Italian Study Looks at the Effects of Exercise in Renal Transplant Recipients

A review of evidence-based results headed up by Giulio Romano, MD and Professor of Nephrology at Misericordia University Hospital, hoped to discover whether or not it is possible to reduce cardiovascular risk and influence graft (kidney) survival of renal transplant recipients (RTRs) other than pharmacologically. The idea came about because, even after a successful kidney transplant, the RTR continues suffering from the consequences of the illness accompanying kidney failure, uremia. And because RTRs already carry the burden of administering a large drug regimen, it becomes very important, the authors say, to introduce "non-pharmacological" therapies to end the medication madness. As you may have guessed, based on the URL of this blog, the "non-pharmacological" therapy in question is exercise.

Romano, Eric Lorenzon, and Domenico Montanaro (the paper's other two contributors) point out many studies have shown over the last twenty years that physical training can improve graft function, work capacity and quality of life, as well as reduce cardiovascular risk. Sadly, a large number of RTRs report low exercise rates. The reasons are varied. Some believe it is because of the fear of injuring the transplanted kidney and/or the transplant professionals' silence (read: ignorance) regarding the benefits of exercise. Other reasons may include an overly protective attitude of family and friends or are simply the result of a lack of structural support (something I strive to at least contribute to through this blog). Lastly, some patients of culturally and ethnically diverse backgrounds may not place a great deal of importance on exercise and self-maintenance.

Measured against the general population, renal patients are at an increased risk of having a cardiovascular event. With a mortality rate 10 to 20 times higher than the at-large population, cardiovascular events remain the major cause of death in kidney patients. The main cause of this elevated risk is accelerated atherosclerosis, which is a chronic inflammatory response in the walls of arteries. The threat of accelerated atherosclerosis continues into post-transplantation and is, in fact, the most important late complication for all organ recipients, representing the main cause of death in RTRs. What are the major risk factors associated with the development of atherosclerosis? High plasma cholesterol levels, high blood pressure, diabetes mellitus, smoking, and a sedentary lifestyle.

Romano et al note that because elevated levels of IL-6 represent a trigger factor of inflammation, they may significantly contribute to the cardiovascular risk of RTRs. Exercise, it has been shown, reduces the levels of IL-6 in RTRs. One note of caution, however, is that overtraining (i.e., strenuous exercise) actually increases IL-6 production. Therefore, the authors advocate RTRs perform an "appropriate level" of exercise consisting of 30-45 minutes of aerobics (walking or cycling) three or more times per week. So while an exercise regimen that is too intense may be bad, moderate exercise is good. When participating in what is considered to be an appropriate amount of exercise, physical strength in RTRs improve while IL-6 levels are reduced. The net biological effect, the authors say, is overwhelmingly positive.

A few other highlights of the review of the evidence-based results include:

• Greater physical activity is a statistically significant predictor of improved graft function over a one-year period, based on glomerular filtration rate. The authors believe that exercise leads to improved cardiovascular function, which likely improves perfusion and oxygen delivery to the grafted kidney.
• Exercise reduces the dependence on blood pressure medication for lung and kidney transplant recipients.
• Patients with advanced chronic kidney disease have lower cardiorespiratory fitness that remains reduced by 30% post-transplant, when compared against age and gender matched control subjects. Exercise improves cardiorespiratory fitness and muscle strength in RTRs.
• Homocysteine is a factor related to a higher prevalence of cardiovascular disease. It remains elevated in RTRs versus the general population, but physical activity may significantly lower the levels of this amino acid.
• Anxiety and depression are common among the RTR population and contribute to an increased cardiovascular risk. Exercise can reduce anxiety and depression in this group.

The authors conclude that an appropriate amount of exercise is a useful, safe, and non-pharmacological contribution to the transplant patient's treatment through the reduced risk of cardiovascular disease, the improvement of the grafted kidney's function, the increase of energetic metabolism, and an improved quality of life.

And regardless of the type we choose, the authors state that physical training can always yield remarkable health benefits. Yet despite all the positives outcomes associated with physical activity, most RTRs do not meet established minimum exercise guidelines. They call on the professional transplant community to consider exercise not as merely an assistant or luxury accessory, but as an integral part of the complex treatment of RTRs.

This article was published in the World Journal of Transplantation and can be accessed at:

http://www.wjgnet.com/2220-3230/full/v2/i4/46.htm

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