9 research outputs found
Recommended from our members
Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c
Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29–39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance
Genome-wide linkage and association analysis of cardiometabolic phenotypes in Hispanic Americans
Linkage studies of complex genetic diseases have been largely replaced by Genome-Wide Association studies (GWAS), due in part to limited success in complex trait discovery. However, recent interest in rare and low-frequency variants motivates reexamination of family-based methods. In this study we investigated the performance of two-point linkage analysis for over 1.6 million SNPs combined with single variant association analysis to identify high impact variants which are both strongly linked and associated with cardiometabolic traits in up to 1 414 Hispanics from the Insulin Resistance Atherosclerosis Family Study (IRASFS). Evaluation of all 50 phenotypes yielded 83 557 000 LOD scores with 9 214 LOD scores ≥ 3.0, 845 ≥ 4.0, and 89 ≥ 5.0, with a maximal LOD score of 6.49 (rs12956744 in the LAMA1 gene for TNFα receptor 2). Twenty-seven variants were associated with p < 0.005 as well as having a LOD score > 4, including variants in the NFIB gene under a linkage peak with TNFα receptor 2 levels on chromosome 9. Linkage regions of interest included a broad peak (31Mb) on chromosome 1q with acute insulin response (max LOD = 5.37). This region was previously documented with type 2 diabetes in family-based studies, providing support for the validity of these results. Overall, we have demonstrated the utility of two-point linkage and association in comprehensive genome-wide array-based SNP genotypes