Improved Detection of Abnormal Glucose Tolerance in Africans: The Value of Combining Hemoglobin A1c With Glycated Albumin.

AMERICA; UNITED States; AFRICA

Objective: In African-born Blacks living in America, we determined by BMI category 1) prevalence of abnormal glucose tolerance (Abnl-GT) and 2) diagnostic value and reproducibility of hemoglobin A1c (HbA1c), fructosamine, and glycated albumin (GA).Research Design and Methods: Participants (n = 416; male, 66%; BMI 27.7 ± 4.5 kg/m2 [mean ± SD]) had an oral glucose tolerance test with HbA1c, GA, and fructosamine assayed. These glycemic markers were repeated 11 ± 7 days later. Abnl-GT diagnosis required 0 h ≥5.6 mmol/L (≥100 mg/dL) and/or 2 h ≥7.8 mmol/L (≥140 mg/dL). Thresholds for HbA1c, GA, and fructosamine were the values at the 75th percentile for the population (39 mmol/mol [5.7%], 14.2%, and 234 μmol/L, respectively).Results: Abnl-GT prevalence in the nonobese was 34% versus 42% in the obese (P = 0.124). Reproducibility was excellent for HbA1c and GA (both κ ≥ 0.8), but moderate for fructosamine (κ = 0.6). Focusing on HbA1c and GA in the nonobese, we found as single tests the sensitivities of HbA1c and GA were 36% versus 37% (P = 0.529). Combining HbA1c and GA, sensitivity increased to 58% because GA identified 37% of Africans with Abnl-GT not detected by HbA1c (P value for both tests vs. HbA1c alone was <0.001). For the obese, sensitivities for HbA1c, GA, and the combined tests were 60%, 27%, and 67%, respectively. Combined test sensitivity did not differ from HbA1c alone (P = 0.25) because GA detected only 10% of obese Africans with Abnl-GT not detected by HbA1c.Conclusions: Adding GA to HbA1c improves detection of Abnl-GT in nonobese Africans. [ABSTRACT FROM AUTHOR]

Copyright of Diabetes Care is the property of American Diabetes Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)