Improved ejection fraction after exercise training in obesity is accompanied by reduced cardiac lipid content.
BACKGROUND
Skeletal muscle and cardiac lipid accumulation are associated with diminished insulin sensitivity and cardiac function, respectively. In skeletal muscle, physical activity paradoxically increases fat accumulation, despite improvement in insulin sensitivity. Whether cardiac muscle responds similarly remains unknown.


OBJECTIVE
The objective of the study was to investigate cardiac lipid content and cardiac function after a 12-wk training program.


METHODS
This was an intervention study with pre/postmeasurements.


METHODS
The study was conducted at Maastricht University Medical Center.


METHODS
Participants included 14 healthy, male overweight/obese subjects (age 58.4 +/- 0.9 yr, body mass index 29.9 +/- 0.01 kg/m(2)).


METHODS
Intervention included a supervised 12-wk training program with three sessions per week (endurance and strength training).


METHODS
Maximal whole-body oxygen uptake, fasting plasma parameters, systolic function (by CINE-magnetic resonance imaging), and cardiac lipid content (by proton magnetic resonance spectroscopy) were measured.


RESULTS
Maximal whole-body oxygen uptake increased (from 2559 +/- 131 to 2702 +/- 124 ml/min after training, P = 0.05). Plasma concentrations of glucose decreased (from 6.3 +/- 0.2 to 5.7 +/- 0.2 mmol/liter, P < 0.001); plasma triacylglycerols and (free) fatty acids did not change. Also, body weight (from 94.2 +/- 3.6 to 92.9 +/- 3.6 kg, P = 0.10) and fat percentage (from 33.6 +/- 1.7 to 32.5 +/- 2.0%, P = 0.14) was unchanged. Left ventricular ejection fraction improved (from 52.2 +/- 1.3 to 54.2 +/- 1.2%, P = 0.02), and cardiac lipid content in the septum was decreased after training (0.99 +/- 0.15 to 0.54 +/- 0.04%, P = 0.02).


CONCLUSIONS
Twelve weeks of endurance/strength training significantly reduced cardiac lipid content in overweight subjects and was paralleled by improved ejection fraction. This is in line with a lipotoxic action of (excess) cardiac lipids on cardiac function, although a causal relationship cannot be derived from this study. Further research is needed to clarify the clinical relevance of cardiac lipid content in the etiology of cardiovascular complications.
Schrauwen-Hinderling
Vera B
VB
Department of Radiology, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands. v.schrauwen@hb.unimaas.nl
Hesselink
Matthijs K C
MK
Meex
Ruth
R
van der Made
Sanne
S
Schär
Michael
M
Lamb
Hildo
H
Wildberger
Joachim E
JE
Glatz
Jan
J
Snoep
Gabriel
G
Kooi
M Eline
ME
Schrauwen
Patrick
P
D015308:Anaerobic Threshold / Q000502:physiology; D000975:Antioxidants / Q000378:metabolism; D001823:Body Composition; D006334:Heart Function Tests; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D050356:Lipid Metabolism / Q000502:physiology*; D008176:Lung Volume Measurements; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D009765:Obesity / Q000503:physiopathology* / Q000628:therapy*; D010809:Physical Fitness; D013318:Stroke Volume / Q000502:physiology*
D000975:Antioxidants