Abstract / Summary
Iranian studies have examined the Lifelines Diet Score (LLDS) in relation to selected anthropometric and metabolic phenotypes, but its association with the Atherogenic Index of Plasma (AIP) and a broader set of correlated cardiometabolic indices in adults with excess body weight remains incompletely characterized. This study examined the association between diet quality, assessed using the Lifelines Diet Score, and the Atherogenic Index of Plasma (AIP) as the primary cardiometabolic outcome among overweight and obese Iranian adults. The triglyceride–glucose (TyG) index, Lipid Accumulation Product (LAP), A Body Shape Index (ABSI), Body Roundness Index (BRI), and Visceral Adiposity Index (VAI) were evaluated as correlated secondary outcomes reflecting complementary aspects of glycemic, atherogenic, and adiposity-related risk. In this cross-sectional study, 672 adults were recruited from outpatient endocrine clinics in Zanjan, Iran. Habitual dietary intake over the previous year was assessed using a validated 168-item food frequency questionnaire, and LLDS was calculated from 12 food groups. Participants were categorized into LLDS tertiles. Multivariable linear regression was used to estimate unstandardized regression coefficients (β) and 95% confidence intervals. Model 2, adjusted for age, sex, education level, smoking status, physical activity, and total energy intake, was the primary adjusted model. Model 3 added baseline clinical-status and medication variables and was used only as a clinical sensitivity analysis. Participants in the highest LLDS tertile had lower BMI, waist circumference, fasting blood glucose, triglycerides, liver enzymes, and cardiometabolic risk indices than those in the lowest tertile. In Model 2, the primary adjusted model, the highest versus lowest LLDS tertile was associated with lower AIP (unstandardized β = -0.041; 95% CI: -0.063, -0.019; P < 0.001). Inverse associations were also observed for TyG, LAP, ABSI, BRI, and VAI. The AIP association remained inverse in Model 3, the clinical sensitivity model (unstandardized β = -0.036; 95% CI: -0.058, -0.014; P = 0.001). Higher LLDS was associated with lower AIP and lower values of several correlated secondary cardiometabolic indices in overweight and obese Iranian adults. Because the study is cross-sectional, these associations do not establish temporal or causal relationships. Prospective studies are needed to determine their longitudinal and clinical significance. Not applicable.