The association between the energy-adjusted Dietary Inflammatory Index (E-DII) and risk of Type 2 Diabetes Mellitus in the Norwegian Women and Cancer Study (NOWAC)

Abstract

Background: The incidence and prevalence of type 2 diabetes mellitus (T2DM) are increasing worldwide. There are several reasons for the growing prevalence, including sedentary lifestyles and increased consumption of unhealthy diets. Inflammation is the immune system’s natural reaction to injury or infection and is suggested to play a key role in the pathogenesis of T2DM. The energy-adjusted dietary inflammatory index (E-DII) is developed to measure the inflammatory potential of the diet. <p>

<p>Aim: To examine the association between the inflammatory potential of the diet measured by the E-DII score and the risk of T2DM. In addition, examining the intake of foods that are central to the Norwegian dietary guidelines in relation to the E-DII score. Material and method: This study included 25 357 middle-aged women from the Norwegian Woman and Cancer (NOWAC) Study. A semi-quantitative food frequency questionnaire (FFQ) was used to assess the dietary intake, and the E-DII score was calculated using the data obtained from this FFQ. To estimate the association between the E-DII and the risk of T2DM, hazard ratios (HR) and 95% confidence intervals (CI) were computed using Cox proportional hazards. E-DII was analyzed both as a continuous variable and by quartiles of exposure in relation to T2DM. <p>

<p>Results: During the median follow-up of 19 years, 916 cases of self-reported T2DM were identified. A high E-DII score indicating a pro-inflammatory diet was associated with an increased risk of T2DM in the age-adjusted model (HR per 1-point increment: 1.11, 95% CI, 1.05 – 1.17) and (HRQ4-Q1: 1.30, 95% CI 1.08 – 1.56). After adjusting for potential confounders in the multivariable model, the associations between the E-DII score and the risk of T2DM were no longer significant. Women in the anti-inflammatory group consumed more of the foods that are recommended in the Norwegian dietary guidelines compared to women in the pro-inflammatory group. <p>

<p>Conclusion: There was no significant association between high E-DII score (indicating a pro-inflammatory diet) and the risk of T2DM. However, the results indicated a trend towards an increased risk of T2DM. In addition, it seems that there is a significant overlap between what is typically considered a healthy diet and an anti-inflammatory diet.