From Weight Gain To Diabetes

Cushing’s syndrome happens when the body has too much cortisol, the stress hormone. It can cause weight gain, high blood pressure, and diabetes. So how to keep your health in check and what are the treatment options available? In an exclusive interview with Times Now, an Endocrinologist explains its symptoms, causes, and treatments.
We often blame stress for everything—from sleepless nights to stubborn weight gain. But did you know your body’s stress hormone, cortisol, could be at the root of more serious health issues like high blood pressure and diabetes? Yes, you read that right! But how? We got in touch with Dr Pranav A Ghody, Endocrinologist at Wockhardt Hospital, Mumbai Central, who explains how excessive cortisol levels can lead to a condition known as Cushing’s Syndrome.
What Exactly is Cortisol, and Why is it Important?
Hormones are the body’s chemical messengers, travelling through the bloodstream to regulate essential functions. Among them, cortisol, produced by the adrenal glands (tiny glands sitting above the kidneys), plays a crucial role in controlling blood pressure, blood sugar, energy metabolism, and inflammation. The pituitary gland, located at the base of the brain, regulates cortisol through another hormone called Adrenocorticotropic Hormone (ACTH).
Often referred to as the “stress hormone,” cortisol spikes when we’re under stress. However, when levels remain high for too long, it can lead to Cushing’s Syndrome, a disorder first identified in 1912 by Dr Harvey Cushing.

What Causes Cushing’s Syndrome?

Dr Ghody explains that Cushing’s Syndrome occurs when the body is exposed to excessive cortisol, which can happen in two ways:

1. Exogenous (External) Cushing’s Syndrome
This is the most common form and results from prolonged use of steroid medications (such as prednisone) to treat conditions like asthma, rheumatoid arthritis, and lupus, or to prevent transplant rejection. Since steroids mimic cortisol, long-term use can disrupt the body’s hormone balance.
2. Endogenous (Internal) Cushing’s Syndrome
This occurs when the body produces too much cortisol due to a tumour in the pituitary gland, adrenal glands, or other organs (lungs, pancreas, thymus). While rare—affecting about 10 to 15 people per million annually—it’s more common in women between 20 and 50 years old. When caused by a pituitary tumour, it’s specifically called Cushing’s Disease.

Symptoms: How To Recognize Signs Of Cushing’s Syndrome

Excess cortisol affects multiple organs, leading to a variety of symptoms. This includes:

– Weight gain around the belly (central obesity)
– Rounded, puffy face (moon face)
– Excess facial and body hair (hirsutism)
– Fat accumulation on the upper back (buffalo hump)
– Thin arms and legs
– Dark red-purple stretch marks on the chest and abdomen
– Extreme fatigue and muscle weakness
– Depression or anxiety
– Easily bruising with minimal trauma
– Irregular menstrual cycles in women
– Reduced fertility or low sex drive
– Difficulty sleeping
High blood pressure and newly diagnosed or worsening diabetes are also common red flags.

Why is Cushing’s Syndrome Often Misdiagnosed?

Dr Ghody explains that while severe cases of Cushing’s Syndrome are easier to identify, milder forms can often be missed or mistaken for conditions like obesity, diabetes, or polycystic ovary syndrome (PCOS).

Diagnosing Cushing’s Syndrome involves:
1. Measuring cortisol levels in the blood, urine, or saliva.
2. Identifying the source through ACTH hormone testing, MRI/CT scans, and advanced techniques like Inferior Petrosal Sinus Sampling (IPSS) or nuclear medicine scans
Treatment Options: How is Cushing’s Syndrome Managed?
Once diagnosed, the treatment depends on the cause:
– If due to steroid medication, the dosage is gradually reduced under medical supervision.
– If caused by a tumour, surgery is the primary treatment. Some patients, especially those with pituitary tumours, may require repeat surgery, gamma knife radiosurgery, or medications to control cortisol levels.

Can You Prevent Cushing’s Syndrome?

While complete prevention isn’t always possible, Dr Ghody shares some key strategies to reduce risk:

– Use steroids cautiously – If prescribed, take the lowest effective dose for the shortest time. Never stop abruptly without consulting a doctor.
– Genetic screening for people at risk – If you have a family history of pituitary or adrenal tumours, regular monitoring can help with early detection.
– Maintain a healthy lifestyle – A diet rich in fresh vegetables, and fruits, low sodium intake, adequate calcium, and vitamin D can help manage the metabolic effects of excess cortisol.
– Avoid alcohol and tobacco – These can further disrupt hormone balance and overall health.
“Cushing’s Syndrome can be life-threatening if left untreated, but early diagnosis and proper management can significantly improve quality of life. So if you experience unexplained weight gain, blood pressure spikes, or other symptoms, consult an endocrinologist to manage hormonal imbalances,” he said.

Older Adults With Cushing’s Disease Present With Fewer Symptoms Than Younger Patients

Key takeaways:

  • Older age was tied to a higher prevalence of 10 comorbidities among a group of 608 people with Cushing’s disease.
  • Younger age was associated with most hallmark features of Cushing’s disease.

The presentation of Cushing’s disease varies by age, with older adults having fewer hallmark features of the condition and more comorbidities, according to study findings published in The Journal of Clinical Endocrinology & Metabolism.

Researchers assessed data from 608 people diagnosed with Cushing’s disease and treated with a transsphenoidal tumor resection at 11 academic pituitary centers in the U.S. from 2003 to 2023 (82% women; 77.3% white). Patients were divided into 10-year age interval groups, with the youngest group consisting of those aged 10 to 19 years and the oldest containing adults aged 70 to 79 years. Researchers found Cushing’s disease presents differently as adults age, with older adults experiencing more comorbidities and complications, but fewer hallmark features such as weight gain, facial rounding and hirsutism.

“The diagnosis of Cushing’s disease remains challenging, particularly with age,” Won Kim, MD, associate clinical professor of neurosurgery and radiation oncology at the David Geffen School of Medicine at UCLA, told Healio. “The older a patient is, the more likely that he or she may have a slower-growing tumor with fewer classic manifestations of the disease.”

Kim and colleagues obtained data from the Registry of Adenomas of the Pituitary and Related Disorders. Hallmark features of Cushing’s disease were identified by consensus opinion.

The number of comorbidities increased with patient age (beta = 0.0466; P < .001), according to the researchers.

Older age was associated with several comorbidities for patients with Cushing’s disease, including hypertension (P < .001), diabetes (P < .001), hyperlipidemia (P < .001), cancer (P < .001), coronary artery disease (P < .001), chronic obstructive pulmonary disease (P = .044), cardiac arrhythmia (P = .023), hepatitis (P = .038), anxiety (P = .039) and osteopenia (P = .024). The most common comorbidity was hypertension, which was prevalent in 67.2% of participants.

In an analysis of presenting hallmark features of Cushing’s disease, younger age was positively associated with weight gain (P < .001), facial rounding (P < .001), abdominal striae (P < .001), hirsutism (P < .001), menstrual irregularities (P < .001) and acne (P < .001). Older age was positively tied to obstructive sleep apnea (P = .007). The most common hallmark feature of Cushing’s disease was weight gain, prevalent in 80.2% of patients.

“Our work highlights that we must lower our threshold for suspecting Cushing’s disease in patients without the classic physical manifestations as the age of the patient increases,” Kim said in an interview. “Subtle clues, such as increasingly difficult to control medical conditions such as hypertension and diabetes, may be the only things we see.”

Older age was associated with lower preoperative 24-hour urinary free cortisol levels (beta = –0.0256; P = 6.89 x 10-7), but higher postoperative nadir cortisol (beta = 0.0342; P = 1.03 x 10-4) and higher adrenocorticotropin (beta = 0.0204; P = 5.22 x 10-4).

In an assessment of tumor characteristics, older age was tied to having a higher Knosp grade tumor (beta = 0.011; P = .00435), greater tumor volume (beta = 0.0261; P = .0233) and higher maximum tumor dimension (beta = 0.009; P = 3.82 x 10-4). Older age was inversely associated with Ki-67 index, which is a measure of tumor’s proliferation (beta = –0.0459; P = 1.39 x 10-4).

Age was not associated with a patient’s number of surgical complications. Older age was linked to a greater prevalence of deep vein thrombosis or venous thromboembolism (beta = 0.07; P = .014). Younger age was tied to a higher prevalence of postoperative arginine vasopressin (beta = –0.02; P = .048).

Kim said the study’s findings should encourage health care professionals to adjust their methods for screening for Cushing’s disease in older adults.

“Improving our diagnostic sensitivity through our standardized assessments for the disease should account for these new findings,” Kim told Healio.

For more information:

Won Kim, MD, can be reached at wonkim@mednet.ucla.edu.

Published by:endocrine today logo

Unveiling the Uncommon: Cushing’s Syndrome (CS) Masquerading as Severe Hypokalemia

Abstract

Cushing’s syndrome (CS) arises from an excess of endogenous or exogenous cortisol, with Cushing’s disease specifically implicating a pituitary adenoma and exaggerated adrenocorticotropic hormone (ACTH) production. Typically, Cushing’s disease presents with characteristic symptoms such as weight gain, central obesity, moon face, and buffalo hump.

This case report presents an unusual manifestation of CS in a 48-year-old male with a history of hypertension, where severe hypokalemia was the primary presentation. Initial complaints included bilateral leg swelling, muscle weakness, occasional shortness of breath, and a general feeling of not feeling well. Subsequent investigations revealed hypokalemia, metabolic alkalosis, and an abnormal response to dexamethasone suppression, raising concerns about hypercortisolism. Further tests, including 24-hour urinary free cortisol and ACTH testing, confirmed significant elevations. Brain magnetic resonance imaging (MRI) identified a pituitary macroadenoma, necessitating neurosurgical intervention.

This case underscores the rarity of CS presenting with severe hypokalemia, highlighting the diagnostic challenges and the crucial role of a collaborative approach in managing such intricate cases.

Introduction

Cushing’s syndrome (CS), characterized by excessive cortisol production, is well-known for its diverse and often conspicuous clinical manifestations. Cushing’s disease is a subset of CS resulting from a pituitary adenoma overproducing adrenocorticotropic hormone (ACTH), leading to heightened cortisol secretion. The classic presentation involves a spectrum of symptoms such as weight gain, central obesity, muscle weakness, and mood alterations [1].

Despite its classic presentation, CS can demonstrate diverse and atypical features, challenging conventional diagnostic paradigms. This case report sheds light on a rare manifestation of CS, where severe hypokalemia was the primary clinical indicator. Notably, instances of CS prominently manifesting through severe hypokalemia are scarce in the literature [1,2].

Through this exploration, we aim to provide valuable insights into the diagnostic intricacies of atypical CS presentations, underscore the significance of a comprehensive workup, and emphasize the collaborative approach essential for managing such uncommon hormonal disorders.

Case Presentation

A 48-year-old male with a history of hypertension presented to his primary care physician with complaints of bilateral leg swelling, occasional shortness of breath, dizziness, and a general feeling of malaise persisting for 10 days. The patient reported increased water intake and urinary frequency without dysuria. The patient was diagnosed with hypertension eight months ago. He experienced progressive muscle weakness over two months, hindering his ability to perform daily activities, including using the bathroom. The primary care physician initiated a blood workup that revealed severe hypokalemia with a potassium level of 1.3 mmol/L (reference range: 3.6 to 5.2 mmol/L), prompting referral to the hospital.

Upon admission, the patient was hypertensive with a blood pressure of 180/103 mmHg, a heart rate of 71 beats/minute, a respiratory rate of 18 breaths/minute, and an oxygen saturation of 96% on room air. Physical examination revealed fine tremors, bilateral 2+ pitting edema in the lower extremities up to mid-shin, abdominal distension with normal bowel sounds, and bilateral reduced air entry in the bases of the lungs on auscultation. The blood work showed the following findings (Table 1).

Parameter Result Reference Range
Potassium (K) 1.8 mmol/L 3.5-5.0 mmol/L
Sodium (Na) 144 mmol/L 135-145 mmol/L
Magnesium (Mg) 1.3 mg/dL 1.7-2.2 mg/dL
Hemoglobin (Hb) 15.5 g/dL 13.8-17.2 g/dL
White blood cell count (WBC) 13,000 x 103/µL 4.5 to 11.0 × 109/L
Platelets 131,000 x 109/L 150-450 x 109/L
pH 7.57 7.35-7.45
Bicarbonate (HCO3) 46 mmol/L 22-26 mmol/L
Lactic acid 4.2 mmol/L 0.5-2.0 mmol/L
Table 1: Blood work findings

In order to correct the electrolyte imbalances, the patient received intravenous (IV) magnesium and potassium replacement and was later transitioned to oral. The patient was also started on normal saline at 100 cc per hour. To further investigate the complaint of shortness of breath, the patient underwent a chest X-ray, which revealed bilateral multilobar pneumonia (Figure 1). He was subsequently treated with ceftriaxone (1 g IV daily) and clarithromycin (500 mg twice daily) for seven days.

A-chest-X-ray-revealing-(arrows)-bilateral-multilobar-pneumonia
Figure 1: A chest X-ray revealing (arrows) bilateral multilobar pneumonia

With persistent abdominal pain and lactic acidosis, a computed tomography (CT) scan abdomen and pelvis with contrast was conducted, revealing a psoas muscle hematoma. Subsequent magnetic resonance imaging (MRI) depicted an 8×8 cm hematoma involving the left psoas and iliacus muscles. The interventional radiologist performed drainage of the hematoma involving the left psoas and iliacus muscles (Figure 2).

Magnetic-resonance-imaging-(MRI)-depicting-an-8x8-cm-hematoma-(arrow)-involving-the-left-psoas-and-iliacus-muscles
Figure 2: Magnetic resonance imaging (MRI) depicting an 8×8 cm hematoma (arrow) involving the left psoas and iliacus muscles

In light of the concurrent presence of hypokalemia, hypertension, and metabolic alkalosis, there arose concerns about Conn’s syndrome, prompting consultation with endocrinology. Their recommended workup for Conn’s syndrome included assessments of the aldosterone-renin ratio and random cortisol levels. The results unveiled an aldosterone level below 60 pmol/L (reference range: 190 to 830 pmol/L in SI units) and a plasma renin level of 0.2 pmol/L (reference range: 0.7 to 3.3 mcg/L/hr in SI units). Notably, the aldosterone-renin ratio was low, conclusively ruling out Conn’s syndrome. The random cortisol level was notably elevated at 1334 nmol/L (reference range: 140 to 690 nmol/L).

Furthermore, a low-dose dexamethasone suppression test was undertaken due to the high cortisol levels. Following the administration of 1 mg of dexamethasone at 10 p.m., cortisol levels were measured at 9 p.m., 3 a.m., and 9 a.m. the following day. The results unveiled a persistently elevated cortisol level surpassing 1655 nmol/L, signaling an abnormal response to dexamethasone suppression and raising concerns about a hypercortisolism disorder, such as CS.

In the intricate progression of this case, the investigation delved deeper with a 24-hour urinary free cortisol level, revealing a significant elevation at 521 mcg/day (reference range: 10 to 55 mcg/day). Subsequent testing of ACTH portrayed a markedly elevated level of 445 ng/L, distinctly exceeding the normal reference range of 7.2 to 63.3 ng/L. A high-dose 8 mg dexamethasone test was performed to ascertain the source of excess ACTH production. The baseline serum cortisol levels before the high-dose dexamethasone suppression test were 1404 nmol/L, which decreased to 612 nmol/L afterward, strongly suggesting the source of excess ACTH production to be in the pituitary gland.

A CT scan of the adrenal glands ruled out adrenal mass, while an MRI of the brain uncovered a 1.3×1.3×3.2 cm pituitary macroadenoma (Figure 3), leading to compression of adjacent structures. Neurosurgery was consulted, and they recommended surgical removal of the macroadenoma due to the tumor size and potential complications. The patient was referred to a tertiary care hospital for pituitary adenoma removal.

Magnetic-resonance-imaging-(MRI)-of-the-brain-depicting-a-1.3x1.3x3.2-cm-pituitary-macroadenoma-(star)
Figure 3: Magnetic resonance imaging (MRI) of the brain depicting a 1.3×1.3×3.2 cm pituitary macroadenoma (star)

Discussion

CS represents a complex endocrine disorder characterized by excessive cortisol production. While the classic presentation of CS includes weight gain, central obesity, and muscle weakness, our case highlights an uncommon initial manifestation: severe hypokalemia. This atypical presentation underscores the diverse clinical spectrum of CS and the challenges it poses in diagnosis and management [1,2].

While CS typically presents with the classic symptoms mentioned above, severe hypokalemia as the initial manifestation is exceedingly rare. Hypokalemia in CS often results from excess cortisol-mediated activation of mineralocorticoid receptors, leading to increased urinary potassium excretion and renal potassium wasting. Additionally, metabolic alkalosis secondary to cortisol excess further exacerbates hypokalemia [3,4].

Diagnosing a case of Cushing’s disease typically commences with a thorough examination of the patient’s medical history and a comprehensive physical assessment aimed at identifying characteristic manifestations such as central obesity, facial rounding, proximal muscle weakness, and increased susceptibility to bruising. Essential to confirming the diagnosis are laboratory examinations, which involve measuring cortisol levels through various tests, including 24-hour urinary free cortisol testing, late-night salivary cortisol testing, and dexamethasone suppression tests. Furthermore, assessing plasma ACTH levels aids in distinguishing between pituitary-dependent and non-pituitary causes of CS. Integral to the diagnostic process are imaging modalities such as MRI of the pituitary gland, which facilitate the visualization of adenomas and the determination of their size and precise location [1-4].

Treatment for Cushing’s disease primarily entails surgical removal of the pituitary adenoma via transsphenoidal surgery, with the aim of excising the tumor and restoring normal pituitary function. In cases where surgical intervention is unsuitable or unsuccessful, pharmacological therapies employing medications such as cabergoline (a dopamine receptor agonist) or pasireotide (a somatostatin analogue) may be considered to suppress ACTH secretion and regulate cortisol levels. Additionally, radiation therapy, whether conventional or stereotactic radiosurgery, serves as a supplementary or alternative treatment approach to reduce tumor dimensions and mitigate ACTH production [5,6]. To assess the effectiveness of treatment, manage any problem, and assure long-term illness remission, diligent long-term follow-up and monitoring are essential. Collaborative multidisciplinary care involving specialists such as endocrinologists, neurosurgeons, and other healthcare professionals is pivotal in optimizing patient outcomes and enhancing overall quality of life [2,4].

The prognosis of CS largely depends on the underlying cause, stage of the disease, and efficacy of treatment. Early recognition and prompt intervention are essential for improving outcomes and minimizing long-term complications. Surgical resection of the adrenal or pituitary tumor can lead to remission of CS in the majority of cases. However, recurrence rates vary depending on factors such as tumor size, invasiveness, and completeness of resection [2,3]. Long-term follow-up with endocrinologists is crucial for monitoring disease recurrence, assessing hormonal function, and managing comorbidities associated with CS.

Conclusions

In conclusion, our case report highlights the rarity of severe hypokalemia as the initial presentation of CS. This unique presentation underscores the diverse clinical manifestations of CS and emphasizes the diagnostic challenges encountered in clinical practice. A multidisciplinary approach involving endocrinologists, neurosurgeons, and radiologists is essential for the timely diagnosis and management of CS. Early recognition, prompt intervention, and long-term follow-up are essential for optimizing outcomes and improving the quality of life for patients with this endocrine disorder.

References

  1. Nieman LK, Biller BM, Findling JW, Newell-Price J, Savage MO, Stewart PM, Montori VM: The diagnosis of Cushing’s syndrome: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2008, 93:1526-40. 10.1210/jc.2008-0125
  2. Newell-Price J, Bertagna X, Grossman AB, Nieman LK: Cushing’s syndrome. Lancet. 2006, 367:1605-17. 10.1016/S0140-6736(06)68699-6
  3. Torpy DJ, Mullen N, Ilias I, Nieman LK: Association of hypertension and hypokalemia with Cushing’s syndrome caused by ectopic ACTH secretion: a series of 58 cases. Ann N Y Acad Sci. 2002, 970:134-44. 10.1111/j.1749-6632.2002.tb04419.x
  4. Elias C, Oliveira D, Silva MM, Lourenço P: Cushing’s syndrome behind hypokalemia and severe infection: a case report. Cureus. 2022, 14:e32486. 10.7759/cureus.32486
  5. Fleseriu M, Petersenn S: Medical therapy for Cushing’s disease: adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers. Pituitary. 2015, 18:245-52. 10.1007/s11102-014-0627-0
  6. Pivonello R, De Leo M, Cozzolino A, Colao A: The treatment of Cushing’s disease. Endocr Rev. 2015, 36:385-486. 10.1210/er.2013-1048

Is Cushing Syndrome More Common in the US Than We Think?

I think members of the Cushing’s Help boards have been saying this forever!  Cushing’s isn’t all that rare.  Just rarely diagnosed,

 

BOSTON — The prevalence of Cushing syndrome (CS) in the United States may be considerably higher than currently appreciated, new data from a single US institution suggest.

In contrast to estimates of 1 to 3 cases per million patient-years from population-based European studies, researchers at the University of Wisconsin, Milwaukee, estimated that the incidence of CS in Wisconsin is a minimum of 7.2 cases per million patient-years. What’s more, contrary to all previous studies, they found that adrenal Cushing syndrome was more common than pituitary adrenocorticotropic hormone (ACTH)– secreting tumors (Cushing disease), and that fewer than half of individuals with adrenal Cushing syndrome had classic physical features of hypercortisolism, such as weight gain, round face, excessive hair growth, and stretch marks.

“Cases are absolutely being missed…. Clinicians should realize that cortisol excess is not rare. It may not be common, but it needs to be considered in patients with any constellation of features that are seen in cortisol excess,” study investigator Ty B. Carroll, MD, Associate Professor of Medicine, Endocrinology and Molecular Medicine, and the Endocrine Fellowship Program Director at Medical College of Wisconsin in Milwaukee, told Medscape Medical News.

There are several contributing factors, he noted, “including the obesity and diabetes epidemics which make some clinical features of cortisol excess more common and less notable. Providers get used to seeing patients with some features of cortisol excess and don’t think to screen. The consequence of this is more difficult-to-control diabetes and hypertension, more advance metabolic bone disease, and likely more advanced cardiovascular disease, all resulting from extended exposure to cortisol excess,” he said.

Are Milder Cases the Ones Being Missed?

Asked to comment, session moderator Sharon L. Wardlaw, MD, professor of medicine at Columbia University College of Physicians and Surgeons, New York City, said “When we talk about Cushing [syndrome], we usually think of pituitary ACTH as more [common], followed by adrenal adenomas, and then ectopic. But they’re seeing more adrenal adenoma…we are probably diagnosing this a little more now.”

She also suggested that the Wisconsin group may have a lower threshold for diagnosing the milder cortisol elevation seen with adrenal Cushing syndrome. “If you screen for Cushing with a dexamethasone suppression test…[i]f you have autonomous secretion by the adrenal, you don’t suppress as much…. When you measure 24-hour urinary cortisol, it may be normal. So you’re in this in-between [state]…. Maybe in Wisconsin they’re diagnosing it more. Or, maybe it’s just being underdiagnosed in other places.”

She also pointed out that “you can’t diagnose it unless you think of it. I’m not so sure that with these mild cases it’s so much that it’s more common, but maybe it’s like thyroid nodules, where we didn’t know about it until everybody started getting all of these CT scans. We’re now seeing all these incidental thyroid nodules…I don’t think we’re missing florid Cushing.”

However, Wardlaw said, it’s probably worthwhile to detect even milder hypercortisolism because it could still have long-term damaging effects, including osteoporosis, muscle weakness, glucose intolerance, and frailty. “You could do something about it and normalize it if you found it. I think that would be the reason to do it.”

Is Wisconsin Representative of Cushing Everywhere?

Carroll presented the findings at the annual meeting of the Endocrine Society. He began by noting that most of the previous CS incidence studies, with estimates of 1.2-3.2 cases per million per year, come from European data published from 1994 to 2019 and collected as far back as 1955. The method of acquisition of patients and the definitions of confirmed cases varied widely in those studies, which reported CS etiologies of ACTH-secreting neoplasms (pituitary or ectopic) in 75%-85% and adrenal-dependent cortisol excess in 15%-20%.

The current study included data from clinic records between May 1, 2017, and December 31, 2022, of Wisconsin residents newly diagnosed with and treated for CS. The CS diagnosis was established with standard guideline-supported biochemical testing and appropriate imaging. Patients with exogenous and non-neoplastic hypercortisolism and those who did not receive therapy for CS were excluded.

A total of 185 patients (73% female, 27% male) were identified from 27 of the total 72 counties in Wisconsin, representing a population of 4.5 million. On the basis of the total 5.9 million population of Wisconsin, the incidence of CS in the state works out to 7.2 cases per million population per year, Carroll said.

However, data from the Wisconsin Hospital Association show that the University of Wisconsin’s Milwaukee facility treated just about half of patients in the state who are discharged from the hospital with a diagnosis of CS during 2019-2023. “So…that means that an actual or approximate incidence of 14-15 cases per million per year rather than the 7.2 cases that we produce,” he said.

Etiologies were 60% adrenal (111 patients), 36.8% pituitary (68 patients), and 3.2% ectopic (6 patients). Those proportions were similar between genders.

On biochemical testing, values for late-night salivary cortisol, dexamethasone suppression, and urinary free cortisol were highest for the ectopic group (3.189 µg/dL, 42.5 µg/dL, and 1514.2 µg/24 h, respectively) and lowest for the adrenal group (0.236 µg/dL, 6.5 µg/dL, and 64.2 µg/24 h, respectively). All differences between groups were highly statistically significant, at P < .0001, Carroll noted.

Classic physical features of CS were present in 91% of people with pituitary CS and 100% of those ectopic CS but just 44% of individuals with adrenal CS. “We found that adrenal-dependent disease was the most common form of Cushing syndrome. It frequently presented without classic physical features that may be due to the milder biochemical presentation,” he concluded.

Carroll reports consulting and investigator fees from Corcept Therapeutics. Wardlaw has no disclosures. 

Miriam E. Tucker is a freelance journalist based in the Washington DC area. She is a regular contributor to Medscape, with other work appearing in The Washington Post, NPR’s Shots blog, and Diatribe. She is on X (formerly Twitter) @MiriamETucker.

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Unveiling the Uncommon: Cushing’s Syndrome (CS) Masquerading as Severe Hypokalemia

Abstract

Cushing’s syndrome (CS) arises from an excess of endogenous or exogenous cortisol, with Cushing’s disease specifically implicating a pituitary adenoma and exaggerated adrenocorticotropic hormone (ACTH) production. Typically, Cushing’s disease presents with characteristic symptoms such as weight gain, central obesity, moon face, and buffalo hump.

This case report presents an unusual manifestation of CS in a 48-year-old male with a history of hypertension, where severe hypokalemia was the primary presentation. Initial complaints included bilateral leg swelling, muscle weakness, occasional shortness of breath, and a general feeling of not feeling well. Subsequent investigations revealed hypokalemia, metabolic alkalosis, and an abnormal response to dexamethasone suppression, raising concerns about hypercortisolism. Further tests, including 24-hour urinary free cortisol and ACTH testing, confirmed significant elevations. Brain magnetic resonance imaging (MRI) identified a pituitary macroadenoma, necessitating neurosurgical intervention.

This case underscores the rarity of CS presenting with severe hypokalemia, highlighting the diagnostic challenges and the crucial role of a collaborative approach in managing such intricate cases.

Introduction

Cushing’s syndrome (CS), characterized by excessive cortisol production, is well-known for its diverse and often conspicuous clinical manifestations. Cushing’s disease is a subset of CS resulting from a pituitary adenoma overproducing adrenocorticotropic hormone (ACTH), leading to heightened cortisol secretion. The classic presentation involves a spectrum of symptoms such as weight gain, central obesity, muscle weakness, and mood alterations [1].

Despite its classic presentation, CS can demonstrate diverse and atypical features, challenging conventional diagnostic paradigms. This case report sheds light on a rare manifestation of CS, where severe hypokalemia was the primary clinical indicator. Notably, instances of CS prominently manifesting through severe hypokalemia are scarce in the literature [1,2].

Through this exploration, we aim to provide valuable insights into the diagnostic intricacies of atypical CS presentations, underscore the significance of a comprehensive workup, and emphasize the collaborative approach essential for managing such uncommon hormonal disorders.

Case Presentation

A 48-year-old male with a history of hypertension presented to his primary care physician with complaints of bilateral leg swelling, occasional shortness of breath, dizziness, and a general feeling of malaise persisting for 10 days. The patient reported increased water intake and urinary frequency without dysuria. The patient was diagnosed with hypertension eight months ago. He experienced progressive muscle weakness over two months, hindering his ability to perform daily activities, including using the bathroom. The primary care physician initiated a blood workup that revealed severe hypokalemia with a potassium level of 1.3 mmol/L (reference range: 3.6 to 5.2 mmol/L), prompting referral to the hospital.

Upon admission, the patient was hypertensive with a blood pressure of 180/103 mmHg, a heart rate of 71 beats/minute, a respiratory rate of 18 breaths/minute, and an oxygen saturation of 96% on room air. Physical examination revealed fine tremors, bilateral 2+ pitting edema in the lower extremities up to mid-shin, abdominal distension with normal bowel sounds, and bilateral reduced air entry in the bases of the lungs on auscultation. The blood work showed the following findings (Table 1).

Parameter Result Reference Range
Potassium (K) 1.8 mmol/L 3.5-5.0 mmol/L
Sodium (Na) 144 mmol/L 135-145 mmol/L
Magnesium (Mg) 1.3 mg/dL 1.7-2.2 mg/dL
Hemoglobin (Hb) 15.5 g/dL 13.8-17.2 g/dL
White blood cell count (WBC) 13,000 x 103/µL 4.5 to 11.0 × 109/L
Platelets 131,000 x 109/L 150-450 x 109/L
pH 7.57 7.35-7.45
Bicarbonate (HCO3) 46 mmol/L 22-26 mmol/L
Lactic acid 4.2 mmol/L 0.5-2.0 mmol/L
Table 1: Blood work findings

In order to correct the electrolyte imbalances, the patient received intravenous (IV) magnesium and potassium replacement and was later transitioned to oral. The patient was also started on normal saline at 100 cc per hour. To further investigate the complaint of shortness of breath, the patient underwent a chest X-ray, which revealed bilateral multilobar pneumonia (Figure 1). He was subsequently treated with ceftriaxone (1 g IV daily) and clarithromycin (500 mg twice daily) for seven days.

A-chest-X-ray-revealing-(arrows)-bilateral-multilobar-pneumonia
Figure 1: A chest X-ray revealing (arrows) bilateral multilobar pneumonia

With persistent abdominal pain and lactic acidosis, a computed tomography (CT) scan abdomen and pelvis with contrast was conducted, revealing a psoas muscle hematoma. Subsequent magnetic resonance imaging (MRI) depicted an 8×8 cm hematoma involving the left psoas and iliacus muscles. The interventional radiologist performed drainage of the hematoma involving the left psoas and iliacus muscles (Figure 2).

Magnetic-resonance-imaging-(MRI)-depicting-an-8x8-cm-hematoma-(arrow)-involving-the-left-psoas-and-iliacus-muscles
Figure 2: Magnetic resonance imaging (MRI) depicting an 8×8 cm hematoma (arrow) involving the left psoas and iliacus muscles

In light of the concurrent presence of hypokalemia, hypertension, and metabolic alkalosis, there arose concerns about Conn’s syndrome, prompting consultation with endocrinology. Their recommended workup for Conn’s syndrome included assessments of the aldosterone-renin ratio and random cortisol levels. The results unveiled an aldosterone level below 60 pmol/L (reference range: 190 to 830 pmol/L in SI units) and a plasma renin level of 0.2 pmol/L (reference range: 0.7 to 3.3 mcg/L/hr in SI units). Notably, the aldosterone-renin ratio was low, conclusively ruling out Conn’s syndrome. The random cortisol level was notably elevated at 1334 nmol/L (reference range: 140 to 690 nmol/L).

Furthermore, a low-dose dexamethasone suppression test was undertaken due to the high cortisol levels. Following the administration of 1 mg of dexamethasone at 10 p.m., cortisol levels were measured at 9 p.m., 3 a.m., and 9 a.m. the following day. The results unveiled a persistently elevated cortisol level surpassing 1655 nmol/L, signaling an abnormal response to dexamethasone suppression and raising concerns about a hypercortisolism disorder, such as CS.

In the intricate progression of this case, the investigation delved deeper with a 24-hour urinary free cortisol level, revealing a significant elevation at 521 mcg/day (reference range: 10 to 55 mcg/day). Subsequent testing of ACTH portrayed a markedly elevated level of 445 ng/L, distinctly exceeding the normal reference range of 7.2 to 63.3 ng/L. A high-dose 8 mg dexamethasone test was performed to ascertain the source of excess ACTH production. The baseline serum cortisol levels before the high-dose dexamethasone suppression test were 1404 nmol/L, which decreased to 612 nmol/L afterward, strongly suggesting the source of excess ACTH production to be in the pituitary gland.

A CT scan of the adrenal glands ruled out adrenal mass, while an MRI of the brain uncovered a 1.3×1.3×3.2 cm pituitary macroadenoma (Figure 3), leading to compression of adjacent structures. Neurosurgery was consulted, and they recommended surgical removal of the macroadenoma due to the tumor size and potential complications. The patient was referred to a tertiary care hospital for pituitary adenoma removal.

Magnetic-resonance-imaging-(MRI)-of-the-brain-depicting-a-1.3x1.3x3.2-cm-pituitary-macroadenoma-(star)
Figure 3: Magnetic resonance imaging (MRI) of the brain depicting a 1.3×1.3×3.2 cm pituitary macroadenoma (star)

Discussion

CS represents a complex endocrine disorder characterized by excessive cortisol production. While the classic presentation of CS includes weight gain, central obesity, and muscle weakness, our case highlights an uncommon initial manifestation: severe hypokalemia. This atypical presentation underscores the diverse clinical spectrum of CS and the challenges it poses in diagnosis and management [1,2].

While CS typically presents with the classic symptoms mentioned above, severe hypokalemia as the initial manifestation is exceedingly rare. Hypokalemia in CS often results from excess cortisol-mediated activation of mineralocorticoid receptors, leading to increased urinary potassium excretion and renal potassium wasting. Additionally, metabolic alkalosis secondary to cortisol excess further exacerbates hypokalemia [3,4].

Diagnosing a case of Cushing’s disease typically commences with a thorough examination of the patient’s medical history and a comprehensive physical assessment aimed at identifying characteristic manifestations such as central obesity, facial rounding, proximal muscle weakness, and increased susceptibility to bruising. Essential to confirming the diagnosis are laboratory examinations, which involve measuring cortisol levels through various tests, including 24-hour urinary free cortisol testing, late-night salivary cortisol testing, and dexamethasone suppression tests. Furthermore, assessing plasma ACTH levels aids in distinguishing between pituitary-dependent and non-pituitary causes of CS. Integral to the diagnostic process are imaging modalities such as MRI of the pituitary gland, which facilitate the visualization of adenomas and the determination of their size and precise location [1-4].

Treatment for Cushing’s disease primarily entails surgical removal of the pituitary adenoma via transsphenoidal surgery, with the aim of excising the tumor and restoring normal pituitary function. In cases where surgical intervention is unsuitable or unsuccessful, pharmacological therapies employing medications such as cabergoline (a dopamine receptor agonist) or pasireotide (a somatostatin analogue) may be considered to suppress ACTH secretion and regulate cortisol levels. Additionally, radiation therapy, whether conventional or stereotactic radiosurgery, serves as a supplementary or alternative treatment approach to reduce tumor dimensions and mitigate ACTH production [5,6]. To assess the effectiveness of treatment, manage any problem, and assure long-term illness remission, diligent long-term follow-up and monitoring are essential. Collaborative multidisciplinary care involving specialists such as endocrinologists, neurosurgeons, and other healthcare professionals is pivotal in optimizing patient outcomes and enhancing overall quality of life [2,4].

The prognosis of CS largely depends on the underlying cause, stage of the disease, and efficacy of treatment. Early recognition and prompt intervention are essential for improving outcomes and minimizing long-term complications. Surgical resection of the adrenal or pituitary tumor can lead to remission of CS in the majority of cases. However, recurrence rates vary depending on factors such as tumor size, invasiveness, and completeness of resection [2,3]. Long-term follow-up with endocrinologists is crucial for monitoring disease recurrence, assessing hormonal function, and managing comorbidities associated with CS.

Conclusions

In conclusion, our case report highlights the rarity of severe hypokalemia as the initial presentation of CS. This unique presentation underscores the diverse clinical manifestations of CS and emphasizes the diagnostic challenges encountered in clinical practice. A multidisciplinary approach involving endocrinologists, neurosurgeons, and radiologists is essential for the timely diagnosis and management of CS. Early recognition, prompt intervention, and long-term follow-up are essential for optimizing outcomes and improving the quality of life for patients with this endocrine disorder.

References

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  2. Newell-Price J, Bertagna X, Grossman AB, Nieman LK: Cushing’s syndrome. Lancet. 2006, 367:1605-17. 10.1016/S0140-6736(06)68699-6
  3. Torpy DJ, Mullen N, Ilias I, Nieman LK: Association of hypertension and hypokalemia with Cushing’s syndrome caused by ectopic ACTH secretion: a series of 58 cases. Ann N Y Acad Sci. 2002, 970:134-44. 10.1111/j.1749-6632.2002.tb04419.x
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