title: Cardiac high-energy phosphate metabolism alters with age as studied in 196 healthy males with the help of 31-phosphorus 2-dimensional chemical shift imaging.
abstract: Recently published studies have elucidated alterations of mitochondrial oxidative metabolism during ageing. The intention of the present study was to evaluate the impact of ageing on cardiac high-energy phosphate metabolism and cardiac function in healthy humans. 31-phosphorus 2-dimensional chemical shift imaging (31P 2D CSI) and echocardiography were performed in 196 healthy male volunteers divided into groups of 20 to 40 years (I, n = 43), 40 to 60 years (II, n = 123) and >60 years (III, n = 27) of age. Left ventricular PCr/β-ATP ratio, myocardial mass (MM), ejection fraction and E/A ratio were assessed. Mean PCr/β-ATP ratios were significantly different among the three groups of volunteers (I, 2.10 ± 0.37; II, 1.77 ± 0.37; III, 1.45 ± 0.28; all p<0.001). PCr/β-ATP ratios were inversely related to age (r(2)  =  -0.25; p<0.001) with a decrease from 2.65 by 0.02 per year of ageing. PCr/β-ATP ratios further correlated with MM (r =  -0.371; p<0.001) and E/A ratios (r = 0.213; p<0.02). Moreover, E/A ratios (r =  -0.502, p<0.001), MM (r = 0.304, p<0.001), glucose-levels (r = 0.157, p<0.05) and systolic blood pressure (r = 0.224, p<0.005) showed significant correlations with age. The ejection fraction did not significantly differ between the groups. This study shows that cardiac PCr/β-ATP ratios decrease moderately with age indicating an impairment of mitochondrial oxidative metabolism due to age. Furthermore, MM increases, and E/A ratio decreases with age. Both correlate with left-ventricular PCr/β-ATP ratios. The findings of the present study confirm numerous experimental studies showing an impairment of cardiac mitochondrial function with age.
authors.affiliation: Department of Radiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Regina
authors.initials: R
authors.lastname: Esterhammer
authors.affiliation: Department of Internal Medicine III, Division of Cardiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Gert
authors.initials: G
authors.lastname: Klug
authors.affiliation: Department of Radiology, Medical University Innsbruck, Innsbruck, Austria; Department of Radiology, District Hospital Reutte, Ehenbichl, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Wolf
authors.affiliation: Department of Radiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Agnes
authors.initials: A
authors.lastname: Mayr
authors.affiliation: Department of Internal Medicine III, Division of Cardiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Reinstadler
authors.affiliation: Department of Internal Medicine III, Division of Cardiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Hans-Josef
authors.initials: HJ
authors.lastname: Feistritzer
authors.affiliation: Department of Internal Medicine III, Division of Cardiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Metzler
authors.affiliation: Department of Radiology, Medical University Innsbruck, Innsbruck, Austria.
authors.forename: Michael F H
authors.initials: MF
authors.lastname: Schocke
mesh_terms: D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001794:Blood Pressure / Q000502:physiology; D015150:Echocardiography, Doppler; D005947:Glucose / Q000378:metabolism; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D010725:Phosphocreatine / Q000096:biosynthesis; D010758:Phosphorus / Q000378:metabolism*; D010759:Phosphorus Isotopes; D013318:Stroke Volume / Q000502:physiology
chemical_list: D010759:Phosphorus Isotopes; D010725:Phosphocreatine; D010758:Phosphorus; D000255:Adenosine Triphosphate; D005947:Glucose