| We developed the 2005 Dietary Guidelines for Americans Index (DGAI) to assess adherence to dietary recommendations included in the most recent, the sixth version of the Dietary Guidelines for Americans.;Insulin resistance (IR) and Metabolic Syndrome (MetS) have been associated with increased risk of cardiovascular disease (CVD) and type 2 diabetes mellitus. MetS was defined by the Adult Treatment Panel III to include five CVD risk factors that have previously been associated with increased CVD risk. Using this definition it affects 31% of US adults. The MetS risk factors have been associated with diet; therefore it is conceivable that Americans could decrease their risk of IR and MetS by adhering to the 2005 DGA.;To assess the relationship between diets consistent with the dietary recommendation of the 2005 DGA and levels of IR and prevalence of MetS, we assessed biochemical markers (fasting insulin, waist circumference, fasting plasma glucose, triglycerides, HDL cholesterol, and blood pressure) and dietary intakes information from Harvard semi-quantitative Food Frequency Questionnaire, collected on over 3000 individuals in the 5th examination cycle of the Framingham Heart Study Offspring Cohort.;Adherence to the 2005 DGA, as measured by the DGAI, was related to decreased IR, as measured by Homeostasis Minimum Model for Insulin Resistance, those in highest quintile of index score had lower HOMA-IR when compared to the lowest (6.4 and 6.8, P-trend=0.03). This relationship was more pronounced in women (5.9 and 6.6, P-trend<0.001).;After adjustment for potential confounders, the DGAI score was inversely related to waist circumference (94 cm in the lowest vs. 89 cm in the highest DGAI quintile category, P-trend<0.001) triglyceride concentration (128 mg/dL vs. 115 mg/dL, P-trend=0.005), and both diastolic and systolic blood pressure. Using the lowest quintile as the reference, the prevalence of the MetS risk factor was lower for waist circumference (Odds Ratio (OR)=0.50, 95% confidence interval (CI):0.39-0.64 P-trend<0.001), and glucose (OR= 0.67, CI:0.51-0.88 P-trend=0.005). The prevalence of MetS was lower in the highest DGAI quintile category (OR=0.64, CI: 0.47-0.88, P-trend=0.005). There was a significant interaction between DGAI score and age for the prevalence of MetS, with the association largely confined to adults younger than 55 years (OR= 0.57, CI:0.360.92, P-trend=0.007).;These results indicate that adherence to the 2005 DGA may be a good approach to decrease IR and MetS, and consequently lower risk of CVD and type 2 diabetes risk in the US adult population. |
