Zhenxing Mao

Prevalence, awareness, treatment, control of type 2 diabetes mellitus and risk factors in Chinese rural population: the RuralDiab study.

The study aimed to investigate prevalence, awareness, treatment and control of type 2 diabetes mellitus (T2DM), and to explore potential risk factors in rural areas of China. A total of 16413 individuals aged 18–74 years in rural districts were recruited from the Rural Diabetes, Obesity and Lifestyle (RuralDiab) study for the epidemiological research. Meanwhile, a meta-analysis including 7 published studies was conducted to validate the result of the cross-sectional study. The rates of crude and age-standardized prevalence, awareness, treatment and control of T2DM were 12.19%, 67.00%, 62.35%, 22.20% and 6.98%, 60.11%, 54.85%, 18.77%, respectively. The prevalence, awareness, treatment and control of T2DM displayed increased trends with age (Ptrend < 0.01) and were strongly associated with education, drinking, more vegetable and fruit intake, physical activity, family history of diabetes, body mass index (BMI). The results of this meta-analysis showed that the pooled prevalence, awareness, treatment and control of T2DM in China countryside were 7.3% (5.3–9.4%), 57.3% (36.9–77.6%), 48.4% (32.4–64.5%) and 21.0% (9.9–32.1%), respectively. The prevalence of T2DM was high with inadequate awareness, treatment and control of T2DM in China rural areas. Healthy lifestyles should be advocated to reduce prevalence and improve awareness, treatment, and control of T2DM in Chinese rural residents.

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 <25 kg/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.

Sex-specific associations of serum uric acid with metabolic syndrome in Chinese rural population: The RuralDiab study

BACKGROUND We explored the association between serum uric acid (SUA) and metabolic syndrome (MetS) in Chinese rural adults. METHODS A total of 16,577 subjects (6354 men and 10,223 women) were from the RuralDiab study. SUA concentration was measured by the enzymatic colorimetric method. A meta-analysis including 12 eligible studies focused on SUA and MetS was preformed to confirm the findings of the cross-sectional study. RESULTS After adjustment for age, educational level, and other covariates, the odds ratio (ORs) for MetS increased smoothly with the increasing SUA concentration in both sexes (P for no-linear trend > 0.05). The adjusted ORs of MetS comparing the fourth and firstly quartiles were 3.11 [95% CI: 2.58-3.74] in men and 3.64 [95% CI: 3.22-4.11] in women (Ptrend < 0.001). In continuous analysis, each 1 mg/dl increment in SUA concentration was significantly associated with a 41% increased risk of MetS in men and 62% in women. The meta-analysis validated the positive association between SUA and MetS (pooled OR: Men, 1.80 [95% CI: 1.57-2.07]; Women, 2.46 [95% CI: 1.95-3.12]). CONCLUSION SUA concentration was positively with the prevalence of MetS in Chinese rural population, and more studies are needed to explore the mechanisms of the relationship. WHAT IS ALREADY KNOWN ON THIS TOPIC?: Previous studies have explored the association between serum uric acid and metabolic syndrome, but evidence on the strength and consistency of the association remains uncertain and limited, especially in rural population. In addition, the epidemiological research and meta-analysis on the association have not been reported. WHAT DOES THIS STUDY ADD?: The results of this study showed that serum uric acid was significantly associated with metabolic syndrome and its components in Chinese rural population. Furthermore, the findings demonstrated that the significant associations varied across sex. In addition, the results of epidemiological research were similar with the meta-analysis, which demonstrates the credible of the results of the epidemiology research.

Prevalence and influencing factors of overweight and obesity in a Chinese rural population: the Henan Rural Cohort Study

The study aimed to estimate prevalence and influencing factors of overweight, general obesity, and abdominal obesity in rural areas of China. A total of 39034 participants aged 18 to 79 years were enrolled from the Henan Rural Cohort Study for the cross-sectional study. The age-standardized prevalence of overweight, general obesity, and abdominal obesity were 34.97%, 16.82%, and 43.71% in the general Chinese rural adults, respectively. Gender differences were: 36.04%, 18.98%, 35.37% for men, and 34.55%, 15.42%, 49.13% for women, respectively. The subgroup analysis showed the rates of overweight, general obesity, and abdominal obesity existed considerable disparities, but were universally high in all subgroups. Further, the study found that there were statistically significant U-shaped associations between the prevalence of overweight, general obesity, and abdominal obesity and age groups. In addition, the prevalence of participants with both abnormal BMI and WC were even at approximate forty percent. Aging, married/cohabiting, higher per capita monthly income, and unhealthy lifestyle were independent influencing factors of overweight, general obesity and abdominal obesity. In conclusion, overweight and obesity were severe in rural China. There is an increased need for closely monitoring high risk factors and promoting healthy lifestyle to curb the obesity epidemic among rural population.

Maternal transmission disequilibrium of rs2248359 in type 2 diabetes mellitus families and its association with vitamin D level in offspring

Association between T2DM and vitamin D deficiency has been reported in many epidemiologic studies. 24-hydroxylase encoded by CYP24A1 is the enzyme that degrades the active vitamin D metabolite. Variation in CYP24A1 may be associated with T2DM. This study investigates the association between rs2248359 in CYP24A1 and T2DM by a family-based association test (FBAT) and in a case-control study. The FBAT results revealed that there was transmission disequilibrium for allele T in both additive model (Z = 2.041, P = 0.041227) and dominant model (Z = 2.722, P = 0.006496). Results of the case-control study suggested that rs2248359 may be a risk factor for female T2DM (P = 0.036) but not for male T2DM (P = 0.816). Furthermore, excessive transmission of allele T in T2DM offspring was observed compared with the non-T2DM offspring (OR 1.392; 95%CI 1.024–1.894; P = 0.035). In addition, combination of maternal CT and paternal CC genotypes had significant synergistic effect on obtaining CT genotype for offspring with T2DM (OR 6.245; 95%CI 1.868–20.883; P = 0.004). Besides, lower level of 25(OH)D in T2DM offspring with genotype CT was observed as compared with the non-T2DM offspring (P = 0.013). These data suggest that maternal transmission disequilibrium of allele T may be a risk factor for T2DM and vitamin D deficiency in T2DM offspring.

Sex-specific relationship between visceral fat index and dyslipidemia in Chinese rural adults: The Henan Rural Cohort Study

The study aimed to explore the relationship between visceral fat index (VFI) and dyslipidemia and evaluate the efficiency of VFI as a marker for identifying dyslipidemia in Chinese rural adults. The cross-sectional study recruited 35,832 aged 18-79 years eligible participants from The Henan Rural Cohort Study. VFI was measured by bioelectrical impendence methods and classified into sex-specific quartiles. Fasting blood samples were collected. Logistic regression models with VFI as a categorical variable and restricted cubic spline regression models with VFI as a continuous variable were performed to obtain odds ratios (ORs) and 95% confidence intervals (CIs). Receiver-operating characteristic (ROC) curve was conducted to evaluate the identifying performance of VFI. The age-standardized prevalence of dyslipidemia was 29.80% and 26.01% in male and female, respectively. Increasing VFI quartiles were significantly positively related to the risk of dyslipidemia and its components (Pfor trend < 0.01). The adjusted ORs (95% CIs) for per 1-SD increase in VFI were 2.11 (2.02-2.20) and 1.52 (1.47-1.56) in male and female, respectively, and dose-response relationships were observed in both genders (Pfor nonlinearity < 0.01). In addition, area under the curves (AUCs) in male (0.697) was larger than in female (0.655) (P < 0.05). VFI was significantly positively related to the risk of dyslipidemia and its components, and the risk was shown to be more prominent in male. Meanwhile, dose-response relationships were observed in both genders. Furthermore, VFI might be a relatively effective marker for identifying dyslipidemia in male, but not in female.

The “T” allele of apolipoprotein A5 rs2075291 is significantly associated with higher total cholesterol and triglyceride and lower high-density lipoprotein cholesterol levels in Asians: a meta-analysis

Previous studies have discussed the association between apolipoprotein A5 (APOA5) gene rs2075291 polymorphism and lipid levels, but the results were inconsistent. The meta-analysis was performed to evaluate the reported effects of rs2075291 polymorphism on blood lipid levels, including total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) in Asians. A literature search was performed in six databases from January 1, 2001 to March 1, 2017. A standardized mean difference (SMD) with 95% confidence interval (95% CI) was computed to estimate the effect value. Overall, 10 articles with 19 reports were included and most of them were from Chinese institutions. Pooled results indicated significant effects of rs2075291 on lipid levels in Asians; the carriers of T allele had higher TC and TG levels but lower HDL-C level than the non-carriers, and the corresponding SMD (95% CI) were 0.20 (0.04-0.36), 0.74 (0.54-0.94), and -0.17 (-0.33 to -0.00), respectively. No significant difference was found for the LDL-C level: P = .172. Although results from the meta-analysis suggest that the T allele of the APOA5 rs2075291 is associated with higher TC and TG levels and lower HDL-C levels, large-scale studies considering the gene-gene and gene-environment interaction are needed to further explore the effects of rs2075291 polymorphism on blood lipid levels in different ethnicities.

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 (n = 538) 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.

The burden, management rates and influencing factors of high blood pressure in a Chinese rural population: the Rural Diabetes, Obesity and Lifestyle (RuralDiab) study

The aim of the present study was to examine the prevalence, awareness, treatment, control, and potentially influencing factors of high blood pressure (HBP) in Chinese rural adults based on a cross-sectional study. Using data from the Rural Diabetes, Obesity and Lifestyle (RuralDiab) study, a total of 30,834 participants aged 18–74 years were enrolled for the epidemiological study. The multivariate logistic regression model including all selected potentially influencing factors was carried out for the adjusted odds ratios (ORs) and 95% confidence intervals (CIs). Overall, a total of 9872 individuals were diagnosed as HBP (32.02%) with substantial imparity between men and women (32.87% vs. 30.58%), and the corresponding age-standardized prevalence of HBP were 19.50% (20.94% in men and 18.85% in women). Among the HBP patients, 6654 were aware of the diagnosis (67.40%), 5391 were taking medication (54.61%), and 2572 had their blood pressure controlled (26.05%).The corresponding age-adjusted awareness, treatment, and control of HBP were 59.35%, 45.91%, and 23.87%, respectively, and the corresponding rates were higher in women than those in men. The age-specific prevalence and management rates of HBP displayed increased trends with aging in both sexes(Ptrend < 0.05). Aging, low level of education, unhealthy lifestyle, positive family history of hypertension, overweight, obesity, diabetes, and dyslipidemia were associated with the prevalence, awareness, treatment, and control of HBP. In conclusion, uncontrolled HBP was common with high prevalence in Chinese rural residents. Strengthening the primary prevention through lifestyle modifications is necessary for reducing the disease burden and improving the management rates of HBP.

Transmission disequilibrium of rs4809957 in type 2 diabetes mellitus families and its association with vitamin D deficiency: A family-based case-control study

AIMS Association between T2DM and vitamin D was found in many epidemiologic reports. And 24-hydroxylase encoded by CYP24A1 is the very enzyme that degrades the active vitamin D metabolite. We aimed to investigate the association between rs4809957 in CYP24A1 and T2DM, as well as vitamin D level. METHODS A total of 419 pedigrees containing 1556 participants were included. T2DM diagnosis, 25(OH)D measurement and genotyping of rs4809957 were conducted for all the individual. Then association between rs4809957 and T2DM, as well as 25(OH)D level, was investigated by family-based association test (FBAT) and 1:1 matched case-control study. RESULTS The FBAT results revealed that there was transmission disequilibrium for allele G in T2DM families by both additive model (Z = 2.183, P = 0.029049) and recessive model (Z = 2.236, P = 0.025347). Allele G was also associated with 25(OH)D level in both additive model (Z = 2.549, P = 0.010811) and dominant model (Z = 2.012, P = 0.044187). On the other hand, results of case-control study suggested that vitamin D deficiency was a risk factor for T2DM (OR 1.987; 95%CI 1.331-2.964; P = 0.001). Further stratified analysis revealed that vitamin D deficiency increased T2DM risk in women (OR 2.347; 95%CI 1.373-4.012; P = 0.002), instead of men (OR 1.600; 95%CI 0.874-2.931; P = 0.127). In addition, T2DM patients with GG and AG genotypes were more susceptible to vitamin D deficiency than the control (P = 0.006 and P = 0.038, respectively). CONCLUSION There was transmission disequilibrium for allele G of rs4809957 in T2DM families, which was linked to vitamin D deficiency.