Is Your Difficult-to-Control Type 2 Diabetes Due to Underlying Hypercortisolism: Are Doctors Missing the Diagnosis?
- Rachelle DiMedia
- Jun 5
- 14 min read

What is Diabetes?
Diabetes is defined by hyperglycemia. Characteristics include insulin resistance in tissues and dysfunction of pancreatic beta cell insulin secretion. Basically, the body becomes resistant to insulin or doesn't produce enough of it. There are 2 kinds: Type 1 and Type 2. Type 1 is an autoimmune disorder that causes the destruction of beta cells, resulting in an absolute deficiency of insulin. Type 2 diabetes (T2D) is a hormonal disorder characterized by pancreatic beta cell dysfunction and insulin resistance. 38.4 million people in the U.S. have T2D and 90% of diabetes cases are T2. ¹,²,³
Causes of T2D are multiple and often multifactorial. Researchers are still unsure of what, exactly, causes insulin production dysfunction and insulin resistance.⁴
Risk factors include:⁴,⁵
Age
Obesity
Lack of physical activity
Racial, ethnic, genetic predisposition
Pregnancy
Certain medications (ie, steroids)
Visceral fat distribution
Around 25% of T2D patients have an HbA1c of greater than 8%, which is considered uncontrolled.
A glycemic index below 7.5% is the goal. Hemoglobin A1c (HbA1c) is a blood test used to assess average blood glucose levels over the last 2 to 3 months, indicating blood sugar control during that period. This test helps diagnose type 2 diabetes and monitors blood glucose regulation in individuals with the condition.⁵
Consequences of Uncontrolled T2D:¹,⁶,⁷
Uncontrolled T2D causes a significant number of complications, morbidity, and mortality.
Retinopathy: retinal nerve damage leads to. blindness
Neuropathy and neuropathology: nerve damage
Atherosclerosis and cardiovascular disease lead to heart attacks, vascular complications and amputations
Cerebrovascular disease leads to stroke, memory and psychiatric issues and cognitive decline
Nephropathy: Kidney damage leads to chronic kidney disease and kidney failure
Impaired wound healing leads to infection
Cancer
What is considered "difficult to control" T2D?
Sustained hyperglycemia: Blood sugar levels ≥ 130 mg/dL before meals for over a year⁸
HbA1c > 7%⁸
Physical symptoms: increased thirst and urination, blurred vision, fatigue⁸
Complications like chronic kidney disease, nephropathy, neuropathy, heart disease, difficult to control high blood pressure (HTN)⁹
Glycemic index not reached despite being on multiple antihyperglycemic medications⁹
38.9-76.9% of people with T2D are considered controlled⁸
47.4% had an A1C of > 7%³
Only 12-13% of T2D patients achieve target HbA1c¹⁰
The presence of long-term difficulty in controlling blood sugar despite optimal therapies may mean that hypercortisolism is present.
What is Hypercortisolism (HC)?
For the purposes of this paper, we will be discussing ACTH-independent Endogenous Hypercortisolism, which will be referred to as HC. Also known as:⁷
Subclinical HC
Adrenal autonomous HC
Less severe HC
Mild HC/Mild Autonomous HC (MACS)
Hidden HC
Cushing's Syndrome
HC occurs when the body produces excessive cortisol, often without the classic symptoms of overt hypercortisolism. Excessive cortisol leads to a multi-systemic hormonal disorder caused by prolonged exposure to high circulating levels of the hormone (aka glucocorticoid) cortisol. This causes hyperglycemia, amongst many other complications (7,11).
HC is caused by endogenous sources (within the body), such as tumors of the adrenal gland(s) or pituitary, or from exogenous sources (outside the body), like chronic steroid use (7,11). We will be discussing endogenous HC.
What is Cortisol?
Known as the "stress hormone", it is present in most tissues in the body and affects nearly every organ system. It is produced by the activation of the HPA = hypothalamic-pituitary axis. Production begins in the brain, with the hypothalamus being stimulated to release CRH (corticotropin-releasing hormone). This stimulates the pituitary (also in the brain) to release ACTH (adrenocorticotropic hormone). ACTH stimulates the adrenal glands, found on top of both kidneys, to produce cortisol (12).
What does it do?
Since cortisol is ubiquitous in the body, it has a wide range of functions and effects(12,13):
Regulates immune function and anti-inflammatory mechanisms
Maintains normal BP and vascular tone
Controls "fight or flight" response
Helps regulate metabolism and blood sugar
Helps regulate cognition and mood
Regulates menstruation and fetal development
Helps control the sleep-wake cycle
What Happens When There Is Too Much Cortisol?

Physical Symtpoms: (14,15)
Atherosclerotic heart disease, left ventricular hypertrophy
Hypercoagulability leading to clots = heart attacks/strokes/amputations
HTN, high cholesterol
Weight gain, especially around the mid-section and torso; unusual dispersion of fat: around the collar bone and between the shoulder blades, known as a buffalo hump. Increase in visceral fat, around the organs, which is particularly dangerous.
Skin changes: striae/purple stretch marks, easy bruising, acne; rounded, pale face known as moon face
Decreased immune function = delayed healing, infections, sepsis
Hirsutism (unwanted, dark, coarse hair in women, usually on face, neck and back)
Delayed puberty or increased weight with slowing growth in youths
Muscle weakness and fatigue
High blood sugar, difficult to control T2D
Osteoporosis = increased bone fragility and fractures
Increased thirst and urination
H20 and electrolyte imbalances, like hypokalemia.
Cognitive Symtpoms: (14,15)
Chronically increased levels of cortisol causes irreversible functional and structural changes to the brain in regions responsible for emotional and cognitive function.
Mood swings and disturbances: anxiety (66%), depression (50-81%), bipolar (30%), and psychosis.
Fatigue, insomnia, obstructive sleep apnea
Impaired cognitive function: memory, language, visual and spatial information, along with verbal learning and language.
Due to its wide range of clinical manifestations, unless obvious symptoms are noted, recognizing and diagnosing HC can be difficult. Patients with endogenous HC don't have severe enough cortisol elevation for these to be seen until the disease has progressed. They often present with nonspecific symptoms in common with the general public: weight gain/obesity, diabetes, high blood pressure and cholesterol, osteoporosis, reproductive and psychiatric disorders.
"Hidden HC," may have no outward symptoms, and is only detectable 5-30% of the time in patients with adrenal incidentalomas (adrenal abnormality found on workup for something else)(17,18).
Up to 2% of people over 60 may have HC, and that number is even higher in people with unexplained, difficult to control T2D and/or HTN and/or osteoporosis.(16)
Despite milder symptoms, HC is associated with an increased risk of other chronic diseases, including progressive type 2 diabetes and hypertension (HTN). HC is associated with an increased risk of cardiovascular and cerebrovascular events, sepsis, and thromboembolism. Over time, cumulative adverse outcomes, including increased morbidity and mortality, will ensue (9). These patients have been found to have:
10% increase in cardiovascular events (9)
4.5x increased risk of heart attack (14)
19.1% decrease in overall survival from cardiovascular events (9)
3.5- 5x increase in mortality compared with the general population (14)
How Does HC Affect T2D
The association between T2D and long-term complications may be linked to HPA axis dysfunction, which is a cause of HC. In turn, HC causes T2D and makes it difficult to control.
HC leads to T2D in 1/3 of affected patients by causing:
Insulin resistance: High cortisol levels impair the body's sensitivity to insulin, resulting in increased blood sugar levels, skeletal muscle insulin resistance, and impaired glucose metabolism.
Visceral fat: Cortisol promotes the accumulation of visceral fat (hidden fat surrounding the organs), leading to further insulin resistance, obesity, hypertension, increased cholesterol, and other metabolic disturbances.
Glucogenesis: (production of glucose) Increased glucose production by the liver.
Beta cell dysfunction: Decreased function of the pancreatic beta cells, which create insulin. Decreased insulin = increased blood sugar.
Lipolysis (breakdown of fats) is activated, free fatty acids to be released, which can lead to high cholesterol and arterial plaques.
What is the Prevalence of HC in Difficult to Control T2D?
There has been a paucity of research done on this debilitating duo, but recent studies have been looking into the prevalence and treatment of people with T2D and HC. Current research suggests the prevalence is as follows:
Approximately 2.9% (575,000-2.5 million people) with "resistant" T2D in the U.S. may have T2D as a result of underlying heart disease (HC) (9).
The recent and ongoing CATALYST study found up 24% of patients with difficult to control T2D have underlying HC, and that number increased to 40% in patients who also had difficult to control HTN (BP > 135mmHg despite being on ≥ 3 BP meds).⁸
Untreated HC is associated with a marked increase in major health complications including early death and decreased quality of life. Endogenous HC is often missed, leading to an unnecessary progression of disease and comorbidities. Main causes of death are cardiovascular or cerebrovascular events, thromboembolism, sepsis and opportunistic infections. Early detection and treatment is critical for decreasing adverse outcomes (15,18).
Who Should be Screened for HC?
Patients displaying these presenations should be considered for HC screening: (15,18)
Resistant or suddenly worsening T2D, metabolic syndrome and/or HTN
Worsening cardiovascular symptoms or events despite optimal therapy
Proximal myopathy (muscle weakness of the limbs)
Distinctive pigmented striae and easy bruising
Unexplained, progressive weight gain
Sudden or suddenly worsening osteoporosis/bone fragility
Young patients with unusual symptoms for their age, especially early onset T2D, HTN, and/or osteoporosis.
Adrenal incidentaloma: up to 50% of these people will have HC
Why Aren't More At-Risk Patients Being Screened?
Knowledge Gaps: Until recently, the prevalence of underlying HC was unknown and not well studied. Primary care physicians (PCPs) are the first person to see the patient and responsible to refer them for further evaluation if HC is a possibility. However, since HC was relatively unthought of until now, physicians may have unknowingly become stymied when traditional attempts failed to control their patients' diabetes. They may suffer from "clinical inertia," which occurs when, despite guidelines, patients are not transitioned to the next tier of treatment when current therapies are ineffective (25,26).
PCP Perspectives: Doctors want to achieve targets. When T2D is uncontrolled, they may become frustrated and blame the patient. They may feel a sense of failure, on their part, that will turn to resignation and further clinical inertia. Also, some PCPs may only refer patients to a specialist as a "last resort", perhaps not realizing the gravity of waiting to enlist help. Delayed diagnosis could cause the patient permanent pain and suffering. (25,26).
Therapeutic Limitations: There is no widely accepted protocol for screening and treating patients with HC. Once HC is suspected, multiple tests are needed that are expensive and time-consuming. The MD and the patient may not want to accept this, even though it is the most prudent course of action (27,28).
Living with HC: Patient Journey
HC is a life-altering and devastating illness, often leading to joblessness, isolation, depression, and loneliness.
Once patients are screened, multiple tests are required and, even then, many are not entirely reliable. The therapeutic regimen is grueling, requiring a multidisciplinary team that should collaborate across disciplines. The complications involved may require multiple hospitalizations and surgeries. There may be different combinations of medications to try, each with side effects. Racial/ethnic disparities, sociodemographics, lack of access to health care, and high cost make it difficult for patients to navigate things like time and transportation while attempting to honor occupational commitments. It can be challenging for both the patient and the primary care physician to maintain long-term participation. (28,29,30).
The symptoms of HC are debilitating, involving multitudinous comorbidities that affect self-esteem, body image, personal relationships, and overall quality of life. They affect the patient physically as well as cognitively, and many may be chronic or lifelong (15,31):
Physical symptoms: Can significantly alter the patient's appearance (e.g., weight gain, moon face, buffalo hump, striae, acne, hirsutism), creating a negative body image and self-perception.
Psychiatric and cognitive symptoms: Mental illness, insomnia, and cognitive decline create more issues with relationships, job life, and daily activities.
Fatigue and muscle weakness: Can Impair activities of daily living, restricting social interaction, leading to joblessness, and necessitating a reliance on others for daily chores, personal hygiene, and financial needs. (15,31,32).
What Treatments Are Available?
Currently, surgery serves as the primary line of defense against HC, aimed at removing the tumor, which is often located on the adrenal gland(s) but can also appear multiple times and in other parts of the body. However, research indicates that surgery may not provide a definitive cure or therapy for HC, and not all patients will be eligible for this surgical intervention.
Up to 75% of patients diagnosed with HC were not candidates or refused surgery. In this instance, pharmacotherapy can offer an acceptable approach for people who can not or will not have surgery. In addition, just treating the comorbidities, as some therapeutic regimens suggest, is not effective enough. If the underlying cause of HC is not dealt with, adverse events will continue and become more numerous (9).

As of now, there is only one drug approved to treat T2D with HC, but there are several other promising, and perhaps better, drugs in the pipeline:
Mifepristone (Korlym): Competitive glucocorticoid receptor (GR) antagonist. Stops cortisol from having effects at the receptor.
Of the medications currently available, Mifeprisone (Korlym) is the only FDA approved agent to treat hyperglycemia due to endogenous Cushing Syndrome in adults with T2D or impaired glucose tolerance who have failed or are not candidates for surgery.
However, due to it's antiprogestational effects (blocks progesterone as well), which causes abortion, it has a box warning and is contraindicated in pregnant women.
May also cause hypokalemia and abnormal menstrual bleeding (20).
Blocks the effects of cortisol but does not affect cortisol levels in the body.
Relacorilant: Selective GR modulator/cortisol antagonist.
Unlike Korlym, it does not block progesterone, reducing risk of adverse side effects (21).
The FDA recently accepted an NDA (new drug application) for Relacorilant, meaning the drug is one step closer to approval (21).
Isturisa (Osilodrostat): Cortisol synthesis inhibitor; blocks the activity of an enzyme (11-beta-hydroxylase) involved in the production of cortisol.
Reduces cortisol production and cortisol levels in the body, thereby relieving the symptoms of the disease.
May cause heart palpitations, hypokalemia, hypocortisolemia
The FDA recently granted expanded approval to treat Cushing Syndrome patients who are not surgical candidates (22).
Clofutriben: HSD-1 inhibitor; blocks cortisol intracellularly.
A new, novel approach to treat HC intracellularly, stopping it before it converts to its active form.
Currently an FDA-approved orphan drug for endogenous HC.
May soon be approved for autonomous HC. (23,24)
Conclusions:
Endogenous HC may be a milder form of HC, but it is easily overlooked. Symptoms can be nonspecific and overlap with those of the general population. Patients may not report symptoms that develop gradually, and primary care physicians (PCPs) may not recognize them for what they are.
PCPs serve as the gatekeepers to patients, playing a crucial role in initial recognition, diagnosis, and referral. They are also often responsible for long-term follow-up, medication management, and interdisciplinary care for these patients. Until recently, the medical community has been unaware of the high prevalence of HC in difficult to control T2D. PCPs may have "given up" on patients they believe are noncompliant. The sole symptom of HC may be progressive, difficult-to-control T2D, despite optimal antihyperglycemic treatments. Physicians should be strongly encouraged to test patients presenting in this manner.
Patients with HC often require a multidisciplinary team of physicians to address all the comorbidities associated with the disease. Care can be time-consuming, costly, and confusing for many individuals, particularly when dealing with the cognitive manifestations of the disease. Sociodemographic factors and limited access to healthcare further complicate this issue.
When HC is overlooked, it leads to unnecessary disease progression and comorbidities, resulting in chronic and often permanent debilitating complications for the patient. This can lead to isolation, unemployment, and a decreased quality of life.
Currently, there is a lack of widely accepted pharmacological therapies proven to be safe and effective, that work quickly, over the long term, and have minimal side effects. Ongoing research aims to develop better pharmacological treatments for HC. Once approved, PCPs should receive education on the uses and side effects of these medications.
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