The Acute Effect Of Aerobic Exercise On Brachial Artery Endothelium Function In Kidney Transplant Recipients

Abstract

PURPOSE Cardiac disease is the leading cause of death in renal transplant recipients. Endothelial dysfunction, a physiologic marker of atherosclerosis, has been reported in this population. Risk factor assessment and disease modification is imperative to reduce cardiovascular risk in transplant patients. Researchers have shown that a single bout of exercise increases endothelial dilatation in animals. However, the effects of acute exercise on endothelial dysfunction in humans have not been extensively studied. Scientific study of the effects of acute exercise on endothelial dysfunction in renal transplant patients is important since atherosclerotic cardiovascular disease risks are associated with significant morbidity and mortality in these patients. METHODS The study was designed to compare the effect of a 30-min walk at moderate intensity on brachial artery endothelial function, fasting cholesterol (FC), triglycerides (TGs), high density lipoproteins (HDL-C), low density lipoproteins (LDL-C), and C-reactive protein (CRP) in kidney transplant recipients compared to healthy individuals. Male and female subjects included 11, kidney transplant recipients, and 11 sedentary healthy individuals. A 2 × 2 × 4 mixed factorial analyses of variance (ANOVA) was conducted to analyze the dependent variable, brachial artery inner absolute diameter. Five 2 × 2 mixed ANOVAs were used to analyze the dependent variables FC, TGs, HDL-C, LDL-C, and CRP. RESULTS: A significant interaction was found for group and occasion for the dependent variable endothelial diameter, F (1, 21) = 18.46, p < .05. No significant interactions were found for group and time (p = .07), occasion and time (p = .58) and group, occasion, and time (p = .78). No significant interaction and main effects (p > .05) were found with regard to the dependent variables: HDL-C, LDL-C, FC, and CRP. A significant main effect for group was found across testing occasions with regard to TGs. The transplant group had significantly (p = .01) higher TGs (M = 151.14 mg/dL, SD = 87.76) when compared to the healthy group (M = 77.73, SD = 17.32). CONCLUSIONS The 30-min walk caused a vasodilatory response on the healthy group and none on the transplant group. No changes in blood parameters were seen for both groups. The increased diameter in the control group may represent an immediate mechanism by which vascular compliance increases with an isolated bout of exercise. No vasodilatory response in post transplant together with the effects of immunosuppressive drugs and several cardiovascular risk factors that included high BMI, and %BF could be associated with endothelial dysfunction in this population.