Development and Validation of the Accelerated Inflammatory-Metabolic Index (AIMI): A Composite Biomarker for Biochemical Assessment of Obesity-Associated Cardiometabolic Dysfunction

Abstract

Objective: To develop and internally evaluate the accelerated inflammatory-metabolic index, integrating malondialdehyde, total antioxidant capacity, superoxide dismutase, interleukin-6, and homeostatic model assessment of insulin resistance and compare its diagnostic performance with that of its individual components across the obesity spectrum.

Study Design: A cross-sectional study
Place and Duration of Study: This study was conducted at the School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran from 1st March 2026 to 31st May 2026.

Methods: 150 adults in five age-matched groups (n = 30 each): non-obese, overweight, obese, severely obese, and trained athletes were enrolled. Accelerated inflammatory-metabolic index = [malondialdehyde x interleukin-6 x homeostatic model assessment of insulin resistance] ÷ [total antioxidant capacity × superoxide dismutase].

Results: Accelerated inflammatory-metabolic index increased progressively across groups (F=187.4, p<0.0001, η2 =0.82), from 0.65±0.19 in athletes to 24.71±8.43 in the severely obese group, and discriminated overweight from non-obese status with area under the curve = 0.976 (95% CI 0.935-1.000), numerically exceeding its strongest component, malondialdehyde (AUC = 0.939), and its weakest, homeostatic model assessment of insulin resistance (area under the curve = 0.693). Athlete accelerated inflammatory-metabolic index scores were significantly lower than non-obese controls (Cohen's d =0.91, p<0.001). Body mass index correlated more strongly than waist-to-hip ratio with every accelerated inflammatory-metabolic index component.

Conclusions: Accelerated inflammatory-metabolic index shows promising diagnostic performance for early metabolic deterioration and exercise-associated metabolic protection. External validation in independent, prospective cohorts is warranted before clinical use.