 1.05% (95% CI, 0.08-2.04%) increase in adult respiratory mortality rate. The air pollution effect is the most salient in northern cities (with central heating system) during the cold season (October-April); a 10μg/m(3) increase in monthly PM10 concentrations is associated with a 1.62% (95% CI, 0.22-3.46%) increase in the elderly respiratory mortality rate. There is no statistically significant association between the young adult respiratory mortality and air pollution.nnnCONCLUSIONSnThe elderly respiratory mortality rate in China is positively and statistically significantly associated with air pollution. The effect is largest in northern cities during cold months when coal is burned for heating.

Status of cardiovascular health in Chinese adults.

BACKGROUNDnCardiovascular disease has become the leading cause of death in China.nnnOBJECTIVESnThe goal of this study was to evaluate the current status of cardiovascular health in Chinese adults.nnnMETHODSnCardiovascular health data were collected from a nationally representative sample of 96,121 Chinese adults age ≥ 20 years in 2010. Ideal cardiovascular health was defined according to the American Heart Associations 2020 Strategic Impact Goals as follows: the simultaneous presence of 4 favorable health behaviors (ideal smoking status, ideal body mass index, physical activity at goal, and healthy dietary habits) and 4 favorable health factors (ideal smoking status, untreated total cholesterol <200 mg/dl, untreated blood pressure <120/<80 mm Hg, and untreated fasting plasma glucose <100 mg/dl) in the absence of a history of cardiovascular disease.nnnRESULTSnThe estimated percentage of ideal cardiovascular health was 0.2% in the general adult population in China (0.1% in men and 0.4% in women). An estimated 0.7% (0.4% in men and 1.0% in women) of Chinese adults had all 4 ideal health behaviors, and 13.5% (5.0% in men and 22.3% in women) had all 4 ideal health factors. Men most frequently had 3 to 4 ideal components, and women most commonly had 4 to 5 ideal components of the 7 cardiovascular health metrics. Ideal diet (1.6%) was the least common among all cardiovascular health metrics. Female sex and younger age were the 2 most common protective factors for cardiovascular health in Chinese adults.nnnCONCLUSIONSnThe percentage of ideal cardiovascular health in Chinese adults is extremely low. Both population-wide and high-risk strategies should be implemented with great effort to promote cardiovascular health in China.

Prevalence of COPD and its association with socioeconomic status in China: Findings from China Chronic Disease Risk Factor Surveillance 2007

BackgroundSocioeconomic status is likely an independent risk factor for Chronic Obstructive Pulmonary Disease (COPD), but little research has been done in China to study this association in a nationwide sample.MethodsWe used data from the 2007 China Chronic Disease Risk Factor Surveillance of 49,363 Chinese men and women aged 15-69 years to examine the association between the prevalence of self-reported physician diagnosed COPD and socioeconomic status defined by both educational level and annual household income. Multivariable logistic regression modelling was performed with adjustement for potential confounders.ResultsBoth low educational attainment and low household income were independently associated with higher risk of physician-diagnosed COPD. Compared to subjects with high educational level, subjects with low educational level had a significantly increased risk of COPD (OR 1.67, 95%CI 1.32-2.13, p for trend< 0.001 for urban, OR 1.76, 95%CI 1.34-2.30, p for trend < 0.001 for rural) after adjusting for age, sex, smoking status, passive smoking and geographic regions. Similarly increased risk was observed for household income and COPD in urban (OR 1.64, 95%CI 1.28-2.09, P for trend< 0.001) but not rural areas. Among never smokers, low educational level and household income were still associated with a significant higher prevalence of COPD (OR 1.77, 95%CI 1.40-2.25, OR 1.31, 95%CI 1.05-1.62). Removal of those with asthma diagnosis did not alter the observed associations.ConclusionsSocioeconomic status is a risk factor for self-reported physician-diagnosed COPD independently of current or passive smoking. Prospective studies are needed in China to better understand the association between socioeconomic status and COPD.

An integrated national mortality surveillance system for death registration and mortality surveillance, China

Abstract In China, sample-based mortality surveillance systems, such as the Chinese Center for Disease Control and Prevention’s disease surveillance points system and the Ministry of Health’s vital registration system, have been used for decades to provide nationally representative data on health status for health-care decision-making and performance evaluation. However, neither system provided representative mortality and cause-of-death data at the provincial level to inform regional health service needs and policy priorities. Moreover, the systems overlapped to a considerable extent, thereby entailing a duplication of effort. In 2013, the Chinese Government combined these two systems into an integrated national mortality surveillance system to provide a provincially representative picture of total and cause-specific mortality and to accelerate the development of a comprehensive vital registration and mortality surveillance system for the whole country. This new system increased the surveillance population from 6 to 24% of the Chinese population. The number of surveillance points, each of which covered a district or county, increased from 161 to 605. To ensure representativeness at the provincial level, the 605 surveillance points were selected to cover China’s 31 provinces using an iterative method involving multistage stratification that took into account the sociodemographic characteristics of the population. This paper describes the development and operation of the new national mortality surveillance system, which is expected to yield representative provincial estimates of mortality in China for the first time.

Geographical Variation in Diabetes Prevalence and Detection in China: Multilevel Spatial Analysis of 98,058 Adults

OBJECTIVE To investigate the geographic variation in diabetes prevalence and detection in China. RESEARCH DESIGN AND METHODS Self-report and biomedical data were collected from 98,058 adults aged ≥18 years (90.5% response) from 162 areas spanning mainland China. Diabetes status was assessed using American Diabetes Association criteria. Among those with diabetes, detection was defined by prior diagnosis. Choropleth maps were used to visually assess geographical variation in each outcome at the provincial level. The odds of each outcome were assessed using multilevel logistic regression, with adjustment for person- and area-level characteristics. RESULTS Geographic visualization at the provincial level indicated widespread variation in diabetes prevalence and detection across China. Regional prevalence adjusted for age, sex, and urban/rural socioeconomic circumstances (SECs) ranged from 8.3% (95% CI 7.2%, 9.7%) in the northeast to 12.7% (11.1%, 14.6%) in the north. A clear negative gradient in diabetes prevalence was observed from 13.1% (12.0%, 14.4%) in the urban high-SEC to 8.7% (7.8%, 9.6%) in rural low-SEC counties/districts. Adjusting for health literacy and other person-level characteristics only partially attenuated these geographic variations. Only one-third of participants living with diabetes had been previously diagnosed, but this also varied substantively by geography. Regional detection adjusted for age, sex, and urban/rural SEC, for example, spanned from 40.4% (34.9%, 46.3%) in the north to 15.6% (11.7%, 20.5%) in the southwest. Compared with detection of 40.8% (37.3%, 44.4%) in urban high-SEC counties, detection was poorest among rural low-SEC counties at just 20.5% (17.7%, 23.7%). Person-level characteristics did not fully account for these geographic variations in diabetes detection. CONCLUSIONS Strategies for addressing diabetes risk and improving detection require geographical targeting.