Increased glycated albumin levels in patients with acromegaly related to glucose fluctuation caused by growth hormone excess but not albumin metabolism

Abstract

Acromegaly is often complicated by impaired glucose tolerance. The accuracy of glycated hemoglobin (HbA 1c ) and glycated albumin (GA) levels in representing glycemic profiles in patients with endocrine disorders, such as acromegaly, is unclear. This retrospective study reviewed data from patients whose GA levels had been recorded. 14 patients with acromegaly without diabetes mellitus (DM) (the acromegaly group), 15 patients with severe adult GH deficiency without DM (the growth hormone deficiency (GHD) group), and 55 nondiabetic patients (the control group) were included in this study. GA levels were significantly increased in the acromegaly group compared with the control and GHD groups, but no significant differences were observed between the control and GHD groups. The three groups were matched using propensity score matching (13 patients with acromegaly, 13 with GHD, and 13 control patients). Nonetheless, the results after matching were the same as those before matching. GA levels in the acromegaly group were significantly associated with plasma glucose (PG) levels at 0, 30, and 120 min after a 75-g oral glucose tolerance test (OGTT). Further, GH levels at 120 min after a 75-g OGTT in the acromegaly group were significantly correlated with GA levels and the difference in PG levels at baseline and 30 min. Our findings suggest that increases in PG levels attributable to excess GH after glucose loading are related to increases in GA levels in patients with acromegaly without DM. Hence, both HbA 1c and GA should be checked to accurately assess impaired glucose tolerance in patients with acromegaly.