Cushing’s Syndrome Epidemiology

By Yolanda Smith, BPharm

Cushing’s syndrome is considered to be a rare disorder that results from prolonged exposure to glucocorticoids. However, there are few epidemiological studies to provide adequate data to describe the incidence and prevalence of the condition accurately. Most cases are diagnosed between the ages of 20 and 50, although any individual may be affected at any age.

The presentation of the symptoms of Cushing’s syndrome can vary greatly. In addition, many of the symptoms overlap with those caused by other health conditions, such as metabolic syndrome and polycystic ovary syndrome. This can make the diagnosis of the condition difficult. It is also difficult to establish epidemiological trends in Cushing’s syndrome, because not all cases of the disease are diagnosed. However, it is important that diagnosis is made as soon as possible, because early diagnosis and treatment of the condition are associated with improved morbidity and mortality rates.

Population-based Studies

There are several population-based studies that have reported the incidence and mortality rates of Cushing’s syndrome in certain populations over a discrete period of time.

A study in Denmark followed 166 patients with Cushing’s syndrome for 11 years, finding an incidence of 2 cases per million population per year. Of the 166 patients, 139 had benign disease. There was a mortality rate of 16.5% in the follow-up period of 8 years, with most deaths occurring in the year after the initial diagnosis, often before the initiation of treatment. The causes of death of patients with Cushing’s syndrome in the study included severe infections, cardiac rupture, stroke and suicide.

A study in Spain found 49 cases of Cushing’s syndrome over a period of 18 years, with an incidence of 2.4 cases per million inhabitants per year and a prevalence of 39.1 cases per million. The standard mortality ratio in this study was 3.8, in addition to an increase in morbidity rates.

Incidence

A low incidence of endogenous Cushing’s syndrome was established by the population-based studies outlined above, corresponding to approximately 2 cases per million. Some studies have an estimated incidence as low as 0.7 people per million.

However, the incidence of subclinical Cushing’s syndrome may be underestimated in certain population groups, such as those with osteoporosis, uncontrolled diabetes mellitus or hypertension. For example, of 90 obese patients with uncontrolled diabetes mellitus in one study, three had Cushing’s syndrome. This yielded a prevalence of 3.3%, which is considerably higher than the incidence reported in the population-based studies. However, these findings should be supported by larger studies.

Females are more likely to be affected by Cushing’s syndrome than males, with a risk ratio of approximately 3:1. There does not appear to be a genetic link that involves an ethnic susceptibility to the condition.

Treatment Outcomes

Surgery is the first-line treatment option for most cases of overt disease and remission is achieved in the majority of patients, approximately 65-85%. However, for up to 1 in 5 patients the condition recurs, and the risk does not appear to level off, even after 20 years of follow-up.

The risk of mortality for individuals with Cushing’s syndrome is estimated to be 2-3 times higher than that of the general population, based on epidemiological studies.

Reviewed by Dr Liji Thomas, MD.

From http://www.news-medical.net/health/Cushings-Syndrome-Epidemiology.aspx

Day 29, Cushing’s Awareness Challenge 2016

People sometimes ask me how I found out I had Cushing’s Disease.  Theoretically, it was easy.  In practice, it was very difficult.

Ladies Home Journal, 1983In 1983 I came across a little article in the Ladies Home Journal which said “If you have these symptoms…”

I found the row with my symptoms and the answer read “…ask your doctor about Cushing’s”.

After that article, I started reading everything I could on Cushing’s, I bought books that mentioned Cushing’s. I asked and asked my doctors for many years and all of them said that I couldn’t have it.  It was too rare.  I was rejected each time.

Due to all my reading at the library, I was sure I had Cushing’s but no one would believe me. My doctors would say that Cushing’s Disease is too rare, that I was making this up and that I couldn’t have it.

In med school, student doctors are told “When you hear hoofbeats, think horses, not zebras“.

According to Wikipedia: “Zebra is a medical slang term for a surprising diagnosis. Although rare diseases are, in general, surprising when they are encountered, other diseases can be surprising in a particular person and time, and so “zebra” is the broader concept.

The term derives from the aphorism “When you hear hoofbeats behind you, don’t expect to see a zebra”, which was coined in a slightly modified form in the late 1940s by Dr. Theodore Woodward, a former professor at the University of Maryland School of Medicine in Baltimore.  Since horses are the most commonly encountered hoofed animal and zebras are very rare, logically you could confidently guess that the animal making the hoofbeats is probably a horse. By 1960, the aphorism was widely known in medical circles.”

So, doctors typically go for the easily diagnosed, common diseases.  Just because something is rare doesn’t mean that no one gets it.  We shouldn’t be dismissed because we’re too hard to diagnose.

When I was finally diagnosed in 1987, 4 years later, it was only because I started bleeding under the skin. My husband made circles around the outside perimeter each hour with a marker so my leg looked like a cut log with rings.

When I went to my Internist the next day he was shocked at the size of the rings. He now thought I had a blood disorder so he sent me to a Hematologist/Oncologist.

Fortunately, that new doctor ran a twenty-four hour urine test and really looked at me and listened to me.  Both he and his partner recognized that I had Cushing’s but, of course, couldn’t do anything further with me.  They packed me off to an endo where the process started again.

My final diagnosis was in October, 1987.  Quite a long time to simply  “…ask your doctor about Cushing’s”.

Looking back, I can see Cushing’s symptoms much earlier than 1983.  But, that ‘s for a different post.

 

Straight Talk Cushing’s

awareness

 

On April 8th, people from around the world unite in support of Cushing’s Disease Awareness Day.

In this animated video, learn more about Cushing’s disease, including the mechanism of disease, clinical manifestations, symptoms and diagnosis challenges.

Day 2, Cushing’s Awareness Challenge 2016

The Seven Dwarves of Cushing's

So, these are only seven of the many, many symptoms of Cushing’s.  I had those above – and I often felt like I looked like one of those little bearded dwarves.

Cushing’s affects every part of the body.  It’s not like when I had kidney cancer and only the kidney was affected.

Here are some of the many areas affected.

  • Progressive obesity and skin changes
  • Weight gain and fatty tissue deposits, particularly around the midsection and upper back, in the face (moon face) and between the shoulders (buffalo hump). Some symptoms such as sudden weight gain, are caused by excess cortisol. The excess cortisol in the body does not increase protein and carbohydrate metabolism. It slows or nearly disables metabolism function, which can cause weight gain (fat accumulation) in the buttocks, abdomen, cheeks, neck, or upper back.
  • Loss of muscle mass. Some areas of the body, such as the arms and legs, will remain thin.
  • Pink or purple stretch marks (striae) on the skin of the abdomen, thighs, breasts and arms
  • Thinning, fragile skin that bruises easily
  • Slow healing of cuts, insect bites and infections
  • Acne

Women with Cushing’s syndrome may experience:

  • Thicker or more visible body and facial hair (hirsutism)
  • Irregular or absent menstrual periods

Men with Cushing’s syndrome may experience:

  • Decreased libido
  • Decreased fertility
  • Erectile dysfunction

Other signs and symptoms include:

  • Fatigue
  • Muscle weakness
  • Depression, anxiety and irritability
  • Loss of emotional control
  • Cognitive difficulties
  • New or worsened high blood pressure
  • Glucose intolerance that may lead to diabetes
  • Headache
  • Bone loss, leading to fractures over time
  • Hyperlipidemia (elevated lipids – cholesterol – in the blood stream)
  • Recurrent opportunistic or bacterial infections
Think you have Cushing’s?  Get to a doctor and don’t give up!

MaryO
         MaryO

Day 1: Cushing’s Awareness Challenge 2016

April is always Cushing’s Awareness Challenge month because Dr. Harvey Cushing was born on April 8th, 1869.

30-posts

Thanks to Robin for this wonderful past logo!  I’ve participated in these 30 days for Cushing’s Awareness several times so I’m not quite sure what is left to say this year but I always want to get the word out when I can.

As I see it, there have been some strides the diagnosis or treatment of Cushing’s since last year.  More drug companies are getting involved, more doctors seem to be willing to test, a bit more awareness, maybe.


April Fool's Day

How fitting that this challenge should begin on April Fool’s Day.  So much of Cushing’s  Syndrome/Disease makes us Cushies seem like we’re the April Fool.  Maybe, just maybe, it’s the doctors who are the April Fools…

Doctors tell us Cushing’s is too rare – you couldn’t possibly have it.  April Fools!

All you have to do is exercise and diet.  You’ll feel better.  April Fools!

Those bruises on your legs?  You’re just clumsy. April Fools!

Sorry you’re growing all that hair on your chin.  That happens as you age, you know.  April Fools!

Did you say you sleep all day?  You’re just lazy.  If you exercised more, you’d have more energy. April Fools!

You don’t have stretch marks.  April Fools!

You have stretch marks but they are the wrong [color/length/direction] April Fools!

The hump on the back of your neck is from your poor posture. April Fools!

Your MRI didn’t show a tumor.  You couldn’t have Cushing’s. April Fools!

This is all in your mind.  Take this prescription for antidepressants and go home.  April Fools!

If you have this one surgery, your life will get back to normal within a few months. April Fools!

What?  You had transsphenoidal surgery for Cushing’s?  You wasted your time and money. April Fools!

I am the doctor.  I know everything.  Do not try to find out any information online. You could not have Cushing’s.  It’s too rare…  April FOOL!

All this reminds me of a wonderful video a message board member posted a while ago:

So now – who is the April Fool?  It wasn’t me.  Don’t let it be you, either!

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