Inaccuracy of haemoglobin A1c among HIV-infected men: effects of CD4 cell count, antiretroviral therapies and haematological parameters.
BACKGROUND
There is limited evidence that among HIV-infected patients haemoglobin A1c (HbA1c) values may not accurately reflect glycaemia. We assessed HbA1c discordance (observed HbA1c - expected HbA1c) and associated factors among HIV-infected participants in the Multicenter AIDS Cohort Study (MACS).


METHODS
Fasting glucose (FG) and HbA1c were measured at each semi-annual MACS visit since 1999. All HIV-infected and HIV-uninfected men for whom at least one FG and HbA1c pair measurement was available were evaluated. Univariate median regression determined the association between HbA1c and FG by HIV serostatus. The relationship between HbA1c and FG in HIV-uninfected men was used to determine the expected HbA1c. Generalized estimating equations determined factors associated with the Hb1Ac discordance among HIV-infected men. Clinically significant discordance was defined as observed HbA1c - expected HbA1c ≤-0.5%.


RESULTS
Over 13 years, 1500 HIV-uninfected and 1357 HIV-infected men were included, with a median of 11 visits for each participant. At an FG of 125 mg/dL, the median HbA1c among HIV-infected men was 0.21% lower than among HIV-uninfected men and the magnitude of this effect increased with FG >126 mg/dL. Sixty-three percent of HIV-infected men had at least one visit with clinically significant HbA1c discordance, which was independently associated with: low CD4 cell count (<500 cells/mm(3)); a regimen containing a protease inhibitor, a non-nucleoside reverse transcriptase inhibitor or zidovudine; high mean corpuscular volume; and abnormal corpuscular haemoglobin.


CONCLUSION
HbA1c underestimates glycaemia in HIV-infected patients and its use in patients with risk factors for HbA1c discordance may lead to under-diagnosis and to under-treatment of established diabetes mellitus.
['Slama|Laurence|L|', 'Palella|Frank J|FJ|', 'Abraham|Alison G|AG|', 'Li|Xiuhong|X|', 'Vigouroux|Corinne|C|', 'Pialoux|Gilles|G|', 'Kingsley|Lawrence|L|', 'Lake|Jordan E|JE|', 'Brown|Todd T|TT|']
D000293:Adolescent D000328:Adult D044966:Anti-Retroviral Agents D001786:Blood Glucose D018791:CD4 Lymphocyte Count D003920:Diabetes Mellitus D003951:Diagnostic Errors D016903:Drug Monitoring D006442:Glycated Hemoglobin A D015658:HIV Infections D006801:Humans D008297:Male D008875:Middle Aged D011446:Prospective Studies D055815:Young Adult
HbA1c HIV mean corpuscular volume diabetes glycosylated haemoglobin