We carried out a multistage genome-wide association study of type 2 diabetes mellitus in Japanese individuals, with a total of 1,612 cases and 1,424 controls and 100,000 SNPs. The most significant association was obtained with SNPs in KCNQ1, and dense mapping within the gene revealed that rs2237892 in intron 15 showed the lowest Pvalue (6.7 x 10(-13), odds ratio (OR) = 1.49). The association of KCNQ1 with type 2 diabetes was replicated in populations of Korean, Chinese and European ancestry as well as in two independent Japanese populations, and meta-analysis with a total of 19,930 individuals (9,569 cases and 10,361 controls) yielded a P value of 1.7 x 10(-42) (OR = 1.40; 95% CI = 1.34-1.47) for rs2237892. Among control subjects, the risk allele of this polymorphism was associated with impairment of insulin secretion according to the homeostasis model assessment of beta-cell function or the corrected insulin response. Our data thus implicate KCNQ1 as a diabetes susceptibility gene in groups of different ancestries.

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Insulin resistance is a major cause of type 2 diabetes mellitus (T2DM). Resistin, an adipocyte-secreted hormone, antagonizes insulin. Transgenic mice that overexpress the resistin gene (Retn) in adipose tissue are insulin-resistant, whereas Retn (-/-) mice show lower fasting blood glucose, suggesting that the altered Retn promoter function could cause diabetes. To determine the role of RETN in human T2DM, we analyzed polymorphisms in its 5' flanking region. We found that the -420G/G genotype was associated with T2DM (397 cases and 406 controls) (P=.008; adjusted odds ratio = 1.97 [by logistic regression analysis]) and could accelerate the onset of disease by 4.9 years (P=.006 [by multiple regression analysis]). Meta-analysis of 1,888 cases and 1,648 controls confirmed this association (P=.013). Linkage disequilibrium analysis revealed that the -420G/G genotype itself was a primary variant determining T2DM susceptibility. Functionally, Sp1 and Sp3 transcription factors bound specifically to the susceptible DNA element that included -420G. Overexpression of Sp1 or Sp3 enhanced RETN promoter activity with -420G in Drosophila Schneider line 2 cells that lacked endogenous Sp family members. Consistent with these findings, fasting serum resistin levels were higher in subjects with T2DM who carried the -420G/G genotype. Therefore, the specific recognition of -420G by Sp1/3 increases RETN promoter activity, leading to enhanced serum resistin levels, thereby inducing human T2DM.

Low risk of bias 2. Directness 3. Precision Low-quality 2 Otherwise Prospective cohort study 2 Pre-specified sub-analysis of RCT 2 Retrospective cohort study 3 Case-control study 3 Post hoc sub-analysis of RCT 3 Single-arm trial 3 Cross-sectional study 3 Case series or case report 3 † Level of evidence: 1+ (highest) to 3 (lowest). Table 2 | Grading for the strength of recommendation Strength of recommendation Grading Note Strongly recommended Grade A Positive rating is ahead for the 4 items below † Weakly recommended Grade B Negative rating is ahead for the 4 items below † † Certainty of overall evidence, balance of benefits and harms, patient preferences and values; and costs.

We have revised a part of the diagnostic criteria for fulminant type 1 diabetes. The new criteria were set both to express the essence of this disease of rapid increase of patients' blood glucose and to be highly sensitive to reduce the misdiagnosis. After analyzing the data of 382 patients with newly-diagnosed fulminant type 1 diabetes, we adopted the glycated hemoglobin (HbA 1c ) level of 8.7% (National Glycohemoglobin Standardization Program [NGSP] value). The new criterion indicates 100% of sensitivity and the best value by receiver operating characteristic curve analysis. In addition, we added a comment that 'This value (HbA 1c <8.7% in NGSP) is not applicable for patients with previously diagnosed glucose intolerance' in the new criteria and also a comment that 'Association with human leukocyte antigen DRB1*04:05-DQB1*04:01 is reported' as a related finding. We did not revise the screening criteria and the other part of the diagnostic criteria, because they are still reliable. (J Diabetes Invest