Exercise training improves cardiac performance in diabetes: in vivo demonstration with quantitative cine-MRI analyses

Abstract

Loganathan R, Bilgen M, Al-Hafez B, Zhero SV, Alenezy MD, Smirnova IV. Exercise training improves cardiac performance in diabetes: in vivo demonstration with quantitative cine-MRI analyses.

Treinamento em natação atenua a disfução contrátil de cardiomiócitos de ratos diabéticos

“…It is also possible that there has been an increase in glucagon secretion in such animals 30 and its counterregulatory action has helped in the maintenance of hyperglycemia. Our results are consistent with those of other studies 7,[11][12][13][14]31 , although these have used different exercise protocols (i.e., treadmill). On the other hand, some studies have shown that exercise was able to improve glucose metabolism in diabetic rats 32,33 .…”

“…These findings at the cellular level are consistent with the diastolic dysfunctions observed in diabetic hearts in vivo 7,11 .…”

“…The reduced contraction amplitude observed in this study reflects important changes in the myocardium of diabetic rats in vivo, such as reduced fractional shortening in end diastolic diameter, left ventricular end systolic diameter and cardiac input 7,11 . Although we have not tested mechanisms, it is knownthat the decreased sensitivity of contractile myofilaments to Ca 2+ and reduced intracellular concentration of Ca 2+ are involved 21 .…”

“…In contrast, chronic exercise increased the contraction amplitude in diabetic animals and controls. For diabetic animals, this fact indicates that exercise promoted positive changes in cardiomyocytes that contribute to alleviating some of the mechanical abnormalities of diabetic myocardium observed in vivo 7,11,12 . Some mechanisms have been proposed as responsible for increasing the contraction amplitude of cardiomyocytes of diabetic rats in response to chronic exercise: there is evidence that chronic exercise can normalize the operation of NCX and calcium calmodulin kinase II (CaMKII), reduce the leakage of Ca 2+ of SR and increase the content of Ca 2+ of SR 7,15 .…”

Exercise Training Improves but Does Not Normalize Left Ventricular Systolic and Diastolic Function in Adolescents With Type 1 Diabetes

“…Training was progressively adjusted to achieve 85% of the participant's maximal heart rate (obtained during the VO 2peak test) during aerobic exercise training (weeks 1-4). After that (weeks [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20], participants were asked to exercise at the target heart rates of 85% of the maximal heart rate for a minimum of 40 min/session during the aerobic sessions. Participants were instructed to perform at least three sessions a week of aerobic training (combination of treadmill, cycling, and rowing machine with interval training) followed by weekly resistance training (weight training and core exercises) from weeks 1-12.…”