Comparison of venous plasma glycemia and capillary glycemia for the screening of type 2 diabetes mellitus in the Japanese-Brazilian community of Mombuca (Guatapará-SP)

Abstract Background To identify the most appropriate cut-off points of fasting glycemia for the screening of diabetes mellitus type 2 (DM2) with the comparison of the properties of capillary glycemia (CG) and venous blood plasma glycemia (PG) in a population of Japanese origin from the community of Mombuca, Guatapará - SP, Brazil. Methods This was a population-based descriptive cross-sectional study conducted on a sample of 131 individuals of both genders aged 20 years or more (66.8% of the target population). CG was measured with a glucometer in a blood sample obtained from the fingertip and PG was determined by an enzymatic method (hexokinase) in venous blood plasma, after a 10-14 hour fast in both cases. Data were analyzed by the receiver operating characteristic (ROC) curve in order to identify the best cut-off point for fasting glycemia (CG and PG) for the diagnosis of DM, using the 2-hour plasma glycemia > 200 mg/dl as gold - standard. Results The ROC curve revealed that the best cut-off point for the screening of DM was 110 mg/dl for CG and 105 mg/dl for PG, values that would optimize the relation between individuals with positive and false-positive results. The area under the ROC curve was 0.814 for CG (p < 0.01) and 0.836 for PG (p < 0.01). Conclusions The cut-off points of 105 mg/dl(5.8 mmol/l) for PG and of 110 mg/dl(6.1 mmol/l) for CG appear to be the most appropriate for the screening of DM2 in the population under study, with emphasis on the fact that the value recommended for CG is 5 mg/dl higher than that for PG, in contrast to WHO recommendations.

Research supported by Fundação de Apoio ao Ensino, Pesquisa e Assistência - Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto - USP. The authors wish to thank Associação Agro-Cultural e Esportiva de Guatapará for the support provided. We are grateful to Sebastião L. Brandão Filho for technical assistance and to E. Greene for English review of the manuscript.

Research supported by Fundação de Apoio ao Ensino, Pesquisa e Assistência Hospital das Clínicas, Faculdade de Medicina de Ribeirão Preto USP. The authors wish to thank Associação AgroCultural e Esportiva de Guatapará for the support provided. We are grateful to Sebastião L. Brandão Filho for technical assistance and to E. Greene for English review of the manuscript.