Glycated albumin is set lower in relation to plasma glucose levels in patients with Cushing's syndrome

Abstract

Background: Glycated albumin (GA) is an indicator of glycemic control, which has some specific characters in comparison with HbA1c. Since glucocorticoids (GC) promote protein catabolism including serum albumin, GC excess state would influence GA levels. We therefore investigated GA levels in patients with Cushing's syndrome.

Methods: We studied 16 patients with Cushing's syndrome (8 patients had diabetes mellitus and the remaining 8 patients were non-diabetic). Thirty-two patients with type 2 diabetes mellitus and 32 non-diabetic subjects matched for age, sex and BMI were used as controls.

Results: In the patients with Cushing's syndrome, GA was significantly correlated with HbA1c, but the regression line shifted downwards as compared with the controls. The GA/HbA1c ratio in the patients with Cushing's syndrome was also significantly lower than the controls. HbA1c in the non-diabetic patients with Cushing's syndrome was not different from the non-diabetic controls, whereas GA was significantly lower. In 7 patients with Cushing's syndrome who performed self-monitoring of blood glucose, the measured HbA1c was matched with HbA1c estimated from mean blood glucose, whereas the measured GA was significantly lower than the estimated GA.

Conclusions: We clarified that GA is set lower in relation to plasma glucose levels in patients with Cushing's syndrome.

Keywords: Cushing's syndrome; Glucocorticoid; Glycated albumin; HbA1c; Type 2 diabetes mellitus.