Association of Dietary Inflammatory Index with Serum IL-6, IL-10, and CRP Concentration during Pregnancy

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.

Maternal pre-pregnancy diet and prenatal depression: the mediating role of pre-pregnancy weight status and prenatal inflammation

Depression is a common prenatal psychological complication. We aimed to investigate if maternal pre-pregnancy diet can impact prenatal depressive symptoms and the mediating role of pre-pregnancy BMI and inflammation. We used data (N 1141) from the Alberta Pregnancy Outcomes and Nutrition cohort study. We calculated Mediterranean diet adherence (MED) and dietary inflammatory index (DII) scores using data from pre-pregnancy FFQ. In the third-trimester, we assessed depressive symptoms using Edinburgh Postpartum Depression Scale (EPDS) and inflammation through serum C-reactive protein (CRP) levels. BMI was calculated from self-reported pre-pregnancy weight. Race-stratified analyses (white and people of colour) were run. We observed no association between MED or DII tertiles and depressive symptoms. However, white participants in the MED tertile-3 had lower risk of depression (EPDS < 10) compared with tertile-1 (OR = 0·56, 95 % CI, 0·33, 0·95). White individuals in MED tertile-3 had lower BMI (MD = -1·08; 95 % CI, -1·77, -0·39) and CRP (MD = -0·53; 95 % CI, -0·95, -0·11) than tertile-1, and those in DII tertile-2 (MD = 0·44; 95 % CI, 0·03, 0·84) and tertile-3 (MD = 0·42; 95 % CI, 0·01, 0·83) had higher CRP than tertile-1. Among people of colour, neither MED nor DII was associated with BMI or CRP, but BMI was negatively associated with depressive symptoms (β = -0·25, 95 % CI, -0·43, -0·06). We found no association between diet and depressive symptoms through BMI or CRP, in either race. Pre-pregnancy diet might affect the risk of prenatal depression in a race-specific way. Further research is required to explore the racial differences in the association between maternal diet and prenatal depressive symptoms/depression risk.

Meta-analysis of the association between dietary inflammation index and C-reactive protein level

BACKGROUND

There have been various clinical studies on the effect of dietary inflammatory index (DII) on circulating inflammatory biomarkers, but the findings from these are contradictory. The aim of the present study was to clarify any association.

METHODS

The PubMed, Embase, Web of Science and Cochrane Library database were searched for relevant studies from inception February 2021. There were no language restrictions. Two investigators independently selected eligible studies. Measures of association were pooled by using an inverse-variance weighted random-effects model. The heterogeneity among studies was examined using the I2 index. Publication bias, sensitivity and subgroup analyses were also performed.

RESULTS

A total of 13 cross-sectional studies were identified, involving 54,813 participants. The adjusted pooled OR of C-reactive protein (CRP) levels for the highest (the most pro-inflammatory diet) versus lowest (the most anti-inflammatory diet) DII categories was 1.25 (95% CI: 1.18-1.32; I2  = 59.4%, P = .002). Subgroup analyses suggested the main source of study heterogeneity was the geographic area (Asia, Europe, or USA) and CRP levels (>3 mg/L or others). This finding was remarkably robust in the sensitivity analysis.

CONCLUSION

The meta-analysis suggests that more pro-inflammatory DII scores were positively associated with CRP, the DII scores can be useful to assess the diet inflammatory properties and its association with low-grade inflammation.

Impact of Bifidobacterium longum1714® on maternal cytokine response in peripheral blood mononuclear cells

PURPOSE

The maternal immune system is implicated in adverse pregnancy outcomes. Manipulation of maternal immune response by probiotics holds potential to reduce pregnancy complications. The MicrobeMom2 study investigates the impact of probiotic supplementation on maternal immune responses to pathogen associated molecular patterns (PAMPs) in peripheral blood mononuclear cells (PBMCs) during pregnancy.

METHODS

This double-blinded randomised-controlled trial involved oral supplementation of Bifidobacterium longum subsp. longum 1714® (B. longum 1714; daily ingestion of a minimum of 1x109 colony forming units) or placebo from 16 to 20-weeks' gestation until delivery in healthy pregnant women. The primary outcome was a change in IL-10 production, after stimulation with Lipopolysaccharide (LPS) or anti-CD3/28/2, in PBMCs isolated from blood samples taken at baseline (11-15 weeks' gestation) and late pregnancy (28-32 weeks' gestation) after 48 h incubation. 68 subjects were needed (34ineachgroup) for 80 % power at an alpha significance of 0.05 to detect differences in IL10.

RESULTS

72 women (mean ± SD age 33.17 ± 4.53 years and median (25th, 75th centile) body mass index 24.93 (21.93, 27.57 kg/m2)) were recruited with primary outcome data. Using LPS, late pregnancy fold change in IL-10 in PBMCs after 48 h incubation was median (25th, 75th centile) 88.45 (4.88, 488.78) in the intervention, 24.18 (6.36, 141.17) in the control group, p = 0.183. Using anti-CD3/28/2, values were 189.69 (425.96, 866.57),148.74 (31.67, 887.03) in intervention and control groups, respectively, p = 0.506. No significant differences were observed between the two groups.

CONCLUSION

Maternal antenatal supplementation with B. longum 1714 did not alter cytokine production by maternal PBMCs in response to PAMPs or anti-CD3/28/2.

TRIAL REGISTRATION NUMBER

ISRCTN registry ISRCTN43013285.

Association between serum interleukin-6, leptin and insulin in gestational diabetes mellitus - a cross- sectional study

Purpose

Gestational diabetes mellitus (GDM) is a state of leptin resistance which develops a vicious cycle of hyperinsulinemia and hyperleptinemia leading to aggravation of an inflammatory situation. This study was done to find out the association between IL-6, leptin and insulin in gestational diabetes among North Indian women.

Method

This cross-sectional study included 100 GDM, 100 non-GDM and 50 non-pregnant women. DIPSI (Diabetes in Pregnancy Study Group India) criteria was used for screening GDM among pregnant women. GDM and non-GDM pregnant women were further categorized into three groups according to the trimester of pregnancy. Serum IL-6, leptin and insulin were measured in all the enrolled women.

Results

Serum IL-6 levels were significantly higher among GDM women as compared to non-GDM and non-pregnant women. Although the mean serum leptin and insulin levels were higher in GDM, but the difference was not statistically significant. When GDM and non-GDM women were categorized into three trimester, serum leptin levels were found to be significantly higher in 3rd trimester (p < 0.002) and IL-6 in 1st trimester (p < 0.017) among GDM women. No correlation was found between serum IL-6, leptin and insulin in GDM.

Conclusion

Absence of any significant association between leptin and IL-6 signifies that leptin may not be associated with inflammation in gestational diabetes. However, IL-6 may serve as an early marker for screening glucose intolerance during pregnancy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01188-3.

Dietary Inflammatory Index during Pregnancy and Congenital Heart Defects

The relationship between diet-related inflammation during pregnancy and congenital heart defects (CHD) is unclear. This study attempted to investigate the association between the dietary inflammation index (DII) during pregnancy, reflecting the overall inflammatory potential of the maternal diet, and CHD in Northwest China. A case-control study with 474 cases and 948 controls was performed in Xi'an City, China. Eligible women awaiting delivery were recruited, and their dietary and other information during pregnancy was collected. Logistic regression models were applied to estimate the risk of CHD in association with DII. The maternal DII ranged from -1.36 to 5.73 in cases, and 0.43 to 5.63 in controls. Pregnant women with per 1 higher DII score were at 31% higher risk of fetal CHD (OR = 1.31, 95%CI = 1.14-1.51), and the adjusted OR (95%CI) comparing the pro-inflammatory diet group with the anti-inflammatory diet group was 2.04 (1.42-2.92). The inverse association of maternal DII score with CHD risk was consistent across various subgroups of maternal characteristics. Maternal DII in pregnancy had good predictive value for CHD in offspring, with the areas under the receiver operating characteristic curve higher than 0.7. These findings suggested that avoiding a pro-inflammatory diet in pregnancy should be emphasized in the prevention of CHD.

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.

Effect of dietary n-6: n-3 Poly-Unsaturated fatty acids ratio on gestational diabetes mellitus: a prospective cohort

OBJECTIVE

The aim of this study was to investigate the relationship between dietary n-6: n-3 poly-unsaturated fatty acids (PUFA) ratio and the risk of developing gestational diabetes mellitus (GDM).

MATERIALS AND METHODS

A total of 100 pregnant women were prospectively included for detailed information on dietary intake at 16-18 weeks evaluated using a three-day food record, and subsequent GDM diagnosis at 24-28 weeks. Participants were divided into two groups for analysis: GDM group (n = 22) and control group (n = 78) based on oral glucose tolerance test results performed between 24 and 28 weeks.

RESULTS

The average dietary n-6: n-3 PUFA ratio in the control group was 5.63 ± 2.12 and that in the GDM group was 8.35 ± 3.45, within a significant difference (p < .05). A significant difference was associated with a higher dietary n-6: n-3 PUFA ratio and GDM (adjusted odds ratio = 4.29, 95%confidence interval:1.303, 14.124).

CONCLUSIONS

Higher dietary n-6: n-3 PUFA ratio was associated with higher odds of GDM. Given the small sample, further studies are required to confirm this hypothesis.

Longitudinal changes in circulating concentrations of inflammatory markers throughout pregnancy: are there associations with diet and weight status?

The natural inflammation occurring during pregnancy can, under certain conditions, be associated with adverse pregnancy outcomes. This study aimed to: 1) quantify changes in circulating concentrations of leptin, adiponectin, interleukin-6 (IL-6) and C-reactive protein (CRP) across trimesters of pregnancy, according to pre-pregnancy body mass index (ppBMI); and 2) examine the trimester-specific associations between the inflammatory markers' concentrations, a Mediterranean diet score (MDS) and the dietary inflammatory index (DII). We measured leptin, adiponectin and IL-6 by ELISA, and CRP by high-sensitivity immunonephelometry, in blood samples from 79 pregnant women (age: 32.1 ± 3.7 years; ppBMI: 25.7 ± 5.8 kg/m2). Three web-based 24h recalls were completed at each trimester and used to compute the MDS and the DII. CRP concentrations remained stable across trimesters, whereas concentrations of leptin and IL-6 increased, and adiponectin concentrations decreased (p<0.001). Changes in leptin and adiponectin concentrations also differed according to ppBMI categories (p<0.05). As for the dietary scores, the only significant association was observed in the second trimester between leptin concentrations and the MDS (r=-0.26, p<0.05). In conclusion, ppBMI and the progression of pregnancy itself probably supplant the potential associations between diet and the inflammation occurring during that period. Novelty: • Circulating leptin and IL-6 concentrations increased across trimesters whereas CRP was stable, and adiponectin decreased. • Variations in circulating leptin and adiponectin concentrations differed by ppBMI categories. • Very few associations were observed between dietary scores and inflammatory markers.