Endocrine Abstracts

Introduction: Acromegaly is characterized by high cardiovascular morbidity and mortality possibly due to increased prevalence of main traditional cardiovascular risk factors. It is not clear though whether the incidence of atherosclerosis is truly enhanced. Moreover recent in vitro studies show a protective role of (GH) and IGF1 (insulin-like growth factor-1) on the endothelium. As expression of endothelial regenerative reserve, endothelial progenitor cells (EPCs) could clarify the complex balance between pro- and anti-atherogenic factors in acromegaly. We therefore aimed to study the distribution of EPCs within a sample of acromegalic patients.

Materials and methods: 42 acromegalic patients (female/male ratio=1.5; mean age=51±12.75 ys) underwent a clinical evaluation and a blood test including count and typization of peripheral EPCs using monoclonal antibodies CD34+ or CD133+ or KDR+ specific. Data were compared to fourty two control subjects matched by age, gender and class of glucose tolerance. In a group of 9 patients with active disease (normalized IGF1>1) the whole evaluation was repeated after 24 weeks of treatment with somatostatin analogues (SSA).

Results: Acromegalic patients show a significantly lower number of CD34+/KDR+ cells than controls (P=0,005) while CD34+/CD133+/KDR+ cells are reduced in active patients compared to the inactive group (P=0.00001) and increase after SSA treatment (P=0.03). In acromegalic patients, the number of CD34+/CD133+/KDR+ cells correlates with IGF1 levels (R=−0.56, P=0.0001), fasting plasma glucose (R=−0.46, P=0.002), plasma insulin (R=−0.33, P=0.03) and HOMA index (R=−0.37, P=0.02), IGF1 showing to be the most important covariate in a multivariate analysis (β=−0.35, P=0.03). In acromegalic and controls the CD34+/KDR+ variability is mainly explained by diastolic blood pressure (β=−0.26, P=0.03).

Conclusions: Acromegalic patients seem to have a reduced endothelial regenerative capacity and an increased cardiovascular risk probably related to IGF-1 levels, glucose metabolism alterations and hypertension. Treatment with SSA could ameliorate EPC peripheral pattern.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.