Adrenal Incidentaloma: A New Cause of the Metabolic Syndrome?

Abstract

A number of patients with adrenal incidentaloma are exposed to a slight degree of cortisol excess resulting from functional autonomy of the adrenal mass (usually a cortical adenoma). At present, there are only scant data on the unwanted effects of this endocrine condition referred to as subclinical Cushing's syndrome. The aim of the present study was to look for some features of the metabolic syndrome in patients with incidental adrenal adenoma. Forty-one patients (9 men and 32 women) bearing adrenal incidentaloma with typical computed tomography features of cortical adenoma were studied. For both patients and controls, exclusion criteria were age equal to 70 yr or greater, previous history of fasting hyperglycemia, or impaired glucose tolerance (IGT), severe hypertension, current use of medication or concomitant relevant illnesses, and body mass index (BMI) equal to 30 kg/m(2) or greater. Forty-one patients with euthyroid multinodular goiter accurately matched for sex, age, and BMI served for a 1:1 case-control analysis. The study design included an oral glucose tolerance test (75 g) and an endocrine workup aimed at the study of the hypothalamic-pituitary-adrenal axis. Age and BMI were fully comparable between patients (54.0 +/- 10.7 yr, 23.8 +/- 2.4 kg/m(2)) and controls (52.2 +/- 11.6 yr, 23.5 +/- 2.8 kg/m(2)). Fasting glucose and fasting insulin levels were not different between the two groups (4.96 +/- 0.61 mmol/liter vs. 4.88 +/- 0.58 mmol/liter; 67 +/- 34 pmol/liter vs. 59 +/- 32 pmol/liter), but the 2-h postchallenge glucose was significantly higher in patients than in controls (7.43 +/- 2.49 mmol/liter vs. 6.10 plus minus 1.44 mmol/liter, P = 0.01). Fifteen patients (36%) reached the World Health Organization criteria for IGT and two other patients (5%) reached those for diabetes, and 14% of the controls qualified for IGT (P = 0.01). No difference in the lipid pattern was seen between the two groups, but either systolic or diastolic blood pressure were higher in patients (135.4 +/- 15.5 mm Hg vs. 125.0 +/- 15.6 mm Hg, P = 0.003; 82.9 +/- 9.1 mm Hg vs. 75.3 +/- 6.6 mm Hg, P < 0.0001). We calculated the whole-body insulin sensitivity index derived from the oral glucose tolerance test that was significantly reduced in the patients (4.3 +/- 1.7 vs. 5.7 +/- 2.5, P = 0.01). In a multiple regression analysis, 2-h glucose was associated with BMI and midnight cortisol values (r(2) = 0.36, P = 0.002). The comparison of the patients with nonfunctioning adenoma (n = 29) with those with subclinical Cushing's syndrome (n = 12) yielded significant differences as to 2-h glucose and triglyceride levels, which were significantly higher in the second group (7.02 +/- 1.76 mmol/liter vs. 8.72 +/- 3.17 mmol/liter, P = 0.03; 1.06 +/- 0.4 mmol/liter vs. 1.73 +/- 0.96 mmol/liter, P = 0.002), but the insulin sensitivity index was conversely reduced (5.2 +/- 1.4 vs. 2.9 +/- 1.2, P < 0.0001). In conclusion, many patients with incidental adrenal adenoma display altered glucose tolerance, that may be explained by reduced insulin sens...

The clinical course of patients with adrenal incidentaloma: is it time to reconsider the current recommendations?

“…Several observational studies reported that subtle cortisol excess in SCS is associated with increased cardiovascular risk (24,25). However, the data onno difference in the prevalence of diabetes, hypertension or dyslipidaemia in the patients with SCS compared to those with non-functional adenoma.…”

THERAPY OF ENDOCRINE DISEASE: Improvement of cardiovascular risk factors after adrenalectomy in patients with adrenal tumors and subclinical Cushing’s syndrome: a systematic review and meta-analysis

“…Patients with an adrenal mass associated with SCS present with an increased prevalence of several cardiovascular risk factors such as hypertension (HTN), diabetes mellitus type 2 (DM2), dyslipidemia and obesity (11,12,13). Previous studies suggest that patients with SCS are at higher risk for developing cardiovascular events (14,15,16) and experience an increased cardiovascular mortality (17,18).…”

Screening for ACTH-dependent hypercortisolism in patients affected with pituitary incidentaloma

“…In particular, a systematic screening test of SH has been carried out, to date, exclusively in adrenal incidentalomas, where this condition was detected in 5-30% of patients. Moreover, SH has been associated with similar complications to chronic hypercortisolism, such as hypertension, diabetes, and osteoporosis (8,9,10,11).…”

“…Interestingly, these patients showed long-term complications of cortisol excess, such as hypertension, insulin resistance, type 2 diabetes, central obesity, dyslipidemia, and an increased risk of osteoporosis and vertebral fractures, that partially reverted by adrenalectomy (8,9,10,11). As no systematic screening of SH has been performed so far in patients with PIs, it is not possible to exclude the presence of a subset of subjects with mild/subclinical Cushing's disease, possibly associated with the same comorbidities observed in overt glucocorticoid excess, in the PI population.…”