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

The dietary inflammatory index and cardiometabolic parameters in US firefighters

Introduction

Dietary choices play a crucial role in influencing systemic inflammation and the eventual development of cardiovascular diseases (CVD). The Dietary Inflammatory Index (DII®) is a novel tool designed to assess the inflammatory potential of one's diet. Firefighting, which is characterized by high-stress environments and elevated CVD risk, represents an interesting context for exploring the dietary inflammatory-CVD connection.

Aim

This study aims to investigate the associations between Energy-adjusted Dietary Inflammatory Index (E-DII™) scores and cardiometabolic risk parameters among US firefighters.

Methods

The study analyzed 413 participants from the Indianapolis Fire Department who took part in a Federal Emergency Management Agency (FEMA)-sponsored Mediterranean diet intervention trial. Thorough medical evaluations, encompassing physical examinations, standard laboratory tests, resting electrocardiograms, and submaximal treadmill exercise testing, were carried out. Participants also completed a detailed food frequency questionnaire to evaluate dietary patterns, and E-DII scores were subsequently computed based on the gathered information.

Results

Participants had a mean body mass index (BMI) of 30.0 ± 4.5 kg/m2 and an average body fat percentage of 28.1 ± 6.6%. Regression analyses, adjusted for sex, BMI, maximal oxygen consumption (VO2 max), max metabolic equivalents (METS), age, and body fat percentage, revealed significant associations between high vs. low E-DII scores and total cholesterol (β = 10.37, p = 0.04). When comparing low Vs median E-DII scores there is an increase in glucose (β = 0.91, p = 0.72) and total cholesterol (β = 5.51, p = 0.26).

Conclusion

Our findings support an association between higher E-DII scores and increasing adiposity, as well as worse lipid profiles.

Geographic disparities of dietary inflammatory index and its association with hypertension in middle-aged and elders in China: results from a nationwide cross-sectional study

Background

Geographic distribution of dietary inflammatory index (DII) in China has not been thoroughly evaluated and evidence on the association between DII and hypertension among Chinese middle-aged and older population was inadequate.

Objective

To investigate the geographic disparities of DII and its association with hypertension among Chinese middle-aged and elders.

Methods

Data was from the China Adults Chronic Diseases and Nutrition Surveillance (CACDNS 2015) for middle-aged and older participants. The DII for each participant was determined through a combination of 3 days 24 h dietary recall interviews and a food frequency questionnaire. Spatial analysis was employed to investigate the geographic distribution of DII in China. Restricted cubic spline models and binary logistic regression analysis were used to assess the relationship between DII and hypertension. The least absolute shrinkage and selection operator (LASSO) regression was applied for identifying key hypertension-related factors, which was then included in the establishment of a risk prediction nomogram model, with the receiver operating characteristic (ROC) curve and decision curve analysis (DCA) being built to evaluate its discriminatory power for hypertension.

Results

A total of 52,087 middle-aged and older participants were included in the study, among whom 36.6% had hypertension. it revealed that a clear spatial correlation in the national distribution of DII scores (Moran I: 0.252, p = 0.001), with higher DII scores concentrated in the northwest region and lower DII scores concentrated in the southeast region. Hypertensive participants had higher DII scores compared to those without hypertension (OR: 1.507 vs. 1.447, p = 0.003). Restricted cubic spline models and binary logistic regression analysis demonstrated a positive association between DII and hypertension after adjusting for potential confounding factors. There was a significant increasing trend in the proportion of hypertensive individuals as DII scores increase (p for trend = 0.004). The nomogram model, constructed using key factors identified through LASSO regression, demonstrated a robust discriminative capacity, with an area under the curve (AUC) of 73.2% (95% CI, 72.4-74.0%). Decision curve analysis confirmed the reliability and effectiveness of the nomogram model. Sensitivity analysis conducted within the subpopulation aged under 45 years yielded results consistent with the primary analysis.

Conclusion

In Chinese adults middle-aged and older, geographic disparities in dietary inflammatory potential are notable, with lower levels observed in the southeastern coastal regions of China and higher levels in the northwestern regions. Meanwhile, there is a positive association between the inflammatory potential of the diet and hypertension. Additional research is needed to investigate regional disparities in dietary inflammatory potential and pinpoint specific dietary patterns associated with lower inflammation.

Impact of the anti-inflammatory diet on serum high-sensitivity C-Reactive protein and new-onset frailty in community-dwelling older adults: A 7-year follow-up of the Kashiwa cohort study

AIM

Chronic inflammation is a pathophysiological cause of age-related diseases, including frailty. Although diet is a determinant of inflammation, few prospective studies have investigated its role in frailty onset. This study used the dietary inflammatory index to investigate whether a proinflammatory diet affects the incidence of frailty in a 7-year follow-up of older Japanese adults.

METHODS

We enrolled community-dwelling older adults without frailty from the 2014 Kashiwa cohort study. Energy-adjusted dietary inflammatory index (E-DII) scores were calculated using a brief self-administered diet history questionnaire. Serum high-sensitivity C-reactive protein (hsCRP) levels were measured by immunoassays. Frailty was defined as meeting three of Fried's five phenotypic criteria. Cox regression was used to analyze associations between E-DII scores and new-onset frailty after adjusting for relevant confounders.

RESULTS

Overall, 95 (11.7%) of 811 participants (73.7 ± 4.8 years, women 47.3%) developed new-onset frailty during the 7-year follow-up. The baseline E-DII scores significantly correlated with log-hsCRP levels, even after adjustment (β = 0.075, P = 0.035). The highest tertile of E-DII scores (proinflammatory diet) showed a 2.03 times (95% confidence interval, 1.22-3.36) higher risk of new-onset frailty than that associated with the lowest tertile (P = 0.006). When E-DII was calculated on the basis of anti-inflammatory food parameters only, the highest tertile showed a 2.32 times (95% confidence interval, 1.36-3.95) higher risk than that associated with the lowest tertile (P = 0.002).

CONCLUSIONS

E-DII scores significantly correlated with serum hsCRP levels. High E-DII scores caused by low intake of anti-inflammatory foods are associated with frailty incidence. For community-dwelling older adults, dietary interventions that lower E-DII scores (e.g., encouraging dietary fiber intake) may help prevent frailty. Geriatr Gerontol Int 2024; 24: 189-195.

Association of Pro-Inflammatory Diet with Long-Term Risk of All-Cause and Cardiovascular Disease Mortality: NIPPON DATA80

AIM

A pro-inflammatory diet may increase the risk of cardiovascular disease (CVD) and all-cause mortality. However, this remains inconclusive as there is yet no study using a dietary record method that has been conducted in a large general population. Furthermore, an underestimation of the pro-inflammatory diet may exist due to the unmeasured effect of salt intake. Thus, in this study, we aimed to examine how pro-inflammatory diet is associated with the long-term risk of all-cause and CVD mortality in a representative Japanese population.

METHODS

A national nutrition survey was conducted throughout Japan in 1980. After considering the exclusion criteria, 9284 individuals (56% women aged 30-92 years) were included in this study. In total, 20 dietary parameters derived from 3-day weighed dietary records were used to calculate the dietary inflammatory index (DII). The causes of death were monitored until 2009. The Cox proportional hazards model was used to determine multivariable-adjusted hazard ratios (HRs). Stratified analysis according to salt intake level was also performed.

RESULTS

Compared with the lowest quartile of DII, multivariable-adjusted HRs (95% confidence intervals) in the highest quartile were 1.28 (1.15, 1.41), 1.35 (1.14, 1.60), 1.48 (1.15, 1.92), 1.62 (1.11, 2.38), and 1.34 (1.03, 1.75) for all-cause mortality, CVD mortality, atherosclerotic CVD mortality, coronary heart disease mortality, and stroke mortality, respectively. Stratified analysis revealed stronger associations among individuals with higher salt intake.

CONCLUSIONS

As per our findings, a pro-inflammatory diet was determined to be positively associated with the long-term risk of all-cause and CVD mortality in a representative Japanese population. Thus, considering both salt intake and pro-inflammatory diet is deemed crucial for a comprehensive assessment of CVD risk.

Association Between the Dietary Inflammatory Index and the Risk of Fracture in Chinese Adults: Longitudinal Study

BACKGROUND

Chronic inflammation plays a crucial role in tissue injury, osteoporosis, and fracture. The dietary inflammatory index (DII) is a tool for assessing the potential for inflammation in the diet. However, the association between the DII and fractures remains controversial from previous studies.

OBJECTIVE

We aimed to explore the correlation between the DII and fracture risk in Chinese adults.

METHODS

We included 11,999 adults (5519 men and 6480 women) who were a part of the China Health and Nutrition Survey (1997-2015) prospective cohort. A 3-day, 24-hour meal review method was used to calculate the DII score. The fractures were identified using a questionnaire. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% CIs for fractures. Subgroup, sensitivity, and restricted cubic spline analyses were performed.

RESULTS

During the 18 years of follow-up (median follow-up 9.0 years), 463 men and 439 women developed fractures. The median DII score was 0.64 (IQR -1.74 to 1.46) for the total sample, 0.75 (IQR -1.68 to 1.50) for men, and 0.53 (IQR -1.79 to 1.42) for women. The DII score had a positive correlation with the risk of fracture among women but not among men. For men, after adjusting for covariates, the HRs for quintiles of DII were 1, 0.96 (95% CI 0.66-1.41), 1.05 (95% CI 0.74-1.49), 0.89 (95% CI 0.62-1.26), and 0.94 (95% CI 0.67-1.34; trend: P=.62). The HRs for women were 1, 1.13 (95% CI 0.72-1.79), 1.24 (95% CI 0.83-1.86), 1.51 (95% CI 1.02-2.22), and 1.62 (95% CI 1.10-2.39; trend: P=.004). The restricted cubic spline analysis showed a significant association between fracture risk and DII score in women (overall association: P=.01); as the DII scores were >0.53, HRs showed a significant upward trend. Women aged <50 years or who are nonsmokers, who are nondrinkers, or with nonabdominal obesity had a positive association between fracture risk and the DII score. In sensitivity analyses, after excluding people with diabetes or hypertension, there was still a positive association between fracture risk and the DII score in women. Among the DII components, the DII scores of protein (trend: P=.03), niacin (trend: P=.002), and iron (trend: P=.02) showed significant associations with the risk of fracture in women.

CONCLUSIONS

Proinflammatory diet consumption increased the fracture risk in Chinese women aged <50 years. The high consumption of anti-inflammatory foods and low consumption of proinflammatory foods may be an important strategy to prevent fractures in women.

Association between dietary inflammatory index and atherosclerosis cardiovascular disease in U.S. adults

Objective

To evaluate the association between dietary inflammatory index (DII) and Atherosclerotic cardiovascular disease (ASCVD) among U.S. adults.

Methods

We collected data from National Health and Nutrition Examination Survey (NHANES) between 1999 and 2018. Adults who reported complete information to diagnose ASCVD and calculate DII were included. We used three models to differentially adjust the covariates, including age, sex, race or ethnicity, education level, smoking status, poverty, insurance, body mass index, hyperlipemia, hypertension, and diabetes. Logistic regression was used to estimate the Odds Ratio (OR) and 95% confidence interval (95% CI) for ASCVD grouped by DII deciles. We additionally conducted spline smoothing with the generalized additive model (GAM) and the log-likelihood ratio to examine the non-linear relationship between DII and ASCVD. If exists, the segmented linear regression will be used to detect the cutoff point. The subgroup analyses were stratified by various atherosclerotic cardiovascular diseases (i.e., CHD, angina, heart attack, and stroke) and sex.

Results

A total of 48,733 participants (mean age, 47.13 ± 0.19 years) with 51.91% women were enrolled, of which 5,011 were diagnosed with ASCVD. In the crude model, participants in the five highest deciles (D6, 7, 8, 9, and 10) of DII score had a significantly higher risk of having ASCVD compared to those in the first decile. In the fully adjusted model, those in the tenth decile [OR = 1.47, 95% CI = (1.18,1.84)] of DII had a significantly increased risk of ASCVD compared to the first decile. Notably, when DII is above 3, the ASCVD risk increased by 41% for each one increase in DII [OR = 1.41, 95% CI = (1.15,1.73)]. This relationship was more pronounced in females.

Conclusion

Our study revealed a positive and non-linearly association between DII and ASCVD in U.S. adults. This relationship was more pronounced in females. The findings provide a reference for future research and diet recommendations.

Relationship between the Dietary Inflammatory Index Score and Cytokine Levels in Chinese Pregnant Women during the Second and Third Trimesters

The impact of dietary inflammatory potential on serum cytokine concentrations in second and third trimesters of Chinese pregnant women is not clear. A total of 175 pregnant women from the Tianjin Maternal and Child Health Education and Service Cohort (TMCHESC) were included. The dietary inflammatory index (DII) was calculated based on 24-h food records. Serum tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), IL-6, IL-8, IL-10, C-reactive protein (CRP), and monocyte chemoattractant protein-1 (MCP-1) levels in the second and third trimesters were measured. The mean DII scores (mean ± SD) were -0.07 ± 1.65 and 0.06 ± 1.65 in the second and third trimesters, respectively. In the third trimester, IL-1β (p = 0.039) and MCP-1 (p = 0.035) levels decreased and then increased with increasing DII scores. IL-10 concentrations decreased in pregnant women whose DII scores increased between the second and third trimesters (p = 0.011). Thiamin and vitamin C were negatively correlated with MCP-1 (β = -0.879, and β = -0.003) and IL-6 (β = -0.602, and β = -0.002) levels in the third trimester. In conclusion, the DII score had a U-shaped association with cytokine levels during the third trimester. Changes in DII scores between the second and third trimesters of pregnancy were correlated with cytokine levels during the third trimester.

Association between the dietary inflammatory index and disability in Japanese older people

OBJECTIVES

To examine the demographic and lifestyle characteristics related to the dietary inflammatory index (DII™) score and to evaluate the association between DII score and disability among older people in Japan.

DESIGN

Cross-sectional design. The DII score was calculated from nutrient intake information obtained from a FFQ. Disability was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence questionnaire. Overall disability and disability in each component of everyday competence, that is, instrumental activities of daily living (IADL), intellectual activities and social participation, were assessed. Those with a deficit in one or more activities were defined as disabled.

SETTING

Five non-urban areas in Japan.

PARTICIPANTS

A total of 1642 Japanese older people aged 65 years or older.

RESULTS

Women, residents of Oga-shi, and those with a higher education and greater frequency of shopping followed a more anti-inflammatory diet, while those living alone and residents of Minamiawaji-shi had higher dietary inflammation. A pro-inflammatory diet was associated with higher odds of overall disability and disability in each component of competence: overall disability, OR (95 % CI) = 1·26 (1·16, 1·36); IADL disability, OR (95 % CI) = 1·16 (1·07, 1·26); disability in intellectual activities, OR (95 % CI): 1·30 (1·20, 1·40); and disability in social participation, OR (95 % CI) = 1·20 (1·11, 1·29).

CONCLUSIONS

Sex, living alone, education, frequency of shopping and area of residence were shown to be determinants of DII score in Japanese older people. DII score was positively associated with disability.

Influence of Nutritional Intakes in Japan and the United States on COVID-19 Infection

The U.S. and Japan are both democratic industrialized societies, but the numbers of COVID-19 cases and deaths per million people in the U.S. (including Japanese Americans) are 12.1-times and 17.4-times higher, respectively, than those in Japan. The aim of this study was to investigate the effects of diet on preventing COVID-19 infection. An analysis of dietary intake and the prevalence of obesity in the populations of both countries was performed, and their effects on COVID-19 infection were examined. Approximately 1.5-times more saturated fat and less eicosapentaenoic acid/docosahexaenoic acid are consumed in the U.S. than in Japan. Compared with food intakes in Japan (100%), those in the U.S. were as follows: beef 396%, sugar and sweeteners 235%, fish 44.3%, rice 11.5%, soybeans 0.5%, and tea 54.7%. The last four of these foods contain functional substances that prevent COVID-19. The prevalence of obesity is 7.4- and 10-times greater in the U.S. than in Japan for males and females, respectively. Mendelian randomization established a causal relationship between obesity and COVID-19 infection. Large differences in nutrient intakes and the prevalence of obesity, but not racial differences, may be partly responsible for differences in the incidence and mortality of COVID-19 between the U.S. and Japan.

Association between inflammatory potential of the diet and sarcopenia/its components in community-dwelling older Japanese men

PURPOSE

Chronic inflammation is a pathophysiological cause of age-related diseases including sarcopenia. However, limited data are available on the association between the diet-derived inflammation and sarcopenia. Here, using the Dietary Inflammatory Index (DII), we examined the associations between inflammatory potentials of the diet, sarcopenia/its components, and serum inflammatory markers.

MATERIALS AND METHODS

This cross-sectional study was performed in 2014 among 1,254 community-dwelling older adults. Energy-adjusted DII score (E-adjusted DII) was calculated using a self-administered diet history questionnaire. Sarcopenia/its components was determined according to the Asian Working Group for Sarcopenia. Serum interleukin (IL)-1β, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)α, and high-sensitivity C-reactive protein (hsCRP) were measured.

RESULTS

The mean of E-adjusted DII was 0.13±2.1 (-4.92~5.29) in participants (74.6±5.5 y). After adjustment of confounders, men in the highest tertile of the E-adjusted DII showed a 2.89-times (95% CI: 1.04-8.04) higher risk of sarcopenia than those in the lowest tertile. Regarding its components (low muscle mass/strength/function), men in the highest tertile did not have significantly greater odds, respectively. Intriguingly, when the E-adjusted DII was calculated only based on anti-inflammatory food parameters, men who did not consume food with anti-inflammatory properties scored high E-adjusted DII and were significantly associated with sarcopenia in the highest tertile (OR: 2.96; 95% CI: 1.06-8.93). Higher serum hsCRP levels were seen in sarcopenic men with the highest E-adjusted DII (p=0.036).

CONCLUSIONS

These results suggest that a diet with pro-inflammatory potential is associated with the risk of sarcopenia. Further investigations whether anti-inflammatory diet could reduce its risk are needed.

A personalised diet study: The interaction between ApoA2 -265T > C polymorphism and dietary inflammatory index on oxidative and inflammatory markers and lipid profile in patients with type 2 diabetes mellitus: A cross-sectional study

BACKGROUND

This study aimed to investigate the interaction between dietary inflammatory index (DII) and apolipoproteinA2 265T > C (ApoA2 -265T > C) polymorphism on inflammatory and oxidative markers and lipid profile in type 2 diabetes mellitus (T2DM) patients.

METHODS

In this cross-sectional study, 157 patients with T2DM were recruited. A food-frequency questionnaire was used for DII calculation. Inflammatory, oxidative and lipid biomarkers were measured. Real-time polymerase chain reaction (PCR) method was used for ApoA2 genotyping determination.

RESULTS

In the current study, serum 8-iso-PGF2α and CRP were significantly higher, and serum SOD activity was significantly lower in subjects with CC genotype than TT homozygous in both crude and adjusted (for DII and AAs intake) models. Also, C-allele carriers compared with people with TT genotype had lower PTX3 in both models. In addition, serum TG level was significantly higher in TC genotype than TT homozygous in adjusted model. Moreover, subjects with CC homozygous and high DII level had significantly higher 8-iso-PGF2α level compared to those with TT genotype and low DII (reference group) in adjusted (for BMI, age, sexuality and AAs intake) model. Our results also showed that in TC genotypes with low DII and CC homozygous with both low and high DII, PTX3 concentrations were significantly lower than the reference group. In addition, CC carriers with low DII had significantly higher CRP level compared to the reference group. Moreover, our results reported significant higher TG in TC genotype with low DII and also higher total cholesterol level in CC genotype with low DII than the reference group.

CONCLUSION

These findings indicate that CC genotype might predict higher inflammatory and oxidative status level compared to T allele carriers. An inflammatory diet may accelerate oxidative stress in subjects with CC genotype. However, the association between APOA2 -265T > C polymorphism and inflammation and lipid profile is presented less modifiable by DII.

"Association between dietary inflammatory index (DII) and risk of irritable bowel syndrome: a case-control study"

Background

Pathophysiology of IBS is not well recognized; however, several studies have shown the possible relationship between diet and risk of IBS. We assessed the ability of the dietary inflammatory index (DII) to predict the risk of IBS.

Methods

The subjects were 155 IBS cases and 310 age- and sex-matched healthy controls (aged ≥18 years). The participants were recruited from June, 2019 to March, 2020. IBS was recognized using the Rome IV criteria. DII score was computed based on dietary intake using a 168-item FFQ. The DII score was calculated based on energy-adjusted amounts of nutrients using residual method. Logistic regression models were used to estimate multivariable odds ratios (ORs).

Results

The mean DII score was significantly higher among IBS patients in comparison to healthy controls (0.78 ± 2.22 vs. − 0.39 ± 2.27). In crude model, increase in DII as continuous variable was associated with a significant increase in the risk of IBS (OR (95% CI): 1.26 (1.1–15.38)). Furthermore, the association remained significant even after adjusting for age and sex (OR (95% CI): 1.28 (1.1–17.41)) and after multivariate adjustment (OR (95% CI): 1.38 (1.2–1.56)). In crude, age and sex adjusted and multivariate-adjusted models subjects in fourth quartile of DII had higher OR in comparison to subjects in first quartile.

Conclusions

This study showed a possible positive association between a pro-inflammatory diet and the risk of IBS. Thus, encouraging intake of more anti-inflammatory dietary factors and reducing intake of pro-inflammatory factors may be a strategy for reducing risk of IBS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00721-5.

Decline in independence after three years and its association with dietary patterns and IADL-related factors in community-dwelling older people: an analysis by age stage and sex

Background

Few studies have shown age stage and sex differences in the association among dietary patterns and various health factors related to disability in older people. This study aimed to reveal the differences of characteristics, including several dietary patterns, associated with a decline in independence over 3 years in community-dwelling independent older people. Specifically, we examined data by age stage, for people between 65 and 75 years (earlier-stage) and people aged 75 years or above (later-stage), and sex.

Methods

We conducted a nationwide longitudinal study of 25 Japanese prefectures from 2013 to 2016; 2250 participants’ complete data (1294 men and 956 women) were analyzed. Independence was evaluated based on instrumental activities of daily living (IADL) scores (maximum = 12). Dietary patterns were derived from a principal component analysis of the seven food groups. Baseline IADL-related factors linked to independence 3 years later were selected. Multiple logistic regression analysis for having low independence—without a full score of IADL 3 years after baseline—was conducted, adjusted for baseline IADL scores. Finally, to compare differences among age stage and sex groups, we used Multiple-Group Path Analysis.

Results

Participants with a full IADL score 3 years later were classified as high independence (69.6%), and those without the full score were classified as low independence (30.4%). Only the later-stage older peoples’ proportion of low independence 3 years later was significantly higher than those at baseline. A high meat frequency pattern was associated with a significantly higher risk of decline in independence 3 years later in later-stage older women. The earlier-stage older people showed that 18.5 ≤ BMI < 25 was associated with a lower risk, referring to BMI < 18.5. In the later-stage, exercising three or more times a week with enjoyment and fulfillment was associated with a significantly lower risk.

Conclusions

The IADL disability in older people aged 75 and over showed a rapid change. The different characteristics associated with the risk of decline in independence among age stage and sex were revealed. Targeting age stage and sex separately for community-based comprehensive supportive strategies would be necessary for a long life globally.

Dietary Inflammatory Index Is Associated With Inflammation in Japanese Men

Background: Dietary components are known to affect chronic low-grade inflammation status. The dietary inflammatory index (DII®) was developed to measure the potential impact of a diet on an individual's inflammatory status, and it has been validated mainly in Western countries.

Objective: This study aimed to examine the validity of the energy-adjusted DII (E-DII^TM) using high-sensitivity C-reactive protein (hs-CRP) concentration in Japanese men and women.

Methods: In total, 6,474 volunteers from a cancer-screening program (3,825 men and 2,649 women) completed a food frequency questionnaire (FFQ) and their hs-CRP concentrations were evaluated. E-DII scores were calculated on the basis of 30 food parameters derived from the FFQ. Higher E-DII scores reflect a greater pro-inflammatory potential of the diet. The associations between E-DII quartiles and hs-CRP concentration were assessed using regression models adjusted for age, body mass index, smoking status, and amount of physical activity.

Results: Mean E-DII in men and women was + 0.62 ± 1.93 and −1.01 ± 2.25, respectively. The proportion of men and women who had hs-CRP concentration >3 mg/L was 4.7 and 3.1%, respectively. A significant positive association was observed between E-DII score and hs-CRP concentration in men; geometric mean of hs-CRP concentration in the lowest and highest E-DII quartiles was 0.56 mg/L and 0.67 mg/L (P_trend < 0.01), respectively. The odds ratio (95% confidence interval) of having an elevated hs-CRP concentration (>3 mg/L) was 1.72 (1.10–2.67) in the highest E-DII quartile (P_trend = 0.03) in men. However, no association was observed between E-DII score and hs-CRP concentration in women, except in those not taking prescription medications.

Conclusions: DII was associated with inflammation status in Japanese men, but the association was limited in Japanese women.

Meta-analysis of the relationship between Dietary Inflammatory Index and esophageal cancer risk

INTRODUCTION

Diet is closely related to the occurrence of esophageal cancer (EC). Dietary Inflammatory Index (DII), as a novel index that describes the inflammatory potential of diet, was widely used in many diseases.

OBJECTIVE

To systematically analyze the relationship between DII and the risk of esophageal cancer.

METHODS

We mainly searched relative studies in PubMed, Cochrane library, Web of Science, and other literature database. The random-effect model was used for meta-analysis, and subgroup analysis and sensitivity analysis were used to detect the origin of heterogeneity.

RESULTS

We finally obtained 6 articles (8 studies). All studies were case-control studies which consisted of 1961 cases and 3577 controls. In this study, compared with the lowest DII category, the highest DII category had a higher risk of esophageal cancer, and the pooled odds ratio (OR) of the 8 studies were 2.54 (95% confidence interval (CI): 1.90-3.40; I = 65.7%, P = .005). Furthermore, regardless of the differences in published year, DII components, geographic location, and study quality, there was still an increased risk of esophageal cancer in the highest DII category compared with the lowest DII category.

CONCLUSIONS

Our results inferred that DII was positively correlated with esophageal cancer risk and it could be used as a tool to predict the esophageal cancer risk and evaluate human health.