Noninvasive assessment of exercise-related intramyocellular acetylcarnitine in euglycemia and hyperglycemia in patients with type 1 diabetes using ¹H magnetic resonance spectroscopy: a randomized single-blind crossover study.
OBJECTIVE
Intramyocellular acetylcarnitine (IMAC) is involved in exercise-related fuel metabolism. It is not known whether levels of systemic glucose influence IMAC levels in type 1 diabetes.


METHODS
Seven male individuals with type 1 diabetes performed 120 min of aerobic exercise at 55-60% of Vo(2max) randomly on two occasions (glucose clamped to 5 or 11 mmol/l, identical insulinemia). Before and after exercise, IMAC was detected by ¹H magnetic resonance spectroscopy in musculus vastus intermedius.


RESULTS
Postexercise levels of IMAC were significantly higher than pre-exercise values in euglycemia (4.30 ± 0.54 arbitrary units [a.u.], P < 0.001) and in hyperglycemia (2.44 ± 0.53 a.u., P = 0.01) and differed significantly according to glycemia (P < 0.01). The increase in exercise-related levels of IMAC was significantly higher in euglycemia (3.97 ± 0.45 a.u.) than in hyperglycemia (1.71 ± 0.50 a.u.; P < 0.01).


CONCLUSIONS
The increase in IMAC associated with moderate aerobic exercise in individuals with type 1 diabetes was significantly higher in euglycemia than in hyperglycemia.
Department of Clinical Research, MR Spectroscopy and Methodology, University of Bern, Bern, Switzerland.
Andreas
A
Boss
Roland
R
Kreis
Stefan
S
Jenni
Michael
M
Ith
Jean-Marc
JM
Nuoffer
Emanuel
E
Christ
Chris
C
Boesch
Christoph
C
Stettler
D000108:Acetylcarnitine / Q000378:metabolism*; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006943:Hyperglycemia / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009132:Muscles / Q000378:metabolism*; D016037:Single-Blind Method
D000108:Acetylcarnitine