Innovative Methodology Short-term flexibility of myocardial triglycerides and diastolic function in patients with type 2 diabetes mellitus

Hammer S, van der Meer RW, Lamb HJ, de Boer HH, Bax JJ, de Roos A, Romijn JA, Smit JW. Short-term flexibility of myocardial triglycerides and diastolic function in patients with type 2 diabetes mellitus. Am J Physiol Endocrinol Metab 295: E714–E718, 2008. First published July 15, 2008; doi:10.1152/ajpendo.90413.2008.— Short-term caloric restriction increases plasma levels of nonesterified fatty acids (NEFAs) and is associated with increased myocardial triglyceride (TG) content and decreased myocardial function in healthy subjects. Whether this flexibility of myocardial TG stores and myocardial function is also present in patients with type 2 diabetes mellitus (T2DM) is yet unknown. Myocardial TG content and left ventricular (LV) ratio between the early (E) and atrial (A) diastolic filling phase (E/A) were determined using magnetic resonance (MR) spectroscopy and MR imaging, respectively, before and after a 3-day very low-calorie diet (VLCD) in 11 patients with T2DM. In addition, we studied patients after a 3-day VLCD combined with the antilipolytic drug acipimox. The VLCD induced myocardial TG accumulation [from 0.66 0.09% (mean SE, baseline) to 0.98 0.16%, P 0.028] and a decrease in E/A ratio [from 1.00 0.05 (baseline) to 0.90 0.06, P 0.002]. This was associated with increased plasma NEFA levels (from 0.57 0.08 mmol/l at baseline to 0.92 0.12, P 0.019). After the VLCD with acipimox, myocardial TG content, diastolic function, and plasma NEFA levels were similar to baseline values. In conclusion, in patients with T2DM, a VLCD increases myocardial TG content and is associated with a decrease in LV diastolic function. These effects were not observed when a VLCD was combined with acipimox, illustrating the physiological flexibility of myocardial TG stores and myocardial function in patients with T2DM.