Glycated Albumin Identifies Prediabetes Not Detected by Hemoglobin A1c: The Africans in America Study.
BACKGROUND
Following immigration to the US, many Africans transition from a low-normal to a high-normal or overweight body mass index (BMI). This weight change is associated with a high rate of prediabetes in the nonobese. Studies in East Asians reveal that glycated albumin is effective in identifying prediabetes in nonobese Asians. Whether this is true in African immigrants is unknown. Therefore, we evaluated the ability of hemoglobin A1c(Hb A1c) and glycated albumin to detect prediabetes in nonobese (BMI <30 kg/m2) and obese (BMI ≥30 kg/m2) African immigrants.


METHODS
Oral glucose tolerance tests (OGTTs) were performed in 236 self-identified healthy African immigrants [mean (SD) BMI 27.6 (4.4) kg/m2]. Prediabetes diagnosis was based on glucose criteria for the OGTT. Diagnostic sensitivity of Hb A1cand glycated albumin was determined by thresholds at the upper quartile for each [Hb A1c≥5.7% (39 mmol/mol), glycated albumin ≥13.77%].


RESULTS
Based on glucose criteria for the OGTT, prediabetes was detected in 36% (85/236). BMI and Hb A1cwere positively correlated (r = 0.22, P < 0.001), whereas BMI and glycated albumin were negatively correlated (r = -0.24, P < 0.001). Although the sensitivities of Hb A1cand glycated albumin were similar in nonobese immigrants (37% vs 42%, P = 0.75), prediabetes was detected in 21 nonobese Africans by glycated albumin alone, in 18 by Hb A1calone, and in 4 by both tests. Therefore, sensitivity of the combined tests was better than for Hb A1calone(72% vs 37%, P < 0.01). In the obese, Hb A1cwas a much better diagnostic test than glycated albumin (64% vs 16%, P < 0.01) and combining the tests did not improve sensitivity (72% vs 64%, P = 0.50).


CONCLUSIONS
Glycated albumin contributes by identifying prediabetes not detected by Hb A1cin nonobese African immigrants. ClinicalTrials.gov Identifier: NCT00001853.
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD; annes@intra.niddk.nih.gov.
Anne E
AE
Sumner
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD.
Michelle T
MT
Duong
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD.
Brianna A
BA
Bingham
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD.
Paola C
PC
Aldana
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD.
Madia
M
Ricks
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD.
Lilian S
LS
Mabundo
Tropical Medicine Research Institute, University of the West Indies, Kingston, Jamaica.
Marshall K
MK
Tulloch-Reid
Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes, Digestive and Kidney Diseases, NIH, Bethesda, MD.
Stephanie T
ST
Chung
Department of Laboratory Medicine, Clinical Center, NIH, Bethesda, MD.
David B
DB
Sacks
D000328:Adult; D001741:Black or African American; D044383:Black People; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis*; D017127:Glycation End Products, Advanced; D006801:Humans; D008297:Male; D008875:Middle Aged; D011236:Prediabetic State / Q000097:blood* / Q000175:diagnosis*; D012709:Serum Albumin / Q000032:analysis*; D055815:Young Adult; D000093423:Glycated Serum Albumin
D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D000093423:Glycated Serum Albumin