Despite the proven evidence of high glycemic index (GI) and glycemic load (GL) diets to increase cardiometabolic risks, knowledge about the meta-evidence for carbohydrate quality within world geographic regions is limited. We conducted a meta-analysis to synthesize the evidence of GI/GL studies and carbohydrate quality, gathering additional exposures for carbohydrate, high glycemic carbohydrate, total dietary fiber, and cereal fiber and risks for type 2 diabetes (T2DM), coronary heart disease (CHD), stroke, and mortality, grouped into the US, Europe, and Asia. Secondary aims examined cardiometabolic risks in overweight/obese individuals, by sex, and dose-response dietary variable trends. 40-prospective observational studies from 4-Medline bibliographical databases (Ovid, PubMed, EBSCOhost, CINAHL) were search up to November 2019. Random-effects hazard ratios (HR) and 95% confidence intervals (CI) for highest vs. lowest categories and continuous form combined were reported. Heterogeneity (I2>50%) was frequent in US GI/GL studies due to differing study characteristics. Increased risks ((HRGI,T2DM,US=1.14;CI:1.06,1.21), HRGL,T2DM,US=1.02 (1.01, 1.03)), HRGI,T2DM,Asia=1.25;1.02,1.53), and HRGL,T2DM,Asia=1.37 (1.17, 1.60)) were associated with cardiometabolic diseases. GI/GL in overweight/obese females had the strongest magnitude of risks in US-and Asian studies. Total dietary fiber (HRT2DM,US = 0.92;0.88,0.96) and cereal fiber (HRT2DM,US = 0.83;0.77,0.90) decreased risk of developing T2DM. Among females, we found protective dose-response risks for total dietary fiber (HR5g-total-dietary-fiber,T2DM,US = 0.94;0.92,0.97), but cereal fiber showed better ability to lower T2DM risk (HR5g-cereal-fiber,T2DM,US = 0.67;0.60,0.74). Total dietary-and cereal fibers' dose-response effects were nullified by GL, but not so for cereal fiber with GI. Overweight/obese females could shift their carbohydrate intake for higher cereal fiber to decrease T2DM risk, but higher GL may cancel-out this effect.

To determine which anthropometric measures are the strongest discriminators of incident type 2 diabetes (T2DM) among White and Black males and females in a large U.S. cohort. We used Atherosclerosis Risk in Communities study data from 12,121 participants aged 45–64 years without diabetes at baseline who were followed for over 11 years. Anthropometric measures included a body shape index (ABSI), body adiposity index (BAI), body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), waist to height ratio (WHtR), and waist to hip to height ratio (WHHR). All anthropometric measures were repeated at each visit and converted to Z-scores. Hazard ratios and 95% confidence intervals adjusted for age were calculated using repeated measures Cox proportional hazard regression analysis. Akaike Information Criteria was used to select best-fit models. The magnitude of the hazard ratio effect sizes and the Harrell’s C-indexes were used to rank the highest associations and discriminators, respectively. There were 1,359 incident diabetes cases. Higher values of all anthropometric measures increased the risk for development of T2DM (p < 0.0001) except ABSI, which was not significant in White and Black males. Statistically significant hazard ratios ranged from 1.26–1.63 for males and 1.15–1.88 for females. In general, the largest hazard ratios were those that corresponded to the highest Harrell’s C-Index and lowest Akaike Information Criteria values. Among White and Black males and females, BMI, WC, WHR, and WHtR were comparable in discriminating cases from non-cases of T2DM. ABSI, BAI, and WHHR were inferior discriminators of incident T2DM across all race-gender groups. BMI, the most commonly used anthropometric measure, and three anthropometric measures that included waist circumference (i.e., WC, WHR, WHtR) were the best anthropometric discriminators of incident T2DM across all race-gender groups in the ARIC cohort.

Background: The aim of the present study was to determine the best anthropometric discriminators of type 2 diabetes mellitus (T2DM) among White and Black males and females in a large US sample.Methods: We used Atherosclerosis Risk in Communities study baseline data (1987–89) from 15 242 participants (1827 with T2DM) aged 45–65 years. Anthropometric measures included a body shape index (ABSI), body adiposity index (BAI), body mass index, waist circumference (WC), waist: height ratio (WHtR), and waist: hip ratio (WHR). All anthropometric measures were standardized to Z‐scores. Using logistic regression, odds ratios for T2DM were adjusted for age, physical activity, and family history of T2DM. The Akaike information criterion and receiver operating characteristic C‐statistic were used to select the best‐fit models.Results: Body mass index, WC, WHtR, and WHR were comparable discriminators of T2DM among White and Black males, and were superior to ABSI and BAI in predicting T2DM (P < 0.0001). Waist circumference, WHtR, and WHR were the best discriminators among White females, whereas WHR was the best discriminator among Black females. The ABSI was the poorest discriminator of T2DM for all race–gender groups except Black females. Anthropometric values distinguishing T2DM cases from non‐cases were lower for Black than White adults.Conclusions: Anthropometric measures that included WC, either alone or relative to height (WHtR) or hip circumference (WHR), were the strongest discriminators of T2DM across race–gender groups. Body mass index was a comparable discriminator to WC, WHtR, and WHR among males, but not females.

Background: Associations have been observed among genetic variants, dietary patterns, and metabolic syndrome (MetS). A gap in knowledge is whether a genetic risk score (GRS) and dietary patterns interact to increase MetS risk among African Americans. We investigated whether MetS risk was influenced by interaction between a GRS and dietary patterns among Whites and African Americans. A secondary aim examined if molecular genetic clusterings differed by racial ancestry.Methods: We used longitudinal data over 4-visits (1987–1998) that included 10,681 participants aged 45–64y at baseline from the Atherosclerosis Risk in Communities study (8451 Whites and 2230 African Americans). We constructed a simple-count GRS as the linear weighted sum of high-risk alleles (0, 1, 2) from cardiovascular disease polymorphisms from the genome-wide association studies catalog associated with MetS risk. Three dietary patterns were determined by factor analysis of food frequency questionnaire data: Western, healthy, and high-fat dairy. MetS was defined according to the 2016 National Cholesterol Education Program Adult Treatment Panel III criteria but used 2017 American Heart Association/American College of Cardiology criteria for elevated blood pressure. Analyses included generalized linear model risk ratios (RR), 95% confidence intervals (CI), and Bonferroni correction for multiple testing.Results: The Western dietary pattern was associated with higher risk for MetS across increasing GRS tertiles among Whites (p < 0.017). The high-fat dairy pattern was protective against MetS, but its impact was most effective in the lowest GRS tertile in Whites (RR = 0.62; CI: 0.52–0.74) and African Americans (RR = 0.67; CI: 0.49–0.91). Among each racial group within GRS tertiles, the Western dietary pattern was associated with development and cycling of MetS status between visits, and the high-fat dairy pattern with being free from MetS (p < 0.017). The healthy dietary pattern was associated with higher risk of MetS among African Americans which may be explained by higher sucrose intake (p < 0.0001). Fewer genes, but more metabolic pathways for obesity, body fat distribution, and lipid and carbohydrate metabolism were identified in African Americans than Whites. Some polymorphisms were linked to the Western and high-fat dairy patterns.Conclusion: The influence of dietary patterns on MetS risk appears to differ by genetic predisposition and racial ancestry.

Cross-sectional studies indicate that the fat mass and obesity-associated (FTO) rs9939609 gene variant is associated with metabolic syndrome (MetS) primarily in European ancestry. However, the association is not fully elucidated in African Americans. We hypothesized that rs9939609 (AT = moderate-risk carriers or AA = high-risk carriers compared to TT = low-risk carriers) is associated with MetS and its component risk factors over time; and that its association is ancestry-specific. A secondary hypothesis was that higher levels of physical activity can decrease the deleterious effect of rs9939609 at higher body mass index (BMI). Atherosclerosis Risk in Communities study repeated measures data from 4 visits (1987–1998) were obtained from the database of Genotypes and Phenotypes for 10,358 participants (8170 Whites and 2188 African Americans) aged 45 to 64 years at baseline. Guidelines for elevated blood pressure by the American College of Cardiology and American Heart Association Task Force were updated within the MetS criteria. Risk ratios (RR) and 95% confidence intervals from generalized estimating equations assessed population-average risks. MetS was present among 3479 (42.6%) Whites and 1098 (50.2%) African Americans at baseline, and 50.3% Whites and 57% African Americans over 11-years of follow-up. Among MetS component risk factors, high waist circumference was most prevalent among White AT (RR = 1.07; 1.06–1.09) and AA (RR = 1.12; 1.10–1.14) higher-risk carriers. High triglycerides were elevated among African American AA high-risk carriers (RR = 1.11; 1.02–1.21) compared to TT low-risk carriers. Over time, White AT-and AA higher-risk carriers had 1.07 and 1.08-fold increase (P < .0001) in MetS risk. Physical activity had independent protective effects on MetS among both races (P < .05). White AA high-risk carriers with normal BMI and low vs high physical activity had higher MetS risk (RR = 1.69; 1.25–2.30 and RR = 0.68;0.53–0.87, respectively). In rs9939609 × BMI× physical activity interaction, White A-allele high-risk carriers had lower MetS risk (RR = 0.68; 0.53–0.87). Among Whites, physical activity can lessen the effect of rs9939609 and high BMI on risk for MetS.