Olsen H, Mjöman M. Moderately impaired renal function increases morning cortisol and cortisol levels at dexamethasone suppression test in patients with incidentally detected adrenal adenomas.
Clin Endocrinol (Oxf) 2015;
83:762-7. [PMID:
26010731 DOI:
10.1111/cen.12823]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 04/15/2015] [Accepted: 05/15/2015] [Indexed: 11/30/2022]
Abstract
OBJECTIVE
Patients with incidentally detected adrenal adenomas may have subclinical hypercortisolism. We hypothesized that impaired renal function could lead to increased cortisol levels in these patients.
DESIGN
Descriptive retrospective study of consecutive patients.
PATIENTS
A total of 166 patients with incidentally detected unilateral adrenal adenomas were examined during 2008-2013.
MEASUREMENTS
Levels of cortisol, ACTH and cortisol at 1 mg overnight dexamethasone suppression test (DST) were measured. The estimated glomerular filtration rate (eGFR) was calculated using the MDRD equation.
RESULTS
Renal function was normal, mildly impaired, moderately impaired or severely impaired (eGFR >90, 60-90, 30-60 and 15-30 ml/min/1·73 m(2)) in 34, 54, 10 and 1% of the patients, respectively. Patients with normal and mildly impaired renal function had similar cortisol levels. Patients with moderately impaired renal function, compared to all the patients with eGFR >60 ml/min/1·73 m(2), exhibited increased cortisol (541 vs 456 nmol/l, P = 0·02), increased cortisol at DST (62 vs 37 nmol/l, P = 0·001), but similar ACTH levels (4·1 vs 2·9 pmol/l, P = 0·21). Patients with moderately impaired renal function thus exhibited cortisol at DST ≥ 50 nmol/l, more often than patients with eGFR >60 ml/min/1·73 m(2) (76% vs 30%, P = 0·000), while the prevalence of ACTH below 2 pmol/l was similar (24% vs 31%, P = 0·51).
CONCLUSIONS
Moderately impaired renal function increases cortisol and cortisol at DST in patients with adrenal adenomas, while mildly impaired renal function has no such effect. Cortisol level at DST ≥ 50 nmol/l therefore seems to have low specificity in diagnosing subclinical adrenal hypercortisolism, and an additional criterion, for example low ACTH, is required.
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