What is the significance of a bedtime salivary cortisol level of 0.046 in a patient with uncontrolled diabetes and Cushingoid (Cushing's syndrome) features?

From the Guidelines

The salivary cortisol level of 0.046 is within normal range, suggesting that Cushing's syndrome is not present despite the cushingoid features, and thus, the priority should be improving glycemic control through optimization of diabetes management. These features are likely pseudocushingoid, secondary to uncontrolled diabetes rather than true hypercortisolism, as supported by the guideline update on diagnosis and management of Cushing's disease 1. The connection between uncontrolled diabetes and cushingoid features relates to insulin resistance and altered fat distribution, which can mimic the physical manifestations of true Cushing's syndrome without actual cortisol excess.

Key Considerations

• The patient's uncontrolled diabetes is the primary concern, and managing blood glucose levels should be the focus, as indicated by the consensus on diagnosis and management of Cushing's disease 1.
• The normal salivary cortisol result suggests that Cushing's syndrome is unlikely, and therefore, specific treatment for hypercortisolism is not needed at this time.
• If clinical suspicion remains high despite this normal screening test, additional testing such as 24-hour urinary free cortisol or overnight dexamethasone suppression test could be considered, as outlined in the guideline update 1.
• Improving glycemic control may lead to an improvement in the cushingoid appearance, including central obesity, moon facies, and buffalo hump, as these features are often associated with insulin resistance and metabolic syndrome, which are common in uncontrolled diabetes 1.

Management Approach

• Optimize diabetes management through adjusting insulin or oral hypoglycemic medications, dietary modifications, and regular physical activity.
• Monitor blood glucose levels closely and adjust the treatment plan as needed to achieve optimal glycemic control.
• Consider additional testing for Cushing's syndrome if clinical suspicion remains high despite normal screening results, but prioritize diabetes management as the primary concern, based on the most recent and highest quality study available 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Uncontrolled Diabetic with Cushingoid Features

• The patient has been screened with bedtime salivary cortisol, with a result of MS 0.046, indicating potential Cushing's syndrome.
• Cushing's syndrome is caused by an excess of glucocorticoids, resulting in symptoms such as central obesity, moon facies, hirsutism, and reddish-purple stretch marks 2.
• The diagnosis of Cushing's syndrome can be made using various tests, including 24-hour urine free cortisol measurement 2 and dexamethasone suppression test 3.

Diagnostic Tests

• The 24-hour urine free cortisol test measures the total amount of cortisol excreted in the urine over a 24-hour period, which can be useful in screening for Cushing's syndrome caused by a tumor 2.
• The dexamethasone suppression test can be used to diagnose Cushing's syndrome, with a sensitivity of 92.54% for a cutoff point of 24-hour urine free cortisol <32 nmol 3.
• The bedtime salivary cortisol test can also be used to diagnose Cushing's syndrome, but its sensitivity and specificity may vary depending on the cutoff point used.

Management

• There is no direct evidence in the provided studies on the management of uncontrolled diabetic patients with Cushingoid features.
• However, the studies suggest that a multidisciplinary approach may be necessary to manage patients with complex conditions, involving primary care clinicians, secondary care specialists, and emergency department physicians 4, 5, 6.
• Referral and consultation between healthcare professionals are crucial in ensuring that patients receive appropriate care and diagnosis 5, 6.