Cardiac and Metabolic Consequences of Aerobic Exercise Training in Experimental Diabetes

Abstract

The experimental literature of the foregoing decade has furnished an assemblage of mechanisms explaining the metabolic perturbations and overall decline in cardiac performance implicated in the pathogenesis of diabetes mellitus. Particularly, the experimentally-induced diabetic rat model has been indispensable in the examination of diabetic cardiomyopathy, an entity distinctly separable from atherosclerosis, hypertension, coronary artery disease and valvular dysfunction, yet convincingly attributable to the increase in cardiac-associated mortality commonly observed in the diabetic patient. The widespread epidemic of diabetes mellitus in developed societies has elicited considerable attention and the role of exercise as an adjuvant therapy in diabetes management has been increasingly emphasized. However, the evidence endorsing the beneficial attributes of exercise in the diabetic state is indeterminate despite markedly observed increases in myocardial and skeletal muscle glucose homeostasis, endothelial and autonomic function, insulin sensitivity and amelioration of diabetes pathogenesis. As evidenced by review of the experimental literature, a mild to moderately intense exercise regime may be a reliably implicated insulin-sensitizing therapy for the experimentally-diabetic rat model as well as the human diabetic patient. Notably, the cardio-protective and metabolic benefits of aerobic exercise are seemingly more pronounced in those individuals most susceptible to diabetes progression.

Resveratrol Is Not as Effective as Physical Exercise for Improving Reproductive and Metabolic Functions in Rats with Dihydrotestosterone-Induced Polycystic Ovary Syndrome

“…There is a large body of evidence from clinical and experimental studies demonstrating that exercise improves or restores insulin resistance in diabetic and obese subjects [21, 32, 33] and in women with PCOS [37]. This confirms our previous findings showing that exercise also restores insulin sensitivity in PCOS rats [34].…”

“…Cyp11a1 , located in the mitochondria, was downregulated in PCOS rats and tended to be increased by exercise although it did not reach a level of significance ( P = 0.058). This is in line with the hypothesis that mitochondrial function is impaired in PCOS [6, 7] and enhanced by exercise [21, 32]. However, when the data were divided into responders and nonresponders based on ovulation pattern it was clear that Cyp11a1 levels were restored in the responding exercise- and resveratrol-treated PCOS rats.…”

“…Exercise is proven to be effective in improving lipid profiles [32], but resveratrol has only shown beneficial changes in some [28, 30], but not all, studies on rodents with diet-induced obesity [27, 31, 40, 43]. On normal chow, serum triglyceride levels were higher in PCOS rats than in controls, and neither exercise nor resveratrol affected plasma levels.…”

Drosophila as a model for age-related impairment in locomotor and other behaviors

“…Exercise training in humans correlates with a reduced incidence of age-related diseases and slower declines in mobility and cardiovascular function (Ascensao et al, 2007; Saraceni and Broderick, 2007). Wessels and co-workers extended this concept by developing a behavioral paradigm for exercising flies called the Power Tower (Piazza et al, 2009).…”

A high-MUFA diet alone does not affect ketone body metabolism, but reduces glycated hemoglobin when combined with exercise training in diabetic rats

“…Exercise training is broadly known to have beneficial effects on glycemic control in diabetic patients by improving glucose tolerance, decreasing pancreatic β cell workload and improving insulin sensitivity [2]. Exercise training can improve glucose homeostasis and fatty acid and ketone metabolism in animal models of diabetes.…”