Association of Dietary Insulin Index and Load With Glucose Homeostasis Markers, C‐Peptide and Novel Metabolic Indices ( TyG ‐ BMI and METS ‐ IR ) in Physically Active Young Population

Abstrakt

ABSTRACT Background DII and DIL reflect the insulinemic potential of diet, but their associations with glucose homeostasis, C‐peptide and metabolic indices in physically active young adults are unclear. Methods This cross‐sectional study included 221 apparently healthy, physically active adults aged 18–35 years recruited from sports clubs in Tabriz, Iran. Dietary intake was assessed using a validated food frequency questionnaire, and DII and DIL were calculated. Anthropometric, demographic and biochemical parameters were measured. Multiple linear regression models were used to evaluate associations of DII and DIL tertiles with fasting blood sugar, insulin, HOMA‐IR, QUICKI, C‐peptide, METS‐IR and TyG‐BMI, adjusting for potential confounders. Results In fully adjusted models, participants in the highest DIL tertile had significantly lower METS‐IR compared with the lowest tertile (β = −1.12; 95% CI: −2.19, −0.05; p = 0.04). In multivariable analysis, lower C‐peptide levels were observed in the second DIL tertile (β = −0.63; 95% CI: −1.25, −0.19; p = 0.04), whereas the third tertile ( p = 0.15) and the overall trend across tertiles ( p ‐trend = 0.09) were not statistically significant. DII showed no significant associations with most metabolic markers, except for a borderline trend with QUICKI. Conclusion DIL may be more closely related than DII to glycemic profile in physically active young adults. These findings suggest that regular physical activity may attenuate adverse metabolic responses to diets with higher insulinemic load.