Evaluation of adrenal morphological and functional alterations in acromegalic patients
Theodora Pappa1, Labrini Papanastasiou1, Vaios Tsiavos1, Ermioni Tseniklidi1, Ioannis Androulakis1, Panagiotis Tsounas1, Peggy Roussaki2, Gregory Kaltsas2 & George Piaditis1
Introduction: Acromegaly is well known to induce hypertrophy and hyperplasia in many organs, i.e. thyroid gland, colon, prostate. This action is presumably exerted by the elevated GH and IGF1 levels. In our study, we investigated the alterations of the adrenal glands seen in acromegaly.
Aim: To assess the changes in adrenal morphology and functional status in a series of patients with acromegaly.
Subjects and methods: Fifty-four acromegalic patients, 24 men and 30 women, mean aged 52 years old, hospitalised in our Endocrinology Department in the time period 20042009, were evaluated. The mean time from diagnosis of acromegaly was 4.9 years. Computed tomography (CT) of the adrenals was performed in all studied subjects to investigate adrenal morphology. In addition, patients underwent hormonal evaluation of the anterior pituitary and adrenal glands as well as dynamic testing procedures (oral glucose tolerance test, low dose dexamethasone suppression test (LDDST)) to assess disease activity and adrenal function. Normal cut-off levels for cortisol after LDDST and baseline aldosterone/renin ratio were developed using the 97th percentile values of a control group with 72 non-acromegalic subjects with normal adrenal CT, i.e. 35 nmol/l and 78 pg/ml/mIU/l respectively.
Results: Twenty-three of 54 patients (42.6%) showed morphological alterations in the adrenal CT, i.e. hyperplasia or adenoma. Fourteen patients (25.9%) were found to have autonomous cortisol secretion using the LDDST, whereas 13 subjects (24.1%) had autonomous aldosterone secretion using the baseline aldosterone/renin ratio. No correlation was found between IGF1 levels, reflecting disease activity, and altered adrenal morphology and function.
Conclusion: In this study, we report an increased prevalence of morphological and functional changes in the adrenal glands of acromegalic patients. Further controlled studies are needed to validate these observations.