Night Cortisol Levels for Diagnosing Cushing’s Syndrome Less Accurate in Clinical Practice

Salivary cortisol levels can be used to diagnose Cushing’s syndrome with relatively high reliability, but each test center should establish its own measurement limits depending on the exact method used for the test, a study from Turkey shows.

Researchers, however, caution that late-night salivary cortisol measurements in clinical practice is likely to be less accurate than that seen in controlled studies, and some patients might require additional tests for a correct diagnosis.

The study, “Diagnostic value of the late-night salivary cortisol in the diagnosis of clinical and subclinical Cushing’s syndrome: results of a single-center 7-year experience,” was published in the Journal of Investigative Medicine

In healthy individuals, the levels of cortisol — a steroid hormone secreted by the adrenal glands — go through changes over a 24-hour period, with the lowest levels normally detected at night.

But this circadian rhythm is disrupted in certain diseases such as Cushing’s syndrome, where night cortisol levels can be used as a diagnostic tool.

Among the tests that can be used to detect these levels are late-night serum cortisol (LNSeC) and late-night salivary cortisol (LNSaC) tests. Since it uses saliva samples, LNSaC is more practical and does not require hospitalization, so it is often recommended for the diagnosis of Cushing’s syndrome.

So far, though, there has been no consensus regarding cutoff values and the sensitivity of the test.

Mustafa Kemal Balci, MD, and his team at the Akdeniz University in Turkey aimed to evaluate the diagnostic use of LNSaC in patients with clinical Cushing’s syndrome and in those with subclinical Cushing’s syndrome — people with excess cortisol but without signs of the disease.

The study involved 58 patients with clinical Cushing’s syndrome (CCS), 53 with subclinical Cushing’s syndrome (SCS), and 213 patients without Cushing’s syndrome who were used as controls.

Saliva and serum cortisol levels were measured in all patients, and statistical tests were used to study differences in these levels among the three groups of patients.

In CSC patients, the median cortisol levels were 0.724 micrograms per deciliter of blood (µg/dL), which dropped to 0.398 and 0.18 in patients with subclinical disease and controls.

The optimal cutoff point to distinguish patients with clinical Cushing’s was set at 0.288 µg/dL, where 89.6% of patients identified as positive actually have the disease (sensitivity), and 81.6% of patients deemed as negative were without the disease (specificity).

With a lower cutoff point — 0.273 µg/dL — researchers were also able to identify patients with subclinical disease with high sensitivity and specificity.

While the test showed high sensitivity and specificity values for clinical Cushing’s syndrome, its diagnostic performance was lower than expected in daily clinical practice, researchers said.

“The diagnostic performance of late-night salivary cortisol in patients with subclinical Cushing’s syndrome was close to its diagnostic performance in patients with clinical Cushing’s syndrome,” researchers wrote.

However, regarding the application of this test in other centers, they emphasize that “each center should determine its own cut-off value based on the method adopted for late-night salivary cortisol measurement, and apply that cut-off value in the diagnosis of Cushing’s syndrome.”

From https://cushingsdiseasenews.com/2018/07/31/late-night-salivary-cortisol-levels-questioned-diagnosis-cushings-syndrome/

Diagnosing and Treating Cortisol Excess and Deficiency

From Day 1 of the 16th International Congress of Endocrinology and the Endocrine Society’s 96th Annual Meeting and Expo »

Chicago, IL – June 21, 2014

A phase 2 study of Chronocort®, a modified release formulation of hydrocortisone, in the treatment of adults with classic congenital adrenal hyperplasia

A Mallappa, L-A Daley, N Sinaii, C Van Ryzin, H Huatan, D Digweed, D Eckland, M Whitaker, LK Nieman, RJ Ross, DP Merke

Summary: Classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency is characterized by cortisol and aldosterone deficiency and androgen excess. Current conventional glucocorticoid therapy is suboptimal as it cannot replace the normal cortisol circadian rhythm and inadequate or inappropriate suppression of adrenal androgens are common. In the preliminary results of a phase 2 study of Chronocort®, a modified release hydrocortisone capsule formulation, researchers found that Chronocort®, a novel modified release hydrocortisone capsule formulation, approximates physiological cortisol secretion, and improves biochemical control of CAH. Further analyses are underway.

Methods:

  • The study objectives were to characterize pharmacokinetics and examine disease control following 6 months dose titration.
  • Serial profiling was obtained at baseline (conventional glucocorticoid) and every 2 months.
  • Twice-daily Chronocort® was initiated: 20 mg at 2300 h, 10 mg at 0700 h.
  • Dose titration was based on clinical status and optimal hormonal ranges (17OHP 300-1200 ng/dL, normal androstenedione (males: 40-150, females: 30-200 ng/dL), with androstenedione prioritized.
  • Chronocort® cortisol pharmacokinetic profile was the primary endpoint.
  • Secondary endpoints included biomarkers of disease control.

Results:

  • A total of 16 adults (8 females; age 29 ±13 years) with classic CAH (12 salt-wasting, 4 simple virilizing) participated.
  • Conventional therapy varied (5 dexamethasone, 7 prednisone, 4 hydrocortisone).
  • Chronocort® cortisol pharmacokinetic profile approximated physiological cortisol secretion.
  • Ten patients required Chronocort® dose adjustments (decrease in 8, increase in 2; mean hydrocortisone equivalent dose conventional vs 6 months: 16.1 ± 6.4 vs 14.7 ± 6.4 mg/m2).
  • Serial androstenedione levels were in the normal range in 8 (50%) of patients on conventional therapy compared with 12 (75%) on Chronocort® at 6 months.
  • The majority of patients on Chronocort® achieved 17O HP levels within the normal range, rather than within the mildly elevated range currently used for management.
  • At 6 months, Chronocort® resulted in lower 24-hr (P=0.02), morning (0700-1500; P=0.008), and afternoon (1500-2300; P=0.03) area-under-the-curve androstenedione compared with conventional therapy.
  • No serious adverse events occurred.
  • Common adverse events were headache, fatigue, early awakening, and anemia.
  • Three patients had unexpected carpal tunnel syndrome, which resolved with wrist splints.

From http://www.mdlinx.com/endocrinology/conference-abstract.cfm/ZZ5BA369FDE9DE4CED82CB6A7CD5BFD1BE/16521/?utm_source=confcoveragenl&utm_medium=newsletter&utm_content=abstract-list&utm_campaign=abstract-ICE/EN2014&nonus=0#

Characterization of persistent and recurrent Cushing’s disease

Pituitary, 09/25/2013  Review Article

Sundaram NK et al. – A case of possible recurrent Cushing’s disease (CD) is presented and data on current definitions of CD remission, persistence, and recurrence are reviewed.

The number and degree of abnormal test results needed to define recurrence, and the determination of which biochemical test has more significance when there are discrepancies between markers is inconsistent among studies. Further inquiry is warranted to examine if patients in apparent CD remission who have subtle hypothalamic pituitary adrenal (HPA) axis abnormalities represent distinctive remission subtypes versus mild or early recurrence.

Additional investigation could also explore the degree to which these HPA axis abnormalities, such as alterations in cortisol circadian rhythm or partial resistance to dexamethasone, are associated with persistence of CD morbidities, including neuropsychiatric impairments, alterations in body composition, and cardiovascular risk.

From MDLinx

%d bloggers like this: