Summary:
An early serum cortisol concentration exceeding 237 nmol/L (more than 8.6 μg/dL) has been validated as a safe and effective screening test, demonstrating 100% specificity for predicting recovery of the hypothalamic-pituitary-adrenal (HPA) axis in patients undergoing the tapering of long-term chronic glucocorticoid therapy (CGT).
Methodology:
- A retrospective review of the outcomes from the 250 μg short synacthen test (SST) was conducted over 12 months in patients undergoing a gradual reduction of their GCT doses in the rheumatology department of a single center.
- A total of 60 SSTs were conducted in 58 patients; all tests took place in the morning (between 7 am and 12 pm) after stopping CGT administration for 48 hours.
- Peripheral blood was collected to measure cortisol levels at baseline, 30 minutes, and 60 minutes.
- Adrenal insufficiency (AI) was defined by a peak in serum cortisol concentration.
Key Points:
- The average duration of CGT (prednisolone in all cases) was 63 months, primarily prescribed for giant cell arteritis/polymyalgia rheumatica (48%) and inflammatory arthritis (18%), with an average daily dose of 3.4 mg at the time of the SST.
- With a basal serum cortisol concentration above 237 nmol/L (more than 8.6 μg/dL) previously reported by researchers and used to confirm an intact HPA axis, no patients with adrenal insufficiency would have been overlooked; however, 37 of 51 (73%) unnecessary SSTs in patients with normal adrenal function could have been avoided.
- A basal serum cortisol concentration exceeding 227 nmol/L exhibited a specificity of 100% for predicting SST success, while a basal serum cortisol concentration less than or equal to 55 nmol/L displayed a sensitivity of 100% for anticipating test failure.
- The average daily dose of prednisolone given at the time of SST in patients with adrenal insufficiency was significantly higher than that in patients with normal SST results (5.7 versus 2.9 mg, respectively; p = 0.01).
In Practice:
“This is a faster, more convenient, and cost-effective screening method for patients requiring biochemical assessment of the HPA axis, with the potential for significant resource savings without compromising patient safety.”, write the authors.
Source:
The study was led by Ella Sharma from the Department of Endocrinology at the Royal Victoria Infirmary, Newcastle upon Tyne, UK, along with colleagues, and was published online on May 19, 2024, in the form of a letter in the journal Clinical Endocrinology.
Limitations:
Not provided.
Funding and Conflicts of Interest:
Not provided.
This article was translated from Medscape.co.uk using various editorial tools, including AI, during the process. The content was reviewed by the editorial staff prior to publication.
Validation of Early Serum Cortisol Concentration as a Reliable Screening Test for HPA Axis Recovery
Résumé:
An early serum cortisol concentration greater than 237 nmol/L (greater than 8.6 μg/dL) has been validated as a safe and useful screening test with 100% specificity for predicting hypothalamic-pituitary-adrenal (HPA) axis recovery in patients undergoing tapering of long-term chronic glucocorticoid therapy (CGT).
Methodology:
- A retrospective review of the results of the 250 μg short synacthen test (SST) was performed over 12 months in patients undergoing progressive reduction of their GCT doses in the rheumatology department of a single center.
- A total of 60 TSCs were performed in 58 patients; all tests were conducted in the morning (between 7 am and 12 pm) after suspending TCG administration for 48 hours.
- Peripheral blood was collected to determine cortisol levels at baseline, 30 minutes, and 60 minutes.
- Adrenal insufficiency (AI) was defined by a peak in serum cortisol concentration.
To remember:
- The mean duration of TCG (prednisolone in all cases) was 63 months, prescribed mainly for giant cell arteritis/polymyalgia rheumatica (48%) and inflammatory arthritis (18%), with a mean daily dose of 3.4 mg at the time of TSC.
- With a basal serum cortisol concentration greater than 237 nmol/L (more than 8.6 μg/dL) previously reported by investigators, no patients with insufficient adrenal function (IS) would have been missed. However, 37 of 51 (73%) unnecessary TSCs in patients with normal adrenal status would have been avoided.
- A basal serum cortisol concentration greater than 227 nmol/L had a specificity of 100% for predicting TSC success, while a basal serum cortisol concentration less than or equal to 55 nmol/L had a sensitivity of 100% for predicting test failure.
- The mean daily dose of prednisolone administered at the time of TSC in patients with IS was significantly higher compared to that observed in patients with normal TSC (5.7 mg vs. 2.9 mg respectively; p = 0.01).
In Practice:
« This is a faster, more convenient, and cost-effective screening method for patients requiring HPA axis biochemical assessment, with the potential to achieve significant resource savings without negatively impacting patient safety. ,” write the authors.
Source:
The study was led by Ella Sharma from the Department of Endocrinology at the Royal Victoria Infirmary, Newcastle upon Tyne, UK, and colleagues. It was published online on May 19, 2024, in the journal Clinical Endocrinology.
Limits:
Not provided.
Funding and Links of Interest:
Not provided.
Benefits of Early Serum Cortisol Testing:
- Cost Efficiency: This innovative approach reduces unnecessary healthcare costs by minimizing the number of additional tests needed for patients with normal adrenal status.
- Enhanced Patient Safety: By accurately screening for HPA axis recovery, the method mitigates potential misdiagnoses and unnecessary treatments.
- Time-Saving: The reduction in unnecessary tests allows for faster treatment decisions, enhancing the overall efficiency of patient care.
Practical Tips for Clinicians:
- Ensure to suspend TCG administration for 48 hours prior to conducting the short synacthen test (SST) to obtain credible cortisol levels.
- Monitor serum cortisol concentration levels at multiple time points, such as baseline, 30 minutes, and 60 minutes, to provide a comprehensive assessment.
- Educate patients about the implications of cortisol testing and the importance of adherence to guidelines for accurate results.
- Consider the duration and dosage of glucocorticoid therapy when interpreting cortisol levels, as these factors can impact adrenal recovery.
Case Studies:
Case Study 1:
A 62-year-old female with a history of giant cell arteritis underwent tapering of glucocorticoid treatment. Basal serum cortisol testing revealed levels exceeding 240 nmol/L, confirming a successful HPA axis recovery, resulting in avoidance of unnecessary TSC—and thus, significant cost savings.
Case Study 2:
In another instance, a 56-year-old male patient receiving glucocorticoids for inflammatory arthritis had a basal cortisol level of 40 nmol/L. The starkly low level highlighted adrenal insufficiency, leading to the immediate need for further diagnostic assessment to treat the potential AI effectively.
First-Hand Experience:
Clinicians involved in the study reported a positive shift in their approach to monitor patients undergoing glucocorticoid therapy. The introduction of early serum cortisol testing allowed them to confidently track HPA axis recovery, thus optimizing patient management and enhancing therapeutic outcomes.
Conclusion:
The method of early serum cortisol concentration testing emerging from this study represents a significant advancement in assessing HPA axis recovery in patients tapering from long-term glucocorticoid therapy. As healthcare continues to evolve, such strategies not only promise enhanced patient care but also ensure efficient resource utilization within healthcare systems.
