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This study aimed to evaluate the predictive performance of genetic risk models based on risk loci identified and/or confirmed in genome-wide association studies for type 2 diabetes mellitus. A systematic literature search was conducted in the PubMed/MEDLINE and EMBASE databases through April 13, 2012, and published data relevant to the prediction of type 2 diabetes based on genome-wide association marker–based risk models (GRMs) were included. Of the 1,234 potentially relevant articles, 21 articles representing 23 studies were eligible for inclusion. The median area under the receiver operating characteristic curve (AUC) among eligible studies was 0.60 (range, 0.55–0.68), which did not differ appreciably by study design, sample size, participants’ race/ethnicity, or the number of genetic markers included in the GRMs. In addition, the AUCs for type 2 diabetes did not improve appreciably with the addition of genetic markers into conventional risk factor–based models (median AUC, 0.79 (range, 0.63–0.91) vs. median AUC, 0.78 (range, 0.63–0.90), respectively). A limited number of included studies used reclassification measures and yielded inconsistent results. In conclusion, GRMs showed a low predictive performance for risk of type 2 diabetes, irrespective of study design, participants’ race/ethnicity, and the number of genetic markers included. Moreover, the addition of genome-wide association markers into conventional risk models produced little improvement in predictive performance. [ABSTRACT FROM PUBLISHER]

BACKGROUND Several studies have examined associations between genetic variants and the risk of gestational diabetes mellitus (GDM). However, inferences from these studies were often hindered by limited statistical power and conflicting results. We aimed to systematically review and quantitatively summarize the association of commonly studied single nucleotide polymorphisms (SNPs) with GDM risk and to identify important gaps that remain for consideration in future studies. METHODS Genetic association studies of GDM published through 1 October 2012 were searched using the HuGE Navigator and PubMed databases. A SNP was included if the SNP–GDM associations were assessed in three or more independent studies. Two reviewers independently evaluated the eligibility for inclusion and extracted the data. The allele-specific odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using random effects models accounting for heterogeneity. RESULTS Overall, 29 eligible articles capturing associations of 12 SNPs from 10 genes were included for the systematic review. The minor alleles of rs7903146 (TCF7L2), rs12255372 (TCF7L2), rs1799884 (−30G/A, GCK), rs5219 (E23K, KCNJ11), rs7754840 (CDKAL1), rs4402960 (IGF2BP2), rs10830963 (MTNR1B), rs1387153 (MTNR1B) and rs1801278 (Gly972Arg, IRS1) were significantly associated with a higher risk of GDM. Among them, genetic variants in TCF7L2 showed the strongest association with GDM risk, with ORs (95% CIs) of 1.44 (1.29–1.60, P < 0.001) per T allele of rs7903146 and 1.46 (1.15–1.84, P = 0.002) per T allele of rs12255372. CONCLUSIONS In this systematic review, we found significant associations of GDM risk with nine SNPs in seven genes, most of which have been related to the regulation of insulin secretion. [ABSTRACT FROM AUTHOR]

The hemochromatosis gene (HFE) has been involved in the etiology of type 2 diabetes mellitus and investigated in numerous epidemiologic studies. The current meta-analysis was conducted to evaluate the gene-disease association in relevant studies. Electronic literature search was performed on June 18, 2011, from databases of PubMed/MEDLINE, EMBASE, and HuGE Navigator. Articles were inspected by 2 authors independently, and data were extracted by identical extraction form. A total of 5,528 type 2 diabetes cases and 6,920 controls in relation to HFE polymorphisms (a cysteine to tyrosine substitution at amino acid position 282 (C282Y) and a histidine to aspartate substitution at amino acid position 63 (H63D)) were included in the meta-analysis (1997–2011). A fixed- or random-effect model was used to calculate the pooled odds ratios based on the results from the heterogeneity tests. An increased odds ratio for type 2 diabetes mellitus was observed in persons carrying a D allele at the H63D polymorphism compared with those with an H allele (odds ratio (OR) = 1.21, 95% confidence interval (CI): 1.03, 1.41; P = 0.02). Moreover, carriers of a D allele had a modestly increased risk compared with persons with the wild genotype (OR = 1.12, 95% CI: 1.00, 1.25; P = 0.04). The C282Y variant was not significantly associated with diabetes risk. In summary, persons with a D allele may have a moderately increased risk of type 2 diabetes mellitus. [ABSTRACT FROM PUBLISHER]

The article reports a study which was conducted to determine whether there is a dose-response association between egg consumption and risk of coronary heart disease or stroke. The results revealed that consumption of one egg per day was not associated with increased risk of coronary heart disease or stroke.