High prevalence of obesity in patients with non-functioning adrenal incidentalomas.

OBJECTIVE: The influence of obesity on cancer development has been proven for numerous tumours. In contrast, the association between obesity and non-secreting adrenal incidentaloma has never been proven. Therefore, the aim of this study was to investigate this relationship in a large sample of patients.

METHODS: 143 patients with benign non-secreting adrenal incidentalomas treated in the Department of Endocrinology at the Poznan University of Medical Sciences between the years 2000-2007 were examined. To rule out subclinical hyperfunctioning lesions, serum dehydroepiandrosterone sulphate, cortisol (8 am, 6 pm, and after 1 mg dexamethasone suppression), sodium and potassium, along with concentrations of sodium, potassium, vanillylmandelic acid, metanephrine and normetanephrine in 24-hour urine collection were determined. Radiological evaluation included computed tomography and/or magnetic resonance imaging. Only non-secreting lesions and those of benign radiologic appearance were considered. The patients body mass index was compared to that of the general population of Poland and the Western Poland Region of Wielkopolska.

RESULTS: The average body mass index of our patients was 28.77 kg/m2 (SD=4.71), with a 40% prevalence of obesity in the study group. One-proportion z-test showed a statistically significantly higher prevalence of obesity as compared to the general population of Poland and Wielkopolska (40% vs 12.5%, p<0.005); the results were similar for the whole cohort, and for each gender separately.

CONCLUSIONS: This clinical research study demonstrates a strong association between obesity and incidentally discovered non-functioning adrenal tumours.