Jianzhong Xiao

Prevalence of Diabetes among Men and Women in China

BACKGROUND Because of the rapid change in lifestyle in China, there is concern that diabetes may become epidemic. We conducted a national study from June 2007 through May 2008 to estimate the prevalence of diabetes among Chinese adults. METHODS A nationally representative sample of 46,239 adults, 20 years of age or older, from 14 provinces and municipalities participated in the study. After an overnight fast, participants underwent an oral glucose-tolerance test, and fasting and 2-hour glucose levels were measured to identify undiagnosed diabetes and prediabetes (i.e., impaired fasting glucose or impaired glucose tolerance). Previously diagnosed diabetes was determined on the basis of self-report. RESULTS The age-standardized prevalences of total diabetes (which included both previously diagnosed diabetes and previously undiagnosed diabetes) and prediabetes were 9.7% (10.6% among men and 8.8% among women) and 15.5% (16.1% among men and 14.9% among women), respectively, accounting for 92.4 million adults with diabetes (50.2 million men and 42.2 million women) and 148.2 million adults with prediabetes (76.1 million men and 72.1 million women). The prevalence of diabetes increased with increasing age (3.2%, 11.5%, and 20.4% among persons who were 20 to 39, 40 to 59, and > or = 60 years of age, respectively) and with increasing weight (4.5%, 7.6%, 12.8%, and 18.5% among persons with a body-mass index [the weight in kilograms divided by the square of the height in meters] of < 18.5, 18.5 to 24.9, 25.0 to 29.9, and > or = 30.0, respectively). The prevalence of diabetes was higher among urban residents than among rural residents (11.4% vs. 8.2%). The prevalence of isolated impaired glucose tolerance was higher than that of isolated impaired fasting glucose (11.0% vs. 3.2% among men and 10.9% vs. 2.2% among women). CONCLUSIONS These results indicate that diabetes has become a major public health problem in China and that strategies aimed at the prevention and treatment of diabetes are needed.

Prevalence of Hypertension in China: A Cross-Sectional Study

Aims The present study aimed to assess the prevalence of hypertension among Chinese adults. Methods Data were obtained from sphygmomanometer measurements and a questionnaire administered to 46239 Chinese adults ≥20 years of age who participated in the 2007–2008 China National Diabetes and Metabolic Disorders Study. Hypertension was defined as blood pressure ≥140/90 mm Hg or use of antihypertensive medication. Results A total of 26.6% of Chinese adults had hypertension, and a significantly greater number of men were hypertensive than women (29.2% vs 24.1%, p<0.001). The age-specific prevalence of hypertension was 13.0%, 36.7%, and 56.5% among persons aged 20 to 44 years (young people), 45 to 64 years (middle-aged people), and ≥65 years (elderly people), respectively. In economically developed regions, the prevalence of hypertension was significantly higher among rural residents than among urban residents (31.3% vs 29.2%, p = 0.001). Among women or individuals who lived in the northern region, the disparity in the prevalence of hypertension between urban and rural areas disappeared (women: 24.0% vs. 24.0%, p = 0.942; northern region: 31.6% vs. 31.2%, p = 0.505). Among hypertensive patients, 45.0% were aware of their condition, 36.2% were treated, and 11.1% were adequately controlled. Conclusions The prevalence of hypertension in China is increasing. The trend of an increase in prevalence is striking in young people and rural populations. Hypertension awareness, treatment, and control are poor. Public health efforts for further improving awareness and enhancing effective control are urgently needed in China, especially in emerging populations.

Effects of Ghrelin and other neuropeptides (CART, MCH, Orexin A and b, and GLP-1) on the release of insulin from isolated rat islets

Background and Aims Ghrelin, a neuropeptide containing 28 amino acids, shows a reciprocal diurnal plasma fluctuation to that of plasma insulin. The aim of this study is to clarify the doseand glucose-dependency of ghrelin on the insulin secretion and to compare its effect with that of other neuropeptides—GLP-1, CART (55-102), CART (55-76), CART (62-76), MCH, orexin A, and B. Materials and Methods Rat islets were incubated with 1 pmol/l–1 &mgr;mol/l of ghrelin, CART fragments, MCH, orexin A or B, or GLP-1 (n = 16–32) in the presence of 16.7 mmol/l glucose. Ghrelin (10 nmol/l) was added to islets at glucose concentrations of 3.3, 6.6, 16.7 and 25 mmol/l, respectively (n = 28–32). Also, INS-1E cells were incubated with ghrelin (1 nmol/l) in the presence of glucose (3.3, 6.6, 16.7, and 25 mmol/l). In addition, we measured the mRNA expression of the ghrelin receptor using RT-PCR. Results Ghrelin inhibited insulin secretion from islets and INS-1E cells in a dose- and glucose-dependent manner. Neither 10 pmol/l–1 &mgr;mol/l of CART fragments, MCH, orexin A, nor orexin B changed the insulin secretion at 16.7 mmol/l glucose, while GLP-1, as expected, stimulated the insulin release from rat islets. Interestingly, ghrelin receptors were expressed both in islets, INS-1E, MIN 6 and alpha cell Tca-9 lines. Conclusions Ghrelin inhibits the insulin secretion in vitro in a dose- and glucose-dependent manner. Beta cells contain ghrelin receptors. CART fragments did not affect the insulin secretion. Ghrelin may play a physiological role for the regulation of insulin secretion.

Serum Lipids and Lipoproteins in Chinese Men and Women

Background— Because of rapid change in lifestyle risk factors, cardiovascular disease has become the leading cause of death in China. We sought to estimate the national levels of serum lipids and lipoproteins among the Chinese adult population. Methods and Results— We conducted a cross-sectional study in a nationally representative sample of 46 239 adults aged ≥20 years. Fasting serum total, high-density lipoprotein, and low-density lipoprotein cholesterol and triglycerides were measured by standard methods. The age-standardized estimates of total, high-density lipoprotein, and low-density lipoprotein cholesterol and triglycerides were 4.72 (95% confidence interval, 4.70–4.73), 1.30 (1.29–1.30), 2.68 (2.67–2.70), and 1.57 (1.55–1.58) mmol/L, respectively, in the Chinese adult population. In addition, 22.5% (21.8–23.3%) or 220.4 million (212.1–228.8) Chinese adults had borderline high total cholesterol (5.18–6.21 mmol/L), and 9.0% (8.5–9.5%) or 88.1 million (83.4–92.8) had high total cholesterol (≥6.22 mmol/L). The population estimates for borderline high (3.37–4.13 mmol/L), high (4.14–4.91 mmol/L), and very high (≥4.92 mmol/L) low-density lipoprotein cholesterol were 13.9% (13.3–14.5%) or 133.5 million (127.0–140.1), 3.5% (3.3–3.8%) or 33.8 million (31.2–36.5), and 3.0% (2.8–3.3%) or 29.0 million (26.3–31.8) persons, respectively. In addition, 22.3% (21.6–23.1%) or 214.9 million (207.0–222.8) persons had low high-density lipoprotein cholesterol (<1.04 mmol/L). The awareness, treatment, and control of borderline high or high total cholesterol were 11.0%, 5.1%, and 2.8%, respectively, in the Chinese adult population. Conclusions— Serum total and low-density lipoprotein cholesterol levels were high and increasing in the Chinese population. Without effective intervention, atherosclerotic cardiovascular diseases may soar in the near future in China.

Medical care and payment for diabetes in China: enormous threat and great opportunity.

Background The Diabetes Impact Study followed up a large national population-based screening study to estimate the use of and expenditures for medical care caused by diabetes in China and to ascertain the use and cost of essential basic medicines and care. Methods In 2009–10, the study team interviewed 1482 adults with diabetes and 1553 adults with glucose tolerance in the normal range from population-based random samples at 12 sites in China. The response rate was 67%. Findings After adjusting for age, sex, and urban/rural location, people with diabetes received 1.93 times more days of inpatient treatment, 2.40 times more outpatient visits, and 3.35 times more medications than people with normal glucose tolerance (all p<0.05). Adjusted expenditures for medical care were 3.38 times higher among people with diabetes than among people with normal glucose tolerance (p<0.01, unadjusted 3.97). Persons who were diagnosed with ≥10 years prior to the survey paid 3.75 times as much for medical care as those with ≤5 years of diagnosed diabetes. Among persons with diabetes, 45.2% took medication to control blood sugar, 21.1% took an antihypertensive medicine, 22.4% took daily aspirin, and 1.8% took a statin. Over the three months before the interview, 46.1% of persons with diabetes recalled seeing a doctor, 48.9% recalled a blood pressure measurement, and 54.5% recalled a blood sugar test. Over the year preceding the interview, 32.1% recalled a retinal screening and 17.9% recalled a foot examination. Conclusions In China, health care use and costs were dramatically higher for people with diabetes than for people with normal glucose tolerance and, in relative terms, much higher than in industrialized countries. Low-cost generic medicines that would reduce diabetes expenditures were not fully used.

Nonlaboratory-Based Risk Assessment Algorithm for Undiagnosed Type 2 Diabetes Developed on a Nation-Wide Diabetes Survey

OBJECTIVE To develop a New Chinese Diabetes Risk Score for screening undiagnosed type 2 diabetes in China. RESEARCH DESIGN AND METHODS Data from the China National Diabetes and Metabolic Disorders Study conducted from June 2007 to May 2008 comprising 16,525 men and 25,284 women aged 20–74 years were analyzed. Undiagnosed type 2 diabetes was detected based on fasting plasma glucose ≥7.0 mmol/L or 2-h plasma glucose ≥11.1 mmol/L in people without a prior history of diabetes. β-Coefficients derived from a multiple logistic regression model predicting the presence of undiagnosed type 2 diabetes were used to calculate the New Chinese Diabetes Risk Score. The performance of the New Chinese Diabetes Risk Score was externally validated in two studies in Qingdao: one is prospective with follow-up from 2006 to 2009 (validation 1) and another cross-sectional conducted in 2009 (validation 2). RESULTS The New Chinese Diabetes Risk Score includes age, sex, waist circumference, BMI, systolic blood pressure, and family history of diabetes. The score ranges from 0 to 51. The area under the receiver operating curve of the score for undiagnosed type 2 diabetes was 0.748 (0.739–0.756) in the exploratory population, 0.725 (0.683–0.767) in validation 1, and 0.702 (0.680–0.724) in validation 2. At the optimal cutoff value of 25, the sensitivity and specificity of the score for predicting undiagnosed type 2 diabetes were 92.3 and 35.5%, respectively, in validation 1 and 86.8 and 38.8% in validation 2. CONCLUSIONS The New Chinese Diabetes Risk Score based on nonlaboratory data appears to be a reliable screening tool to detect undiagnosed type 2 diabetes in Chinese population.

Prevalence of cardiovascular disease and risk factors in the Chinese population with impaired glucose regulation: the 2007-2008 China national diabetes and metabolic disorders study.

Cardiovascular disease (CVD) is one of the most common chronic diseases in China. This aim of this study is to determine the prevalence of CVDs and risk factors in Chinese impaired glucose regulation subjects.We used a multistage, stratified sampling method to select subjects from the general Chinese population aged 20 years and older. Subjects underwent an oral glucose tolerance test to identify normal glucose tolerance (NGT) and impaired glucose regulation including isolated impaired fasting glucose (i-IFG), impaired glucose tolerance (i-IGT), and combined IFG/IGT and diabetic mellitus (DM). A logistic regression analysis was performed to examine the association between glucose abnormalities and CVD events.We identified that 34 293 subjects had NGT, 1 469 i-IFG, 4 571 i-IGT, 957 IFG/IGT and 4 949 DM. The age-sex standardized prevalence rate of cardiovascular disease was 1.06% (95% CI 0.87-1.28), 1.79% (95% CI 1.37-2.33) and 3.83% (95% CI 2.79-5.24) in NGT, impaired glucose regulation and DM, respectively. Among impaired glucose subjects, prevalence of defined CVD risk factors (smoking, overweight, obesity, hypertension and dyslipidemia) was 29.52% (95% CI: 27.8-31.21), 36.25% (95% CI: 34.29-38.26), 10.05% (95% CI: 8.86-11.37), 36.43% (95% CI: 34.53-38.36) and 69.96% (95% CI: 67.87-71.98), respectively. Compared to 1 risk factor, the odds ratios (ORs) of CVDs with 2, 3 or 4 risk factors were 1.94 (95% CI: 0.74-5.09), 2.76 (95% CI: 1.06-7.21) and 5.84 (95% CI: 1.68-20.26), respectively. Additionally, compared to i-IFGs, ORs of CVDs with i-IGT and IFG/IGT were 2.88 (95%CI 1.36-6.01) and 2.12 (95% CI 0.83-5.44), respectively.The prevalence of cardiovascular risk factors was high in the Chinese impaired glucose regulation population. The postprandial hyperglycemia is more associated with CVD than isolated fasting hyperglycemia.

Can Stevioside in Combination with a Soy-Based Dietary Supplement Be a New Useful Treatment of Type 2 Diabetes? An In Vivo Study in the Diabetic Goto-Kakizaki Rat

The diterpene glycoside stevioside (SVS) and soy bean protein isolate have both been shown to have beneficial effects in diabetes treatment. As they each show different benefits we investigated whether the combination of both substances shows an improvement in the treatment of diabetes in Goto-Kakizaki (GK) rats. Over the course of 4 wk, the rats were fed with the following four test diets (n = 12 per group): 1. Standard carbohydrate-rich laboratory diet (chow), 2. chow + SVS (0.03 g/kg BW/day), 3. 80% SPI + 20% chow and 4. 80% SPI + 20 % chow + SVS (0.03 g/kg BW/day). At the end of the course conscious rats underwent an intra-arterial glucose tolerance test (IAGTT) (2.0 g glucose/kg BW). Compared to normal chow diet, stevioside in combination with SPI shows the following beneficial effects in GK rats with mild type 2 diabetes: 1. a 56% reduction in plasma glucose (p < 0.001), 2. a 118% increase in first-phase insulin (p < 0.005), 3. a 20% reduction in glucagons (p < 0.05), 4. a 28% reduction in total cholesterol (p < 0.001), 5. a 13% reduction in FFA (p < 0.01), 6. a 49% reduction in TG (p < 0.001) and 7. a 11% reduction in the systolic blood pressure (p < 0.001). In conclusion, the combination of stevioside and SPI has synergistic positive effects on the characteristic features of the metabolic syndrome, i.e. hyperglycemia, hypertension and dyslipidemia.

Obesity-Related Genomic Loci Are Associated with Type 2 Diabetes in a Han Chinese Population

Background and Aims Obesity is a well-known risk factor for type 2 diabetes. Genome-wide association studies have identified a number of genetic loci associated with obesity. The aim of this study is to examine the contribution of obesity-related genomic loci to type 2 diabetes in a Chinese population. Methods We successfully genotyped 18 obesity-related single nucleotide polymorphisms among 5338 type 2 diabetic patients and 4663 controls. Both individual and joint effects of these single nucleotide polymorphisms on type 2 diabetes and quantitative glycemic traits (assessing β-cell function and insulin resistance) were analyzed using logistic and linear regression models, respectively. Results Two single nucleotide polymorphisms near MC4R and GNPDA2 genes were significantly associated with type 2 diabetes before adjusting for body mass index and waist circumference (OR (95% CI) = 1.14 (1.06, 1.22) for the A allele of rs12970134, P = 4.75×10−4; OR (95% CI) = 1.10 (1.03, 1.17) for the G allele of rs10938397, P = 4.54×10−3). When body mass index and waist circumference were further adjusted, the association of MC4R with type 2 diabetes remained significant (P = 1.81×10−2) and that of GNPDA2 was attenuated (P = 1.26×10−1), suggesting the effect of the locus including GNPDA2 on type 2 diabetes may be mediated through obesity. Single nucleotide polymorphism rs2260000 within BAT2 was significantly associated with type 2 diabetes after adjusting for body mass index and waist circumference (P = 1.04×10−2). In addition, four single nucleotide polymorphisms (near or within SEC16B, BDNF, MAF and PRL genes) showed significant associations with quantitative glycemic traits in controls even after adjusting for body mass index and waist circumference (all P values<0.05). Conclusions This study indicates that obesity-related genomic loci were associated with type 2 diabetes and glycemic traits in the Han Chinese population.

BMI and waist circumference are associated with impaired glucose metabolism and type 2 diabetes in normal weight Chinese adults

AIMS To examine the associations of BMI and waist circumference with glucose metabolism and (pre)diabetes among adults with BMI < 25 kg/m². METHODS We conducted a cross-sectional study in a nationally representative sample (10,098 men and 17,454 women) of Chinese adults aged ≥ 20 years with BMI < 25 kg/m². Glucose levels after at least 10 hours of overnight fasting, at 30 minutes and at 120 minutes after a standard 75-g oral glucose load were measured. Associations of BMI and waist circumference with outcomes were examined by general linear models for continuous outcomes and by logistic regression models for dichotomous outcomes. RESULTS Among those with BMI < 25 kg/m², 18.8% of men and 17.1% of women had abnormal glucose metabolism, including 4.9% of men and 3.8% of women with undiagnosed type 2 diabetes. For each SD increase in BMI (2.1 kg/m²) and waist circumference (8.3 cm), fasting glucose levels increased by 0.128 and 0.170 mmol/L in men, and by 0.112 and 0.167 mmol/L in women, respectively; the corresponding increases for 2-hour post-load glucose levels were 0.121 and 0.217 mmol/L in men, and 0.241 and 0.362 mmol/L in women. When simultaneously included in the same model, these associations with waist circumference were stronger than with BMI. CONCLUSION Obesity measures are associated with abnormal glucose metabolism and diabetes, with central obesity playing a more prominent role than general obesity in Chinese population with BMI < 25 kg/m². Chinese diabetes prevention and treatment programs should incorporate targeting of normal weight adults with central obesity.