Biomarkers and prediction of myocardial triglyceride content in non-diabetic men

• Intramyocardial triglycerides associate with fatty acid overload to the heart.
• β-hydroxybuturate (β-OHB) is a product of fatty acid oxidation and used as a surrogate marker.
• β-OHB was reduced in non-diabetic men with increasing amount of myocardial triglyceride content.
• Among metabolic biomarkers β-OHB was the best predictor of myocardial triglyceride content.
• Reduced lipid oxidation may be implicated in the pathogenesis of cardiac steatosis.

Background and aimsLipid oversupply to cardiomyocytes or decreased utilization of lipids leads to cardiac steatosis. We aimed to examine the role of different circulating metabolic biomarkers as predictors of myocardial triglyceride (TG) content in non-diabetic men.Methods and resultsMyocardial and hepatic TG contents were measured with 1.5 T magnetic resonance (MR) spectroscopy, and LV function, visceral adipose tissue (VAT), abdominal subcutaneous tissue (SAT), epicardial and pericardial fat by MR imaging in 76 non-diabetic men. Serum concentration of circulating metabolic biomarkers [adiponectin, leptin, adipocyte-fatty acid binding protein 4 (A-FABP 4), resistin, and lipocalin-2] including β-hydroxybuturate (β-OHB) were measured. Subjects were stratified by tertiles of myocardial TG into low, moderate, and high myocardial TG content groups. Concentrations of β-OHB were lower (p = 0.003) and serum levels of A-FABP 4 were higher (p < 0.001) in the group with high myocardial TG content compared with the group with low myocardial TG content. β-OHB was negatively correlated with myocardial TG content (r = −0.316, p = 0.006), whereas A-FABP 4 was not correlated with myocardial TG content (r = 0.192, p = 0.103). In multivariable analyses β-OHB and plasma glucose levels were the best predictors of myocardial TG content independently of VAT and hepatic TG content. The model explained 58.8% of the variance in myocardial TG content.ConclusionOur data showed that β-OHB and fasting glucose were the best predictors of myocardial TG content in non-diabetic men. These data suggest that hyperglycemia and alterations in lipid oxidation may be associated with cardiac steatosis in humans.