Prevalence of hypertension in acromegalic patients: clinical measurement versus 24-hour ambulatory blood pressure monitoring

Abstract

Objective: Hypertension is thought to play an important role in the pathogenesis of acromegalic cardiomyopathy. So far, hypertension has been defined by clinical measurement, with considerable variations reported concerning its prevalence in acromegalics.

Design: To determine the mean blood pressure (BP) values and the prevalence of hypertension in patients with active acromegaly according to non-invasive 24-hour ambulatory BP monitoring (ABPM) and to compare the data obtained with those provided by clinical measurement.

Patients: Forty patients with active acromegaly (22 women, 18 men, mean age 48.6 +/- 12.5 years) were included. Patients were in wash-out for antihypertensive treatment and none had been using any medical treatment for acromegaly for at least 3 months before the study. All were studied as outpatients.

Measurements: Clinical BP values were calculated as the mean of BP values obtained by standard sphygmomanometric measurement in three separate occasions. Mean 24-hour, daytime and night-time BP values were obtained by ABPM.

Results: The mean 24-hour BP values were lower than clinical BP values, the difference being significant for both systolic BP (SBP: 131.1 +/- 21.5 versus 136.1 +/- 16.3 mmHg, P < 0.02) and for diastolic BP (DBP: 74.6 +/- 10.6 versus 88.8 +/- 9.1 mmHg, P < 0.0001). ABPM values recorded during the daytime were 137.8 +/- 20.9 mmHg for SBP and 78.6 +/- 11.5 mmHg for DBP, the latter being significantly lower than the corresponding clinical BP values (P < 0.0001). About 60% of the patients considered hypertensive by clinical measurement were found to be normotensive by ABPM, thereby decreasing the prevalence of hypertension in this series from 42.5% to 17.5% according to ABPM (P < 0.02). In contrast, all patients defined as normotensive by clinical measurement were also normotensive by ABPM.

Conclusions: Ambulatory blood-pressure monitoring indicated a lower prevalence of hypertension in acromegalic patients then usually reported, suggesting that the role of hypertension in the pathogenesis of acromegalic cardiomyopathy is commonly overestimated. We propose that ambulatory blood-pressure monitoring should be routinely proposed in acromegalics with high or borderline clinical blood pressure values although it is not useful in patients defined normotensive according to repeated clinical measurement.