[Abnormalities of carbohydrate metabolism in acromegaly].

BACKGROUND AND OBJECTIVE: Carbohydrate metabolism (CHM) is impaired in over 50% of acromegalic patients. Natural history of acromegaly and treatment modalities may impact in a different way on CHM. We assessed CHM alterations in acromegaly and their relationship with clinical features and treatment options.

PATIENTS AND METHOD: Retrospective study with 55 patients with acromegaly. Age, sex, body mass index (BMI), tumor size, insulin growth factor type 1 (IGF-1) levels and the presence of impaired fasting glucose (IFG) or diabetes mellitus (DM) were analyzed before and after surgery or medical treatment.

RESULTS: There were 30 men and 25 women. Mean age was 50 ± 17 years and mean BMI was 27.9 ± 3.8 Kg/m(2). Impaired CHM was found in 50.9% (n = 28) (DM in 27% and IFG in 24%). In diabetic patients, we found no differences in age, sex, BMI and IGF-1 levels between IFG/DM and patients without CHM impairment. However, IFG/DM patients had macroadenomas more commonly. In diabetic patients, glycosylated hemoglobin (HbA1c) decreased after surgery from 7.6 to 6.7% and after somatostatin analogues from 7.1 to 6.6%; in patients on pegvisomant we observed a significant reduction of HbA1c: from 9.8 to 5.6% (P < .005). Furthermore, only in the pegvisomant group, insulin and/or oral agents had to be lowered.

CONCLUSIONS: Up to 50% of patients with active acromegaly have CHM impairment which correlates with tumor size. Only pegvisomant is associated with significant improvement in glycemic control and a reduction in hypoglycemic treatment.