i-MaRS Cardio-Metabolic Index and Metabolic Elite notion

This work introduces the i-MaRS Cardio-Metabolic Index (i-MaRS CMI), a novel metabolic assessment framework explicitly defined as an isomorphic derivative of the original Cardio-Metabolic Index (CMI) proposed by Wakabayashi and Daimon. While the classical CMI is polymorphic—combining a paraclinical lipid marker (TG/HDL-C) with an anthropometric component (waist-to-height ratio)—the i-MaRS index preserves the multiplicative structure of CMI while shifting entirely into the paraclinical domain. In i-MaRS CMI, the anthropometric term is replaced by a dynamic glucidic component, the Postprandial Glycemic Dynamic (PGD), derived from a standardized low-dose (12 g) sucrose challenge. This transformation renders i-MaRS CMI a state-dependent index, capable of capturing rapid metabolic fluctuations over short time intervals (daily or weekly), in contrast to classical indices that primarily reflect slow-changing structural or anthropometric traits. The core advantage of i-MaRS CMI lies in its ability to function as a rapid metabolic state equation, integrating lipid metabolism (via TG/HDL-C) with real-time glucidic dynamics (via PGD). This allows sensitive intra-individual monitoring, early detection of insulin resistance, and precise longitudinal comparison within the same subject—features not achievable with static or anthropometry-dependent indices. Within this framework, the work introduces the notion of “Metabolic Elite” as a state, not a phenotype or diagnosis. Metabolic Elite represents a condition of optimal metabolic synergy, defined numerically by low TG/HDL-C values and minimal postprandial glycemic excursions, reflecting superior insulin sensitivity, efficient glucose clearance, and favorable lipid handling. This state is reversible, measurable, and aspirational, particularly relevant for athletic populations but applicable to the general population. Beyond the Metabolic Elite state, i-MaRS CMI also provides a classification of metabolic states, ranging from optimal (Super-Elite / Elite) through normal and moderate risk, to incipient metabolic syndrome. These states are separated using physiologically justified postprandial timing points and baseline-relative thresholds, emphasizing metabolic dynamics rather than absolute clinical cut-offs. Overall, this work positions i-MaRS Cardio-Metabolic Index not as a strict clinical diagnostic tool, but as a framework for metabolic state assessment, training, and evolution, offering a practical, low-cost, and conceptually rigorous approach to understanding and improving metabolic health.