A Toini, A Dolci, E Ferrante, E Verrua, E Malchiodi, E Sala, A G Lania, I Chiodini, P Beck-Peccoz, M Arosio, A Spada and G Mantovani
Pituitary incidentalomas (PIs) are commonly encountered in clinical practice. The management of these asymptomatic pituitary lesions is still controversial. Systematic screening for subclinical or mild ACTH-dependent hypercortisolism (AH) is not presently recommended, due to the limited data available thus far on the epidemiological and clinical relevance of this condition in patients with PIs. As subclinical hypercortisolism (SH) was considered to be associated with chronic complications of overt cortisol excess, such as hypertension, diabetes, and osteoporosis, this disorder should be diagnosed at the early stage.
The objective of this study was to evaluate the prevalence of hypercortisolism in a population of subjects with PIs.
Design, subjects, and methods
A total of 68 consecutive patients (48 females and 20 males, aged 18–82 years) without clinically overt hypercortisolism, who were referred for evaluation of PIs between January 2010 and March 2013, were prospectively investigated for AH. Pituitary hypercortisolism was diagnosed in the presence of cortisol >50 nmol/l after 1 mg dexamethasone suppression test, non-suppressed ACTH, and the additional finding of one of the following: urinary free cortisol (UFC) >193 nmol/24 h, and midnight serum and salivary cortisol levels >207 and 2.8 nmol/l respectively.
Among patients with PIs, we found a 7.3% rate of pituitary hypercortisolism diagnosed with biochemical criteria and a 4.4% rate of histologically confirmed AH.
Subclinical or mild hypercortisolism may be more common than generally perceived in patients with PIs.
C L Ronchi, C Giavoli, E Ferrante, E Verrua, S Bergamaschi, D I Ferrari, S Corbetta, L Montefusco, M Arosio, B Ambrosi, A Spada and P Beck-Peccoz
Radiotherapy (RT) for pituitary adenomas, including GH-secreting ones, frequently leads to GH deficiency (GHD). Data on the effects of surgery alone (S) on dynamic GH secretion are limited. The aim of the study was to investigate the occurrence of GHD in acromegalic patients treated with different therapeutic options.
Design and methods
Fifty-six patients in remission from acromegaly, (33 F & 23 M, age: 54±13 years, body mass index (BMI): 28.4±4.1 kg/m2, 21 with adequately substituted pituitary deficiencies) treated by S alone (n=33, group 1) or followed by RT (n=23, group 2), were investigated for GHD by GHRH plus arginine testing, using BMI-adjusted cut-offs. Several metabolic and cardiovascular parameters (waist circumference, body fat percentage, blood pressure, fasting and post-oral glucose tolerance test glucose, HbA1c, insulin resistance and lipid profile) were evaluated in all the patients and 28 control subjects with known diagnosis of GHD.
Serum GH peak after challenge was 8.0±9.7 μg/l, without any correlation with post-glucose GH nadir and IGF-1 levels. The GH response indicated severe GHD in 34 patients (61%) and partial GHD in 15 patients (27%). IGF-1 were below the normal range in 14 patients (25%). The frequency of GHD was similar in the two treatment groups (54% in group 1 and 70% in group 2). No significant differences in metabolic parameters were observed between acromegalic patients and controls with GHD.
Severe GHD may occur in about 60% of patients treated for acromegaly, even when cured after S alone. Thus, a stimulation test (i.e. GHRH plus arginine) is recommended in all cured acromegalic patients, independently from previous treatment.