A retrospective analysis of postoperative hypokalemia in pituitary adenomas after transsphenoidal surgery

Abstract.

Background

Pituitary adenoma is one of the most common intracranial neoplasms, and its primary treatment is endoscopic endonasal transsphenoidal tumorectomy. Postoperative hypokalemia in these patients is a common complication, and is associated with morbidity and mortality. This study aimed to analyze the etiopathology of postoperative hypokalemia in pituitary adenomas after endoscopic transsphenoidal surgery.

Methods and Materials

This retrospective study included 181 pituitary adenomas confirmed by histopathology. Unconditional logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Repeated measures ANOVA was used to analyze change in serum potassium levels at different time points.

Results

Multiple Logistic regression analysis revealed that only ACTH-pituitary adenoma (OR = 4.92, 95% CI [1.18–20.48], P = 0.029) had a significant association with postoperative hypokalemia. Moreover, the overall mean serum potassium concentration was significantly lower in the ACTH versus the non-ACTH group (3.34 mmol/L vs. 3.79 mmol/L, P = 0.001). Postoperative hypokalemia was predominantly found in patients with ACTH-pituitary adenoma (P = 0.033).

Conclusions

ACTH-pituitary adenomas may be an independent factor related postoperative hypokalemia in patients despite conventional potassium supplementation in the immediate postoperative period.

Cite this as

You L, Li W, Chen T, Tang D, You J, Zhang X. (2017) A retrospective analysis of postoperative hypokalemia in pituitary adenomas after transsphenoidal surgery. PeerJ5:e3337 https://doi.org/10.7717/peerj.3337

Read the entire article at https://peerj.com/articles/3337/

Hair Test for Cushing Syndrome?

Cortisol levels in hair correlated strongly with standard tests

by Jeff Minerd
Contributing Writer, MedPage Today

Analyzing the levels of cortisol in hair may aid in the diagnosis of Cushing syndrome, perhaps one day replacing invasive blood tests, scientists said.

Cortisol levels in the proximal ends of hair samples taken from patients with the syndrome correlated strongly with blood tests (R=0.4; P=0.03) and urine tests (R=0.5; P=0.005) for cortisol, reported Mihail Zilbermint, MD, of the National Institute of Child Health and Human Development in Bethesda, Md., and colleagues.

“The diagnosis of Cushing syndrome is often challenging and inconclusive, despite numerous tests used for the detection of hypercortisolemia and its origin, and is associated with high morbidity and high risk for mortality, if undiagnosed and untreated,” Zilbermint and colleagues wrote online in Endocrine: International Journal of Basic and Clinical Endocrinology.

“As a potential solution to the limitations of these tests, hair cortisol has been increasingly studied as an additional means to diagnose patients with Cushing Syndrome. Much like hemoglobin A1C is a longitudinal marker of blood glucose levels, hair cortisol can be a measure of the body’s glucocorticoid levels over the previous several weeks to months.”

“Our results are encouraging,” Zilbermint said in a statement. “We are hopeful that hair analysis may ultimately prove useful as a less-invasive screening test for Cushing syndrome or in helping to confirm the diagnosis.”

The study included 30 patients with Cushing syndrome and six control individuals without the disease. The participants’ average age was 26, and 75% were female and 75% were Caucasian.

The investigators took 3 cm-long hair samples from all patients, analyzed the proximal, medial, and distal segments of the samples for cortisol, and compared the results with results of standard blood and urine tests. Cortisol levels were highest in the proximal segments and correlated best with the standard tests, the investigators reported.

“We found that proximal hair cortisol directly correlates with late night serum cortisol and UFC [urinary free cortisol] in patients with and without Cushing syndrome. The most proximal 1 cm of hair was the best section of hair for stratifying the two groups of patients in our cohort.

“These findings support further research on the use of this modality in the workup for Cushing syndrome.”

Regarding the study’s limitations, the team pointed to the small control group of only six patients. Another limitation is that more than half of the participants (58%) were younger than age 18, and pubertal status on cortisol metabolism may be a factor in hair cortisol measurement.

“However, our study’s strengths are that it is the largest sample so far to analyze segmental hair cortisol in Cushing syndrome, and that it is the largest study to compare hair cortisol to any biochemical test for hypercortisolemia in patients with Cushing syndrome,” Zilbermint and colleagues said. “Our study also included a large cohort of Cushing Disease patients, which has been under-represented in prior studies on hair cortisol.”

The study was funded by the National Institutes of Health. Zilbermint and colleagues reported having no relevant financial relationships with industry.

Cushing’s Syndrome Epidemiology

By Yolanda Smith, BPharm

Cushing’s syndrome is considered to be a rare disorder that results from prolonged exposure to glucocorticoids. However, there are few epidemiological studies to provide adequate data to describe the incidence and prevalence of the condition accurately. Most cases are diagnosed between the ages of 20 and 50, although any individual may be affected at any age.

The presentation of the symptoms of Cushing’s syndrome can vary greatly. In addition, many of the symptoms overlap with those caused by other health conditions, such as metabolic syndrome and polycystic ovary syndrome. This can make the diagnosis of the condition difficult. It is also difficult to establish epidemiological trends in Cushing’s syndrome, because not all cases of the disease are diagnosed. However, it is important that diagnosis is made as soon as possible, because early diagnosis and treatment of the condition are associated with improved morbidity and mortality rates.

Population-based Studies

There are several population-based studies that have reported the incidence and mortality rates of Cushing’s syndrome in certain populations over a discrete period of time.

A study in Denmark followed 166 patients with Cushing’s syndrome for 11 years, finding an incidence of 2 cases per million population per year. Of the 166 patients, 139 had benign disease. There was a mortality rate of 16.5% in the follow-up period of 8 years, with most deaths occurring in the year after the initial diagnosis, often before the initiation of treatment. The causes of death of patients with Cushing’s syndrome in the study included severe infections, cardiac rupture, stroke and suicide.

A study in Spain found 49 cases of Cushing’s syndrome over a period of 18 years, with an incidence of 2.4 cases per million inhabitants per year and a prevalence of 39.1 cases per million. The standard mortality ratio in this study was 3.8, in addition to an increase in morbidity rates.

Incidence

A low incidence of endogenous Cushing’s syndrome was established by the population-based studies outlined above, corresponding to approximately 2 cases per million. Some studies have an estimated incidence as low as 0.7 people per million.

However, the incidence of subclinical Cushing’s syndrome may be underestimated in certain population groups, such as those with osteoporosis, uncontrolled diabetes mellitus or hypertension. For example, of 90 obese patients with uncontrolled diabetes mellitus in one study, three had Cushing’s syndrome. This yielded a prevalence of 3.3%, which is considerably higher than the incidence reported in the population-based studies. However, these findings should be supported by larger studies.

Females are more likely to be affected by Cushing’s syndrome than males, with a risk ratio of approximately 3:1. There does not appear to be a genetic link that involves an ethnic susceptibility to the condition.

Treatment Outcomes

Surgery is the first-line treatment option for most cases of overt disease and remission is achieved in the majority of patients, approximately 65-85%. However, for up to 1 in 5 patients the condition recurs, and the risk does not appear to level off, even after 20 years of follow-up.

The risk of mortality for individuals with Cushing’s syndrome is estimated to be 2-3 times higher than that of the general population, based on epidemiological studies.

Reviewed by Dr Liji Thomas, MD.

From http://www.news-medical.net/health/Cushings-Syndrome-Epidemiology.aspx

Six controversial issues on subclinical Cushing’s syndrome

Abstract

Subclinical Cushing’s syndrome is a condition of hypercortisolism in the absence of signs specific of overt cortisol excess, and it is associated with an increased risk of diabetes, hypertension, fragility fractures, cardiovascular events and mortality.

The subclinical Cushing’s syndrome is not rare, being estimated to be between 0.2–2 % in the adult population. Despite the huge number of studies that have been published in the recent years, several issues remain controversial for the subclinical Cushing’s syndrome screening, diagnosis and treatment.

The Altogether to Beat Cushing’s syndrome Group was founded in 2012 for bringing together the leading Italian experts in the hypercortisolism-related diseases. This document represents the Altogether to Beat Cushing’s syndrome viewpoint regarding the following controversial issues on Subclinical Cushing’s syndrome (SCS):

(1) Who has to be screened for subclinical Cushing’s syndrome?
(2) How to screen the populations at risk?
(3) How to diagnose subclinical Cushing’s syndrome in patients with an adrenal incidentaloma?
(4) Which consequence of subclinical Cushing’s syndrome has to be searched for?
(5) How to address the therapy of choice in AI patients with subclinical Cushing’s syndrome?
(6) How to follow-up adrenal incidentaloma patients with subclinical Cushing’s syndrome surgically or conservatively treated?

Notwithstanding the fact that most studies that faced these points may have several biases (e.g., retrospective design, small sample size, different criteria for the subclinical Cushing’s syndrome diagnosis), we believe that the literature evidence is sufficient to affirm that the subclinical Cushing’s syndrome condition is not harmless and that the currently available diagnostic tools are reliable for identifying the majority of individuals with subclinical Cushing’s syndrome.

Keywords

Subclinical hypercortisolism, Adrenal incidentalomas, Hypertension, Diabetes, Osteoporosis

Surgery Preferred Option in Cushing’s Disease for Best Survival

Patients with Cushing’s disease who have been in remission for more than 10 years still have an increased mortality risk compared with the general population, says an international team of researchers, who found the risk of early death was particularly increased in those with Cushing’s and accompanying circulatory disease.

Richard N Clayton, MD, department of medicine, Keele University, Stoke-on-Trent, United Kingdom, showed that Cushing’s disease, which is characterized by increased secretion of adrenocorticotropic hormone by the anterior pituitary gland, is associated with an increased mortality risk of more than 60% and a median survival of around 40 years.

In patients who also had circulatory disease, the mortality risk was even higher, say Dr Clayton and colleagues.

However, patients who had undergone curative pituitary surgery had a long-term risk of death no different from that of the general population. US Endocrine Society guidelines published last August recommend that optimal treatment of Cushing’s syndrome involves direct surgical removal of the causal tumor.

But Dr Clayton and colleagues point out that even patients who undergo pituitary surgery will nevertheless “require lifelong follow-up at a center experienced in dealing with this condition, having regular checks for diabetes, hypertension, and other cardiovascular risk factors.”

The study was published online June 2 in Lancet Diabetes & Endocrinology.

In an accompanying editorial, Rosario Pivonello, MD, PhD, department of clinical medicine and surgery, section of endocrinology, University of Naples Federico II, Italy, and colleagues write that, although surgery is not suitable for all patients, “Prompt pituitary surgery might be the preferred treatment for Cushing’s disease to guarantee the best mortality outcome.”

Calling for further research to better understand why one treatment “has a better effect on mortality than another,” they state: “The results from this study might also motivate rapid interventions, cure, and long-term follow-up in patients with Cushing’s disease — even for a long time after hypercortisolism resolution.”

Studying Those Who Have Survived More Than 10 Years

Dr Clayton and colleagues explain that previous studies have explored mortality in patients with Cushing’s disease during either active disease or remission. But the outcome of patients in remission, especially long-term remission, is still a matter of debate, and assessing long-term survival has been limited by various methodological differences. To overcome some of these issues, they performed a retrospective analysis of case records from specialist referral centers in the United Kingdom, Denmark, the Netherlands, and New Zealand.

They identified 320 patients diagnosed with Cushing’s disease and cured for a minimum of 10 years at enrollment and had no relapses during the study period. The ratio of women to men was 3:1.

Median patient follow-up was 11.8 years, yielding a total of 3790 person-years of follow-up 10 years after cure. There was no difference in follow-up between countries. And as there were no significant demographic and clinical differences between men and women, the data were pooled.

During the study 16% of patients died. Median survival was 31 years for women and 28 years for men, at approximately 40 years following remission. The overall standardized mortality ratio (SMR) for all-cause mortality compared with the general population was 1.61 (P = .0001).

Patients with Cushing’s and circulatory disease had an SMR vs the general population of 2.72 (P < .0001), but deaths from cancer among those who had survived Cushing’s disease were not higher than the general population, at an SMR of 0.79 (P = .41).

Patients with Cushing’s and diabetes also had an increased mortality risk, at a hazard ratio (HR) of 2.82 (P < .0096) compared with the general population, while hypertension was not significantly associated with increased mortality, at an HR of 1.59 (P = .08).

There was also an association between mortality and number of treatments, at an HR of 1.77 for two vs one treatment (P = .08) and an HR of 2.6 for three vs one treatment (P = .02).

Pituitary Surgery Alone Associated With No Increased Risk of Death

Pituitary surgery performed as the first and only treatment was associated with an SMR vs the general population of 0.94 compared with an SMR of 2.58 for other patients (P < .0005).

Patients who had pituitary surgery only had a median survival of 31 years compared with 24 years if surgery had been required at any time (P = 0.03).

The research team states: “For patients who have been cured of Cushing’s disease for 10 years or more, treatment complexity and an increased number of treatments, reflecting disease that is more difficult to control, appears to negatively affect survival.”

“Pituitary surgery alone achieves a mortality outcome that is not different from the normal population and should be performed in a center of excellence,” they conclude.

However, in the editorial, Dr Pivonello and colleagues point out that the surgical approach “is not a treatment option for some patients, either because of contraindications (eg, severe clinical complications) or because of an absence of clear indication for surgery (eg, tumor is not completely removable by surgery).”

The authors and editorialist have reported no relevant financial relationships.

Lancet Diabetes Endocrinol. Published online June 2, 2016. Abstract, Editorial

From http://www.medscape.com/viewarticle/865073#vp_2

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