Endocrine Abstracts

Introduction: Cardiovascular complications are the most relevant cause of mortality in patients with acromegaly.

Aims: To evaluate the effects of chronic excess of GH, IGF1 and PRL on blood pressure, heart rate and pulse in patients with active acromegaly.

Subjects and methods: Sixty-three patients (22 men and 41 women; aged 18–76 years) with macroadenoma of hypophysis (45 – somatotropinoma, 19 – somatomammotropinoma) were under investigation. Blood samples for GH, IGF1, prolactine (PRL), insulin (IRI) were taken in fasting state. Routine measurements of blood pressure (SBP and DBP), heart rate (HR) and pulse (P) were done. Disease activity was evaluated by means of OGTT according to the Consensus Conference criteria. Hypertension was diagnosed in the presence of DBP above 90 mm/Hg. Data are given as M±S.E.M. and multiple regression model equations.

Results: In patients with somatotropinoma (GH – 22.8±3.5 ng/ml) and somatomamotropinoma (GH – 26.3±5.3 ng/ml) vital signs varied in large (SBP (80 – 176, mmHg); DBP (58–116, mmHg); HR (48–95, bpm); P (50–95, bpm)). Arterial hypertension was recorded in 64.5%, tachycardia – in 12.5% and bradycardia – in 4.5% of patients. It was revealed significant associations of GH and IRI with cardiovascular signs, approximated by equations: SBP ≈ 2.32*GH+2.13*IRI (R²=75.4%; P<0.001); DBP≈1.48*GH+1.31*IRI (R²=75.4%; P<0.001); HR≈1.06*GH+1.01*IRI (R²=70.4%; P<0.001); P≈1.13*GH+1.19*IRI (R²=73.54%; P<0.001).

Conclusion: High prevalence of arterial hypertension may be part of metabolic complications of chronic GH and IGF1 excess mediated by hyperinsulinemia. Increased or decreased heart rate may be due to sympathovagal imbalance in patients with acromegaly.