Early detection and prevention of diabetic nephropathy: A challenge calling for mandatory action for Mexico and the developing world RICARDO CORREA-ROTTER and LUIS GONZALEZ ´ -MICHACA Department of Nephrology and Mineral Metabolism Instituto Nacional de Ciencias Medicas y Nutrici ´ on Salvador Zubir ´ an, ´ Tlalpan, Mexico Early detection and prevention of diabetic nephropathy: A challenge calling for mandatory action for Mexico and the developing world. During the last decades, developing countries have experienced an epidemiologic transition characterized by a reduction of infectious diseases and an increase of chronic degenerative diseases. This situation is generating tormenting public health, financial, and social consequences. Of particular relevance is type 2 diabetes mellitus and its chronic complications, particularly cardiovascular disease and diabetic nephropathy, because mortality of the patient with diabetes is, in most instances, related to these complications. There is a clear need to implement diagnostic and treatment strategies to reduce risk factors for development of diabetes (primary prevention), to detect risk factors of chronic complications in early stages of diabetes (secondary prevention), and to prevent further progression of those that already have renal injury (tertiary prevention). Microalbuminuria is an early marker of renal injury in diabetes, and its early detection can help the timely use of renal preventive measures, which would avoid the extremely high costs of renal replacement treatment for end-stage renal disease as well as that of other cardiovascular complications. Preventive strategies are of very little or no impact, if the primary physician has limited knowledge about the natural history of diabetic nephropathy, the beneficial effect of early preventive maneuvers for delaying its progression, and the social and economic impact of end-stage renal disease. It is therefore imperative to assure in our health systems that general practitioners have the ability and commitment to detect early diabetes complications, in order to promote actions that support regression or retard highly morbid cardiovascular and renal conditions. DEMOGRAPHIC AND EPIDEMIOLOGIC TRANSITION During the second half of the last century, the world experienced highly significant demographic and epidemiologic changes, some of which have positively influenced Key words: prevention, diabetic nephropathy, CME, primary physicians, Mexico, developing nations. C 2005 by the International Society of Nephrology life expectancy and the public health scenario in most nations. Some of the most important changes worth mentioning are: major improvements of general sanitation procedures, the development of specific public health interventions, and the advent of specific medical therapies including vaccination and antibiotics. This improvement in life expectancy has conditioned major global demographic changes, with those observed in developing nations being particularly significant. While incidence of infectious diseases has been consistently declining, chronic diseases have become the main cause of morbidity and mortality in most of the emerging world, a trend initiated decades before in developed countries. Figure 1 shows mortality causes in Mexico in 1940 as compared with those in the year 2000; these data clearly support the previous statement. Parallel to the increase in life expectancy, there has been a worldwide declination of fertility and birth rates with consequent increase in the mean age of populations; this being more pronounced in the developing world [1, 2]. The increased length of human life is a consequence of a combination of several factors including: reduction of malnourishment, advances in medical practice and technology, in particular those related to communicable and perinatal diseases, urbanization, education initiatives, development of public health programs and, as previously mentioned, the implementation of adequate sanitation practices [3]. In Mexico, one of the major achievements during the last century was indeed reduction in mortality. Life expectancy of Mexicans has risen more than double in less than 7 decades, increasing from a mean of 36 years in 1930 to 75 years in 2000 [4]. The National Population Council of Mexico has estimated the change in the shape of the population pyramid from its actual status (Fig. 2A) to a significantly different change in 2005 (Fig. 2B), in which the actual high number of young people under 20 years of age will be substituted by a much older population [5]. These demographic changes are linked to an epidemiologic transition characterized by a reduction of S-69 S-70 Correa-Rotter and Gonzalez-Michaca: Diabetic nephropathy prevention in Mexico ´ 1940s 2000 Infectious Gastrointestinal Acute respiratory Accidents and violence Perinatal Neurologic Cardiovascular Cancer Chronic respiratory Genitourinary Metabolic Congenital 25 20 15 10 5 0 5 10 15 20 25 % of deaths Data obtained and adapted from Minister of Health, Mexico, 2003 Fig. 1. Mortality causes in Mexico in 1940 compared