Food-dependent Cushing syndrome: a new entity of organic hypercorticism

Matejka G, et al. Rev Med Interne. 1996.

Abstract

Diagnosis of Cushing’s syndrome is quite difficult in endocrinology. Spontaneous Cushing’s syndrome is usually divided into two subgroups, one which is dependent on corticotropin (ACTH) and another one which is not.

In the first class are Cushing’s disease, the ectopic corticotropin syndrome and the rare ectopic corticotropin-releasing hormone (CRH) syndrome; these ACTH-dependent Cushing’s syndrome have usually diffusely enlarged adrenal glands.

In the second class are cortisol producing unilateral adrenocortical adenomas or carcinomas, and the recent Cushing’s syndrome with food dependent periodic hormonogenesis.

This food dependent Cushing’s syndrome is an ACTH-independent Cushing’s syndrome with multinodular enlargement of both adrenal glands. Pathogenesis is an aberrant adrenal sensitivity to physiologic secretion of gastric inhibitory peptide (GIP). Ectopic expression of GIP receptors on adrenal cells involve pathologic food induced cortisol secretion.

Food dependent Cushing’s syndrome is a new cause of Cushing’s syndrome. Food induced cortisol secretion may have to be explored in the ACTH-independent Cushing’s syndrome.

PMID

8758532 [PubMed – indexed for MEDLINE]

Full text

Full text from provider (Elsevier Science) Article in French.

From http://www.ncbi.nlm.nih.gov/m/pubmed/8758532/

Biography of a Food-Dependent Cushing’s patient

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 May 23. doi: 10.1111/cen.12823. [Epub ahead of print]

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 m2 ) 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 m2 , 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 m2 (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.

© 2015 John Wiley & Sons Ltd.

PMID:
26010731
[PubMed – as supplied by publisher]

From http://www.ncbi.nlm.nih.gov/pubmed/26010731

Multiple aberrant hormone receptors in Cushing’s Syndrome

Eur J Endocrinol. 2015 May 13. pii: EJE-15-0200. [Epub ahead of print]
Multiple Aberrant Hormone Receptors in Cushing’s Syndrome.

Abstract

The mechanisms regulating cortisol production when ACTH of pituitary origin is suppressed in primary adrenal causes of Cushing’s syndrome include diverse genetic and molecular mechanisms. These can lead either to constitutive activation of the cAMP system and steroidogenesis or to its regulation exerted by the aberrant adrenal expression of several hormone receptors, particularly G-protein coupled hormone receptors (GPCR) and their ligands.

Screening for aberrant expression of GPCR in BMAH and unilateral adrenal tumors of patients with overt or subclinical CS demonstrates the frequent co-expression of several receptors. Aberrant hormone receptors can also exert their activity by regulating the paracrine secretion of ACTH or other ligands for those receptors in BMAH or unilateral tumors.

The aberrant expression of hormone receptors is not limited to adrenal Cushing’s syndrome but can be implicated in other endocrine tumors including primary aldosteronism and Cushing’s disease. Targeted therapies to block the aberrant receptors or their ligands could become useful in the future.

PMID:
25971648
[PubMed – as supplied by publisher]

“My feet are killing me!” An unusual presentation of Cushing’s syndrome

Adverse effects of steroid excess on bone metabolism are well established but presentation of Cushing’s syndrome with metabolic bone disease is reported to be uncommon. We describe a case of Cushing’s syndrome presenting with pathological fractures probably present for 8 years before diagnosis.

A 33 year old nurse first sustained spontaneous stress fractures of her metatarsals in 1994, with repeated fractures occurring up to 2002. In 2001 she developed hypertension, acute lumbar back pain and gained weight.

In 2002 she was admitted to hospital with chest/back pain. Lumbar spine X-ray showed new fracture of L3,old fractures of L4/5,with fractured ribs on CXR. Isotope bone scan revealed multiple hot spots. MRI showed collapse of T8 with features consistent with malignant disease. The primary malignancy was sought and a left-sided 1.5 centimetre thyroid nodule detected.

Suspicious cytology prompted thyroid lobectomy revealing follicular variant of papillary carcinoma. T8 biopsy revealed chronic infection with Propionobacteria rather than metastatic carcinoma. Despite antibiotic therapy further spontaneous vertebral fractures developed. Bone densitometry revealed Z scores of minus 2.4 at L2-4, minus 2.5 and 2.9 at the hips.

Referral to our centre prompted investigations for Cushing’s syndrome. Serum potassium was 4.1 millimols per litre, androgens, calcitonin and urinary catecholamines all normal. TSH was suppressed by T4 therapy. Urinary free cortisol values were raised,(563-959 nanomols per 24hours) with loss of diurnal rhythm in cortisol secretion (9am 429-586,midnight 397-431 nanomols per litre)and no suppression on low or high dose dexamethasone. Abdominal CT showed a 3.5 centimetre adrenal mass. These findings were consistent with adrenal dependent Cushing’s syndrome. Risedronate and metyrapone were commenced before adrenalectomy, completion thyroidectomy and ablative radioiodine.
Comment: Cushing’s syndrome may present with spontaneous fractures in both axial and appendicular skeleton in the absence of marked clinical features. This case demonstrates the importance of thorough investigation of unexplained fractures.

LM Albon, JD Rippin & JA Franklyn

From http://www.endocrine-abstracts.org/ea/0005/ea0005p26.htm

Cushing’s Syndrome

Prof André Lacroix, MDcorrespondence,  Richard A Feelders, MD, Constantine A Stratakis, MD, Lynnette K Nieman, MD