Findings from a recently published local chronic renal failure study are shedding new light on previously held conclusions about cardiovascular risk among people with kidney disease in SA.
The research, which was conducted as part of a doctoral thesis by experienced nephrologist, Dr Peter Hsu who practises at Netcare Milpark Hospital, is the largest known study of its kind to date in SA. The study found that black patients with renal failure carry as much cardiovascular risk as their white counterparts, contrary to previous thought.
“There are very few local studies on chronic renal failure, and with our particular set of population demographics there was great potential to extract meaningful information that could help to improve medical understanding and patient outcomes,” Dr Hsu said.
“It was highly beneficial being able to work with patients who already knew me well, as this meant there was greater patient trust in the study and patients would return for follow up sessions, which helped a great deal in collecting more conclusive data.”
“In renal patients there is a high risk of heart attack and stroke but before now it was generally believed that black renal patients were at lower risk for cardiovascular concerns than white renal patients in SA due to various internal and external factors,” he explained.
“The study has shown that the cardiovascular risk is in fact equal between these two race groups and that the cardiovascular burden is very high in both. We also observed that white renal patients suffer more from atherosclerosis, which is a build-up of fats and other deposits on the artery walls that over time can restrict blood flow. Black renal patients on the other hand suffer more from arteriosclerosis, which is the stiffening and thickening of blood vessels that carry oxygen and nutrients from the heart to other parts of the body – this results in increased blood pressure.”
Dr Hsu said that the findings of his academic research, which was conducted in private practice, have been published sooner than he anticipated, with five separate papers appearing in five international journals.
Dr Hsu has been in private practice for 25 years, 20 of which he has spent treating patients with chronic kidney disease at Netcare Milpark Hospital. He began this doctoral study five years ago under the supervision of Professor Patrick Dessein, chief professor of the schools of medicine and physiology at the University of the Witwatersrand.
“With the approval of the Netcare ethics committee, we were able to recruit participants from Netcare Milpark Hospital and certain other dialysis units. We had a total of 200 participants, which meant this was the largest renal patient study that we know of in SA. Of the 201 patients that I approached, only one declined to participate for personal reasons. The other 200 patients were only too eager to take part in something that might be of help to other sufferers of chronic kidney disease.
“We included a full spectrum of chronic renal patients with 33% in chronic renal failure but not yet undergoing dialysis, 33% on dialysis and 33% having had a kidney transplant. Specific risk factors that were identified included arterial stiffness, anaemia, diastolic dysfunction where the muscles of the heart become stiff, and parathyroid hormone that is not well known but which, if elevated, significantly impacts on cardiovascular risk after a kidney transplant,” notes Dr Hsu.