Dietary inflammatory index scores are associated with blood inflammatory markers in healthy Koreans: Data from the Health Examinee Cohort (2012–2014)

Inflammation is known to be associated with chronic diseases such as cardiovascular disease and cancer. In particular, a high‐sensitivity C‐reactive protein (hs‐CRP) has been reported as a predictor of chronic disease induction. Dietary inflammatory index (DII) is a score used to determine the overall inflammatory potential of diet. There are limited studies which have shown the association between the DII score and inflammatory biomarkers in Korean. In this study we performed to analyze the association between two inflammatory biomarkers such as hs‐CRP and WBC and DII in healthy Korean. We performed cross‐sectional analysis of Health Examinee Cohort (2012–2014). Subjects were between the ages of 40 or 79 (8,332 males and 19,754 females). Information on food consumption was obtained using a 24 hour recall method which was used for calculating DII scores. Blood samples provided measurement of hs‐CRP and WBC counts. The dichotomous variable was entered into logistic regression models to measure odds ratios (ORs) of having higher hs‐CRP levels (>3mg/L) or WBC levels (>median) compared to lower levels (≤3mg/L or ≤median), with increasing DII, respectively. The DII scores of females (0.02 ± 2.50) were higher than males (−0.058 ± 2.48) (p<0.001). There was a positive correlation between DII and hs‐CRP and WBC (hs‐CRP; r=0.032, p=0.000, WBC; r=0.039, p=0.000). Odds of an elevated hs‐CRP or WBC were 1.181 times and 1.143 times higher in participants with the most proinflammatory diets compared to those with the most anti‐inflammatory diets, respectively [hs‐CRP; OR(95% CI) for T3 vs T1:1.181 (1.019,1.370); P trend=0.085, WBC; OR(95% CI) for T3 vs T1:1.143 (1.066,1.2261); P trend=0.001]. The analysis of association between DII, hs‐CRP and WBC in Korean showed that the higher DII, the higher hs‐CRP and WBC. Therefore the DII can be used for assessing the inflammatory potential of diet in Korean. Furthermore, the DII can be applied to measure the association between diets and chronic diseases. Support or Funding Information This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIP) (No. NRF‐2016R1A2B1014466) 1 Characteristics of subjectCharacteristic Total (n=28,086) Men (n=8,332) Women (n= 19,754) p‐valueAge (years)* 52.47 ± 8.00 53.27 ± 8.422 52.14 ± 7.79 0.000 BMI (kg/m 2 ) 23.58 ± 2.91 24.27 ± 2.74 23.29 ± 2.93 0.000 SBP (mmgh) 121.10 ± 14.82 124.18 ± 14.06 119.80 ± 14.94 0.000 DBP (mmgh) 74.73 ± 9.78 77.28 ± 9.65 73.65 ± 9.63 0.000 Fasting glucose (mg/dl) 91.87 ± 9.23 94.26 ± 9.83 90.86 ± 8.78 0.000 hS‐CRP 0.97 ± 1.19 1.13 ± 1.32 0.90 ± 1.13 0.000 WBC blood (Thous/uL) 5.60 ± 1.50 6.02 ± 1.61 5.42 ± 1.41 0.000 DII −0.002 ± 2.49 −0.058 ± 2.48 0.02 ± 2.50 0.014 DII/1000 kcal 0.002 ± 2.28 0.190 ± 2.26 −0.076 ± 2.28 0.000 Smoker Past, smoking 3778 (13.5) 3514 (42.2) 264 (1.3) 0.000 Yes 3123 (11.1) 2667 (32.0) 456 (2.3)No 21185 (75.4) 2151 (25.8) 19034 (96.4)Education Uneducated 546 (2.0) 90 (1.1) 456 (2.3) 0.000 Elementary school 2781 (9.9) 524 (6.3) 2257 (11.5)Middle school 3938 (14.1) 870 (10.5) 3068 (15.6)High school 10855 (38.8) 2698 (32.4) 8157 (41.5)University 8430 (30.2) 3308 (39.8) 5122 (26.1)Graduate school 1408 (5.0) 826 (9.9) 582 (3.0)Family income (10,000 won) less than 100 2033 (7.4) 433 (5.2) 1600 (8.3) 0.000 100‐less than 200 11532 (41.8) 3148 (38.1) 8384 (43.4)300‐less than 400 6252 (22.7) 1892 (22.9) 4360 (22.6)400‐less than 600 5063 (18.4) 1679 (20.3) 3384 (17.5)Over 600 2690 (9.8) 1101 (13.3) 1589 (8.2)2 Characteristics of subject by tertile of DIICharacteristic Tertile 1 (n=9,391) Tertile 2 (n=9,359) Tertile 3 (n=9,336) p‐valueDII −2.78 ± 1.117 −0.013 ± 0.687 2.81 ± 1.138 0.000(−7.21–1.22) (−1.21–1.18) (−1.19–7.34)Age (years)* 53.26 ± 7.892 52.35 ± 7.986 51.81 ± 8.070 0.000 Sex0.111 Men 2843 (30.3) 2791 (29.8) 2698 (28.9)Women 6548 (69.7) 6568 (70.2) 6638 (71.1)BMI (kg/m 2 ) 23.4782 ± 2.79658 23.5991 ± 2.90675 236848 ± 3.02237 0.000 SBP (mmgh) 121.282 ± 14.7331 120.943 ± 14.7769 121.088 ± 14.9594 0.290 DBP (mmgh) 74.619 ± 9.8040 74.624 ± 9.6909 7.4960 ± 9.8503 0.024 Fasting glucose (mg/dl) 91.973 ± 9.2174 91.912 ± 9.2024 91.739 ± 9.2971 0.199 hs‐CRP 0.9381 ± 1.16046 0.9658 ± 1.17561 1.0222 ± 1.25450 0.000 WBC blood(Thous/uL) 5.5230 ± 1.46777 5.6034 ± 1.49021 5.6749 ± 1.54109 0.000 SmokerPast. smoking 1344 (14.3) 13.7 (14.0) 1127 (12.1) 0.000 Yes 874 (9.3) 1023 (10.9) 1226 (13.1)Ho 7173 (76.4) 7029 (75.1) 6983 (74.8)chronic disease(n)0 8252 87.9% 8384 89.6% 8374 89.7% 0.000 1 1097 11.7% 954 10.2% 933 10.0%2 42 0.4% 21 0.2% 29 0.3%exercise practice (for a week)0 3865 41.2% 4527 48.4% 5088 54.5% 0.000 1–2 1260 13.4% 1159 12.4% 1073 11.5%3–4 2094 22.3% 1834 19.6% 1564 16.8%5–6 1225 13.0% 1044 11.2% 861 9.2%7 947 10.1% 795 8.5% 750 8.0%EducationUneducated 131 (1.4) 169 (1.8) 246 (2.7) 0.000 Elementary school 858 (9.2) 938 (10.1) 985 (10.6)Middle school 1317 (14.1) 1281 (13.7) 1340 (14.5)High school 3609 (38.6) 3646 (39.1) 3600 (38.8)University 2919 (31.2) 2816 (30.2) 2695 (29.1)Graduate school 524 (5.6) 478 (5.1) 406 (4.4)Family income (10,000 won)less than 100 583 (6.3) 640 (7.0) 810 (8.9) 0.000 100‐les* than 200 3840 (41.3) 3820 (41.5) 3872 (42.7)300‐less than 400 2074 (22.3) 2125 (23.1) 2053 (22.6)400‐less than 600 1794 (19.3) 1686 (18.3) 1583 (17.4)Over 600 1003 (10.8) 928 (10.1) 759 (8.4)3 Correlation between anthropometric and dietary inflammatory index with inflammatory markers(hs‐CRP, WBC)Variable log hs‐CRP WBCr P r PAge 0.151 0.000 −0.042 0.000 BMI 0.328 0.000 0.154 0.000 SBP 0.150 0.000 0.108 0.000 DBP 0.152 0.000 0.112 0.000 Exercise practice −0.026 0.000 −0.078 0.000 Chronic disease 0.036 0.000 −0.034 0.000 DII 0.032 0.000 0.039 0.000by spearman's correlation coeffients.4 Associations between the dietary inflammatory index and hs‐CRPVariable Tertile 1 Tertile 2 OR (95% CI) Tertile 3 OR (95% CI) p‐valuehs‐CRP Crude 1(reference) 1.135(0.999–1.290)1) 1.282(1.131–1.452) 0.001 Adjusted 1 1 1.134(0.997–1.290) 1.277(1.125–1.449) 0.001 Adjusted 2 1 1.084(0.947–1.240) 1.181(1.019–1.370) 0.085 WBC Crude 1(reference) 1.071(1.011–1.134) 1.169(1.104–1.238) 0.000 Adjusted 1 1 1.053(0.993–1.117) 1.144(1.079–1.214) 0.000 Adjusted 2 1 1.059(0.995–1.126) 1.143(1.066–1.226) 0.001OR(95% CI): Odds ratios (95% confidence Interval)