Shenghan Lai

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.

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

CONTEXTnBisphenol 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.nnnOBJECTIVEnOur objective was to determine whether BPA associates with obesity and insulin resistance.nnnDESIGN, SETTING, AND PARTICIPANTSnThis cross-sectional study included 3390 adults aged 40 yr or older, in Songnan Community, Baoshan District, Shanghai, China.nnnMAIN OUTCOME MEASURESnQuestionnaire, 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.nnnRESULTSnThe 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.nnnCONCLUSIONSnBPA was positively associated with generalized obesity, abdominal obesity, and insulin resistance in middle-aged and elderly Chinese adults.

Effects of Metformin Versus Glipizide on Cardiovascular Outcomes in Patients With Type 2 Diabetes and Coronary Artery Disease

OBJECTIVE The two major classes of antidiabetic drugs, sulfonylureas and metformin, may differentially affect macrovascular complications and mortality in diabetic patients. We compared the long-term effects of glipizide and metformin on the major cardiovascular events in type 2 diabetic patients who had a history of coronary artery disease (CAD). RESEARCH DESIGN AND METHODS This study is a multicenter, randomized, double-blind, placebo-controlled clinical trial. A total of 304 type 2 diabetic patients with CAD, mean age = 63.3 years (range, 36–80 years), were enrolled. Participants were randomly assigned to receive either glipizide (30 mg daily) or metformin (1.5 g daily) for 3 years. The primary end points were times to the composite of recurrent cardiovascular events, including death from a cardiovascular cause, death from any cause, nonfatal myocardial infarction, nonfatal stroke, or arterial revascularization. RESULTS At the end of study drug administration, both groups achieved a significant decrease in the level of glycated hemoglobin (7.1% in the glipizide group and 7.0% in the metformin group). At a median follow-up of 5.0 years, 91 participants had developed 103 primary end points. Intention-to-treat analysis showed an adjusted hazard ratio (HR) of 0.54 (95% CI 0.30–0.90; P = 0.026) for the composites of cardiovascular events among the patients that received metformin, compared with glipizide. The secondary end points and adverse events were not significantly different between the two groups. CONCLUSIONS Treatment with metformin for 3 years substantially reduced major cardiovascular events in a median follow-up of 5.0 years compared with glipizide. Our results indicated a potential benefit of metformin therapy on cardiovascular outcomes in high-risk patients.

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

BACKGROUNDnGreater bisphenol A exposure has been shown to be associated with a higher risk for self-reported adverse health outcomes, including diabetes.nnnOBJECTIVEnTo examine the association between bisphenol A exposure and type 2 diabetes in adults.nnnDESIGNnCross-sectional study.nnnSETTINGnSongnan, Baoshan District, Shanghai, China.nnnPARTICIPANTSn3423 local residents aged 40 years or older who were enrolled from 27 June 2008 to 10 August 2009.nnnMEASUREMENTSnUrinary 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).nnnRESULTSnMedian 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.nnnLIMITATIONSnThe 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.nnnCONCLUSIONnThese findings do not confirm a previously reported association between urinary bisphenol A levels and self-reported type 2 diabetes.

Gut microbiome and serum metabolome alterations in obesity and after weight-loss intervention

Emerging evidence has linked the gut microbiome to human obesity. We performed a metagenome-wide association study and serum metabolomics profiling in a cohort of lean and obese, young, Chinese individuals. We identified obesity-associated gut microbial species linked to changes in circulating metabolites. The abundance of Bacteroides thetaiotaomicron, a glutamate-fermenting commensal, was markedly decreased in obese individuals and was inversely correlated with serum glutamate concentration. Consistently, gavage with B. thetaiotaomicron reduced plasma glutamate concentration and alleviated diet-induced body-weight gain and adiposity in mice. Furthermore, weight-loss intervention by bariatric surgery partially reversed obesity-associated microbial and metabolic alterations in obese individuals, including the decreased abundance of B. thetaiotaomicron and the elevated serum glutamate concentration. Our findings identify previously unknown links between intestinal microbiota alterations, circulating amino acids and obesity, suggesting that it may be possible to intervene in obesity by targeting the gut microbiota.

Cohort profile: Risk evaluation of cancers in Chinese diabetic individuals: A longitudinal (REACTION) study

To demonstrate whether abnormal glucose metabolism (diabetes and prediabetes) is associated with increased risk for cancer in the Chinese population and to identify factors that modify the risk of cancer among individuals with abnormal glucose metabolism.

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

OBJECTIVEnObesity 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.nnnRESEARCH DESIGN AND METHODSnAt 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.nnnRESULTSnControlling 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).nnnCONCLUSIONnBoth 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.

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.

Diabetes Genetic Risk Score Modifies Effect of Bisphenol A Exposure on Deterioration in Glucose Metabolism.

CONTEXTnEpidemiology studies showed inconsistent results regarding the relationship between bisphenol A (BPA) exposure and risk of type 2 diabetes (T2D).nnnOBJECTIVEnThis study sought to prospectively investigate associations of BPA with incident T2D risk and the longitudinal changes in glycemic traits, particularly examining the interaction between gene and BPA exposure on the associations.nnnDESIGN, SETTING, AND PARTICIPANTSnA community-based study was conducted at baseline in 2009, including 2209 nondiabetic middle-age and elderly subjects followed for 4 y. Urinary BPA levels were measured at baseline. A genetic risk score (GRS) based on 34 T2D common variants that identified and validated in East Asians was created.nnnMAIN OUTCOME MEASURESnIncident T2D was defined according to the 1999 World Health Organization criteria. Fasting (FPG) and 2-h post-loading plasma glucose were measured at baseline and followup.nnnRESULTSnMultivariable logistic regression analysis demonstrated no significant association of risk of incident T2D with BPA while with increase in the weighted T2D-GRS (odds ratio, 1.89; 95% confidence interval, 1.31-2.72 for each 10-point increment). Similar results were found in 4-y changes of FPG and 2-h post-loading plasma glucose. The GRS modified the effect of BPA exposure on 4-y changes in FPG (P for interaction = .01). Each 1 unit of Log_BPA was associated with 0.1 mmol/L increase in FPG (P = .007) in the highest quartile of GRS; no associations were found in the lower three quartiles of GRS.nnnCONCLUSIONSnThe T2D genetic susceptibility significantly modulated the association of BPA exposure with longitudinal increase in FPG levels.

Sleep duration and snoring associate with hypertension and glycaemic control in patients with diabetes

Few studies have analysed the effect of sleep duration and snoring on hypertension and glycaemic control in patients with diabetes. This study aims to investigate the relationship of sleep duration and snoring on prevalent hypertension and glycaemic control in people with diabetes.