HemoglobinA1c level in healthy Thai adults: Reference interval and fasting plasma glucose

doi:10.1016/j.diabres.2008.11.028

Diabetes Research and Clinical Practice

Volume 83, Issue 2, February 2009, Pages e43-e46

https://doi.org/10.1016/j.diabres.2008.11.028 Get rights and content

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.

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 HbA1c_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.

Section snippets

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 tubes. Complete blood count (CBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) was analyzed by Sysmex XT-1800i (Sysmex, Illinois, U.S.A.), while creatinine (Cr) and FPG were analyzed by Liasys III (AMS, Rome, Italy). Dichlorophenol-indophenol precipitation test (DCIP) was used for hemoglobinopathies

Reference interval

After exclusion of abnormal samples, 323 samples were left for reference interval analysis. The characteristics of subjects were shown in the Table 1.

The histogram plot of HbA1c_IFCC_INTEGRA (Fig. 1) showed a normal distribution. The reference interval of HbA1c_IFCC_INTEGRA could be set between 2.5th and 97.5th percentiles to be 2.90–4.90%. HbA1c was not influenced by sex. However HbA1c was significantly increased with age regardless of methods (Fig. 2).

HbA1c_IFCC and fasting plasma glucose

HbA1c_IFCC_INTEGRA and FPG showed a

Discussion

Reference interval for HbA1c_IFCC in this study is 2.90–4.90% which comparable to previous data [10]. However, the upper reference limit is slightly higher than in western data [11]. Since HbA1c was affected by age then further study should be done to determine an effect of age on HbA1c at the clinical determination level. If it does, the reference interval according to age group should be established.

Regarding association between HbA1c_IFCC and fasting plasma glucose, a 1% change in HbA1c_IFCC

Conflict of interest

The authors state that they have no conflict of interest.

References (14)

The Diabetes Control and Complications Trial Research Group
The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus
N. Engl. J. Med.
(1993)
UK Prospective Diabetes Study (UKPDS) Group
Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33)
The Lancet
(1998)
American Diabetes Association, European Association for the study of Diabetes, International Federation of Clinical...
S. Manley et al.
Introduction of IFCC reference method for calibration of HbA1c: implications for clinical care
Diabet. Med.
(2004)
Roche Diagnostics GmbH D-M, Cobas INTEGRA 400/700/800: Hemoglobin A1C Hemolysate Application Standardized According to...
D. Behring
Dimension Clinical Chemistry System: HbA1C Kit
(2006)
BIO-RAD, D-10 Hemoglobin A1c Program: Instruction Manual, BIO-RAD Laboratories Inc. Hercules, CA...

There are more references available in the full text version of this article.

Cited by (4)

Measurement of glycated haemoglobin in a Tunisian population: Reference values in healthy adults and correlation with fasting blood glucose in diabetic patients
2011, Immuno-Analyse et Biologie Specialisee
Studies hold a debate on use of glycated haemoglobin (HbA1c) as diabetes screening method.
Establish HbA1c level in healthy Tunisians and find a correlation between HbA1c and fasting blood glucose (FBG) in diabetics.
All the 289 healthy people benefit from FBG, 75 g oral glucose tolerance test (OGTT) and HbA1c. For the 853 diabetic patients, we collected level of FBG and HbA1c.
In healthy people, FBG average = 5.19 mmol/L (3.86–6.09); HbA1c = 5.83 ± 0.45% (3.75–6.50). HbA1c increased by age but was correlated with FBG. Reference intervals of HbA1c were established: six groups from (20–30 years) until (over 70 years) with an increased HbA1c level respectively from 5.46 till 5.94%. For both healthy and diabetics, there was no statistical difference between sexes. In diabetics, 1% change in HbA1c corresponded to 18 mg/dL change in FBG.
It is important for clinicians to know reference intervals in order to screen diabetes when FBG is normal. The G0/HbA1c correlation might be clinically useful to achieve good diabetic control.
La connaissance des valeurs usuelles de l’hémoglobine glyquée (HbA1c) en fonction de l’âge permettrait le dépistage du diabète chez le sujet normal.
Établir les valeurs de référence de l’HbA1c chez le tunisien non diabétique et rechercher une corrélation entre HbA1c et glycémie à jeun (G0) chez les diabétiques.
Les 289 témoins ont bénéficié de : G0, hyperglycémie provoquée orale (HGPO75) et HbA1c. Six groupes étaient définis de l’intervalle (20–30 ans) à (plus de 70 ans) ; les 853 diabétiques ont bénéficié de G0 et HbA1c.
Chez les témoins, G0 était de 5,19 mmol/L (3,86–6,09) ; l’HbA1c est égale à 5,83 ± 0,45 % (3,75–6,50). L’HbA1c augmentait avec l’âge mais restait corrélée à G0. L’HbA1c était croissante de (20–30 ans) à (> 70 ans) respectivement de 5,46 à 5,94 %. Il n’y avait pas de différence statistiquement significative entre les deux sexes pour les témoins et les malades. Chez les diabétiques, une élévation de 1 % de l’HbA1c correspondrait à une élévation de 18 mg/dL pour G0.
Il est important pour les cliniciens de connaître l’intervalle de référence correspondant à leur patient afin de mieux interpréter un diabète chez un sujet présentant une G0 normale. La corrélation G0/HbA1c permettrait un meilleur contrôle de l’équilibre glycémique.
A first-degree relative with diabetes mellitus is an important risk factor for rural Thai villagers to develop type 2 diabetes mellitus
2015, Asia-Pacific Journal of Public Health
Age and sex variations of HbA <inf>1C</inf> in a French population without known diabetes aged 6 to 79 years
2011, Annales de Biologie Clinique
Comparison of IFCC and NGSP methods for determination of glycated haemoglobin using advanced regression techniques
2010, Central European Journal of Chemistry

View full text

Brief reportHemoglobinA1c level in healthy Thai adults: Reference interval and fasting plasma glucose

Abstract

Aim

Materials and Methods

Results

Conclusion

Introduction

Section snippets

Subjects

Reference interval

HbA1c_IFCC and fasting plasma glucose

Discussion

Conflict of interest

The effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus

N. Engl. J. Med.

Intensive blood-glucose control with sulphonylureas or insulin compared with conventional treatment and risk of complications in patients with type 2 diabetes (UKPDS 33)

The Lancet

Introduction of IFCC reference method for calibration of HbA1c: implications for clinical care

Diabet. Med.

Dimension Clinical Chemistry System: HbA1C Kit

Brief report
HemoglobinA1c level in healthy Thai adults: Reference interval and fasting plasma glucose