—from Epidemiological Bulletin, Vol. 22 No. 2, June 2001

Diabetes in the Americas

Introduction
In the year 2000, the number of people who suffered from diabetes in the Americas was estimated at 35 million, of which 19 million (54%) lived in Latin America and the Caribbean (1). The projections indicate that in 2025 this number will rise to 64 million, of which 40 million (62%) will live in Latin America and the Caribbean.

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
Since the majority of the countries of Latin America and the Caribbean do not carry out epidemiological surveillance of diabetes in adults, there is not a great deal of information on the prevalence of this disease. Diabetes surveys have been carried out in several countries, but these have not been part of a policy of regional epidemiological surveillance. As a result, these surveys have been sporadic and differ in methodological aspects such as selection of the population, sampling and the diagnostic criteria used, all of which hinders the comparison between studies. Regardless of these limitations, surveys on diabetes (and its risk factors) are the only source of information that can be used to measure the magnitude of this problem in the population.

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.

Table 1: Prevalence of Diabetes Mellitus (DM) by education level, Bolivia, 1998
Education level
Prevalence of DM
Confidence Interval (95%)
None
13.1
(6.0 - 20.8)
Elementary
8.4
(7.1 - 9.7)
Secondary
6.8
(4.8 - 8.6)
Technical
4.4
(2.8 - 5.9)
TOTAL
7.2
(6.2 - 8.3)

Interventions
A public health approach of this action plan requires the involvement of those affected by diabetes, interested organized groups and health care multidisciplinary teams from both public and private sector. It is necessary to strengthen the contact with health providers to assure early diagnosis and an adequate management of diabetes and its complications.

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:

  • To increase the availability and use of epidemiological information.
  • To promote a rational use of the available services through the implementation or evaluation of diabetes care programs and activities.
  • To promote the design and implementation of culturally sensitive diabetes education and self-management programs.

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
(1) King H, Aubert RE, Herman WH. Global Burden of Diabetes, 1995-2025. Diabetes Care 1998;21:1414-1431.
(2) Karvonen M, Viik-Kajander MV, Moltchanova E, Libman I, LaPorte R, Tuomilehto J. For the Diabetes Mondiale (DiaMond) Project Group. Diabetes Care 2000;23:1516-26.
(3) Knowler WC et al. Determinants of Diabetes Mellitus in the Pima Indians. Diabetes Care 1993;16(1):216-227.
(4) Foster C; Rotimi C, Fraser H, Sundarum C, Liao Y, Gibson E, Holder Y, Hoyos M, Mellanson-King R. Hypertension, diabetes, and obesity in Barbados: findings from a recent population-based survey. Ethn Dis 1993; 3(4):404-12.
(5) Díaz-Díaz O, Hernández M, Collado F, Seuc A, Márquez A. Prevalencia de diabetes mellitus y tolerancia a la glucosa alterada, sus cambios en 20 años en una comunidad de Ciudad de la Habana. (Summary) Primera reunión científica conjunta GLED/EDEG. Programa Científico. Buenos Aires, Argentina 1999.
(6) Santos JL, Perez Bravo F, Carrasco E, Calvillan M, Albala C. Low prevalence of type 2 diabetes despite a high average Body Mass Index in the Aymara Natives from Chile. Nutrition 2001;17:305-309
(7) Larenas G, Arias G, Espinosa O, Chalres M, Lan-Daeta O, Villanueva S, Espinoza A. Prevalencia de diabetes mellitus en una comunidad Mapuche de la IX Región, Chile. Rev Me Chile 1985;113:1121-5.
(8) Pérez-Bravo F, Carrasco E, Santos JL, Calvillan M, Larenas G, Albala C. Prevalence of Type 2 Diabetes and Obesity in Rural Mapuche Population from Chile. Nutrition 2001;236-238.
(9) Barceló A, Daroca MC, Rivera R, Duarte E, Zapata A. Diabetes in Bolivia (in the process of being published in the Pan American Journal of Public Health)


Source: Prepared by Dr. Alberto Barceló of PAHO's Non-Communicable Diseases Program, Division of Disease Prevention and Control (HCP/HCN).

Return to Index
Epidemiological Bulletin, Vol. 22 No. 2, June 2001