Dietary Inflammatory Index Positively Associated With High-Sensitivity C-Reactive Protein Level in Japanese From NIPPON DATA2010

Abstract

Background: It has been reported that chronic inflammation may play an important role in the pathogenesis of several serious diseases and could be modulated by diet. Recently, the Dietary Inflammatory Index (DII^®) was developed to assess the inflammatory potential of the overall diet. The DII has been reported as relevant to various diseases but has not been validated in Japanese. Thus, in the present study, we analyzed the relationship between DII scores and high-sensitivity C-reactive protein (hs-CRP) levels in a Japanese population.

Methods: Data of the National Integrated Project for Prospective Observation of Non-communicable Disease and its Trends in the Aged 2010 (NIPPON DATA2010), which contained 2,898 participants aged 20 years or older from the National Health and Nutrition Survey of Japan (NHNS2010), were analyzed. Nutrient intakes derived from 1-day semi-weighing dietary records were used to calculate DII scores. Energy was adjusted using the residual method. Levels of hs-CRP were evaluated using nephelometric immunoassay. Multiple linear regression analyses were performed.

Results: After adjusting for age, sex, smoking status, BMI, and physical activity, a significant association was observed between DII scores and log(CRP+1) (standard regression coefficient = 0.05, P < 0.01). Although it was not statistically significant, the positive association was consistently observed in almost all age-sex subgroups and the non-smoker subgroup.

Conclusions: The current study confirmed that DII score was positively associated with hs-CRP in Japanese.

Keywords: CRP; Japanese; Japanese diet; dietary inflammatory index; inflammation.

Figure 1.. Flow diagram of study population. Participants were excluded for the following reasons: 1) younger than 20 years old or absence of blood examination; 2) without informed consent; 3) data could not be utilized; 4) having incomplete data on food and nutrient intake; 5) calorie intake less than 500 kcal/d or more than 5,000 kcal/d; 6) high-sensitivity C-reactive protein level >3 mg/L; 7) physical activity unknown; 8) smoking status unknown; 9) BMI could not be calculated.