Assessment of adrenal functions in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disease and extrarenal manifestations may be observed in many organ systems. Hypothalamus-pituitary-adrenal axis was not evaluated extensively in patients with ADPKD. We aimed to evaluate this axis in these patients.

METHODS: Twenty two patients with ADPKD and 27 healthy subjects were enrolled. Basal dehydroepiandrosterone sulfate (DHEAS) levels and cortisol and DHEA responses to low dose short adrenocorticotropin stimulation test were assessed. Correlation analyses of these parameters with glomerular filtration rates (GFR), renal volumes and pain characteristics in patients with ADPKD were performed.

RESULTS: Patients with ADPKD had higher basal cortisol levels (12.1 ± 3.4 vs. 9.6 ± 4.3 μg/dL, p=0.033), and higher basal cortisol/DHEAS ratios (0.073 ± 0.05 vs. 0.045 ± 0.02, p=0.015) compared to controls. None of the subjects had inadequate response to adrenocorticotropin stimulation. Patients with ADPKD had lower delta cortisol (absolute increase between peak and basal) levels (10.3 ± 2.8 vs. 12.6 ± 4.2 μg/dL, p=0.026) compared to controls. Subgroup analysis showed that significant differences existed only between female patients and female controls. There was no significant correlation between cortisol levels and renal volumes or GFR. A significant correlation was found only between delta cortisol and pain frequency in female patients.

CONCLUSIONS: Patients with ADPKD had higher basal cortisol levels, higher basal cortisol/DHEAS ratios and lower delta cortisol levels compared to controls, indicating promptly stimulated zona fasciculata function. Further studies are needed to confirm these results and to investigate possible underlying mechanisms.