Tiange Wang

Prevalence and Control of Diabetes in Chinese Adults

IMPORTANCE Noncommunicable chronic diseases have become the leading causes of mortality and disease burden worldwide. OBJECTIVE To investigate the prevalence of diabetes and glycemic control in the Chinese adult population. DESIGN, SETTING, AND PARTICIPANTS Using a complex, multistage, probability sampling design, we conducted a cross-sectional survey in a nationally representative sample of 98,658 Chinese adults in 2010. MAIN OUTCOMES AND MEASURES Plasma 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. RESULTS The 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. CONCLUSIONS AND RELEVANCE The 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.

Urinary bisphenol A (BPA) concentration associates with obesity and insulin resistance.

CONTEXT Bisphenol A (BPA) is one of the worlds highest-volume chemicals in use today. Previous studies have suggested BPA disturbs body weight regulation and promotes obesity and insulin resistance. But epidemiological data in humans were limited. OBJECTIVE Our objective was to determine whether BPA associates with obesity and insulin resistance. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study included 3390 adults aged 40 yr or older, in Songnan Community, Baoshan District, Shanghai, China. MAIN OUTCOME MEASURES Questionnaire, clinical and biochemical measurements, and urinary BPA concentration were determined. Generalized overweight was defined as body mass index (BMI) of 24 to less than 28 kg/m(2) and obesity was defined as BMI of 28 kg/m(2) or higher. Abdominal obesity was defined as waist circumference at least 90 cm for men and at least 85 cm for women. Insulin resistance was defined as the index of homeostasis model assessment of insulin resistance higher than 2.50. RESULTS The participants in the highest quartile of BPA had the highest prevalence of generalized obesity [odds ratio (OR) = 1.50; 95% confidence interval (CI) = 1.15-1.97], abdominal obesity (OR = 1.28; 95% CI = 1.03-1.60), and insulin resistance (OR = 1.37; 95% CI = 1.06-1.77). In participants with BMI under 24 kg/m(2), compared with the lowest quartile, the highest quartile of BPA increased the prevalence of insulin resistance by 94% (OR = 1.94; 95% CI = 1.20-3.14), but this association was not observed in those with BMI of 24 kg/m(2) or higher. CONCLUSIONS BPA was positively associated with generalized obesity, abdominal obesity, and insulin resistance in middle-aged and elderly Chinese adults.

Relationship of urinary bisphenol A concentration to risk for prevalent type 2 diabetes in Chinese adults: a cross-sectional analysis.

BACKGROUND Greater bisphenol A exposure has been shown to be associated with a higher risk for self-reported adverse health outcomes, including diabetes. OBJECTIVE To examine the association between bisphenol A exposure and type 2 diabetes in adults. DESIGN Cross-sectional study. SETTING Songnan, Baoshan District, Shanghai, China. PARTICIPANTS 3423 local residents aged 40 years or older who were enrolled from 27 June 2008 to 10 August 2009. MEASUREMENTS Urinary concentrations of bisphenol A from morning spot urine samples (exposure) and fasting plasma glucose concentration, plasma glucose concentration 2 hours after an oral glucose tolerance test, and serum insulin concentration (outcomes). RESULTS Median age of the participants was 59.0 years (interquartile range, 53.0 to 68.7 years), 40% were men, and 1087 had type 2 diabetes. The median urinary bisphenol A level was 0.81 ng/mL (interquartile range, 0.47 to 1.43 ng/mL). Clinical characteristics differed between participants with normal glucose regulation and those with impaired glucose regulation and by bisphenol A quartile, but in multivariable analyses, there was no clear association between bisphenol A levels and type 2 diabetes. The adjusted odds ratio (OR) of type 2 diabetes was slightly increased for participants in the second bisphenol A quartile (0.48 to 0.81 ng/mL) (adjusted OR, 1.30 [95% CI, 1.03 to 1.64]) and the fourth quartile (>1.43 ng/mL) (adjusted OR, 1.37 [CI, 1.08 to 1.74]) but not the third quartile (0.82 to 1.43 ng/mL) (adjusted OR, 1.09 [CI, 0.86 to 1.39]), and a test of the trend of the association was not statistically significant. LIMITATIONS The cross-sectional study design and nonrandom sample of participants limit the conclusions that can be drawn. Many patients in the study already had diabetes, successful treatment of which could have obscured apparent associations. Dietary variables were not measured; however, this is necessary in observational studies of bisphenol A and diabetes because the presence of the chemical in the body may reflect consumption of sugared drinks in plastic bottles. CONCLUSION These findings do not confirm a previously reported association between urinary bisphenol A levels and self-reported type 2 diabetes.

Combined Effects of 19 Common Variations on Type 2 Diabetes in Chinese: Results from Two Community-Based Studies

Background Many susceptible loci for type 2 diabetes mellitus (T2DM) have recently been identified from Caucasians through genome wide association studies (GWAS). We aimed to determine the association of 11 known loci with T2DM and impaired glucose regulation (IGR), individually and in combination, in Chinese. Methods/Principal Findings Subjects were enrolled in: (1) a case-control study including 1825 subjects with T2DM, 1487 with IGR and 2200 with normal glucose regulation; and (2) a prospective cohort with 734 non-diabetic subjects at baseline. The latter was followed up for 3.5 years, in which 67 subjects developed T2DM. Nineteen single nucleotide polymorphisms (SNPs) were selected to replicate in both studies. We found that CDKAL1 (rs7756992), SLC30A8 (rs13266634, rs2466293), CDKN2A/2B (rs10811661) and KCNQ1 (rs2237892) were associated with T2DM with odds ratio from 1.21 to 1.35. In the prospective study, the fourth quartile of risk scores based on the combined effects of the risk alleles had 3.05 folds (95% CI, 1.31–7.12) higher risk for incident T2DM as compared with the first quartile, after adjustment for age, gender, body mass index and diabetes family history. This combined effect was confirmed in the case-control study after the same adjustments. The addition of the risk scores to the model of clinical risk factors modestly improved discrimination for T2DM by 1.6% in the case-control study and 2.9% in the prospective study. Conclusions/Significance Our study provided further evidence for these GWAS derived SNPs as the genetic susceptible loci for T2DM in Chinese and extended this association to IGR.

Association between Nonalcoholic Fatty Liver Disease (NAFLD) and Osteoporotic Fracture in Middle-Aged and Elderly Chinese

CONTEXT Nonalcoholic fatty liver disease (NAFLD) has been considered as a hepatic manifestation of the metabolic syndrome and is associated with various metabolic abnormalities, which may link to an increased risk of osteoporotic fracture. However, epidemiological studies investigating the association between NAFLD and osteoporotic fracture were not available. OBJECTIVE The objective of the study was to determine whether NAFLD associates with osteoporotic fracture. DESIGN, SETTING, AND PARTICIPANTS This was a cross-sectional study of 7797 Chinese adults aged 40 yr or older in the Jiading District, Shanghai, China. MAIN OUTCOME MEASURES A questionnaire, anthropometric measurements, laboratory tests, and a hepatic ultrasonic examination were conducted. NAFLD was diagnosed by hepatic ultrasound after the exclusion of alcohol abuse and other liver diseases. A history of fractures was collected with an interviewer-assisted questionnaire. Osteoporotic fractures were defined as fractures that occurred due to low-trauma in 2 yr prior to the study. RESULTS Among men, the prevalence of osteoporotic fractures was significantly higher in those with NAFLD (3.6 vs. 1.7%, P = 0.003); however, no difference was found in women (3.4 vs. 2.6%, P = 0.14). The presence of NAFLD was significantly associated with increased odds of osteoporotic fracture among men (odds ratio 2.53; 95% confidence interval 1.26-5.07; P = 0.009) after controlling for potential confounders. The significant associations were not detected in women. CONCLUSIONS The presence of NAFLD was significantly associated with a recent history of osteoporotic fracture in middle-aged and elderly Chinese men.

Nonalcoholic Fatty Liver Disease Is Associated With Atherosclerosis in Middle-Aged and Elderly Chinese

Objective—To evaluate the associations between nonalcoholic fatty liver disease (NAFLD) and atherosclerosis. Methods and Results—A total of 8632 participants aged ≥40 years from Jiading district, Shanghai, were included in the present study. The presence of NAFLD was evaluated by ultrasonography. Carotid intima-media thickness (CIMT) and brachial-ankle pulse wave velocity (ba-PWV) were measured in each participant. The prevalence of NAFLD was 30.0% in the total population, with 30.3% in men and 29.9% in women, respectively. Subjects with NAFLD had remarkably higher CIMT and ba-PWV compared with those without NAFLD (0.594±0.105 mm versus 0.578±0.109 mm, P<0.0001; 1665±424 cm/s versus 1558±430 cm/s, P<0.0001). Subjects with both NAFLD and metabolic syndrome had significantly higher CIMT and ba-PWV compared with those with neither or either of these 2 diseases after adjustment for age and sex (all P<0.05). Logistic regressions also revealed that NAFLD conferred 35% and 30% increased odds ratios of elevated CIMT and ba-PWV, independent of conventional risk factors and the presence of metabolic syndrome. Conclusion—NAFLD was associated with elevated CIMT and ba-PWV, independent of conventional cardiovascular disease risk factors and metabolic syndrome. The effects of NAFLD and metabolic syndrome on atherosclerosis might not fully overlap.

The relationship between insulin-sensitive obesity and cardiovascular diseases in a Chinese population: results of the REACTION study.

OBJECTIVE Obesity and insulin resistance are risk factors for cardiovascular diseases. Whether insulin-sensitive obese individuals are at higher risk for cardiovascular diseases is still debated. We aim to investigate whether insulin-sensitive obesity associates with prevalent cardiovascular diseases and 10-year coronary heart disease (CHD) risk. RESEARCH DESIGN AND METHODS At the baseline of the Risk Evaluation of cAncers in Chinese diabeTic Individuals: a lONgitudinal (REACTION) study, 211,641 participants aged 40 years or older were recruited from 25 communities across the China mainland, in 2011 to 2012. Participants were categorized by insulin-sensitive/resistant and general/abdominal obese status. Cardiovascular diseases included CHD, stroke, and myocardial infarction. Framingham risk score (FRS) was calculated according to National Cholesterol Education Program-Adult Treatment Panel III and FRS greater than 20% or cardiovascular diseases were identified as high risk for 10-year CHD. RESULTS Controlling for potential confounders, compared with insulin-sensitive normal weight individuals, insulin-sensitive general obese individuals had increased risks for prevalent cardiovascular diseases (men: OR, 2.55, 95% CI, 2.04-3.18; women: 1.73, 1.45-2.06) and 10-year Framingham risk for CHD (men: 2.26, 1.86-2.76; women: 1.73, 1.46-2.06). Compared with insulin-sensitive normal waist subgroup, insulin-sensitive abdominal obesity was associated with higher risks for prevalent cardiovascular diseases (men: 1.32, 1.20-1.46; women: 1.36, 1.27-1.47) and 10-year Framingham risk for CHD (men, 1.34, 1.23-1.45; women, 1.37, 1.27-1.47). CONCLUSION Both general and abdominal obesity were associated with elevated prevalent cardiovascular diseases and 10-year CHD risk, regardless of the presence or absence of insulin resistance.

Serum Fetuin-A Associates with Type 2 Diabetes and Insulin Resistance in Chinese Adults

Background Previous studies have demonstrated that fetuin-A is related to insulin resistance among subjects with normal glucose tolerance but not patients with type 2 diabetes. There are limited data available concerning fetuin-A and insulin resistance in Chinese. We aimed to study the association of feuin-A with insulin resistance among participants with or without type 2 diabetes in a large sample size of adults aged 40 and older. Methodology and Principal Findings A community-based cross-sectional study was performed among 5,227 Chinese adults. The average age of our study was 61.5±9.9 years. Serum fetuin-A concentrations were not significantly different between male and female (296.9 vs. 292.9 mg/l, p = 0.11). Compared with the lowest quartile, the highest quartile of serum fetuin-A revealed a significant higher proportion of type 2 diabetic patients (34.8% vs. 27.3%, p<0.0001). In the multinomial logit models, the risk of type 2 diabetes was associated with each one quartile increase of serum fetuin-A concentrations when referenced not only to normal glucose tolerance (OR 1.24, 95% CI 1.07–1.43, p = 0.004) but also to impaired glucose regulation (OR 1.25, 95% CI 1.08–1.44, p = 0.003, respectively), after adjustment for age, sex, community, current smoking, and current drinking. The logistic regression analysis showed that fetuin-A were associated with elevated HOMA-IR and fasting serum insulin both among the participants with or without type 2 diabetes in the full adjusted analysis. There was no significant association between elevated serum fetuin-A concentrations and impaired glucose regulation (all p≥0.12). Conclusions and Significance Higher fetuin-A concentrations were associated with type 2 diabetes and insulin resistance in middle aged and elderly Chinese.

Advanced research on risk factors of type 2 diabetes.

The prevalence of type 2 diabetes is increasing globally and poses a heavy burden on public health and socioeconomic development of all nations. Type 2 diabetes is a multifactorial disease and due to a combination of environmental and genetic risk factors. Many environmental risk factors contribute to the pathogenesis of type 2 diabetes, including lifestyles such as sedentary behaviour, diet, smoking and alcohol consumption, internal environmental factors such as inflammatory factors, adipocytokines and hepatocyte factors, external environmental factors such as environmental endocrine disruptors. This review summarizes current research efforts concentrated on the contributors for accelerated type 2 diabetes epidemic. It also provides a novel prospect for future researches.

Urinary bisphenol a concentration and thyroid function in Chinese adults

Background: Bisphenol A (BPA) is an endocrine disruptor that in animal studies can bind to the thyroid hormone receptor and affect thyroid function. Relevant epidemiologic studies are limited and results are inconsistent. We explored the relationship between urinary BPA and thyroid function in a Chinese population. Methods: The study population included 3394 subjects age 40 years or older who were enrolled in a population-based study from Songnan Community, Baoshan District, Shanghai, China, from June through August 2009. We analyzed the association between urinary BPA and thyroid function using multivariate linear regression. Participants were further divided according to thyroid function status, and logistic regression was applied to determine the relationship between urinary BPA and thyroid function. Results: Each one-quartile increase in BPA was related to an increase of 0.068 pmol/l (95% confidence interval = 0.065– 0.071) in free triiodothyronine and a 0.084 &mgr;IU/ml decline (−0.099 to −0.069) in thyroid-stimulating hormone (TSH) in men. For women, there was a 0.10 pmol/l (0.09 to 0.11) increase in free triiodothyronine and a 0.13 &mgr;IU/ml decline (−0.14 to −0.11) in TSH. High urinary BPA level was associated with increased thyroid function (adjusted odds ratio= 1.71 [1.26 to 2.32]). Conclusions: Our results support previous reports of associations between BPA exposure and altered thyroid hormones in animal models and epidemiologic studies. Because our study is cross-sectional, no causal relationships can be established.