GLYCATED HEMOGLOBIN (HbA1c)

SCREENING FOR UNDIAGNOSED DIABETES IN HEALTHY INDIVIDUALS IN SARGODHA

Abstract

HbA1c gives an integrated index of glycemia over the entire 120 days life
span of red blood cells. Therefore, measuring HbA1c would be appropriate in diagnosing a
disease characterized by chronic hyperglycemia and a gradual progression to complications.
Objectives: our primary objective was to evaluate the use of HbA1c as screening test for
undiagnosed diabetes (WHO criteria of Fasting plasma glucose (FPG) of ≥ 7mmol/l (126mg/dl))
in healthy asymptomatic individuals in Pakistani population. Study Design and Methodology:
A cross sectional population survey was carried on asymptomatic, healthy individuals without
past history of diabetes. Venous blood was obtained to measure fasting plasma glucose
(fasting > 8 hours) and Hb A1c. Place and Duration of Study: Khan lab Sargodha from July
2013 to March 2014. The test: It was performed by using NycoCard HbA1c in vitro diagnostic
medical device for quantitative determination of glycated hemoglobin in whole blood. Results:
In our sample size of 775, the lowest HbA1c was found to be 5% and Highest 13.2%. Arithmetic
means was 6.7565%, while the median value was 6.2% and standard deviation 1.3323. When
using FPG only, the detection rate of diabetes was 32.65% (female, 14.71%; male, 17.94%).
When HbA1c was included as a diagnostic test, the detection rate increased to 40% (female,
18.84%; male, 21.16 %). An additional 7.6% of participants were diagnosed with diabetes when
using HbA1c criteria. ROC (A receiver operating characteristic) curve was used for analysis.
At HbA1c cutoff of ≥6.5% it demonstrated sensitivity of 98.02% (95% CI) and specificity of
88.12% (95% CI) for detection of undiagnosed diabetes mellitus in healthy asymptomatic
individuals in Pakistani population. Area under the ROC curve was 0.981354 with significance
level P (Area=0.5) 0.0001. Conclusions: Our study reveals that HbA1c is a highly specific and
convenient alternative to fasting plasma glucose for screening of diabetes mellitus in Pakistani
population. A large scale survey should be carried out to set our own national standardizations.