The Association between Energy-Adjusted Dietary Inflammatory Index, Body Composition, and Anthropometric Indices in COVID-19-Infected Patients: A Case-Control Study in Shiraz, Iran

Dietary inflammatory index could increase the risk of sarcopenia in patients with chronic kidney disease

Using a system that incorporates a variety of food items rather than focusing on individual components can aid in assessing the inflammatory effects of a diet on disease outcomes such as chronic kidney disease (CKD). Therefore, we decided to investigate the association between dietary inflammatory index (DII) and the risk of protein-energy wasting (PEW) and sarcopenia in patients with CKD. In this cross-sectional study, 109 patients with CKD were selected from two clinics in Shiraz, Iran. The intake of individuals' diets was recorded using a validated 168-item food frequency questionnaire. Additionally, Asian Working Group for Sarcopenia (AWGS) guidelines were utilized to evaluate muscles' strength, mass, and function. Also, four International Society of Renal Nutrition and Metabolism (ISRNM) criteria (body mass index, intake of protein, albumin, and urine creatinine) were used  to diagnose PEW. Logistic regression was used to assess the association between DII and sarcopenia as well as PEW. The results showed that the intake of saturated fatty acids, trans fatty acids, niacin, beta-carotene, and vitamin C was significantly different between lower and higher DII groups. In the univariate model, higher odds of sarcopenia was observed by each unit increase in DII (odds ratio (OR) = 1.379, 95% confidence interval (CI): 1.042-1.824) and age (OR = 1.073, 95% CI: 1.017-1.132). Additionally, in the multivariate model, the association between DII and age with odds of sarcopenia remained significant (DII: OR = 1.379, 95% CI: 1.030-1.846 and age: OR = 1.063, 95% CI: 1.007-1.121). The current study suggests the possible role of pro-inflammatory foods in worsening muscle health, specifically sarcopenia, in CKD patients. Future longitudinal studies may reveal the causative nature of these correlations.

Association of dietary inflammatory index and the SARS-CoV-2 infection incidence, severity and mortality of COVID-19: a systematic review and dose-response meta-analysis

BACKGROUND

Several studies have reported the association between dietary inflammatory index (DII) and the SARS-CoV-2 infection risk, severity or mortality of COVID-19, however, the outcomes remain controversial.

OBJECTIVE

We sought to examine whether a dose-response association of DII and SARS-CoV-2 infection exists.

DESIGN

A dose-response meta-analysis was performed to investigate the association of DII and SARS-CoV-2 infection. We conducted a systematic search of PubMed, Embase and Web of Science up to March 15th, 2023. The odds ratios (OR) of DII and COVID-19 risk and severity were computed.

RESULTS

Totally, 5 studies were included (1 from UK and 4 from Iran), consisting of 197,929 participants with 12,081 COVID-19 cases. Although there was heterogeneity among studies, the results indicated that higher DII was independently related to higher SARS-CoV-2 infection incidence (OR = 1.57, 95% CI: 1.14, 2.17) and COVID-19 severity (OR = 1.11, 95% CI: 1.07, 1.15) but not COVID-19 mortality (risk ratio = 1.13, 95% CI: 1.00, 1.27). The incidence of SARS-CoV-2 infection increased by 31% for each 1-point increase in the E-DII (OR = 1.31, 95% CI: 1.20, 1.43).

CONCLUSIONS

This meta-analysis suggests that an elevated DII score is associated with increased SARS-CoV-2 infectious risk and severity of COVID-19. There were not enough studies on COVID-19 mortality. Further large prospective studies in different countries are warranted to validate our results.

The association between inflammatory and immune system biomarkers and the dietary inflammatory index in patients with COVID-19

Background

Inflammation and cytokine storm have been reported to be the main cause of acute symptoms of coronavirus disease (COVID-19). Diet-induced inflammation may affect the condition of patients with COVID-19. Therefore, this study aimed to investigate the relationship between disease severity, inflammatory and immune system biomarkers, and the dietary inflammatory index (DII) in patients with COVID-19.

Methods

This cross-sectional study was conducted on 500 adult patients with COVID-19. Patients were divided into mild, moderate, and severe conditions based on clinical and laboratory evidence. A validated food frequency questionnaire (FFQ) was used to determine DII and energy-adjusted DII (E-DII) scores. The serum C-reactive protein (CRP) level and blood cell count were measured for all patients. Multiple linear regression was used to explore the association between DII and E-DII and CRP, blood cell counts, and hospitalization in patients with COVID-19.

Results

Coronavirus disease (COVID-19) patients with higher DII had higher consumption of fat and carbohydrate and lower intakes of protein, anti-inflammatory nutrients, garlic, caffeine, tea, onion, and fiber (P < 0.05). There was a positive association between DII and CRP (β = 1.024, P < 0.001), hospitalization (β = 1.062, P < 0.001), WBC count (β = 0.486, P < 0.009), neutrophil count (β = 0.565, P < 0.001), and neutrophil-to-lymphocyte ratio (β = 0.538, P < 0.001) and a negative association between DII and the lymphocyte count (β = −0.569, P < 0.001). There was a positive association between E-DII and hospitalization (β = 1.645, P < 0.001), WBC count (β = 0.417, P < 0.02), and neutrophil-to-lymphocyte ratio (β = 0.35, P < 0.03).

Conclusion

There is a positive correlation between DII and inflammation, immune hyperactivation, and length of hospital stay in patients with COVID-19. Further longitudinal studies are necessary.