Fat consumption and HbA(1c) levels: the EPIC-Norfolk study.

Abstract

To describe the relationship between total dietary fat and the pattern of fat intake and HbA(1c). In this cross-sectional study, 2,759 men and 3,464 women (40-78 years of age) without a previous diagnosis of type 2 diabetes were recruited from a population-based sampling frame. Diet was assessed using a self-reported semiquantitative food frequency questionnaire. The HbA(1c) level was negatively associated with the polyunsaturated fat-to-saturated fat ratio (P:S ratio) of the diet (beta = -0.0338 HbA(1c)% per SD change in P:S ratio; P < 0.001) and positively associated with the total level of fat intake (beta = 0.0620 HbA(1c)% per SD change in total fat intake; P < 0.001), adjusted for age and total energy intake. The associations remained significant when adjusted for each other and for total energy, protein, age, sex, family history of diabetes, BMI, waist-to-hip ratio, physical activity, and smoking (for P:S ratio, beta = -0.0200 HbA(1c)% per SD change in P:S ratio, P = 0.013; for total fat, beta = 0.420% HbA(1c)% per SD change in total fat intake, P < 0.001). The benefits from a high P:S ratio were attributed to a lower saturated fat intake. These findings demonstrate independent associations between HbA(1c) concentration across the normal range of HbA(1c) and both total fat intake and the pattern of dietary fat intake. They provide further support to efforts promoting modifications in the intake of dietary fat.