Markers of hemostasis and inflammation are considered risk factors in the pathogenesis of type 2 diabetes (1,2). Data from the Insulin Resistance Atherosclerosis Study (IRAS) indicate that the effect of plasminogen activator inhibitor-1 (PAI-1) on diabetes risk is independent not only of adiposity but also of insulin sensitivity (1). In the context of diabetes prevention, these findings challenge us to explore the determinants of the prothrombotic and inflammatory state, particularly modifiable risk factors such as dietary intake.
The importance of food and nutrient intake in the development of diabetes and its precursors is well recognized (3). The Diabetes Prevention Program trial provides evidence for the effectiveness of dietary and lifestyle modification approaches in the prevention of type 2 diabetes among high-risk individuals (4). The focus of the lifestyle intervention in the Diabetes Prevention Program was weight loss via modification of energy and fat intake and physical activity. To date, very few intervention trials have evaluated the impact of larger dietary patterns on health outcomes (5-7).
Two general approaches have dominated the field of observational research on dietary patterns: the a priori approach uses prior knowledge such as dietary recommendations to create quality indexes (8); and the exploratory approaches such as principal components, factor analysis, or cluster analysis are entirely empirical, data-driven methods. Recently, reduced rank regression (RRR) has been introduced as a method that combines the strengths of both approaches (9) because it identifies patterns among food groups by concurrently using data on a set of response variables (ideally biomarkers) selected because of known associations with the disease of interest. Two recent studies using RRR have revealed strong associations between food intake patterns and risk of diabetes (10,11). We aimed to identify RRR-deterrnined food intake patterns that affect diabetes-related inflammatory biomarkers and to evaluate their association with incident type 2 diabetes, taking into account measures of insulin sensitivity and secretion in the IRAS population.