Brief report HemoglobinA1c level in healthy Thai adults: Reference interval and fasting plasma glucose Karan Paisooksantivatana a, *, Anucha Kongsomgan a , Lakana Leohirun b , Kalyanee Atamasirikul a , Mongkol Kunakorn a a Department of Pathology, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Thailand b Biochemistry Unit, Faculty of Tropical Medicine, Mahidol University, Thailand 1. Introduction The measurement of HbA1c has become the gold standard for diabetic control monitoring since the strong relationship of HbA1c level and risk for the development of complications in diabetes mellitus (DM) patients was demonstrated by two hallmark studies, Diabetes Control and Complication Trial (DCCT) [1] and UK Prospective Diabetes Study (UKPDS) [2]. From the expert committee recommendation in the year 2007, every laboratory should immediately adopt the IFCC reference method as new calibration standard to improve the specificity and traceability [3,4]. To prepare for using the novel IFCC methods, first objective of this study is to establish HbA1- c_IFCC reference interval in Thai. The second is the correlation between HbA1c_IFCC and fasting plasma glucose (FPG) to facilitate clinicians and patients setting up daily FPG goal to achieve HbA1c_IFCC level. 2. Material and method 2.1. Subjects 595 samples sent for routine annual check up program were received. Whole blood samples were kept in NaF tube for fasting plasma glucose (FPG) determination and in K3EDTA diabetes research and clinical practice 83 (2009) e 43– e 46 article info Article history: Received 21 August 2007 Received in revised form 16 November 2008 Accepted 17 November 2008 Published on line 8 January 2009 Keywords: HemoglobinA1c IFCC DCCT NGSP Fasting plasma glucose Reference interval abstract Aim: To establish reference interval of HbA1c IFCC in Thai. Materials and Methods: 699 whole blood samples were used. Samples had fasting plasma glucose 126 mg/dl (7.00 mmol/L), renal problem or hemoglobinopathy was excluded. Results: Reference interval of HbA1c IFCC was 2.90–4.90%. Conclusion: Effect of age should be determined. # 2008 Elsevier Ireland Ltd. All rights reserved. * Corresponding author. Tel.: +66 2 2011436; fax: +66 2 2011150. E-mail address: Litteboy@hotmail.com (K. Paisooksantivatana). Contents lists available at ScienceDirect Diabetes Research and Clinical Practice journal homepage: www.elsevier.com/locate/diabres 0168-8227/$ – see front matter # 2008 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.diabres.2008.11.028