Utility of glycated hemoglobin in diagnosing type 2 diabetes mellitus: a community-based study.
BACKGROUND
Although glycated hemoglobin (HbA1c) has recently been incorporated as a diagnostic test by the American Diabetes Association, its validity needs to be established in Asian Indians in a community setting.


OBJECTIVE
The objective of the study was to assess the validity of HbA1c as a screening and diagnostic test in individuals with newly detected diabetes mellitus.


METHODS
Community based randomized cross sectional study in urban Chandigarh, a city in north India, from April 2008 to August 2009.


METHODS
Subjects included 1972 subjects aged 20 yr or older.


METHODS
Intervention included an oral glucose tolerance test and glycated hemoglobin in all the subjects.


METHODS
Utility of HbA1c as a diagnostic method in newly detected diabetes mellitus subjects was evaluated.


RESULTS
Using World Health Organization criteria for diagnosis of diabetes mellitus, 134 (6.7%) had newly detected diabetes mellitus, 192 (9.7%) known diabetes mellitus, 329 (16.6%) prediabetes, and 1317 (69.4%) were normal of 1972 people screened. Using only the ADA criteria, 38% people were underdiagnosed. An HbA1c level of 6.1% had an optimal sensitivity and specificity of 81% for diagnosing diabetes. A HbA1c level of 6.5% (+/-2 SD) and 7% (+/-2.7 SD) had sensitivity and specificity of 65 and 88% and 42 and 92%, respectively, with corresponding positive predictive value and negative predictive value of 75.2 and 96.5% and 90.4 and 94.4%, respectively, for diagnosis of newly detected diabetes mellitus.


CONCLUSIONS
A HbA1c cut point of 6.1% has an optimal sensitivity and specificity of 81% and can be used as a screening test, and a cut point of 6.5% has optimal specificity of 88% for diagnosis of diabetes.
Kumar
Padala Ravi
PR
Department of Endocrinology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
Bhansali
Anil
A
Ravikiran
Muthuswamy
M
Bhansali
Shobhit
S
Dutta
Pinaki
P
Thakur
J S
JS
Sachdeva
Naresh
N
Bhadada
Sanjay Kumar
SK
Walia
Rama
R
D000328:Adult; D000368:Aged; D000886:Anthropometry; D015415:Biomarkers; D002851:Chromatography, High Pressure Liquid; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood / Q000175:diagnosis; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results
D015415:Biomarkers; D006442:Glycated Hemoglobin