N-terminal pro-brain natriuretic peptide in newly diagnosed acromegaly

The mechanisms of acromegalic cardiomyopathy are not clearly understood. Brain natriuretic peptide (BNP) and N-terminal fragment of its pro-hormone (NT-proBNP) are released by the cardiac ventricles and increase in heart failure. In the present study, we aimed to evaluate serum NT-proBNP levels in acromegalic patients and determine a relationship between NT-proBNP levels and echocardiographic parameters.

Twenty-two newly diagnosed acromegalic patients [mean age 38.85 ± 11.06 yr; body mass index (BMI): 28.51 ± 3.48 kg/m2] and 26 age- and BMI-matched healthy control subjects (mean age 32.9 ± 12.6 yr; BMI: 26.2 ± 5.3 kg/m2) were included in the study. Standard oral glucose tolerance test (OGTT) was performed. Serum NT-proBNP and GH were measured at the beginning of the OGTT (0 min). Body fat analyses were measured by bioelectrical impedance. Echocardiography was used in cardiac evaluations.

The mean NT-proBNP level in the acromegalic group was not significantly different from the control subjects (55.89 ± 46.64 pg/ml in acromegaly vs 28.76 ± 22.13 pg/ml in control subjects). There were no correlations between the serum NTproBNP, GH, and IGF-I levels. Echocardiography revealed significantly increased left ventricular end-diastolic diameter (p=0.008), interventricular septum thickness (p=0.009), left atrium (p=0.029), and right ventricle diameter (p=0.027) in the acromegalic group.

NT-proBNP levels were found to be slightly higher in acromegalic patients as an indicator of heart failure, but the increase was not statistically significant. Although these cardiac structural changes in newly diagnosed acromegalic patients are present, the normal level of NT-proBNP shows that NT-proBNP may not be a good indicator in acromegaly.