• The Association Between Energy-adjusted Dietary Inflammatory Index and Metabolic Syndrome: Fasa Adult Cohort Study (FACS)
  • Hossein Pourmontaseri,1 Matin Sepehrinia,2 Reza Homayounfar,3,* Mohammad Mehdi Naghizadeh,4
    1. 1. Student Research Committee, Fasa University of Medical Sciences, Fasa, Iran. 2. Projects Support Division, Medical Students Association, Fasa University of Medical Sciences, Fasa, Iran. 3. Shiraz Nutrition Interest Group, Bitab Enterprise, Shiraz, Iran.
    2. 1. Student Research Committee, Fasa University of Medical Sciences, Fasa, Iran. 2. Projects Support Division, Medical Students Association, Fasa University of Medical Sciences, Fasa, Iran. 3. Shiraz Nutrition Interest Group, Bitab Enterprise, Shiraz, Iran.
    3. National Nutrition and Food Technology Research Institute (WHO Collaborating Center), Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
    4. Non-Communicable Diseases Research Center, Fasa University of Medical Sciences, Fasa, Iran


  • Introduction: Metabolic Syndrome (MetS) serves as a combination of risk factors including low high-density lipoprotein-cholesterol and high fasting blood sugar, blood pressure, triglyceride, and waist circumference, that increase the probability of diabetes and cardiovascular disease. The prevalence of MetS has been reported between 20% and 45% and seems to have an incremental trend, reaching 53% in 2035. Improving lifestyle including a healthy diet and regular physical activity showed promising results for controlling MetS. Previous dietary interventions focused on decreasing energy intake, blood glucose, and triglyceride. Recent studies suggested that the anti-inflammatory nature of the Mediterranean diet has an effective role in MetS management. Also, inflammation plays an important role in the development and progression of obesity-related MetS and MetS complications such as cardiovascular diseases. The dietary inflammatory index (DII) was innovated to estimate the inflammatory potential of diet. As energy intake affects the inflammatory potential of diet, an energy-adjusted dietary inflammatory index (E-DII) was developed. Previous studies linked a pro-inflammatory diet with a higher risk of chronic diseases like diabetes, cancers, and cardiovascular diseases. Also, several studies investigated the association between DII and MetS. However, studies about the association of E-DII and MetS are scarce. The present study aimed to investigate the association between E-DII and MetS in the Fasa Adult Cohort Study (FACS).
  • Methods: This cross-sectional study was conducted on the FACS with 10,138 participants from Sheshdeh, Fasa, Iran. After excluding the participants with missing data, the remaining participants were divided into MetS and non-MetS. The sociodemographic characteristics, including, age (year), gender (men, women), ethnicity (Turkish, Arab, Fars, and others), marital status (single, married, widow, and divorced), occupation (having job or not), education (no education, primary school, secondary school, university), and physical activity (metabolic equivalent of tasks) was included. Also, the health status of participants including having cardiovascular disease, myocardial infarction, diabetes, hypertension, stroke, and fatty liver diseases were detected based on self-report, specialist diagnosis, medication, or recorded documents of participants. Anthropometric characteristics of each participant, including body mass index (kg/m2), waist, wrist, and hip circumference (cm), and systolic and diastolic blood pressure (mmHg) were measured and reported based on International Units. Fasting blood sugar (mg/dL), triglyceride (mmHg), and high-density lipoprotein-cholesterol (mmHg) were assessed using a plasma sample gathered at phase one and stored in the data bank of FACS. E-DII was calculated based on the recorded food frequency questionnaire. The MetS was assessed based on Adult Treatment Panel III criteria. The MetS is defined as having three or more out of these 5 items: 1) High waist circumference (>102 cm for men, > 88 cm for women); 2. High triglyceride (> 150 mg/dL); 3. low HDL-C (<40mg/dL for men and <50mg/dL for women); 4. High blood pressure (systolic >130mmHg or diastolic >85mmHg); 5. High fasting blood sugar (>100mg/dL). The data of the present study were recorded and analyzed in SPSS v.23. The qualitative and quantitative variables were reported as frequency (percent) and mean (standard deviation or standard error) or median (Quartile). Independent T-test and chi-square were used to compare the mean of quantitative and frequency of qualitative variables among MetS and non-MetS groups. The crude and adjusted association of EDII with MetS was investigated by logistic Regression (significant level: p-value<0.05).
  • Results: After exclusion, 10030 individuals (mean age of 48.6±10.0 years) including 4523 (45.1%) men were analyzed. The mean of EDII was -0.278±2.07, ranging from -6.5 to 5.6. Approximately 24% of participants had MetS. Individuals with MetS were more likely to be women, less educated, less physically active, and poor socioeconomically. However, smoking, opium, and alcohol consumption were significantly lower among individuals with MetS. They had a significantly higher rate of hypertension, myocardial infarction, diabetes, stroke, and fatty liver disease. The EDII was significantly associated with MetS (OR=1.55, 95%CI: [1.51, 1.59], p-value <0.001) and its components. Also, the result was consistent after adjusting for age, gender, education, physical activity, socioeconomic status, and smoking (OR=1.55, 95%CI: [1.51, 1.59], p-value < 0.001). The highest association was observed between EDII and high WC (OR =2.17, 95%CI: [2.08, 2.25], p-value = 0.000), as an indicator of obesity in MetS.
  • Conclusion: The pro-inflammatory diet is significantly associated with a higher risk of MetS. Therefore, an anti-inflammatory diet could prevent MetS and subsequently, its complications such as diabetes and cardiovascular diseases.
  • Keywords: health, nutrition, inflammation, metabolic syndrome