Exercise as it relates to Disease/The effect of aerobic exercise in overweight chronic kidney disease patients

This page is a critical analysis of the research article “A Randomized controlled trial to evaluate the impact of aerobic exercise on visceral fat in overweight chronic kidney disease patients” by Flavia Baria, Maria Ayako Kamimura, Danilo Takashi Aoike, Adriano Ammirati, Mariana Leister Rocha, Marco Túlio de Mello and Lilian Cuppar. This analysis was completed for the unit Health, Disease and Exercise at the University of Canberra.

What is the background to this research?
Obesity rates are becoming a global issue spanning through all age groups with the frequency of being diagnosed with chronic obesity being more prevalent in individuals who also have chronic kidney disease. This is due to obesity being a known risk factor of hypertension and high visceral fat levels, which are two main causes for chronic kidney disease. This study aimed to investigate the effect that aerobic exercise, performed in either an exercise centre or at home, has on overall visceral fat in the targeted over weight population with chronic kidney disease.

Where is the research from?
This study was conducted by the Nutrition Graduation Program of the Federal University of São Paulo in Brazil and was published within the Nephrology Dialysis Transplantation, a medical journal produced by Oxford University. This article mentions other studies with similar parameters that were used to improve and adapt for a specific focus on visceral fat and chronic kidney disease. The American college of sports medicine recommendations were used to create and conduct the training programs.

What kind of research was this?
This article was a prospective, randomised, controlled interventional trial that covered twelve weeks.

What did the research involve?
The research consisted of the observation of twenty-seven sedentary men, aged between eighteen and seventy, who had been diagnosed with chronic kidney disease stages three and four but where non-dialysed. The eligibility criteria for these participants included: Each participant was randomly assigned to either an exercise center-based or at home-based workout program. Both assigned groups were advised to participate in a light to moderate aerobic based exercise routine three times per week. The participants where monitored weekly through telephone calls checking compliance rates, had mandatory monthly progress assessments and the participants physical capacities, body composition and blood pressure where assessed at baseline and at the end of the twelfth week.
 * Male
 * Sedentary behaviour patterns
 * BMI >30 kg/m2
 * No use of heart medication
 * Cleared to exercise by medical professional
 * No presence of:
 * Pulmonary disease
 * Congestive heart failure
 * Coronary disease

The main outcome of the study was to measure the presence of visceral fat with results being obtained by the use of computed tomography. Anthropometric markers where also taken such as BMI, body composition using a Dual-energy X-ray absorptiometry (DEXA) scan, waist circumference and blood pressure to further clarify the observations seen relating to visceral fat presence.

Limitations:

The use of BMI is not recommended in a research environment due to the inaccurate measurement given resulting from the lack of inclusion of any body composition besides height and weight. This is a large limitation of the study as this is one of the main criteria for being chosen to be included in the study. When implementing a trial such as this there are many limiting factors to the participants compliance such as lack of knowledge with both exercise and the benefits, lack of time and limited place and equipment required. It was mentioned that participants had the option to seek advice about their movements through exercise center employees or supervised session at home to insure they correctly performed each exercise given. This leaves the question of how many participants chose not to seek advice and either performed the exercises incorrectly effecting their results or not at all due to worry of injury and embarrassment.

Whilst this study had a large range of ages from eighteen to seventy, there are many questions in relation to the exercise capacity and general normative physical activity data that the results found can relate to. This large sample group may affect the final results of this study due to the circumstance that an eighteen-year-old is expected to have a greater aerobic capacity to begin with, despite their disease, when compared to a seventy-year-old. Whilst results may be further affected if the randomised groups had a different average age leading possibility of the results to be skewed.

What were the basic results?
This study showed that overall visceral fat and waist circumference decreased in the individuals who participated in the exercise center based routines, with an increase of lean leg mass also seen. There was also a decrease in mean blood pressure, due to the known result aerobic exercise has on reducing peripheral vascular resistance. The decrease in general hypertension is beneficial due to the reduction of the known risk factor but also has a positive influence on kidney function within these obese chronic kidney disease participants.

There were no significant changes in the home-based group when compared to the center based-group due to once standardise, the home based-group had a higher average age, but it was highlighted that this form of exercise helped to prevent the increase of visceral fat.

Group: Center-Based

Group: Home-Based

What conclusions can we take from this research?
The implementation of exercise center-based routines are an effective approach in relation to the reduction of visceral fat within overweight chronic kidney diseased males. Light to moderate aerobic exercise has a positive impact on visceral fat reduction and prevention, high blood pressure and lean muscle mass within the body. These results although cannot provide evidence to revert the disease but they do suggest that aerobic exercise can aid in the prevention of progression for further stages of chronic kidney disease.

Practical advice
As previously mentioned, aerobic exercise at low to moderate intensity has positive health results in relation to visceral fat levels and blood pressure within chronic kidney disease participants. Although no significant results where seen through the home-based group, it is to note that this form of program prevented an increase in visceral fat. Individuals with chronic kidney disease should at a minimum participate in these forms of activity, recommended at an exercise centre but if not at their home in order to prevent further deterioration with their disease.

Information found from studies conducted subsequently to this found that exercise generating between 6 to 10 METS, otherwise moderate to vigorous intensity, had a significant relationship to the reduction of visceral fat levels.

Further information/resources
Below are both, websites and articles with further information relating to the topics and information previously mentioned.

Information about Chronic kidney Disease: https://www.kidney.org/atoz/content/about-chronic-kidney-disease

An informative article about visceral fat: https://www.healthline.com/health/visceral-fat#rating-and-measurements

Systemic review of similar studies on aerobic exercise and visceral fat: https://www.nature.com/articles/0803683/