Comparative study of HbA1cand fasting plasma glucose vs the oral glucose tolerance test for diagnosis of diabetes in people with tuberculosis.
To compare HbA1cand fasting plasma glucose assessment, with the 2-h oral glucose tolerance test as reference, in screening for diabetes in people with turberculosis.



Individuals (N=268) with newly diagnosed smear-positive tuberculosis were screened for diabetes at a tertiary hospital in Lahore, Pakistan. Diabetes diagnosis was based on WHO criteria: thresholds were ≥48 mmol/mol (≥6.5%) for HbA1cand ≥7.0mmol/l for fasting plasma glucose.



The proportion of participants diagnosed with diabetes was 4.9% (n =13) by oral glucose tolerance test, while 11.9% (n =32) and 14.6% (n =39) were diagnosed with diabetes using HbA1cand fasting plasma glucose criteria, respectively. The area under the receiver-operating characteristic curve was 0.79 (95% CI 0.64 to 0.94) for HbA1cand 0.61 (95% CI 0.50 to 0.73) for fasting plasma glucose, with a borderline significant difference between the two tests (P=0.07).



HbA1cand fasting plasma glucose performed equally in terms of diagnosing new diabetes cases in individuals with tuberculosis, but the proportion of participants falsely classified as positive was higher for fasting plasma glucose. This may be explained by acute blood glucose fluctuations when using fasting plasma glucose. HbA1cmay be a more reliable test in individuals with transient hyperglycaemia.
Global Health Section, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
H
0000-0003-2957-0544
H
Aftab
Gulab Devi Chest Hospital, Lahore, Pakistan.
A
A
Ambreen
Gulab Devi Chest Hospital, Lahore, Pakistan.
M
M
Jamil
Laboratory of Molecular Medicine, Department of Clinical Immunology, University of Copenhagen, Copenhagen, Denmark.
P
P
Garred
Section of Biostatistics, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
J H
JH
Petersen
Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark.
S D
SD
Nielsen
Global Health Section, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
I C
IC
Bygbjerg
Global Health Section, Department of Public Health, University of Copenhagen, Copenhagen, Denmark.
D L
DL
Christensen
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001786:Blood Glucose / Q000032:analysis*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D005189:False Positive Reactions; D005215:Fasting / Q000097:blood*; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D010154:Pakistan; D014376:Tuberculosis / Q000097:blood* / Q000150:complications
D001786:Blood Glucose; D006442:Glycated Hemoglobin