When to think Cushing’s syndrome in type 2 diabetes

ESTES PARK, COLO. – Diabetes mellitus, osteoporosis, and hypertension are conditions that should boost the index of suspicion that a patient with some cushingoid features may in fact have endogenous Cushing’s syndrome, Dr. Michael T. McDermott said at a conference on internal medicine sponsored by the University of Colorado.

An estimated 1 in 20 patients with type 2 diabetes has endogenous Cushing’s syndrome. The prevalence of this form of hypercortisolism is even greater – estimated at up to 11% – among individuals with osteoporosis. In hypertensive patients, the figure is 1%. And among patients with an incidentally detected adrenal mass, it’s 6%-9%, according to Dr. McDermott, professor of medicine and director of endocrinology and diabetes at the University of Colorado.

“Endogenous Cushing’s syndrome is not rare. I suspect I’ve seen more cases than I’ve diagnosed,” he observed. “I’ve probably missed a lot because I failed to screen people, not recognizing that they had cushingoid features. Not everyone looks classic.”

There are three screening tests for endogenous Cushing’s syndrome that all primary care physicians ought to be familiar with: the 24-hour urine cortisol test, the bedtime salivary cortisol test, and the overnight 1-mg dexamethasone suppression test.

“I think if you have moderate or mild suspicion, you should use one of these tests. If you have more than moderate suspicion – if a patient really looks like he or she has Cushing’s syndrome – then I would use at least two screening tests to rule out endogenous Cushing’s syndrome,” the endocrinologist continued.

The patient performs the bedtime salivary cortisol test at home, obtaining samples two nights in a row and mailing them to an outside laboratory. The overnight dexamethasone suppression test entails taking 1 mg of dexamethasone at bedtime, then measuring serum cortisol the next morning. A value greater than 1.8 mcg/dL is a positive result.

Pregnant women constitute a special population for whom the screening method recommended in Endocrine Society clinical practice guidelines (J. Clin. Endocrinol. Metab. 2008;93:1526-40) is the 24-hour urine cortisol test. That’s because pregnancy is a state featuring high levels of cortisol-binding globulins, which invalidates the other tests. In patients with renal failure, the recommended screening test is the 1-mg dexamethasone suppression test. In patients on antiepileptic drugs, the 24-hour urine cortisol or bedtime salivary cortisol test is advised, because antiseizure medications enhance the metabolism of dexamethasone.

Dr. McDermott said that “by far” the most discriminatory clinical features of endogenous Cushing’s syndrome are easy bruising, violaceous striae on the trunk, facial plethora, and proximal muscle weakness.

“They’re by no means specific. You’ll see these features in people who don’t have Cushing’s syndrome. But those are the four things that should make you really consider Cushing’s syndrome in your differential diagnosis,” he stressed.

More widely recognized yet actually less discriminatory clinical features include facial fullness and the “buffalo hump,” supraclavicular fullness, central obesity, hirsutism, reduced libido, edema, and thin or poorly healing skin.

Endogenous Cushing’s syndrome can have three causes. An adrenocorticotropic hormone (ACTH)-secreting pituitary adenoma accounts for 80% of cases. A cortisol-secreting adrenal tumor is the cause of 10%. And another 10% are due to an ectopic ACTH-secreting tumor, most commonly a bronchial carcinoid tumor.

Once the primary care physician has a positive screening test in hand, it’s typical to refer the affected patient to an endocrinologist in order to differentiate which of the three causes is present. This is accomplished based upon the results of a large, 8-mg dexamethasone suppression test coupled with measurement of plasma ACTH levels.

Dr. McDermott recommended as a good read on the topic of evaluating a patient with endogenous Cushing’s syndrome a recent review article that included a useful algorithm (N. Engl. J. Med. 2013;368:2126-36).

He reported having no financial conflicts.

bjancin@frontlinemedcom.com

From http://www.clinicalendocrinologynews.com

Pregnancy and pituitary disorders

Pituitary and pineal glands

Pituitary and pineal glands (Photo credit: Wikipedia)

Z Karaca, F Tanriverdi, K Unluhizarci and F Kelestimur
+ Author Affiliations

Department of Endocrinology,
Erciyes University Medical School, 38039 Kayseri, Turkey
(Correspondence should be addressed to F Kelestimur; Email: fktimur@erciyes.edu.tr)

Abstract

Major hormonal changes emerge during pregnancy. The pituitary gland is one of the most affected organs with altered anatomy and physiology. The pituitary gland is enlarged as a result of lactotroph hyperplasia. Due to physiological changes in the pituitary and target hormone levels, binding globulins, and placental hormones, hormonal evaluation becomes more complex in pregnant women. As a consequence of physiological hormonal changes, the evaluation of pituitary functions in pregnant women is quite different from that done in the prepregnant state. Pituitary adenomas may cause problems by their hormone secretion that affects the mother and the fetus besides causing an increased risk of tumor growth.

Furthermore, diagnosis, course, and treatment of pituitary diseases point out differences. The changes in anatomy and physiology of the pituitary gland during pregnancy are reviewed.

Pituitary disorders namely Cushing’s disease; acromegaly; prolactinoma; TSH-secreting, gonadotropin-producing, and clinically nonfunctioning adenomas; craniopharyngioma; and Sheehan’s syndrome, which is one of the most common causes of hypopituitarism, lymphocytic hypophysitis, and hypopituitarism, in relation to pregnancy are discussed. Being aware of all this information will prevent any serious problems which mother and child will be exposed to.

Read the entire article here: http://www.eje-online.org/content/162/3/453.full

Classifying hypertension

HYPERTENSION is classified into two categories according to its cause: essential and secondary.

The vast majority of patients have essential or primary hypertension, while only about 5-10% of patients have secondary hypertension, which are mainly caused by kidney and hormonal conditions like renal artery stenosis, hyperthyroidism, Cushing’s syndrome, and even pregnancy, among others.

The exact cause of essential hypertension is still unknown, although it is certainly the result of a combination of factors, including increasing age, having relatives with high blood pressure (ie family history), a sedentary lifestyle, a poor diet with too much salt, drinking too much alcohol, smoking and too much stress.

Says Malaysian Society of Hypertension president and Universiti Malaya Department of Primary Care Medicine senior consultant Prof Datin Dr Chia Yook Chin: “Each factor increases blood pressure by just a little, but when you add them all together little by little, it raises it by quite a lot.”

Despite not knowing the root cause of hypertension, it has been established that there is overstimulation of the sympathetic nerves in people with this condition.

This in turn increases the secretion of certain hormones involved in the regulation of sodium and fluids in the body, called renin, angiotensin, and aldosterone.

The amount of salt and water in our body affects our blood pressure – the more salt and water present, the higher our blood pressure.

These two elements are regulated by our kidneys through the three hormones mentioned above, which are produced by the adrenal glands located on top of the kidneys.

The overstimulation of the sympathetic nerves also results in increased vascular tone, which causes our arteries to become constricted, thus, also raising blood pressure.

From The Star

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