Characterization of premature atherosclerosis of carotid arteries in acromegalic patients

OBJECTIVE Acromegalic patients have increased mortality from vascular disea ses. Although atherosclerotic risk factors such as hypertension, diabetes m ellitus and dyslipoproteinaemia are highly associated with acromegaly, the prevalence of premature atherosclerosis in acromegalic patients and its rel ationship to these risk factors have not been reported. DESIGN We measured mean intima-media thickness (IMT) of the carotid arterie s in 21 acromegalic patients without symptomatic atherosclerotic vascular d isease, by ultrasound high-resolution B-mode imaging. In analysis 1, it was compared with the predicted mean IMT based on data from existing risk fact ors (age, male sex, dyslipoproteinaemia, hypertension, diabetes mellitus, s moking status) in 282 non-acromegalic subjects. In analysis 2, the mean IMT in the 21 acromegalic patients was compared with that in 42 non-acromegali c subjects matched for age, sex and the other atherosclerotic risk factors. We also analysed clinical characteristics between the acromegalic patients with and without the atherosclerosis, RESULTS Mean IMT in 21 acromegalic patients was 0.92 +/- 0.21 (mean +/- SD) mm, It was significantly (P < 0.05) lower than the mean IMT (1.03 +/- 0.12 mm) predicted from their existing risk factors (analysis 1), It was also l ess than that in 42 non-acromegalic subjects matched for atherosclerotic ri sk factors (1.07 +/- 0.37 mm; P < 0.05) (analysis 2), Among the acromegalic patients, 10 patients (48%) had increased mean IMT (greater than or equal to 1.1 mm) and/or plaque lesions whereas the other 11 had no such atheroscl erotic changes. In the patients without the atherosclerotic changes, plasma insulin-like growth factor-I (IGF-I) concentration was significantly (P < 0.01) higher, and the prevalence of hypertension was significantly (P < 0.0 5) lower than in those with the atherosclerotic changes. CONCLUSIONS The extent of carotid atherosclerosis in the acromegalic patien ts was not higher than that in non-acromegalic subjects, considering their atherosclerotic risk factors. Increased concentration of IGF-I might be inv olved in the lack of susceptibility to atherosclerosis in some acromegalic patients.