Comparison of diagnostic accuracy of glycated hemoglobin (HBA1C) and 2-hour post glucose for diabetes using American Diabetic Association (ADA) cut offs in Pakistani population

Document Type



Pathology and Laboratory Medicine


To determine median HbA1c level in patients screened for DM and compare the diagnostic accuracy of HbA1c with the currently recommended ADA cut off, using 2 hours (h) plasma glucose (2-h PG) post 75 grams oral glucose tolerance test (OGTT) as gold standard.
Study Design:
Cross sectional study.
Place and Duration of Study:
Aga Khan University Hospital Karachi, from Jul 2014 to Nov 2015
Patients and Methods:
Consecutive subjects screened by OGTT for diabetes mellitus (DM) were included. Blood sample for plasma glucose and HbA1c were analyzed on ADVIA 1800.
Total 146 subjects were included with median age 45 (IQR 54.2-35) years; 53% (n=77) being females. Median HbA1c of the study subjects was 6% (IQR 6.6-5.6). Positive correlation was observed between age and HbA1c [5.7% (IQR 6.2-5.3) <40 y, 6.2% (IQR 6.8-5.8) in >40 y subjects; r 0.34, p=0.000). Males had higher HbA1c than females [6.1% (IQR 6.8-5.7) years. 5.9% (IQR 6.4-5.4); r 0.17, p=0.036). HbA1c levels were significantly different amongst the different ethnic groups residing in Pakistan (p-value<0.03). HbA1c was positively correlated with FPG (r=0.59, p-value<0.001) and 2-h PG (r=0.56, p-value<0.001).Sensitivity, specificity, PPV, NPV for HbA1c at cutoff of 6.5% in diagnosing diabetes mellitus (DM) were 70%, 89%, 72% and 80% respectively.
High median HbA1c levels is noted in our subjects. At cut off level of HbA1c ≥6.5%, 70% of subjects with DM were diagnosed using ADA criteria of 2-h PG for diabetes as gold standard. Ethnic differences were also observed in levels of HbA1c.There is a need to define cut off for our population


Pakistan Armed Forces Medical Journal