Does the time of day matter when performing cosyntropin stimulation test on my patient with suspected adrenal insufficiency?

No, it doesn’t! Although there is a diurnal variation in serum cortisol level, time of the day does not have an appreciable impact on the synthetic ACTH, also known as cosyntropin (Cortrosyn), stimulation test results.

A 2018 retrospective cohort study found that outcomes from cosyntropin stimulation (CS) testing was not affected by time of the day (0800-1000 h vs 1001-1200 h vs after 1200 h).1

An experimental study involving healthy volunteers with normal adrenal function also found that the time of day of CS testing (250  mcg IV) did not influence the peak or the delta of cortisol levels when measured by immunoassay.2 Similarly, an experiment involving normal volunteers concluded that while compared to testing at 0800 h the afternoon (1600) cortisol response to CS was more pronounced at 5 and 15 min, there was no significant difference in cortisol levels at 30 min.3  Parenthetically, peak cortisol level is usually obtained at 1 h after IV cosynstropin administration.

So if you think your patient should undergo CS testing, there is no reason to wait until the next morning!

Bonus Pearl: Did you know that while the half-life of cortisol is between 70-120 min, the half-life of cosyntropin is only 15 min? 4

 

References

  1. Munro V, Elnenaei M, Doucette S, et al. The effect of time of day testing and utility of 30 and 60 min cortisol values in the 250 mcg ACTH stimulation test. Clin Biochem 2018;54:37-41. https://www.ncbi.nlm.nih.gov/pubmed/29458002
  2. Jonklaas J, Holst JP, Verbalis JG, et al. Changes in steroid concentration with the timing of corticotropin stimulation testing in participants with adrenal insufficiency. Endocr Pract 2012;18:66-75. https://www.ncbi.nlm.nih.gov/pubmed/21856601
  3. Dickstein G, Shechner C, Nicholson WE, et al. Adrenocorticotropin stimulation test: effect of basal cortisol level, time of day, and suggested new sensitive low dose test. J Clin Endocrinol Metab 72:773-78. https://www.ncbi.nlm.nih.gov/pubmed/2005201
  4. Hamilton DD, Cotton BA. Cosyntropin as a diagnostic agent in the screening of patients for adrenocortical insufficiency. Clinical Pharmacology Advances and Applications 2010;2:77-82. https://www.ncbi.nlm.nih.gov/pubmed/22291489

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Does the time of day matter when performing cosyntropin stimulation test on my patient with suspected adrenal insufficiency?

Can I rule out primary adrenal insufficiency by obtaining a single morning serum cortisol level in my hospitalized patient with unexplained hyponatremia?

Primary adrenal insufficiency (PAI) can be confidently ruled out when the morning (eg, 6 AM) serum cortisol level is greater than 17 ug/dl. Lower cut-off values are associated with lower probability of excluding PAI: > 10 ug/dl, 62%-67% and ≥5 ug/dl, 36%. 1,2 Conversely, PAI is highly likely when the morning serum cortisol level is less than 3 ug/dl. 3

Since many patients may have serum cortisol levels between 3 ug/dl and 17 ug/dl (ie, in the “indeterminate” range), confirmatory testing commonly performed through cosyntropin stimulation test (CST) is often necessary.

Although the standard CST involves measuring serum cortisol levels at baseline, 30 min, and 60 min with peak cortisol level <18 ug/dl indicative of PAI, several studies have reported that a single post-CST cortisol level obtained at 60 min may also be diagnostic. 3

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References

  1. Erturk E, Jaffe CA, Barkan AL. Evaluation of the integrity of the hypothalamic-pituitary-adrenal axis by insulin hypoglycemia test. J Clin Endocrinol Metab 83;2350-54. https://www.ncbi.nlm.nih.gov/pubmed/9661607
  2. Bornstein SR, Allolio B, Arlt W, et al. Diagnosis and treatment of primary adrenal insufficiency: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2016;101:364-89. https://academic.oup.com/jcem/article/101/2/364/2810222
  3. Odom DC, Gronowski AM, Odom E, et al. A single, post-ACTH cortisol measurement to screen for adrenal insufficiency in the hospitalized patient. J Hosp Med 2018;13: E1-E5. https://www.ncbi.nlm.nih.gov/pubmed/29444197
Can I rule out primary adrenal insufficiency by obtaining a single morning serum cortisol level in my hospitalized patient with unexplained hyponatremia?

My patient is admitted with diabetic ketoacidosis (DKA) and is testing positive for cocaine. Can cocaine cause DKA?

Cocaine use has been generally linked to DKA but whether it’s through its antagonizing effect on insulin action or more indirectly through its association with non-compliance with insulin, or both, is not totally clear.

A retrospective study found cocaine users to account for 14% of all DKA admissions.1 Cocaine users were also less likely than controls to have an intercurrent illness identified as a precipitant for DKA, and more likely to have missed taking insulin prior to admission. Another study also reported active cocaine use to be associated with DKA, but found its effect to be independent of non-compliance. 2

Yet another retrospective study limited to patients admitted with hyperglycemia, found no significant association between active cocaine use and development of hyperglycemic crisis.

There are reasons to believe that cocaine may contribute to DKA. Cocaine has been proposed as a possible precipitant of DKA due to its ability to potentially enhance counterregulatory mechanisms designed to antagonize the effect of insulin by increasing catecholamine and cortisol levels. 1,3

So next time you have a patient with DKA, consider cocaine as a possible precipitant, particularly when the cause of DKA is unclear.

 

References

  1. Warner EA, Greene GS, Buchsbaum MS et al. Diabetic ketoacidosis associated with cocaine use. Arch Intern Med 1998; 158:1799-802. https://www.ncbi.nlm.nih.gov/pubmed/9738609
  2. Nyenwe E, Loganathan R, Blum S, et al. Active use of cocaine: An independent risk factor for recurrent diabetic ketoacidosis in a city hospital. Endocr Pract 2007;13:22-29. https://www.ncbi.nlm.nih.gov/pubmed/17360297
  3. Modzelewski KL, Rybin DV, Weinberg JM, et al. Active cocaine use does not increase the likelihood of hyperglycemic crisis. J Clin Transl Endocrinol 2017;9:1-7 http://www.jctejournal.com/article/S2214-6237(16)30056-4/pdf

 

Contributed in part by Quin L Sievers, Medical Student, Harvard Medical School

My patient is admitted with diabetic ketoacidosis (DKA) and is testing positive for cocaine. Can cocaine cause DKA?

What is the connection between cirrhosis and adrenal insufficiency (AI)?

The prevalence of AI in patients with liver disease varies widely (30-60%). However, there is no consensus on how to define AI in such patients, nor is the methodology for its evaluation standardized. 

A common criticism is the frequent reliance on total, not free, serum cortisol in cirrhosis which may overestimate the prevalence of AI because cortisol is bound to corticosteroid binding globulin and albumin, commonly found at lower concentrations in cirrhosis. However, even when based on measuring free cortisol, AI is found in 12%-29% of clinically stable cirrhotic patients. 1

 Secondary AI due to hypothalamic-pituitary dysfunction has also been reported in Child-Pugh class A, B, and C patients (42%, 69%, and 80%, respectively). 2

The mechanism of AI in cirrhosis is unclear, but low serum cholesterol in cirrhosis leading to lack of substrate for steroidogenesis, and increased levels of circulating endotoxin and pro-inflammatory cytokines impairing the hypothalamic-pituitary-adrenal axis have been postulated. 1

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References

  1. Fede G, Spadaro L, Purrello F. Review: adrenal insufficiency in liver disease. J Liver 2014;3:1. https://www.ncbi.nlm.nih.gov/pubmed/22234976
  2. Zietz, B, Lock, G, Plach, B, et al. Dysfunction of the hypothalamic-pituitary-glandular axes and relation to Child-Pugh classification in male patients with alcoholic and virus-related cirrhosis. Eur J Gastroenterol Hepatology 2003;15:495-501. https://www.ncbi.nlm.nih.gov/pubmed/12702906
What is the connection between cirrhosis and adrenal insufficiency (AI)?