Top Story:
Cuba Launches Study
on Renal Disease Prevention

By Gail Reed

This November, nephrologists, family physicians, family nurses and the entire health system on Cuba’s Isle of Youth implemented the first steps of what promises to be a study with international importance on the prevention of renal disease and related cardiovascular disease.

Dr. Raúl Herrera, Director of the national Institute of Nephrology in Havana, notes that this kind of research is being carried out for the first time in total population, since virtually all 80,000 residents of the Isle will be involved, each person requested to give their informed consent. The project will transform the island into the world’s first community-based epidemiological laboratory for risk-factor identification, diagnosis and surveillance of the progress of renal diseases, providing the basis for study, implementation and evaluation of comprehensive prevention strategies to reduce the appearance of chronic kidney failure.

Dr. Herrera says it will also provide important data on early vascular damage, the factor that renal disease and cardiovascular disease have in common.

The study itself will include all eligible persons among the 80,000 people on the Isle, involving the Isle’s three community polyclinics and its 115 family doctor-and-nurse teams. The research is designed to:

• Identify main demographic and risk factors for chronic renal insufficiency, through a questionnaire and individual interview;
  
  
• Track these risk factors over time;
  
  
• Identify those persons with affected kidney function (through laboratory testing of the whole population, including microalbuminuria, albumin and series creatinin).
  
  
• Track those persons identified with affected kidney function, applying secondary preventive measures to slow the progress of the disease;
  
  
• Identify and apply primary preventive strategies for those patients identified as healthy;
  
  
• Analyze the results of all stages of the study, and present the conclusions to national and international experts in the field.

Getting the kinks out: directors of the study look on as family doctor and nurse team carry out a dry run of patient interviews.

Additionally, Dr. Herrera emphasizes, new chronic renal disease patients identified through the study will have access to nephrology services and substitute therapy (dialysis), since the Isle of Youth hospital has nephrologists on board and a new dialysis care center. “For us,” he says, “this is an important ethical factor, since we cannot identify new patients and then not have the means to treat them.”

Background on the Study

Chronic renal failure is increasing dramatically worldwide, fast becoming the “chronic disease of the new century”. One big reason is the aging of the world’s populations, and the fact that they are living today with diseases once responsible for early deaths. This is the case with diabetes and hypertension, the two main causes of chronic kidney failure. As people live more years with these conditions, they are more likely to develop end-stage renal disease (“ESRD”, or the point when a person needs dialysis or a kidney transplant to survive).

Of all chronic conditions, ESRD is the most expensive to treat, and so, more quietly than AIDS, its expansion threatens to bankrupt entire health systems or keep millions of patients outside treatment protocols altogether. In the case of Cuba and other developing countries, this economic dimension takes on an acute urgency.

Experts in the field, such as Harvard’s Dr. Barry M. Brenner, Director of the Renal Division of Brigham and Women’s Hospital in Boston, insist that the only way to reverse such a worldwide disaster is to generate the sorely lacking effective and comprehensive prevention models. And this can only be done through well-monitored, population-based studies in discrete but significant populations. One of the few places in the world that this is possible is Cuba, given its universal health care system based on accessible community-level health care services, primary care providers who keep lifelong records on their entire patient populations, and its reservoir of medical scientists well-prepared to carry out research.

In the United States today, rates of chronic kidney failure among African-Americans, Hispanics and Native Americans (indigenous peoples) far surpass those among whites.

Source:ESRD Atlas, p. S-18.

Evidence suggests that numbers of Hispanics in dialysis, as a percentage of the total, are also on the rise. (Atlas of ESRD, p. S-47).

Thus, while only incomplete data is available from Latin America and the Caribbean, racial and ethnic patterns of ESRD in the United States suggest that the region may be among the world’s most seriously affected by the disease especially as life expectancies continue to increase.

Published information points to serious under-diagnosis and under-treatment of chronic renal failure in the region, reflecting the lack of access to care. As the Year 2000 Latin American Registry of Dialysis and Transplant notes: “The low prevalence of patients with renal replacement therapy (either dialysis or transplant) registered in Latin America is due to the fact that in many countries of the region, the access to this treatment is limited.

Nevertheless, even as the disease is under-reported, rates of Latin American patients in treatment doubled over the seven years from 1992 to 1998: from 123 per million inhabitants to 258 per million. And the numbers continue to rise.

Pioneering research in prevention is an urgent need for Latin America, the Caribbean and the United States—in the latter case, with particular relevance to African-American, Hispanic and Native American under-served populations.

In Cuba, the prevalence or total number of patients in dialysis is now 144 per one million inhabitants; and the number of new cases of ESRD is growing annually, consistent with the aging of the population and the fact that patients with hypertension and diabetes are living longer.

Thus, the Cuban public health system has identified research into renal disease prevention as a top priority. “This importance derives from two fundamental premises,” notes Dr. Herrera. “First, to realize the full potential of our health system for the benefit of our own patients, each of whom has a constitutional right to quality health care, including a strong preventive emphasis; and second, to cultivate Cuba’s comprehensive approach in order to contribute to teaching, research, treatment and—above all—prevention in the region.”