Abstract P407: Associations between Red Meat Intake and Biomarkers of Inflammation and Glucose Metabolism in Women

Background: Greater red meat intake is associated with increased type 2 diabetes and cardiovascular disease risk (CVD). Recently, inclusion of lean red meat in a heart-healthy diet to reduce CVD risk was suggested based on short-term controlled feeding trial evidence, indicating that varying amounts of lean red meat intakes had similar effects on a lipid profile. However, the fat content of red meat may not be solely responsible for the adverse effects of red meat contributing to progression of metabolic abnormalities. Other components and mediating pathways including obesity-related inflammation and insulin resistance may be involved. We hypothesized that greater red meat intake would be associated with biomarkers of inflammation and glucose metabolism and that these potential associations would be partly explained by body mass index (BMI). Design: We analyzed data from diabetes-free female participants in the Nurses’ Health Study (n=3690). Multiple linear regression was conducted to assess the associations of total, unprocessed and processed red meat intakes (quartile categories) with plasma C-reactive protein (CRP), ferritin, adiponectin, fasting insulin, and hemoglobin A1c (HbA1c). The contribution of BMI on the associations between red meat intake and biomarkers was evaluated using publicly available SAS macro. The effect of substituting a serving of red meat with a serving of another major protein food source was estimated. Results: Greater total, unprocessed and processed red meat consumptions were associated with higher plasma CRP, ferritin, fasting insulin, and HbA1c and lower adiponectin after adjustment for demographic information (all p for trend ≤0.03). Adiponectin was not associated with any types of red meat intake when further adjusted for medical and lifestyle factors. After adjustment for BMI, most of these associations with inflammatory and glucose metabolic biomarkers were substantially attenuated and no longer significant. BMI accounted for a statistically significant proportion of associations with CRP, HbA1c, and fasting insulin (all p for contribution ≤0.02), but not with ferritin. Substituting a serving of total red meat intake with alternative protein food in a combination of poultry, fish, legumes and nuts was associated with significantly lower CRP (β±SE: -0.106±0.043), ferritin (-0.212±0.075), HbA1c (-0.052±0.015), and fasting insulin (-0.0119±0.036)(all p≤0.02 for comparing extreme quartiles). Conclusions: Greater red meat intake is associated with unfavorable plasma concentrations of inflammatory and glucose metabolic biomarkers in diabetes-free women. BMI accounts for a significant proportion of the associations with these biomarkers, except for ferritin. Substituting red meat with another protein food is associated with a healthier biomarker profile of inflammatory and glucose metabolism.