Endocrine Abstracts

Context: Although diabetes mellitus is a major complication in patients with acromegaly, prevalence and determinants of microvascular and macrovascular complications of diabetes remains unexplored in this population.

Aim: To investigate prevalence and determinants of microvascular and macrovascular complications in acromegaly patients with diabetes and to compare them with a group of diabetic patients without acromegaly.

Methods: Prospective case-control cross-sectional study evaluating 53 acromegaly patients with diabetes (ACRODIAB) and 53 diabetic patients (DIAB) similar for gender and age.

Results: No significant difference in age at diabetes diagnosis, diabetes duration, fasting glucose, and HbA1c levels were found between ACRODIAB and DIAB groups. Prevalence of retinopathy was similar between the two groups (18.4% vs 14.3%,P=0.602), whereas ACRODIAB patients had a significantly higher eGRF (P=0.01) and a significantly lower prevalence of chronic kidney failure (P<0.001) compared to DIAB group. Albuminuria was slightly but not significantly lower in ACRODIAB than in DIAB group (12.7±18.4 vs 22.3±38.3,P=0.185). Prevalence of ischemic heart disease (27.3% vs 41.5%, P=0.03) and cerebrovascular disease (1.9% vs 14.3%,P=0.03) were significantly lower in ACRODIAB than DIAB group. Similarly, atherosclerotic plaques (78.4% vs 95.2%,P=0.09) and lower limb peripheral arterial disease (14.7% vs 28.6%, P=0.211) were slightly less frequent in ACRODIAB than DIAB group. In ACRODIAB group, patients with retinopathy were significantly younger both at the evaluation (P=0.02) and at diabetes diagnosis (P=0.009) and had slightly higher IGF-I levels (P=0.06) as compared to those without retinopathy. In ACRODIAB group, patients diagnosed with diabetes before the age of 52 years (median) had a significantly higher prevalence of retinopathy (37.5% vs 4.3%,P=0.008), mainly proliferative (18.7% vs 4.3%, P=0.07), and a slightly higher prevalence of lower limb peripheral arterial disease (23.1% vs 9.5%, P=0.278) as compared to those diagnosed at older age. ACRODIAB patients in whom diabetes onset occurred before acromegaly exhibited a significantly higher prevalence of atherosclerotic plaques (55.5% vs 16.7%, P=0.04) and of lower limb peripheral arterial disease (32.3% vs 0%, P=0.01) as compared to those diagnosed with diabetes after acromegaly. Retinopathy was slightly more frequent in ACRODIAB patients diagnosed with diabetes before acromegaly than those in whom the diagnosis was simultaneous (42.8% vs 9.1%, P=0.09).

Conclusions: ACRODIAB patients are affected by a lower number of diabetes complications, particularly macrovascular, as compared to DIAB. So far, a protective role of GH and IGF-I on diabetes complications cannot be excluded. In ACRODIAB patients, age at diagnosis of diabetes and diabetes occurrence before acromegaly are the main determinants of diabetes complications.