High prevalence of diabetes and intermediate hyperglycemia - The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Abstract

Background: The global burden of diabetes mellitus and other chronic diseases is high, and 80% of those with diabetes now live in low and middle income countries. Yet, little information is available regarding prevalence of diabetes and intermediate hyperglycemia in these countries, especially when a full range of diagnostic tests is employed. The purpose of this study is to provide a full accounting of these prevalences in a large, free-living Brazilian population.

Methods: We report baseline data (2008-2010) from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), a cohort study of 15,105 civil servants aged 35-74 years. Diabetes mellitus was ascertained by self-report of diagnosis, medication use, fasting glucose, an oral glucose tolerance test, and/or glycated hemoglobin. Cut-offs for diabetes and intermediate hyperglycemia followed the recommendations of the World Health Organization and the American Diabetes Association. Adjusted prevalences were estimated through logistic regression.

Findings: With this full accounting, 19.7% (19.0%-20.3%) had diabetes mellitus, 50.4% being previously undiagnosed. Frequencies of intermediate hyperglycemia according to various criteria ranged from 16.1% to 52.6%. Diabetes or intermediate hyperglycemia was present in 79.1% of participants when using the most comprehensive definitions. The burden was greatest in the elderly, the obese, non-whites, and those with less formal education (p < 0.001).

Interpretation: That four of every five free-living individuals aged 35-74 years working in selected public institutions in six Brazilian state capitals presented either diabetes or intermediate hyperglycemia highlights the advanced stage of the obesity - diabetes epidemic in urban Brazil and indicates the need for urgent action.

Keywords: Brazil; Diabetes mellitus; Hyperglycemia; Prediabetic state; Prevalence.

Figure 1

Percent of the total sample presenting a glucose abnormality by category and age. Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), N = 15102, 2008-2010. Smoothing performed using a spline routine (Statistical Analysis System). DM = diabetes mellitus; IGT = impaired glucose tolerance; iIFG (WHO) = isolated impaired fasting glucose; iIFG(ADA) represents the additional cases of IFG when ascertained by the ADA criteria; iPre-diabetes by HbA1c represents the additional cases of intermediate hyperglycemia when diagnosed by ADA criteria; WHO = World Health Organization; ADA = American Diabetes Association. See Methods for diagnostic criteria.