Glycated Hemoglobin, Albuminuria and Surrogate Markers of Macrovascular Disease in Adults Without Diabetes: The Guangzhou Biobank Cohort Study, Cardiovascular Disease Subcohort

Objectives: To explore the clinical utility of glycated hemoglobin (A1C) levels as an early marker of albuminuria, macrovascular disease and subclinical cardiovascular disease in comparison to fasting and postprandial glucose levels in a well-characterized Chinese population with no history of diabetes. Methods: The study population consisted of 1223 individuals who were enrolled in the Guangzhou Biobank Cohort Study, Cardiovascular Disease Subcohort, and who had undergone oral glucose tolerance tests. The associations between each glycemic measure and albuminuria, carotid intima-media thickness (CIMT) and CIMT-based presence of carotid plaques and aortic arch calcification were assessed by chest radiographs. Results: The overall prevalence of albuminuria, carotid plaque and any aortic arch calcification was 20.6%, 22.8% and 25.8%, respectively. All 3 glycemia indices were significantly associated with albuminuria, but only 1 (fasting glucose) was associated with carotid plaques. No significant difference was detected among them in the area under the curve for albuminuria (chi-square test; p=0.84), carotid plaques (p=0.28) or calcifications (p=0.29). In sensitivity analysis, adjusted for age and sex, the above findings remained unchanged. Conclusions: Although there was evidence suggesting differential associations, the performance of the glycemic indices was similar, and their association with macrovascular disease and albuminuria was modest.