Objective: To describe the distribution characteristics of type 2 diabetes in twins in Chinese National Twin Registry (CNTR), provide clues and evidence for revealing the influence of genetic and environmental factors for type 2 diabetes. Methods: Of all twins registered in the CNTR during 2010-2018, a total 18 855 twin pairs aged ≥30 years with complete registration information were included in the analysis. The random effect model was used to describe the population and area distribution characteristics and concordance of type 2 diabetes in twin pairs. Results: The mean age of the subjects was (42.8±10.2) years, the study subjects included 10 339 monozygotic (MZ) twin pairs and 8 516 dizygotic (DZ) twin pairs. The self-reported prevalence rate of type 2 diabetes was 2.2% in total population and there was no sighificant difference between MZ and DZ. Intra-twin pairs analysis showed that the concordance rate of type 2 diabetes was 38.2% in MZ twin pairs, and 16.0% in DZ twin pairs, the difference was statistically significant (P<0.001). The concordance rate of type 2 diabetes in MZ twin parts was higher than that in DZ twin pairs in both men and women, in different age groups and in different areas (P<0.05). Further stratified analysis showed that in northern China, only MZ twin pairs less than 60 years old were found to have a higher concordance rate of type 2 diabetes compared with DZ twin pairs (P<0.05). In southern China, the co-prevalence rate in male MZ twin pairs aged ≥60 years was still higher than that in DZ twin pairs (P<0.05). Conclusion: The twin pairs in this study had a lower self-reported prevalence of type 2 diabetes than the general population. The study results suggested that genetic factors play a role in type 2 diabetes prevalence in both men and women, in different age groups and in different areas, however, the effect might vary.
Adult ; China/epidemiology* ; Diabetes Mellitus, Type 2/genetics* ; Diseases in Twins/genetics* ; Female ; Humans ; Male ; Middle Aged ; Registries ; Twins, Dizygotic ; Twins, Monozygotic/genetics*

Humans ; Diabetes Mellitus, Type 2/genetics* ; Rural Population ; Case-Control Studies ; Obesity/genetics* ; China/epidemiology* ; Receptors, Calcitriol

Aged ; Case-Control Studies ; China ; epidemiology ; Diabetes Mellitus, Type 2 ; epidemiology ; genetics ; Exercise ; Female ; Genetic Predisposition to Disease ; Humans ; Male ; Middle Aged ; Polymorphism, Genetic ; Receptors, Calcitriol ; genetics ; Risk ; Rural Population

This prospective study was designed to examine the combined influence of insulin resistance (IR) and inflammatory biomarker levels on type 2 diabetes mellitus (T2DM) among 1,903 Inner Mongolians. During follow-up, 205 (10.77%) participants developed T2DM, and the incidence of T2DM was higher among subjects with IR, elevated C-reactive protein (CRP), elevated sICAM-1, elevated sE-selectin, or the coexistences of IR with elevated CRP, elevated sICAM-1, elevated sE-selectin, and elevated angiotensin II (all P < 0.05) compared with patients without IR or any elevated biomarkers. In multivariate analysis, the odd ratios [OR, (95% confidence intervals)] for these conditions were 1.944 (1.405-2.691), 2.003 (1.449-2.767), 1.706 (1.232-2.362), 1.560 (1.123-2.165), 2.708 (1.809-4.054), 1.885 (1.155-3.078), 2.101 (1.340-3.295), and 2.260 (1.426-3.582), respectively. Our findings demonstrated that IR and elevated inflammatory biomarkers were associated with T2DM, and that the coexistence of IR and elevated inflammatory biomarkers increased the risk of T2DM.
Asian Continental Ancestry Group ; Biomarkers ; China ; epidemiology ; Cohort Studies ; Diabetes Mellitus, Type 2 ; blood ; epidemiology ; genetics ; Humans ; Inflammation ; metabolism ; Insulin Resistance ; genetics ; physiology ; Multivariate Analysis ; Odds Ratio ; Prospective Studies

Type 2 diabetes (T2D) has been associated with a high prevalence of depression.We aimed to determine the causal relation by performing a Mendelian randomization (MR) study using 34 T2D risk genetic variants validated in East Asians as the instrumental variable (IV). An MR analysis was performed involving 11 506 participants from a large longitudinal study. The T2D genetic risk score (GRS) was built using the 34 typical T2D common variants. We used T2D_GRS as the IV estimator and performed inverse-variance weighted (IVW) and Egger MR analysis. The T2D_GRS was found to be associated with depression with an OR of 1.21 (95% CI: 1.07-1.37) after adjustments for age, sex, body mass index, current smoking and drinking, physical activity, education, and marital status. Using T2D_GRS as the IV, we similarly found a causal relationship between genetically determined T2D and depression (OR: 1.84, 95% CI: 1.25-2.70). Though we found no association between the combined effect of the genetic IVs for T2D and depression with EggerMR(OR: 0.95, 95%CI: 0.42-2.14), we found an association for T2D and depression with IVW (OR: 1.75, 95% CI: 1.31-2.46) after excluding pleiotropic SNPs. Overall, the MR analyses provide evidence inferring a potential causal relationship between T2D and depression.
Aged ; Causality ; China ; epidemiology ; Depression ; epidemiology ; etiology ; Diabetes Mellitus, Type 2 ; complications ; genetics ; psychology ; Female ; Genetic Variation ; Genotype ; Humans ; Linear Models ; Longitudinal Studies ; Male ; Mendelian Randomization Analysis ; Middle Aged ; Polymorphism, Single Nucleotide ; Psychiatric Status Rating Scales ; Risk Factors ; Sensitivity and Specificity

OBJECTIVEThe aim of this study is to determine whether the SUMO4 M55V polymorphism is associated with susceptibility to type 2 diabetes mellitus (T2DM).

METHODSA meta-analysis was performed to detect the potential association of the SUMO4 M55V polymorphism and susceptibility to T2DM under dominant, recessive, co-dominant (homogeneous and heterogeneous), and additive models.

RESULTSA total of eight articles including 10 case-control studies, with a total of 2932 cases and 2679 controls, were included in this meta-analysis. The significant association between the SUMO4 M55V polymorphism and susceptibility to T2DM was observed in the dominant model (GG + GA versus AA: OR = 1.21, 95% CI = 1.05-1.40, P = 0.009), recessive model (GG versus GA + AA: OR = 1.29, 95% CI = 1.07-1.356, P = 0.010), homozygous model (GG versus AA: OR = 1.41, 95% CI = 1.06-1.56, P = 0.001), and additive model (G versus A: OR = 1.18, 95% CI = 1.08-1.29, P = 0.001), and marginally significant in the heterozygous model (GA versus AA: OR = 1.16, 95% CI = 0.98-1.36, P = 0.080). In subgroup analyses, significant associations were observed in the Chinese population under four genetic models excluding the heterozygous model, whereas no statistically significant associations were observed in the Japanese population under each of the five genetic models.

CONCLUSIONThe meta-analysis demonstrated that the G allele of the SUMO4 M55V polymorphism could be a susceptible risk locus to T2DM, mainly in the Chinese population, while the association in other ethnic population needs to be further validated in studies with relatively large samples.

Diabetes Mellitus, Type 2 ; epidemiology ; genetics ; Genetic Predisposition to Disease ; epidemiology ; genetics ; Humans ; Small Ubiquitin-Related Modifier Proteins ; genetics ; metabolism

Contribution of genetic predisposition to risk prediction of type 2 diabetes mellitus (T2DM) was investigated using a prospective study in middle-aged adults in Korea. From a community cohort of 6,257 subjects with 8 yr' follow-up, genetic predisposition score with subsets of 3, 18, 36 selected single nucleotide polymorphisms (SNPs) (genetic predisposition score; GPS-3, GPS-18, GPS-36) in association with T2DM were determined, and their effect was evaluated using risk prediction models. Rs5215, rs10811661, and rs2237892 were in significant association with T2DM, and hazard ratios per risk allele score increase were 1.11 (95% confidence intervals: 1.06-1.17), 1.09 (1.01-1.05), 1.04 (1.02-1.07) with GPS-3, GPS-18, GPS-36, respectively. Changes in AUC upon addition of GPS were significant in simple and clinical models, but the significance disappeared in full clinical models with glycated hemoglobin (HbA1c). For net reclassification index (NRI), significant improvement observed in simple (range 5.1%-8.6%) and clinical (3.1%-4.4%) models were no longer significant in the full models. Influence of genetic predisposition in prediction ability of T2DM incidence was no longer significant when HbA1c was added in the models, confirming HbA1c as a strong predictor for T2DM risk. Also, the significant SNPs verified in our subjects warrant further research, e.g. gene-environmental interaction and epigenetic studies.
Adult ; Aged ; Cohort Studies ; Diabetes Mellitus, Type 2/diagnosis/*epidemiology/*genetics ; Female ; Genetic Association Studies ; Genetic Predisposition to Disease/*epidemiology/*genetics ; Genetic Testing/methods ; Humans ; Incidence ; Male ; Middle Aged ; Polymorphism, Single Nucleotide/*genetics ; *Proportional Hazards Models ; Reproducibility of Results ; Republic of Korea/epidemiology ; Risk Assessment/methods ; Sensitivity and Specificity

OBJECTIVETo identify the possible association between C(-106)T polymorphism of the aldose reductase (ALR) gene and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM).

METHODSFrom November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy (DWR) group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C(-106)T polymorphism (rs759853) in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed.

RESULTSA total of 268 T2DM patients (129 in the DR group and 139 in the DWR group) were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset (P=0.10) and gender (P=0.78). The success rate of genotyping for the study subjects was 99.6% (267/268), with one case of failure in the DR group. The frequencies of the T allele in the C(-106)T polymorphism were 16.0% (41/256) in the DR group and 19.4% (54/278) in the DWR group (P=0.36). There was no significant difference in the C(-106)T genotypes between the 2 groups (P=0.40). Compared with the wild-type genotype, odds ratio (OR) for the risk of DR was 0.7 (95% CI, 0.38-1.3) for the heterozygous CT genotype and 0.76 (95% CI, 0.18-3.25) for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria (OR=4.61; 95% CI, 2.34-9.05) and insulin therapy (OR=3.43; 95% CI, 1.94-6.09).

CONCLUSIONSMicroalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C(-106)T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.

Albuminuria ; epidemiology ; urine ; Aldehyde Reductase ; genetics ; Asian Continental Ancestry Group ; China ; Cohort Studies ; Diabetes Mellitus, Type 2 ; complications ; drug therapy ; ethnology ; genetics ; Diabetic Retinopathy ; drug therapy ; ethnology ; etiology ; genetics ; Female ; Gene Frequency ; Humans ; Hypoglycemic Agents ; administration & dosage ; adverse effects ; therapeutic use ; Insulin ; administration & dosage ; adverse effects ; therapeutic use ; Logistic Models ; Male ; Multivariate Analysis ; Polymorphism, Single Nucleotide ; Risk

OBJECTIVETo study the association of polymorphisms in the potassium voltage-gated channel, KQT-like subfamily,member 1(KCNQ1) gene with type 2 diabetes in Chinese population from Jiangsu province.

METHODSSubjects consisting of 2925 cases and 3281 controls were enrolled from a community based cohort study of type 2 diabetes in Wuxi in 2007 and a community based cross-sectional survey on chronic non-communicable disease in Nantong in 2009. Epidemiological questionnaire survey and physical examinations were conducted and 10 h overnight fasting blood samples of 5 ml were drawn for all subjects.Genotypes were determined by TaqMan OpenArray Genotyping System and i-PLEX Sequenom MassARRAY platform. The relationship between KCNQ1 gene polymorphism and risk of type 2 diabetes after adjustment for age,sex and body mass index (BMI) was analyzed.

RESULTSThe C allele of rs2237897, rs2237892 and rs2237895 at KCNQ1 increased the risk of type 2 diabetes with adjusted OR (95%CI) value being 1.41(1.30-1.54), 1.35(1.24-1.47), 1.22(1.12-1.33) respectively (all P value < 0.05) under the additive genetic model after adjusted by age,sex and BMI. Stratification analyses in additive genetic model showed that the C allele of rs2237897 increased the risk of type 2 diabetes in subgroups stratified by age ( ≤ 56 years and > 56 years), sex (females and males), BMI (< 24 kg/m(2) and ≥ 24 kg/m(2)) with OR (95%CI) value being 1.39(1.22-1.59), 1.43(1.28-1.60), 1.40(1.26-1.55), 1.44(1.26-1.66), 1.48(1.33-1.66), 1.34(1.17-1.53) respectively (all P value< 0.05).

CONCLUSIONPolymorphisms of rs2237897, rs2237892 and rs2237895 in the KCNQ1 gene were associated with occurrence of type 2 diabetes among Jiangsu province population.

Aged ; Asian Continental Ancestry Group ; genetics ; China ; epidemiology ; Cohort Studies ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2 ; epidemiology ; genetics ; Female ; Genotype ; Humans ; KCNQ1 Potassium Channel ; genetics ; Male ; Middle Aged ; Polymorphism, Single Nucleotide

This investigation was directed to the metabolic syndrome and the islet beta-cell secretory function in the first-degree relatives (FDR) of type 2 diabetic patients in Sichuan province. A large cohort study was designed. Totally 1929 subjects were investigated. They were in two groups: FDR group comprising 505 first-degree relatives of type 2 diabetic patients, and Control group comprising 1424 controls without positive family history of Diabetes. Blood pressure, weight, waist, plasma glucose, lipids and insulin were measured. HOMA-IR and HOMA-beta indexes were used to evaluate insulin resistance and beta-cell secretion function. The insulin sensitivity index (ISI) and glucose disposition index (DI) were also used to evaluate insulin resistance. After adjustment for age and sex, HOMA-IR increased, ISI, DI and HOMA-beta decreased in FDR group when compared with controls (P < 0.05). The incidence of co-existed three or more metabolic disorders and metabolic syndrome was higher in FDR group than that in control group (P < 0.05). In FDR group, HOMA-IR increased, HOMA-beta, DI and ISI decreased while the number of co-existing metabolic disorders increased. But when the number of co-existing metabolic disorders > or = 4, HOMA-IR increased no longer and ISI decreased no more. Metabolic disorders occurred more frequently in FDR of diabetic patients than those in individuals without positive family history. As the number of co-existing metabolic disorders increased, the beta-cell secretion function and insulin sensitivity became worse. Our study indicated that it is necessary to keep on monitoring the metabolic index in FDR of type 2 diabetes and provide early preventive interventions.
Adult ; China ; epidemiology ; Cohort Studies ; Diabetes Mellitus, Type 2 ; genetics ; Female ; Glucose Tolerance Test ; Humans ; Insulin Resistance ; Islets of Langerhans ; physiopathology ; Male ; Metabolic Syndrome ; epidemiology ; genetics ; Middle Aged ; Surveys and Questionnaires