Endocrine Abstracts

Introduction: Carbohydrate metabolism (CHM) is impaired in over 30% of acromegalic patients. Natural history of acromegaly and treatment modalities, i.e. surgery, somatostatin analogues (SSA) and pegvisomant, may impact in a different way on CHM.

Aim: To assess CHM alterations (impaired fasting glucose (IFG) and diabetes mellitus (DM)) in acromegaly and their relationship with clinical features and treatment options.

Patients and methods: In a retrospective study we have included 55 patients, with acromegaly. Age, gender, BMI, tumor size, IGF1 levels and the presence of IFG or DM have been analyzed before and after surgery or medical treatment.

Results: There were 30 men and 25 women. Mean age before treatment was 57±17 years and mean BMI was 28±3.8 kg/m². We have found IFG in 13 and DM in 15 patients (total 28; 50%). We have found no statistically significant differences in age, gender, BMI and IGF1 levels between IFG/DM and patients without CHM impairment. However, IFG/DM patients have more frequently macroadenomas. Transsphenoidal resection was performed in 49 (88%) cases. Because of persistence of high postsurgical IGF1 levels (n=24) or as a primary therapy (n=6), 30 patients received SSA. For persistence of high IGF1 levels, nine cases were shifted to pegvisomant.

In diabetic patients, HbA1c decreased after surgery from 7.6% (6.7–8.5) to 6.7% (6.2–6.8) and after SSA from 7.1% (6.7–7.4) to 6.6% (5.7–8.5), but only in patients on pegvisomant we have observed a significant reduction HbA1c from 9.8% (8.9–10.5) to 5.6% (5.5–6.8). Furthermore, only in pegvisomant group, we had to lower insulin and/or oral agents whereas with surgery or SSA the diabetic treatment requirement was higher.

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