Commentary on the Prognostic Interpretation of the Triglyceride-Glucose Index in Patients with HCM and HFpEF

titled "Association Between Triglyceride-Glucose Index and Prognosis of Patients with Hypertrophic Cardiomyopathy and Heart Failure with Preserved Ejection Fraction," recently published in the Anatolian Journal of Cardiology.The authors should be congratulated for addressing the prognostic relevance of the triglyceride-glucose (TyG) index in a challenging and understudied clinical population.Several methodological and pathophysiological considerations, however, merit further discussion.The proposed physiological explanation for the "protective effect" of higher TyG levels appears insufficient.Elevated TyG is widely recognized as a marker of insulin resistance, metabolic impairment, and proarrhythmogenic electrical abnormalities.[2][3][4] In high-risk populations such as hypertrophic cardiomyopathy (HCM) with heart failure with preserved ejection fraction (HFpEF)-where electrical instability and myocardial remodeling are prominent-an increase in TyG would typically be expected to worsen, rather than improve, mortality.The hypothesis of "adaptive glucose oxidation" in hypertrophied myocardium remains speculative and lacks mechanistic evidence.More plausible explanations, including residual confounding, selection bias, metabolic reverse epidemiology, and unmeasured clinical variables, should be considered.Clarifying this paradox requires prospectively designed and phenotypically more homogeneous studies.