Diastolic dysfunction is associated with altered myocardial metabolism in asymptomatic normotensive patients with well-controlled type 2 diabetes mellitus.
OBJECTIVE
This study evaluated myocardial function in relation to high-energy phosphate (HEP) metabolism in asymptomatic patients with uncomplicated type 2 diabetes mellitus using magnetic resonance (MR) techniques.


BACKGROUND
Myocardial dysfunction may occur in patients with type 2 diabetes mellitus in the absence of coronary artery disease or left ventricular (LV) hypertrophy. The mechanisms underlying this diabetic cardiomyopathy are largely unknown, but may involve altered myocardial energy metabolism.


METHODS
We assessed myocardial systolic and diastolic function and HEP metabolism in 12 asymptomatic normotensive male patients with recently diagnosed, well-controlled type 2 diabetes and 12 controls, using MR imaging and phosphorus-31-nuclear MR spectroscopy (31P-MRS) on a 1.5 T clinical scanner; 31P-MR spectra were quantified, and myocardial HEP metabolism was expressed as phosphocreatine to adenosine-triphosphate (PCr/ATP) ratio.


RESULTS
No differences were found in LV mass and systolic function between patients and controls. However, early (E) acceleration peak, deceleration peak, peak filling rate, and transmitral early-to-late diastolic peak flow (E/A) ratio, all indexes of diastolic function, were significantly decreased in patients compared with controls (p < 0.02). In addition, myocardial PCr/ATP in patients was significantly lower than in controls (1.47 vs. 1.88, p < 0.01). Inverse associations were found between myocardial PCr/ATP and E acceleration peak, E deceleration peak, and E peak filling rate (all, p < 0.05).


CONCLUSIONS
These results indicate that altered myocardial energy metabolism may contribute to LV diastolic functional changes in patients with recently diagnosed, well-controlled and uncomplicated type 2 diabetes.
Diamant
Michaela
M
Department of Endocrinology, Leiden University Medical Center, Leiden, The Netherlands. m.diamant@vumc.nl
Lamb
Hildo J
HJ
Groeneveld
Ymte
Y
Endert
Edwin L
EL
Smit
Jan W A
JW
Bax
Jeroen J
JJ
Romijn
Johannes A
JA
de Roos
Albert
A
Radder
Jasper K
JK
D000255:Adenosine Triphosphate / Q000378:metabolism; D000368:Aged; D000704:Analysis of Variance; D001786:Blood Glucose / Q000378:metabolism; D009202:Cardiomyopathies / Q000175:diagnosis / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000378:metabolism / Q000517:prevention & control; D003971:Diastole; D018450:Disease Progression; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000378:metabolism; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D010725:Phosphocreatine / Q000378:metabolism; D010759:Phosphorus Isotopes; D012307:Risk Factors; D013599:Systole; D016277:Ventricular Function, Left
D000255:Adenosine Triphosphate; D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D006442:Glycated Hemoglobin; D010725:Phosphocreatine; D010759:Phosphorus Isotopes