Dietary Insulin Index and Dietary Insulin Load in Relation to Metabolic Syndrome: The Shahedieh Cohort Study.

BACKGROUND

Insulin resistance and hyperinsulinemia are involved in the etiology of metabolic syndrome (MetS) and its components.

OBJECTIVE

The current study assessed the association of dietary insulin load (DIL) and dietary insulin index (DII) with the odds of having MetS among a large population of Iranian adults.

DESIGN

This study was a cross-sectional analysis of the Shahedieh cohort study, which began in 2015-2016 and continues to the present day.

PARTICIPANTS/SETTING: A total of 5,954 Iranian adults, aged 35 to 70 years, were included in the current analysis. To collect dietary data, the validated block-format 120-item semiquantitative Food Frequency Questionnaire was used. MetS was defined using the criteria belonging to the Iranian-modified National Cholesterol Education Program for Adults.

MAIN OUTCOME MEASURES

Enzymatic colorimetric tests were used to measure fasting blood glucose, triglyceride, and high-density lipoprotein cholesterol concentrations; blood pressure and waist circumference were measured using the standard protocols.

STATISTICAL ANALYSIS

Binary logistic regression with adjusted models was used to examine the association of DIL and DII with MetS.

RESULTS

After taking potential confounders into account, moderate DIL was associated with increased odds of MetS in men, meaning that men in the third quartile of DIL had 61% greater odds for having MetS compared with those in the first quartile (odds ratio [OR]: 1.61, 95% confidence interval [CI]: 1.02-2.54). Such a significant association was not seen for DII. In women, DIL was significantly associated with increased odds of developing MetS. After controlling for potential confounders, women in the top quartile of DIL had 77% greater odds for having MetS compared with women in the bottom quartile (OR: 1.77; 95% CI: 1.08-2.91). This significant positive association was also seen for DII, such that a higher score of DII was associated with 41% greater odds of MetS (OR: 1.41, 95% CI: 1.08-1.83).

CONCLUSIONS

Adherence to a diet with a high DIL and DII is associated with greater odds of having MetS in women. Also, moderate DIL was associated with increased odds of MetS in men.