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—from Epidemiological Bulletin, Vol. 22 No. 2, June 2001— Diabetes in the AmericasIntroduction Diabetes is characterized by deficiencies in the secretion and/or action of the hormone insulin, resulting in high levels of blood glucose. Diabetes is associated with an increased risk of premature death, particularly because it is associated with a greater risk of cardiovascular diseases. In addition, diabetes patients are at greater risk of becoming blind, of suffering from renal insufficiency and losing their lower limbs by amputation. There are two major types of diabetes: type 1, which appears most frequently during infancy or adolescence, and type 2, which is related to obesity and physical inactivity. Diabetes type 2 represents around 90% of all diabetes cases and appears most frequently after the age of 40. Epidemiological surveillance of type 2 diabetes is hampered by several factors. The existence of many subclinical cases (between 30% and 50% of the total cases in a majority of the populations) make it difficult to detect in the population, there exists a great variety of therapeutic regimens (insulin, oral treatment, diet, physical exercise or a combination of these), and its clinical course, if often apparently benign, can result in chronic complications, which increase the risk of dying or permanent disability. Surveillance of type 1 diabetes is a bit less complicated due to its acute onset, which often leads to a medical emergency. Type 1 can be treated only with insulin. The burden of diabetes is not reflected in all its magnitude in mortality statistics since the majority of the patients die of chronic complications such as cardiovascular diseases and nephropathy. In many of those cases, diabetes does not appear among the diseases listed on death certificates. Presence of diabetes in the Americas Many countries have registries of type 1 diabetes, especially in children who are part of the WHO project called DIAMOND. The risk of suffering diabetes types 1 during childhood varies greatly in the Americas. Karvonen et al. (2) showed that the incidence rate ranged between 24 per 100,000 population in the 1990-1993 period in Prince Edward Island, Canada and 0.5 per 100,000 population in 1992 in Venezuela (Figure 1). Figure 2 shows results of studies of prevalence of diabetes in adult populations in the Americas. The highest prevalence rate in adults (mainly type 2) has been reported among the Pima Indians of Arizona, United States (3). In Latin America and the Caribbean, the highest rate was registered in Barbados (16.4%) (4), followed by Cuba with 14.8% (5), while the lowest rate was registered in 1998 among the Aymara indians of a rural area in Chile (1.5%) (6). In the majority of the countries the prevalence of diabetes is higher in women than men. Figure 3 shows the estimated prevalence of diabetes in adult populations of the Americas in 2000, calculated by the World Health Organization. In the United States, Canada, Argentina, Chile, and Uruguay the prevalence is estimated between 6.1% and 8.1% of the adult population. In Brazil, Peru, Venezuela, Colombia, and Cuba the prevalence of diabetes was estimated between 5.1% and 6.0% of the adults, while in Bolivia, Paraguay, Ecuador, Panama, Costa Rica and Guatemala rates varied from 4.1% to 5%. In Suriname, Guyana, Nicaragua, and Honduras from 3.1% to 4.0% of the adult population have diabetes. It was estimated that urban populations (such as those where most prevalence surveys were carried out) showed prevalence rates twice as high as in populations living in rural areas. The increase in prevalence of diabetes is amplified by the progressive migration of rural populations to cities and by the assimilation of habits that favor the appearance of obesity. In the United States, the prevalence of diabetes increased for these reasons. Some studies showed that the same is occurring in Latin America and the Caribbean. In a population of Havana, Cuba, for example, two diabetes surveys were conducted over a period of 27 years. The original study, carried out in 1971, included 3,268 people. In 1998 the same study was repeated in a sample of 251 people representative of the same health area. On both occasions, the diagnostic was made using a glucose tolerance test and the criterion used was a level 140 mg/dl or more (Impaired Glucose Tolerance (IGT): 140-199 mg/dl and Diabetes (DM): 200 mg/dl or more) two hours after the ingestion of 75gms of glucose. The prevalence of IGT-DM increased from 8.4% in 1971 to 23.6% in 1998 (diabetes 14.4% and IGT 9.2%) (5). A study involving native Mapuche Indians in Chile evaluated the 1985 prevalence of diabetes at 0.4 % in men and 1.4% in women (7), however, the repetition of this survey in 1999 showed a prevalence of 3.2% in men and 4.5% in women (8). This suggests that a process of acculturation is occurring in this rural community, with an increase in the prevalence of diabetes and perhaps of other chronic diseases. In 1998, the ministry of health of Bolivia, with the support of PAHO/WHO, conducted a survey of diabetes, hypertension, and risk factors for noncommunicable diseases (9). The study included a sample by conglomerates of 2,948 people in La Paz, El Alto, Cochabamba, and Santa Cruz. The results showed a prevalence of diabetes of 7.2% with similar prevalence in men and women. The prevalence of IGT was 7.8%, with a higher prevalence in women (9.1%) than in men (6.6%). The prevalence rates of the three categories of glucose intolerance (known diabetes, new cases of diabetes and IGT) were higher among those with lower levels of education (Table 1). The most disadvantaged people of Bolivia are those most affected by diabetes (9). These results suggest that diabetes constitutes an important health problem even in countries that are still clearly in development and where the so-called epidemiological transition is in process. Regardless of the fact that communicable diseases continue to be a health problem for developing countries, noncommunicable diseases such as diabetes, hypertension, and obesity are becoming an important human and social burden as well.
Interventions The purpose of the Diabetes Initiative for the Americas (DIA) is to increase the capability of health care services and systems to organize diabetes surveillance and control in the Americas. DIA has three lines of action:
The Pan American Health Organization, in partnership with the International Diabetes Federation (IDF) and the pharmaceutical industry created in 1996 the Declaration of the Americas on Diabetes (DOTA). DOTA has successfully coordinated various activities in the region of the Americas during recent years. The role of DIA is to strengthen efforts to improve diabetes control, taking in account PAHO’s experience in the collaboration with countries, with DOTA and with various other institutions. References Return to Index | |||||||||||||||||||||
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