Dongdong Zhang

Risk of type 2 diabetes mellitus associated with plasma lipid levels: The rural Chinese cohort study

AIMnTo investigate the association of type 2 diabetes mellitus (T2DM) risk and plasma lipid levels in rural Chinese.nnnMETHODSnEach lipid variable was divided into quartiles and dichotomized by clinical cutoff points. Cox proportional-hazards model was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of T2DM risk and plasma lipid levels and explore the interaction between plasma lipid levels and other risk factors.nnnRESULTSn11,929 participants were included in the analysis. We documented 720 incident cases of T2DM over 70,720.84 person-years of follow-up, for an incidence of 10.18/1,000 person-years. In the multivariable-adjusted model, risk of T2DM was increased with the highest versus lowest quartiles of total cholesterol (TC) and triglycerides (TG) levels and TC/high-density lipoprotein-cholesterol (HDL-C) and TG/HDL-C ratios. The HRs (95% CIs) for the fourth quartiles, for example, were 1.34 (1.03-1.74), 2.32 (1.73-3.13), 1.66 (1.23-2.25), and 1.84 (1.38-2.45), respectively. In addition, risk of T2DM was increased with high TG level and TC/HDL-C and TG/HDL-C ratios by clinical cutoffs. The HRs (95% CIs) were 1.50 (1.25-1.80), 1.24 (1.03-1.48), and 1.44 (1.18-1.75), respectively. Risk of T2DM was associated with interactions between all lipid variables and age and BMI. TG level and TG/HDL-C ratio additionally interacted with gender (all Pinteractionu202f<u202f0.0001).nnnCONCLUSIONSnRisk of T2DM was increased with elevated serum levels of TC and TG and TC/HDL-C and TG/HDL-C ratios and also with interactions between high TC and TG levels and TC/HDL-C and TG/HDL-C ratios and age and BMI in a rural Chinese population.

Meta-analyses of the association of G6PC2 allele variants with elevated fasting glucose and type 2 diabetes

Objective To collectively evaluate the association of glucose-6-phosphatase catalytic unit 2 (G6PC2) allele variants with elevated fasting glucose (FG) and type 2 diabetes (T2D). Design Meta-analysis Data sources PubMed, Web of Knowledge and Embase databases. Study selection Full text articles of studies that identified an association of G6PC2 with T2D and elevated FG. Patient involvement There was no T2D patient involvement in the analyses on the association of FG with G6PC2, there were T2D patients and non-diabetes patient involvement in the analyses on the association of T2D with G6PC2. Statistical analysis Random-effects meta-analyses were used to calculate the pool effect sizes. I2 metric and H2 tests were used to calculate the heterogeneity. Beggs funnel plot and Egger’s linear regression test were done to assess publication bias. Results Of the 423 studies identified, 21 were eligible and included. Data on three loci (rs560887, rs16856187 and rs573225) were available. The G allele at rs560887 in three ethnicities, the C allele at rs16856187 and the A allele at rs573225 all had a positive association with elevated FG. Per increment of G allele at rs560887 and A allele at rs573225 resulted in a FG 0.070 mmol/l and 0.075 mmol/l higher (ß (95% CI) = 0.070 (0.060, 0.079), p = 4.635e-50 and 0.075 (0.065, 0.085), p = 5.856e-48, respectively). With regard to the relationship of rs16856187 and FG, an increase of 0.152 (95% CI: 0.034–0.270; p = 0.011) and 0.317 (95% CI: 0.193–0.442, p = 6.046e-07) was found in the standardized mean difference (SMD) of FG for the AC and CC genotypes, respectively, when compared with the AA reference genotype. However, the G-allele of rs560887 in Caucasians under the additive model and the C-allele of rs16856187 under the allele and dominant models were associated with a decreased risk of T2D (OR (95% CI) = 0.964 (0.947, 0.981), p = 0.570e-4; OR (95% CI) = 0.892 (0.832, 0.956), p = 0.001; and OR (95% CI) = 0.923(0.892, 0.955), p = 5.301e-6, respectively). Conclusions Our meta-analyses demonstrate that all three allele variants of G6PC2 (rs560887, rs16856187 and rs573225) are associated with elevated FG, with two variants (rs560887 in the Caucasians subgroup and rs16856187 under the allele and dominant model) being associated with T2D as well. Further studies utilizing larger sample sizes and different ethnic populations are needed to extend and confirm these findings.

Body mass index, abdominal fatness, and hypertension incidence: a dose-response meta-analysis of prospective studies

Despite the established relationship of obesity to hypertension, the question as to whether there is a linear association between these two morbidities is unanswered. To quantitatively evaluate the relationship between obesity and hypertension, we carried out a dose–response meta-analysis of studies that looked at the relationship of different adiposity measures to hypertension. We searched PubMed, Embase, and Web of Science databases for articles published before 27 June 2017. A random-effects model was used to pool relative risks and 95% confidence intervals. Restricted cubic spline analysis was used to model the relationship. A total of 59 studies were included. Fifty-seven cohort studies with 125,071 incident cases among 830,685 participants were included in the analysis of body mass index and hypertension with the summary relative risk for per 5-unit increment in body mass index of 1.50 (95% confidence interval: 1.40–1.59). We found that the risk of hypertension in the body mass index analysis was greater in populations where the baseline body mass index was <25u2009kg/m2. The summary relative risk for a 10-cm increase in waist circumference was 1.25 (95% confidence interval: 1.19–1.32) and per 0.1-unit increase in waist-to-hip ratio was 1.27 (95% confidence interval: 1.18–1.37). This meta-analysis suggests that in normal range of obesity indexes, as lean as possible may be the best suggestion to prevent hypertension incidence.

Association of long-term dynamic change in body weight and incident hypertension: The Rural Chinese Cohort Study

OBJECTIVESnThe association of long-term dynamic change in body weight and incident hypertension among general Chinese adults is still unknown. The aim of this study was to evaluate the hypertension risk in a large prospective study of rural Chinese adult using relative weight gain or loss.nnnMETHODSnA total of 10 149 nonhypertensive Chinese adults 18 to 75 y of age completed a questionnaire interview and anthropometric and laboratory measurements at both baseline (2007-2008) and follow-up (2013-2014). Participants were divided into five categories based on relative weight change. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for hypertension risk by categories of weight change.nnnRESULTSnDuring 6 y of follow-up, about one-third of the participants retained a stable weight (33.3%) or gained >6% (32.7%). Only 7.9% lost >6% weight. For every 1% increase in relative body weight, systolic and diastolic blood pressures increased 0.27 and 0.22u2009mm Hg, respectively. Risk for hypertension was reduced and increased with weight loss >6% (OR, 0.78; 95% CI, 0.61-0.99) and gain >6% (OR, 2.08; 95% CI, 1.79-2.42), respectively, compared with weight loss or gain ≤3%. With baseline prehypertension, compared with maintaining a stable weight, weight loss >6% reduced the risk for hypertension (OR, 0.71; 95% CI, 0.54-0.95). With baseline overweight, compared with maintaining the overweight status during follow-up, changing to normal weight reduced the risk for hypertension (OR, 0.67; 95% CI, 0.49-0.92), but changing to general obesity increased the risk (OR, 1.73; 95% CI, 1.35-2.22).nnnCONCLUSIONSnLong-term excessive weight gain is positively associated with increased risk for incident hypertension. Losing weight by lifestyle modification could be helpful for the primary prevention of hypertension in the general rural Chinese population.

Gene-gene interactions lead to higher risk for development of type 2 diabetes in a Chinese Han population: a prospective nested case-control study

BackgroundThe purpose of this study was to evaluate the effect of single-nucleotide polymorphisms (SNPs) of the GCKR and G6PC2 genes on risk for type 2 diabetes and the SNP-SNP and haplotype-based interactions between these genes.MethodsSubjects of this nested case-control study were selected from a prospective cohort residing in the rural area of Luoyang city in China. Cases (nu2009=u2009538) were individually matched with controls. Six SNPs in the GCKR and G6PC2 genes were selected and genotyped using an SNPscan™ kit. Stratified Cox proportional hazards regression models were used to generate odds ratios (ORs) and 95% confidence intervals (CI) for different genotype models for the risk of T2DM. Generalized multifactor dimensionality reduction (GMDR) was used to analyze the interactions between two genes with among six SNPs. The linkage disequilibrium (LD) analysis and the haplotype analysis were carried out by SHEsis online.ResultsWe found that the C allele of rs780094 was associated with increased risk for T2DM in Han Chinese population. However, the rs492594-C allele in G6PC2 was associated with a decreased risk of T2DM. We also found a significant SNP-SNP interaction between rs2293572 and rs492594, and the CCCCGC and CGCCCA haplotypes significantly increased the risk of T2DM, however, the CCCCCA haplotype had lower susceptibility to T2DM.ConclusionThe results suggest that the GCKR and G6PC2 genes may contribute to the risk of T2DM independently and/or in an interactive manner in the Han Chinese population.

Body mass index and risk of all-cause mortality with normoglycemia, impaired fasting glucose and prevalent diabetes: results from the Rural Chinese Cohort Study

Background Previous evidence of an association between body mass index (BMI) and mortality in patients with diabetes was inconsistent. The BMI–mortality association with normal fasting glucose (NFG), impaired fasting glucose (IFG) and prevalent diabetes is still unclear in the Chinese population. Methods We analysed data for 17u2009252 adults from the Rural Chinese Cohort Study during 2007–2008 and followed for mortality during 2013–2014. Participants were classified with NFG, IFG and diabetes according to baseline measurement values of fasting glucose and self-reported diabetes. Multivariable Cox proportional hazard models were used to calculate HRs and 95% CIs across BMI categories by glycemic status. Results During the 6-year follow-up, 1109 participants died (563/10 181 with NFG, 349/5572 with IFG and 197/1499 with diabetes). The BMI–mortality association was curvilinear, with low BMI (even in normal range) associated with increased mortality regardless of glycemic status. In adjusted Cox models, risk of mortality showed a decreasing trend with BMI≤18u2009kg/m2, 18<BMI≤20u2009kg/m2 and 20<BMI≤22u2009kg/m2 vs 22<BMI≤24u2009kg/m2: HR 2.83 (95% CI 1.78 to 4.51), 2.05 (1.46 to 2.87) and 1.45 (1.10 to 1.90), respectively, for NFG; 2.53 (1.25 to 5.14), 1.36 (0.86 to 2.14) and 1.09 (0.76 to 1.57), respectively, for IFG; and 4.03 (1.42 to 11.50), 2.00 (1.05 to 3.80) and 1.52 (0.88 to 2.60), respectively, for diabetes. The risk of mortality was lower for patients with diabetes who were overweight or obese versus normal weight. Conclusions Low BMI was associated with increased mortality regardless of glycemic status. Future studies are needed to explain the ‘obesity paradox’ in patients with diabetes.

Dose-response association between the triglycerides: High-density lipoprotein cholesterol ratio and type 2 diabetes mellitus risk: The rural Chinese cohort study and meta-analysis: TG/HDL-C ratio and T2DM

High triglyceride (TG) and low high‐density lipoprotein cholesterol (HDL‐C) levels are traditional risk factors for type 2 diabetes mellitus (T2DM). This study evaluated the dose–response relationship between the TG/HDL‐C ratio and T2DM risk.

Sleep Duration Interacts With Lifestyle Risk Factors and Health Status to Alter Risk of All-Cause Mortality: The Rural Chinese Cohort Study

STUDY OBJECTIVESnMany studies suggest an association of both short and long sleep duration with all-cause mortality, but the effect of co-occurrence of sleep duration and other lifestyle risk factors or health status remains unclear.nnnMETHODSnA total of 17,184 participants aged 18 years or older from rural areas of China were examined at baseline from 2007 to 2008 and followed up from 2013 to 2014. Cox proportional hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI).nnnRESULTSnDuring 6-year follow-up, we identified 1,101 deaths. The multivariable-adjusted mortality risk was significantly higher with short-duration sleepers (< 6.5 hours) (HR = 1.37, 95% CI 1.01-1.86) and long-duration sleepers (≥ 9.5 hours) (HR = 1.35, 95% CI 1.05-1.74) versus 6.5-7.5 hours. The multiplicative interaction of long sleep duration with some lifestyle risk factors and health statuses increased the mortality risk in men (low level of physical activity: HR = 1.03, 95% CI 1.02-1.04; hypertension: HR = 1.06, 95% CI 1.04-1.09; type 2 diabetes mellitus [T2DM]: HR = 1.07, 95% CI 1.04-1.11). Similar results were found in women (low level of physical activity: HR = 1.03, 95% CI 1.02-1.05; T2DM: HR = 1.07, 95% CI 1.05-1.10).nnnCONCLUSIONSnSleep duration could be a predictor of all-cause mortality and its interaction with physical activity, hypertension, and T2DM may increase the risk of mortality.

Chocolate consumption and risk of cardiovascular diseases: a meta-analysis of prospective studies

Objective Studies investigating the impact of chocolate consumption on cardiovascular disease (CVD) have reached inconsistent conclusions. As such, a quantitative assessment of the dose–response association between chocolate consumption and incident CVD has not been reported. We performed a systematic review and meta-analysis of studies assessing the risk of CVD with chocolate consumption. Methods PubMed and EMBASE databases were searched for articles published up to 6 June 2018. Restricted cubic splines were used to model the dose–response association. Results Fourteen publications (23 studies including 405u2009304 participants and 35u2009093 cases of CVD) were included in the meta-analysis. The summary of relative risk (RR) per 20u2009g/week increase in chocolate consumption was 0.982 (95% CI 0.972 to 0.992, I2=50.4%, n=18) for CVD (heart failure: 0.995 (0.981 to 1.010, I2=36.3%, n=5); total stroke: 0.956 (0.932 to 0.980, I2=25.5%, n=7); cerebral infarction: 0.952 (0.917 to 0.988, I2=0.0%, n=4); haemorrhagic stroke: 0.931 (0.871 to 0.994, I2=0.0%, n=4); myocardial infarction: 0.981 (0.964 to 0.997, I2=0.0%, n=3); coronary heart disease: 0.986 (0.973 to 0.999, n=1)). A non-linear dose–response (pnon-linearity=0.001) indicated that the most appropriate dose of chocolate consumption for reducing risk of CVD was 45u2009g/week (RR 0.890;95%CI 0.849 to 0.932). Conclusions Chocolate consumption may be associated with reduced risk of CVD at <100u2009g/week consumption. Higher levels may negate the health benefits and induce adverse effects associated with high sugar consumption.

Cohort study to determine the waist circumference cutoffs for predicting type 2 diabetes mellitus in rural China

Limited information is available on the cutoffs of waist circumference (WC) for predicting type 2 diabetes mellitus (T2DM). We aimed to define the optimal WC cutoffs for predicting T2DM among rural Chinese people.