Introduction: Acromegaly, caused by excess of growth hormone, has high cardiovascular mortality and morbidity. Aortic pulse wave velocity (aPWV) and Ambulatory arterial stiffness index (AASI) are known measures of arterial stiffness. We evaluated the factors influencing aPWV and AASI in patients with acromegaly.

Method: Patients with acromegaly at various stages in their disease were assessed for disease activity by IGF-1, presence of hypopituitarism, other co-morbidities, aPWV and measurement of 24 hour ambulatory blood pressure and thereby AASI.

Results: 55 patients (mean age: 52.8±14.0 years, aPWV:11.7±3.6m/sec, AASI: 0.31±0.27), 32.7% female, took part in the study. 36.4% had hypopituitarism. Their blood pressure was 126.0±16.7 / 78.1±11.8 mm Hg and 45.5% were dippers. The IGF-1 was in the age related normal range in 54.5% of patients. There were no significant differences in aPWV or AASI between patients with high or normal IGF-1. Multivariate analysis including pulse pressure, heart rate, gender, presence of hypopituitarism, nocturnal dipping of blood pressure, proteinuria, cigarette smoke exposure, diabetes and hypertension, identified Age (β: 0.25,95% CI of β 0.11 to 0.38, p = 0.002) and hyperlipidaemia (−4.9, −9.1 to −0.7,0.026) independently influenced aPWV, while IGF-1 (β: 0.001,95% CI of β: 0.0 to 0.002, p = 0.042) independently influenced AASI.

Conclusion: In patients with acromegaly, IGF-1 independently influences AASI but not aPWV which is affected by traditional cardiovascular risk factors, namely age and hyperlipidaemia. These findings suggest that IGF-1, by its effects on vascular smooth muscle cells, affects the stiffness of muscular arteries but not that of the elastic arteries.