Temporal changes in the diagnosis of type 1 diabetes by diabetic ketoacidosis in Brazil: a nationwide survey

Abstract

Aims: To examine the temporal trends in the frequency of diabetic ketoacidosis at onset compared to other modalities of diagnosis of Type 1 diabetes in Brazil.

Methods: This was a retrospective, cross-sectional and multicenter study conducted between December 2008 and December 2010 in 28 public clinics at secondary and tertiary levels of care, located in 20 cities in four geographic regions of Brazil. Each clinic provided data extracted from at least 50 outpatients with Type 1 diabetes diagnosed between 1960 and 2010, using standardized chart review forms. Data were obtained from 3591 patients (56.0% females, 57.1% Caucasians). Median values (range) for age, age at diagnosis and duration of diabetes were, respectively, 19 years (1-66 years), 10 years (< 1-44 years) and 7 years (< 1-50 years). Logistic regression was performed with diabetic ketoacidosis (Yes/No) as the dependent variable and other clinical features as independent variables.

Results: Type 1 diabetes diagnosis was made by diabetic ketoacidosis in 1,520 (42.3%), by fasting plasma glucose in 1413 (39.4%), by random blood glucose in 516 (14.4%), by oral glucose tolerance test in 66 (1.8%) and by other methods in 76 (2.1%) cases, respectively. Diagnosis made before the year 2000 had a greater odds to occur by diabetic ketoacidosis (Odds ratio 1.26, 95% confidence intervals (CI) 1.09-1.48). Since then, a decrease has occurred. Economic status, geographic region and age were significantly related to diabetic ketoacidosis at diagnosis.

Conclusions: Although high prevalence of diabetic ketoacidosis at diagnosis of Type 1 diabetes in Brazil is observed, recently, more patients have been diagnosed by other methods.