Abnormal carotid arterial wall dynamics in symptom-free hypopituitary adults

Although vascular mortality is increased in hypopituitary adults on routine replacement, there are limited data on the atherosclerotic process during life in these patients. Measurement of arterial stiffness may provide an index of early vascular changes that predispose to the development of major vascular accidents.

Thirty-four hypopituitary adults on conventional replacement therapy and 39 age- and sex-matched controls were studied. They had no history or clinical evidence of macrovascular disease. The common carotid artery distensibility coefficient (DC), compliance coefficient (CC) and arterial stiffness index (beta index) were calculated from high-resolution ultrasonic imaging of the two common carotid arteries and from the brachial blood pressure.

There was no difference between patients and controls in carotid diastolic diameter (mean +/- S.E.M) (5.55 +/- 0.16 vs 5.45 +/- 0.08 mm) and pulse pressure (6.66 +/- 0.30 vs 6.58 +/- 0.24 kPa). The increase in diameter during systole was significantly lower in the hypopituitary patients (0.39 +/- 0.02 vs 0.50 +/- 0.03 mm, P < 0.001). The DC was significantly lower in patients than in controls (24.2 +/- 2.29 vs 30.1 +/- 2.01 10(-3) kPa-1, P < 0.05). The carotid CC was also significantly lower in patients than in controls (5.7 +/- 0.49 vs 7.0 +/- 0.45 10(-7) m2 kPa-1, P < 0.05). The beta index was higher in the patient group (8.4 +/- 1.3 vs 5.9 +/- 0.37, P < 0.05). When men and women were considered separately, the differences between patients and controls were statistically significant in women but not in men and were more marked in the older women subgroup.

Asymptomatic hypopituitary adults (especially women) on conventional replacement therapy have increased stiffness of the common carotid arteries. These findings provide additional evidence for a process leading to premature atherosclerosis in this group of patients.