Strategies for national health care systems in emerging countries: the case of screening and prevention of renal disease progression in Bolivia.

There are close to 1 million people in the world who are alive simply because they have access to one form or another of renal replacement therapy (RRT). Ninety percent live in high-income countries. Little is known of prevalence and incidence of chronic kidney disease and of end-stage renal disease (ESRD) in middle-income and low-income countries, where the use of RRT is scarce or nonexistent. However, no intervention is undertaken, these people will experience progression to ESRD and death from uremia, because RRT is out of reach for them. These are the individuals for whom efforts should be focused to prevent or delay progression toward ESRD. In 1992, the Mario Negri Institute for Pharmacological Research in Bergamo, Italy, with the cooperation of the young doctors of the Ospedale Giovanni XXIII in La Paz (Bolivia), activated a specific project titled "El Proyecto de Enfermedades Renales en Bolivia" (The Project for Renal Diseases in Bolivia). The project sought to demonstrate that in emerging countries the best strategies against renal disease are prevention and early detection. After proper training of local personnel at the Clinical Research Center "Aldo e Cele Dacco" of the Mario Negri Institute in Bergamo, Italy, an educational campaign titled "First Clinical and Epidemiological Program of Renal Diseases"-under the auspices of the Renal Sister Center Program of the International Society of Nephrology-was conducted in 3 selected areas of Bolivia, including tropical, valley, and plains areas. The goal was to define the frequency of asymptomatic renal disease in these areas by screening a large population of patients at relatively low costs. The screening was formally performed at first-level health centers (Unidad de Salud). Participants were instructed to void a clean urine specimen, and a dipstick test was performed. Patients with positive urinalysis were enrolled in a follow-up program with subsequent laboratory and clinical checks. The study was conducted by 21 clinical centers. Apparently healthy patients (14,082) were enrolled over a period of 7 months. Urinary abnormalities were found on first screening in 4261 patients, but only 1019 patients (23.9%) were available for follow-up. At second urinalysis, 35% of patients had no abnormalities. In the remaining positive group of patients, further investigations disclosed the following abnormalities: urinary tract infection (48.4%), isolated hematuria (43.9%), chronic renal failure (1.6%), renal tuberculosis (1.6%), and other diagnoses 4.3% (kidney stones, 1.3%; diabetic nephropathy, 1%; polycystic kidney diseases, 1.9%). The experience gained from this initial screening program formed the basis for a second study aimed to prevent renal disease progression in a selected Bolivian population with high altitude polycythemia. In conclusion, our studies show that mass screening of the population for renal disease is feasible in developing countries and can provide useful information on frequency of renal diseases. Also, in patients with altitude polycythemia, long-term treatment with low doses of enalapril safely prevents increase in arterial blood pressure and progressively reduces hematocrit and proteinuria. Aside from its scientific value, this last study can be taken as an example of how, by rationalizing resources and investing in research programs, renal disease progression and cardiovascular risk may eventually improve, which ultimately should translate into less demand for dialysis, and thus provide alternatives to costly RRT. The transformation of the Bolivian pilot model into a systematic program applicable to most emerging countries may be seen as a task of national nephrology societies, along with methodologic and economic support of international bodies.

Angiotensin-converting-enzyme inhibition therapy in altitude polycythaemia: a prospective randomised trial.

BACKGROUND: Angiotensin-converting-enzyme (ACE) inhibitors reduce packed cell volume and haemoglobin concentration in polycythaemia that follows renal transplantation, which, like altitude polycythaemia, is an erythropoietin-dependent form of polycythaemia. We aimed to establish the effect of ACE-inhibitor treatment in people with altitude polycythaemia. METHODS: We did a prospective randomised study in 26 people with altitude polycythaemia (packed cell volume > or = 55%) and 24-h rate of urinary protein excretion greater than 150 mg, who had been referred to the Renal Disease Project in La Paz, Bolivia. 13 participants were assigned 5 mg/day enalapril for 2 years (study group), and 13 no treatment (controls). Blood pressure, packed cell volume and haemoglobin concentration, proteinuria, and renal function were compared by intention-to-treat analyses. FINDINGS: Baseline packed cell volume and haemoglobin concentration were positively correlated with bodyweight (p=0.02), systolic (p=0.01) and diastolic (p=0.04) blood pressure, serum creatinine (p=0.009), blood urea (p=0.008), and proteinuria (p=0.003). Systolic and diastolic blood pressure remained stable in the study group, but increased in controls. In study patients, mean (SD) packed cell volume, haemoglobin concentration, and proteinuria fell from 63.5% (4.9) to 56.8% (4.1), p<0.0001; 207 (18) to 164 g/L (13), p<0,0001; and from 358.6 (260.3) to 247.7 mg/24-h (208.2), p<0.002, respectively, but did not change significantly in controls. At 12 and 24 months of follow-up, packed cell volume, haemoglobin concentration, and proteinuria differed significantly between the groups (p<0.0001 for each comparison). In study patients, follow-up changes in packed cell volume (r=0.88, p<0.0001) or haemoglobin concentration (r=0.83, p<0.0001) and proteinuria were strongly correlated. Enalapril was well tolerated by all patients. INTERPRETATION: ACE-inhibition therapy effectively and safely ameliorates altitude polycythaemia and reduces proteinuria.