Age Dependency of Myocardial Triglyceride Content: A 3T High-Field 1H-MR Spectroscopy Study

Purpose: The role of myocardial triglyceride (mTG) content in the aging human heart is not entirely understood. The aim of this study was to measure concentrations of mTG content from healthy volunteers and to determine the association between age, mTG content and systolic heart function. Furthermore, the technical stability of the H-1-magnetic resonance spectroscopy (H-1-MRS) and the reliability of peak evaluation at 3 T were evaluated. Materials and Methods: The total study population of 47 healthy volunteers was divided into 4 age classes, according to the age of the subjects (1st cohort 20 - 29 years (yrs.), n = 20; 2nd cohort 30 - 39 yrs., n = 10; 3rd cohort 40 - 49 yrs., n = 9; 4th cohort 50 - 60 yrs., n = 8). Cardiac MRI and double triggered 1H-MRS of the myocardium were consecutively performed using a 3 T scanner. Each participant underwent spectroscopic measurements twice in the same investigation. Results: mTG content increases with age. The correlation of age and mTG is minimal (r = 0.48; p < 0.001). The following age-averaged mTG content values expressed as % of mTG signal compared to the water signal were determined for each cohort: 1st cohort 0.25 % (+/- 0.17); 2nd cohort 0.48 % (+/- 0.30); 3rd cohort 0.48 % (+/- 0.18); 4th cohort 0.77 % (+/- 0.70). There was no significant correlation (r = 0.04; p = n.s.) between LV mass and mTG content in healthy volunteers. Within our cohorts, no effects of age or mTG content on systolic heart function were seen (r = -0.01; p = n.s.). The intraclass correlation coefficient of spectroscopic measurements was high (r = 0.965; p < 0.001). Conclusion: Myocardial TG content increases with age. The normal age-dependent concentration ranges of myocardial lipid metabolites reported in this study may be helpful for the correction of acquired 1H-MRS data in patients when evaluating metabolic and cardiovascular diseases in future magnetic resonance spectroscopy studies.