Tohoku J. Exp. Med., 2007, 213(1)

Combined Use of Fasting Plasma Glucose and Glycated Hemoglobin A1c in a Stepwise Fashion to Detect Undiagnosed Diabetes Mellitus

TOMOKO NAKAGAMI,¹ MAKOTO TOMINAGA,² RIMEI NISHIMURA,³ MAKOTO DAIMON,⁴ TOSHIHIDE OIZUMI,⁴ NOBUO YOSHIIKE⁵ and NAOKO TAJIMA³

¹Diabetes Center, Tokyo Women's Medical University, Tokyo, Japan
²Department of Laboratory Medicine, Yamagata University School of Medicine, Yamagata, Japan
³Division of Diabetes, Metabolism and Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Tokyo, Japan
⁴Department of Neurology, Hematology, Metabolism, Endocrinology and Diabetology, Yamagata University School of Medicine, Yamagata, Japan
⁵National Institute of Health and Nutrition, Tokyo, Japan

Type 2 diabetes mellitus (DM) is a common and serious condition related with considerable morbidity. Screening for DM is one strategy for reducing this burden. In Japan National Diabetes Screening Program (JNDSP) guideline, the combined use of fasting plasma glucose (FPG) and glycated hemoglobin A1c (HbA1c) in a stepwise fashion has been recommended to identify the group of people needing life-style counseling or medical care. However, the efficacy of this program has not been fully evaluated, as an oral glucose tolerance test (OGTT) is not mandatory in the guideline. The aim of this study was to assess the validity of the screening test scenario, in which an OGTT would be applied to people needing life-style counseling or medical care on this guideline: FPG 110-125 mg/dl and HbA1c over 5.5%. Subjects were 1,726 inhabitants without a previous history of DM in the Funagata study, which is a population-based survey conducted in Yamagata prefecture to clarify the risk factors, related conditions, and consequences of DM. DM was diagnosed according to the 1999 World Health Organization criteria. The prevalence of undiagnosed DM was 6.6%. The tested screening scenario gave a sensitivity of 55.3%, a specificity of 98.4%, a positive predictive value of 70.8%, and a negative predictive value of 96.9% for undiagnosed DM. In conclusion, the screening test scenario, in which an OGTT would be followed by the combined use of FPG and HbA1c in a stepwise fashion according to the JNDSP guideline, was not effective in identifying people with undiagnosed DM.

keywords —— hemoglobin A1c; fasting plasma glucose; diabetes; stepwise screening; Japan National Diabetes Screening Program

© 2007 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2007, 213, 25-32

Correspondence: Tomoko Nakagami, Diabetes Center, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.

e-mail: nakagami@dmc.twmu.ac.jp