The Effect of Biochemical Remission on Bone Metabolism in Cushing’s Syndrome: A 2‐Year Follow‐Up Study

https://doi.org/10.1002/jbmr.4033

 

ABSTRACT

Endogenous Cushing’s syndrome (CS) is a rare cause of secondary osteoporosis. The long‐term consequences for bone metabolism after successful surgical treatment remain largely unknown. We assessed bone mineral density and fracture rates in 89 patients with confirmed Cushing’s syndrome at the time of diagnosis and 2 years after successful tumor resection. We determined five bone turnover markers at the time of diagnosis, 1 and 2 years postoperatively. The bone turnover markers osteocalcin, intact procollagen‐IN‐propeptide (PINP), alkaline bone phosphatase, CTX‐I, and TrAcP 5b were measured in plasma or serum by chemiluminescent immunoassays. For comparison, 71 sex‐, age‐, and body mass index (BMI)‐matched patients in whom Cushing’s syndrome had been excluded were studied. None of the patients received specific osteoanabolic treatment. At time of diagnosis, 69% of the patients had low bone mass (mean T‐score = −1.4 ± 1.1). Two years after successful surgery, the T‐score had improved in 78% of patients (mean T‐score 2 years postoperatively −1.0 ± 0.9). The bone formation markers osteocalcin and intact PINP were significantly decreased at time of diagnosis (p ≤ 0.001 and p = 0.03, respectively), and the bone resorption marker CTX‐I and TrAcP 5b increased. Postoperatively, the bone formation markers showed a three‐ to fourfold increase 1 year postoperatively, with a moderate decline thereafter. The bone resorption markers showed a similar but less pronounced course. This study shows that the phase immediately after surgical remission from endogenous CS is characterized by a high rate of bone turnover resulting in a striking net increase in bone mineral density in the majority of patients. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Introduction

Cushing’s syndrome (CS) is a rare disease with approximately 0.7 to 2.4 new cases per 1 million per year.1 Osteoporosis and osteopenia are typical comorbidities of patients with endogenous and exogenous CS. Depending on the study, 60% to 80% of patients have evidence for a reduced bone mineral density2 characteristically affecting the entire skeleton.3 About 5% of all cases of secondary osteoporosis are caused by hypercortisolism.4 However, data from prospective, well‐powered studies are rare, and few risk factors that would predict bone health have been identified so far. Guidelines for the management of osteoporosis due to endogenous CS are still missing.5 In terms of risk assessment, the subtype of CS does not seem to influence osteoporosis risk,6 whereas the morning cortisol levels are negatively correlated with lumbar bone mineral density.6 The duration of endogenous Cushing’s syndrome (or the duration of exogenous replacement therapy after successful surgery) obviously affects bone mineral density.7 Whether the T‐score is the best predictor for fracture risk is not quite clear.2

Another area of uncertainty is the natural course of osteoporosis and bone turnover markers once the diagnosis of Cushing’s syndrome has been established. A number of studies have addressed this topic, but the interpretation of the results is hampered because of limited patient numbers, concomitant osteoanabolic treatment, or both.810 In‐depth insight on bone remodeling in CS might come from bone turnover marker studies. For example, the bone formation marker osteocalcin is suppressed in untreated CS,3 a consistent observation making it useful as a diagnostic marker for CS.2

Based on the paucity of data, the lack of evidence for treatment guidelines, and the pressing open questions regarding risk assessment and management of osteoporosis, we performed a sufficiently powered study to analyze the natural course of bone turnover and bone mineral density in a monocentric cohort of patients with endogenous Cushing’s syndrome. To the best of our knowledge, this is the first such study, and the data obtained will be instrumental for clinicians who care for patients with Cushing’s syndrome.

Materials and Methods

Patients

This study was performed as part of the prospective German Cushing registry, which has included 450 consecutive patients referred to our department for suspected CS since 2012. Structure and general characteristics of the registry have been described in detail previously.1114 All patients included in the registry underwent a standardized biochemical screening and clinical examination at time of diagnosis and a yearly follow‐up after treatment to treat comorbidities and diagnose recurrence of the disease early.

In all patients, standard screening for CS with a 1 mg low‐dose overnight dexamethasone suppression test (LDDST), collection of 24‐hour urine (UFC), and sampling of midnight salivary cortisol were performed. When the diagnosis of CS was confirmed, further subtyping was based on plasma adrenocorticotropic hormone (ACTH), corticotropin‐releasing hormone (CRH) test, high‐dose dexamethasone suppression test, imaging, and inferior petrosal sinus sampling (in case of ACTH dependence). Final diagnosis was CS in 156 patients and exclusion of CS in the remaining 294 patients. Patients with excluded CS were a quite heterogenic group with lead symptoms such as obesity (73%), arterial hypertension (50%), or hirsutism (33%). Final diagnoses in these subjects were metabolic syndrome, polycystic ovary syndrome (PCOS), obesity, depression, or primary hyperaldosteronism. Patient selection is shown in Fig. 1.

image
Patient selection. *Very young age; patient conducted densitometry in a different clinic/outpatient clinic; patient refused densitometry. CS = Cushing’s syndrome; BMD = bone mineral density; BMI = body mass index. Bold text indicates actual cohort of the study.

In our analysis, we excluded patients for whom no densitometry data were available (n = 63) and patients receiving pharmacologic treatment for osteoporosis following diagnosis (n = 4). Densitometry data were not available for multiple reasons (very young age, external densitometry in a different clinic, missing consent to perform densitometry).

We matched the remaining 89 patients with 71 controls subjects selected from those subjects in whom CS was excluded. Matching was done according to sex, age, and body mass index (BMI). None of the patients and controls received specific osteoanabolic or antiresorptive treatment, but 47% of patients with CS received vitamin D supplementation after remission. At time of diagnosis, 11% of controls and 17% of patients with CS received vitamin D supplementation.

Methods

In patients with confirmed CS, a bone mineral densitometry was conducted. Bone mineral density (BMD) was determined at the lumbar spine and the femur (neck and total femur).

If a reduced bone mineral density was diagnosed, a follow‐up densitometry was performed 2 years after surgery. If bone mineral density was normal initially or during follow‐up, only one further densitometry was performed 2 or 3 years after initial diagnosis. An improvement or decrease of bone mineral density was defined according to the least significant change (LSC = 2.8 × 1.8%).15 Accordingly, an alteration of more than 5.04% of BMD was rated as significant. A detailed fracture history was taken and X‐ray of the spine was performed when clinical suspicion for fractures was high.

In all patients, blood samples (serum and plasma) were taken at time of diagnosis and also 1 and 2 years after successful transsphenoidal surgery or adrenalectomy. Blood was taken in the fasting state between 8:00 and 10:00 a.m. Samples were centrifuged within 20 minutes at 4°C and stored at −80° until assayed. Three bone formation markers and two bone resorption markers were measured: osteocalcin, intact procollagen I‐N‐propeptide (PINP), and bone alkaline phosphatase (BAP) as bone formation markers, and CrossLaps (CTX‐I) and tartrate‐resistant acid phosphatase (5b TrAcP5b) as bone resorption marker, on basis of published data demonstrating their usefulness in CS and primary osteoporosis.216

Samples were measured at the Endocrine Laboratory of the Department of Internal Medicine IV on the iSYS automated analyzer (IDS‐iSYS, Boldon, UK) by well‐validated assays.1718 Published, method‐specific reference intervals are available from a large healthy population.1920 For the determination of osteocalcin, an N‐MID assay was used, as pre‐analytics are less critical in this assay.21 TrAcp 5b is a new marker, which, in contrast to CTX‐1, can also reliably be measured in the non‐fasting state.22

Statistical analysis

In a priori power analysis, we calculated that a total sample size of 102 would be sufficient to identify significant differences between groups, assuming a medium effect size (0.5), a power of 1 – β = 0.80 and a type I error of α = 0.05, with 51 subjects having Cushing’s syndrome and 51 subjects being control subjects after excluding Cushing’s syndrome.

For statistical analysis, SPSS 25 (IBM Corp., Armonk, NY, USA) was used. Clinical characteristics are shown as mean and standard deviation when data is normal distributed; otherwise as median and ranges. Because of the lack of normal distribution of bone turnover markers, nonparametric tests were used to test differences between groups. Differences between bone turnover markers at different times were tested by Friedman test. Multiple regression analysis was used to investigate differences between CS and the control group regarding bone turnover markers adjusted for sex, age, and BMI. Any p values < 0.05 were considered to indicate statistical significance.

Results

Patient characteristics

The clinical and biochemical characteristics of the patient sample are summarized in Table 1. Sixty‐five percent of patients had pituitary CS, 28% adrenal, and 7% suffered from ectopic CS. Patients and controls were well‐matched regarding sex, age, and vitamin D levels and supplementation, but differed in terms of diabetes prevalence.

Table 1. Clinical and Biochemical Baseline Characteristics of Patients with Cushing’s Syndrome (CS) and Control Subjects in Whom CS Has Been Excluded
CS at time of diagnosis (n = 89) CS excluded (n = 71) p Value
Sex 66 women (74%), 23 men (26%) 53 women (75%), 18 men (25%) 0.94
Age (years) 44 ± 13 43 ± 14 0.56
BMI 30 ± 7 31 ± 6 0.11
Vitamin D (ng/mL) 24 ± 10 24 ± 12 0.59
Vitamin D supplementation 17% 11% 0.37
Diabetes mellitus 30% (26) 11% (7) 0.007
Morning serum cortisol (μg/dL) 18 (11.7–24.9) 8.4 (5.9–11.6) ≤0.001
LDDST (μg/dL) 14.7 (7.7–23.7) 1.0 (0.8–1.2) ≤0.001
UFC (μg/24 h) 587 (331–843) 140 (78–216) ≤0.001
ACTH (pg/mL) 47 (9–76) 13 (9–18) ≤0.001
Late‐night salivary cortisol (ng/mL) 7.9 (3.3–11.8) 1.2 (0.6–1.8) ≤0.001
Bone turnover markers
Osteocalcin (ng/mL) 8 (5–13) 13 (10–17) <0.001
PINP (ng/mL) 35 (29–62) 52 (35–73) 0.025
BAP (μg/L) 23 (16–31) 17 (14–24) 0.006
CTX‐I (ng/mL) 0.28 (0.17–0.42) 0.23 (0.12–0.32) 0.033
TrAcP (U/L) 2.3 (1.7–3.4) 1.9 (1.3–2.4) 0.009
  • Date are shown as mean ± standard deviation or median and ranges.
  • BMI = body mass index; LDDST = low‐dose dexamethasone suppression test; UFC = urinary free cortisol; ACTH = adrenocorticotropic hormone; PINP = intact procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; CTX‐I = CrossLaps; TrAcP = tartrate‐resistant acid phosphatase. Bold numbers indicate statistical significance.

Baseline evaluation

At time of diagnosis, the mean levels of bone formation markers osteocalcin and intact PINP were significantly decreased compared with the controls, and the bone formation marker bone alkaline phosphatase was increased (Table 1; Fig. 2). Both bone degradation markers CTX and TrAcP were increased (Table 1). Taken together, this demonstrates increased bone resorption and decreased bone formation in florid CS. Results of multiple linear regression analysis comparing Cushing’s syndrome patients and controls are shown in Table 2. Bone markers were similar in patients with a reduced bone mass versus those with a normal bone mass (data not shown).

image
Bone turnover markers and bone mineral density at baseline and 1 and 2 years after remission. Boxplot = median and ranges of bone turnover marker in patients with Cushing’s syndrome.Gray box = median and ranges of bone turnover markers in the control group.PINP = procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; TrAcP = tartrate‐resistant acid phosphatase; CTX‐I = CrossLaps.
Table 2. Results of Multiple Linear Regression Analysis Comparing Cushing’s Syndrome Patients Versus Controls
Dependent variable Standardized regression coefficient and p value for group variable
Unadjusted Adjusted for age, sex, and BMI
Osteocalcin (ng/mL) −0.392, 0.006 −0.375, 0.010
PINP (ng/mL) −0.215, 0.204 −0.256, 0.145
BAP (μg/L) 0.404, 0.001 0.470, <0.001
CTX‐I (ng/mL) 0.111, 0.366 0.065, 0.616
TrAcP (U/L) 0.227, 0.014 0.186, 0.069
  • PINP = procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; CTX‐I = CrossLaps; TrAcP = tartrate‐resistant acid phosphatase. Bold numbers indicate statistical significance.

Overall, bone mineral density was decreased with an average lowest T‐score of −1.4 (±1.1). BMD was significantly lower (p = 0.001) at the femoral neck (T‐score = −0.9 ± 1.0) and the spine (T‐score = −1.0 ± 1.5) compared with the total femur (T‐score = −0.5 ± 1.2). Twenty‐eight patients (32%) had a normal bone mineral density, 46 (52%) osteopenia, and the other 15 patients (17%) osteoporosis with a T‐score lower than −2.5.

Seventeen of the patients (19%) had a history of low‐trauma osteoporotic fractures (9 vertebral fractures, 8 nonvertebral fractures). The fractures took place shortly before diagnosis (58%) or more than 2 years before diagnosis of the CS (42%). Patients with osteoporotic fractures had a significantly lower T‐score than patients without fractures (T‐score = −1.9 ± 0.8 versus −1.3 ± 1.1, p = 0.03) but did not differ in the values of the bone turnover markers or standard biochemical screening. Subtype, age, or BMI also did not differ between groups. However, men were significantly at higher risk of having fractures than women (35% of men had fractures versus 14% of women, p = 0.03). Both severity of hypercortisolism and duration of CS did not contribute to fractures rates (data not shown), but UFC was significantly higher in patients with a T‐score lower than −1.5 (Table 3).

Table 3. Biochemical Markers in Patients With Cushing’s Syndrome With a T‐Score Lower Than −1.5 and Above −1.5 Shown in Median and Ranges
Variable T‐score < −1.5 (n = 39) T‐score ≥ −1.5 (n = 42) p Values
LDDST (μg/dL) 16.6. (10.3–28.3) 11.9 (6.1–21.9) 0.12
UFC (μg/24 h) 706 (410–906) 398 (285–787) 0.03
Late‐night salivary cortisol (ng/mL) 8.3 (3.5–13.6) 5.7 (2.9–11.7) 0.39
ACTH (pg/mL) 53 (16–73) 42 (6–82) 0.88
  • LDDST = low‐dose dexamethasone suppression test; UFC = urinary free cortisol; ACTH = adrenocorticotropic hormone. Bold numbers indicate statistical significance.

One‐ and 2‐year follow‐up

Surgical tumor resection leading to biochemical remission of CS resulted in a strong increase of bone formation markers tested at 1‐year follow‐up (Table 4; Fig. 2AB). After 2 years, the markers had decreased slightly but remained elevated. Bone resorption markers were mildly increased at time of diagnosis, increased further at 1 year post‐surgery, and returned almost to normal levels at 2 years (Table 4; Fig. 2DE). A follow‐up bone densitometry conducted in 40 patients showed a parallel increase of the T‐score of 0.6 ± 0.8 (Fig. 2F). In particular, BMD of the spine improved (Table 5).

Table 4. Bone Turnover Markers and Bone Mass in Patients With Cushing’s Syndrome at Time of Diagnosis and During 2 Years of Follow‐Up
Time of diagnosis (n = 50) 1 year in remission (n = 45) 2 years in remission (n = 38) p (0 versus 1) p (0 versus 2) p (1 versus 2)
T‐score −1.5 (−2.0 to −0.8) −1.1 (−1.5 to −0.4) <0.001
Osteocalcin (ng/mL) 8 (5–13) 30 (14–60) 21 (13–31) <0.001 0.008 0.3
PINP (ng/mL) 35 (29–62) 117 (52–221) 69 (46–113) <0.001 0.1 0.1
BAP (μg/L) 23 (16–31) 26 (19–38) 22 (15–31) 0.2 0.4 0.1
CTX‐I (ng/mL) 0.28 (0.17–0.42) 0.51 (0.22–0.91) 0.25 (0.18–0.73) 0.01 0.1 0.04
TrAcP (U/L) 2.3 (1.7–3.4) 2.8 (1.8–4.0) 2.3 (2–3.2) 0.1 0.6 0.002
  • PINP = procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; CTX‐I = CrossLaps; TrAcP = tartrate‐resistant acid phosphatase. Bold numbers indicate statistical significance.
Table 5. Overview: T‐Scores, Z‐Scores, and BMD Values With Percent Changes (Mean and Standard Deviation)
Variable CS at time of diagnosis CS 2 years in remission p Values, percent changes (↑)
Femoral neck
T‐score femoral neck −0.81 ± 0.97 −0.59 ± 0.86 0.06
Z‐score femoral neck −0.59 ± 0.98 −0.28 ± 0.79 0.02
BMD (g/cm2) femoral neck 0.91 ± 0.12 0.95 ± 0.12 0.16; 4% ↑
Femur
T‐score femur −0.49 ± 1.11 −0.42 ± 1.04 0.67
Z‐score femur −0.40 ± 1.04 −0.37 ± 0.85 0.31
BMD (g/cm2) femur 0.95 ± 0.15 0.97 ± 0.14 0.77, 2% ↑
Spine
T‐score spine −0.96 ± 1.56 −0.55 ± 1.25 <0.001
Z‐score spine −0.85 ± 1.53 −0.58 ± 1.14 <0.001
BMD (g/cm2) spine 1.08 ± 0.22 1.13 ± 0.15 0.001, 0.6% ↑
  • BMD = bone mineral density; CS = Cushing’s syndrome. Bold numbers indicate statistical significance.

In 78% of patients, bone mineral density improved after 2 years; in 45% of patients, T‐score improved more than 0.5. No clinical fractures occurred after successful treatment of the CS. There was no significant correlation between improvement of bone mineral density and any of the bone turnover markers.

Discussion

This study investigated for the first time to our knowledge a panel of bone formation and resorption markers in a large cohort of patients with CS over the long term. The unique and comprehensive data show that initially bone metabolism is characterized by decreased bone formation and increased bone resorption, in line with the classical action of glucocorticoids. Successful treatment of endogenous Cushing’s syndrome leads to a strong activation of bone turnover, characterized by increased bone formation and bone resorption, a process that is continuous beyond year 2 after remission of CS, although at a reduced activity level. In parallel, bone mineral density increases in the majority of patients. Although 19% had low‐trauma fractures at baseline, none of the subjects experienced clinical fractures during follow‐up. In summary, these data give new insight into bone healing after remission of CS. They strongly suggest that an observational approach to the bone phenotype is justified as long as remission from CS is secured.

Reversibility of osteoporosis and bone turnover markers

Although established in osteoporosis research, bone turnover markers are not measured on a routine basis in patients with CS. However, it is a consistent result from different studies that osteocalcin is depressed in patients with CS. In fact, this finding is so reliable that it was even suggested to use osteocalcin in the diagnosis of CS.2 P1NP and procollagen carboxy‐terminal propeptide (P1CP) have also been studied in several studies, with contradictory results.23 In a retrospective study with 21 patients with CS, it was shown that osteocalcin is depressed; this applies also for PINP, whereas CTX is increased.24

Some studies already have focused on the reversibility of osteoporosis after treatment of CS. In the majority of patients, bone mineral density increased within 2 years after successful treatment81025 Hermus and colleagues showed in a study with 20 patients that bone mineral density did not change 3 or 6 months after surgery but increased thereafter in almost all patients.8 In a study with 68 patients, the patients were followed up for 4 years. Bone mineral density increased over lumbar spine and femur but decreased at the forearm.25 The authors concluded that bone minerals were redistributed from the peripheral to the axial skeleton.

In our study, bone mineral density also improved in the majority of patients but remained reduced in some. We did not find any difference in bone turnover markers between patients with improvement and without improvement.

Current treatment guidelines and treatment suggestions

As observed in our study, bone formation markers increase significantly after surgical cure, whereas bone degradation markers are mildly elevated at baseline and increase slightly at 1 year, returning within the normal range at 2 years. So far, there is no international guideline on the treatment of osteoporosis induced by endogenous CS and very few controlled interventional studies. In an opinion paper, Scillitani and colleagues recommended to treat all patients with vitamin D and calcium but not with bisphosphonates.5 In a randomized open‐label study by Di Somma and colleagues,26 39 patients (18 patients with active CS and 21 patients with CS in remission) received alendronate or no medication. Patients with active CS also received ketoconazole to control hypercortisolism. Bone mineral density improved and serum levels of osteocalcin increased in patients who received alendronate to a greater extent than those receiving no alendronate.

In a small study by the same research group,27 15 patients with CS (9 adolescent patients and 6 adults) were observed for 2 years after successful treatment, showing that osteocalcin levels and bone mineral density increased significantly.

Strengths and limitations

Although this study has several strengths, including the large prospective design and measuring a panel of bone formation and resorption markers, there are a few limitations. Some asymptomatic fractures may have been overlooked because an X‐ray was not taken systematically in each patient. Furthermore, a follow‐up bone densitometry was not available for all patients. Additionally, patients in the control group suffered from diabetes, overweight, arterial hypertension, or other diseases.

Novel aspects and outlook

This study analyzes for the first time in a comprehensive way bone turnover markers during the course of CS. The data show that cure from CS leads to increases in bone remodeling and bone mineral density, in line with spontaneous “bone healing.” Our data support a wait‐and‐watch strategy despite a high endogenous risk for additional fractures, based on the baseline assessment. This observation will influence future therapeutic strategies in patients with CS.

Our data suggest that the phase immediately after remission from CS is characterized by a high rate of bone turnover, resulting in a spontaneous net increase in bone mineral density in the majority of patients. Both bone attachment and bone degradation markers increase significantly, leading to an increase in bone mass and to a reduced risk of osteoporotic fractures. This unconstrained increase in bone formation markers after remission should be considered before specific therapy is initiated. Our data do not favor specific pharmacologic interventions with bisphosphonates or denosumab during this phase of remodeling because they may disrupt the osteoblast‐mediated bone mass increase.

Disclosures

All authors state that they have no conflicts of interest.

Acknowledgments

This work is part of the German Cushing’s Registry CUSTODES and has been supported by a grant from the Else Kröner‐Fresenius Stiftung to MR (2012_A103 and 2015_A228). Additionally, AR, FB, and MR received funding by the Deutsche Forschungsgemeinschaft (CRC/TRR 205/1 “The Adrenal Gland”). Furthermore, funds for this project were provided by the Verein zur Förderung von Wissenschaft und Forschung an der Medizinischen Fakultät der Ludwig‐Maximilians‐Universität München eV to LB.

The data are stored on the following repository: https://figshare.com/ and will be made accessible after publication of the article.

Authors’ roles: LB served as the principal investigator in this work and was responsible for the study conception and design, the analysis and interpretation of the data, and the drafting of the manuscript. JF, SZ, AO, AR, GR and SB contributed to the collection and analysis of the data. MS, FB, MD, MB substantially contributed to the interpretation of the data and the drafting of the manuscript. RS contributed to the conceptual design of the study, the interpretation of data and the revision of the paper. MR contributed to the conceptual design of the study, the collection, analysis and interpretation of data, and the drafting and revision of the paper. All authors contributed to the critical revision of the manuscript and approved the final version for publication.

From https://asbmr.onlinelibrary.wiley.com/doi/full/10.1002/jbmr.4033

Cortisol Levels Predict Remission in Cushing’s Patients Undergoing Transsphenoidal Surgery

In patients with Cushing’s disease, removing the pituitary tumor via an endoscopic transsphenoidal surgery (TSS) leads to better remission rates than microscopic TSS, according to new research.

But regardless of surgical approach, plasma cortisol levels one day after surgery are predictive of remission, researchers found.

The study, “Management of Cushing’s disease: Changing trend from microscopic to endoscopic surgery,” was published in the journal World Neurosurgery.

Because it improves visualization and accessibility, endoscopic TSS has been gaining popularity over microscopic TSS to remove pituitary tumors in Cushing’s disease patients. Yet, although this surgery has been associated with high remission rates, whether it outperforms microscopic surgery and determining the factors affecting long-term outcomes may further ease disease recurrence after TSS.

A team with the All India Institute of Medical Sciences addressed this topic in 104 patients who underwent surgery from January 2009 to June 2017. Among these patients, 47 underwent microscopic surgery and 55 endoscopic surgery. At presentation, their ages ranged from 9 to 55 (mean age of 28). Also, patients had been experiencing Cushing’s symptoms over a mean duration of 24 months.

Eighty-seven patients showed weight gain. Hypertension (high blood pressure) and diabetes mellitus were among the most common co-morbidities, found in 76 and 33 patients, respectively. Nineteen patients had osteoporosis and 12 osteopenia, which refers to lower-than-normal bone mineral density.

As assessed with magnetic resonance imaging, 68 patients had a microadenoma (a tumor diameter smaller than one centimeter) and 27 had a macroadenoma (a tumor one centimeter or larger). Only two patients had an invasive pituitary adenoma.

Two patients with larger tumors were operated on transcranially (through the skull). The surgery resulted in total tumor removal in 90 cases (86.5%). A blood loss greater than 100 milliliter was more common with endoscopic than with microscopic TSS.

Ten patients developed transient diabetes inspidus, two experienced seizures after surgery, and six of nine patients with macroadenoma and visual deterioration experienced vision improvements after TSS.

The incidence of intraoperative leak of cerebrospinal fluid — the liquid surrounding the brain and spinal cord — was 23.2%, while that of post-operative leak was 7.7% and was more common in microadenoma than macroadenoma surgery (9.8% vs. 5.0%).

Seventeen patients were lost to follow-up and two died due to metabolic complications and infections. The average follow-up was shorter for endoscopic than with microscopic surgery (18 months vs. 35 months).

Among the remaining 85 cases, 65 (76.5%) experienced remission, as defined by a morning cortisol level under 5.0 μg/dL, restored circadian rhythm (the body’s internal clock, typically impaired in Cushing’s patients), and suppression of serum cortisol to below 2 μg/dl after overnight dexamethasone suppression test.

The remission rate was 54.5% in pediatric patients and was higher with endoscopic than with microscopic TSS (88.2% vs. 56.6%). Also, patients with microadenoma showed a trend toward more frequent remission than those with macroadenoma (73.2% vs. 64.3%).

Ten of the remaining 20 patients experienced disease recurrence up to 28 months after surgery. Sixteen cases revealed signs of hypopituitarism, or pituitary insufficiency, which were managed with replacement therapy.

A subsequent analysis found that morning cortisol level on day one after surgery was the only significant predictor of remission. Specifically, a one-unit increase in cortisol lowered the likelihood of remission by 7%. A cortisol level lower than 10.7 μgm/dl was calculated as predicting remission.

Overall, the study showed that “postoperative plasma cortisol level is a strong independent predictor of remission,” the researchers wrote, and that “remission provided by endoscopy is significantly better than microscopic approach.”

From https://cushingsdiseasenews.com/2019/09/24/cortisol-levels-predict-remission-cushings-patients-undergoing-transsphenoidal-surgery/

Metoclopramide Can Mask Adrenal Insufficiency After Gland Removal in BMAH Patients

Metoclopramide, a gastrointestinal medicine, can increase cortisol levels after unilateral adrenalectomy — the surgical removal of one adrenal gland — and conceal adrenal insufficiency in bilateral macronodular adrenal hyperplasia (BMAH) patients, a case report suggests.

The study, “Retention of aberrant cortisol secretion in a patient with bilateral macronodular adrenal hyperplasia after unilateral adrenalectomy,” was published in Therapeutics and Clinical Risk Management.

BMAH is a subtype of adrenal Cushing’s syndrome, characterized by the formation of nodules and enlargement of both adrenal glands.

In this condition, the production of cortisol does not depend on adrenocorticotropic hormone (ACTH) stimulation, as usually is the case. Instead, cortisol production is triggered by a variety of stimuli, such as maintaining an upright posture, eating mixed meals — those that contain fats, proteins, and carbohydrates — or exposure to certain substances.

A possible treatment for this condition is unilateral adrenalectomy. However, after the procedure, some patients cannot produce adequate amounts of cortisol. That makes it important for clinicians to closely monitor the changes in cortisol levels after surgery.

Metoclopramide, a medicine that alleviates gastrointestinal symptoms and is often used during the postoperative period, has been reported to increase the cortisol levels of BMAH patients. However, the effects of metoclopramide on BMAH patients who underwent unilateral adrenalectomy are not clear.

Researchers in Japan described the case of a 61-year-old postmenopausal woman whose levels of cortisol remained high after surgery due to metoclopramide ingestion.

The patient was first examined because she had experienced high blood pressure, abnormal lipid levels in the blood, and osteoporosis for ten years. She also was pre-obese.

She was given medication to control blood pressure with no results. The lab tests showed high serum cortisol and undetectable levels of ACTH, suggesting adrenal Cushing’s syndrome.

Patients who have increased cortisol levels, but low levels of ACTH, often have poor communication between the hypothalamus, the pituitary, and the adrenal glands. These three glands — together known as the HPA axis — control the levels of cortisol in healthy people.

Imaging of the adrenal glands revealed they were both enlarged and presented nodules. The patient’s cortisol levels peaked after taking metoclopramide, and her serum cortisol varied significantly during the day while ACTH remained undetectable. These results led to the BMAH diagnosis.

The doctors performed unilateral adrenalectomy to control cortisol levels. The surgery was successful, and the doctors reduced the dose of glucocorticoid replacement therapy on day 6.

Eight days after the surgery, however, the patient showed decreased levels of fasting serum cortisol, which indicated adrenal insufficiency — when the adrenal glands are unable to produce enough cortisol.

The doctors noticed that metoclopramide was causing an increase in serum cortisol levels, which made them appear normal and masked the adrenal insufficiency.

They stopped metoclopramide treatment and started replacement therapy (hydrocortisone) to control the adrenal insufficiency. The patient was discharged 10 days after the surgery.

The serum cortisol levels were monitored on days 72 and 109 after surgery, and they remained lower than average. Therefore she could not stop hydrocortisone treatment.

The levels of ACTH remained undetectable, suggesting that the communication between the HPA axis had not been restored.

“Habitual use of metoclopramide might suppress the hypothalamus and pituitary via negative feedback due to cortisol excess, and lead to a delayed recovery of the HPA axis,” the researchers said.

Meanwhile, the patient’s weight decreased, and high blood pressure was controlled.

“Detailed surveillance of aberrant cortisol secretion responses on a challenge with exogenous stimuli […] is clinically important in BMAH patients,” the study concluded. “Caution is thus required for assessing the actual status of the HPA axis.”

From https://cushingsdiseasenews.com/2019/05/07/metoclopramide-conceals-adrenal-insufficiency-after-gland-removal-bmah-patients-case-report/

Mild Cases of Cushing’s Syndrome Present Diagnostic Challenges

By Tori Rodriguez, MA, LPC

 

In the early 20th century, the term “pluriglandular syndrome” was coined by Harvey Cushing to describe the disorder that results from chronic tissue exposure to excessive levels of glucocorticoids.1 Now called Cushing’s syndrome, the condition affects an estimated 10-15 million people annually, most often women and individuals between the ages of 20 and 50 years.2 Risk factors and common comorbidities include hypertension, obesity, osteoporosis, uncontrolled diabetes, depression, and anxiety.3

Presentation

The clinical presentation of the disorder is heterogenous and varies by sex, age, and disease severity. Common signs and symptoms include central adiposity, roundness of the face or extra fat around the neck, thin skin, impaired short-term memory and concentration, irritability, hirsutism in women, fatigue, and menstrual irregularity.4 Because each of these features may be observed in a wide range of other conditions, it may be difficult to diagnose cases that are not severe.

“It can be challenging to differentiate the milder forms from pseudo-Cushing’s states,” which are characterized by altered cortisol production and many of the same clinical features as Cushing’s syndrome, according to Roberto Salvatori, MD, the medical director of the Johns Hopkins Pituitary Center, Baltimore, Maryland. These may include alcoholism, obesity, eating disorders, and depression. “Because Cushing’s can cause depression, for example, it is sometimes difficult to determine which came first,” he says. In these states, however, hypercortisolism is believed to be driven by increased secretion of hypothalamic corticotropin-releasing hormone, which is suppressed in Cushing’s syndrome.5

Causes and Diagnosis

If Cushing’s syndrome is suspected on the basis of the patient’s physical appearance, the diagnostic workup should include a thorough medical history, physical exam, and 1 or more of the following tests to establish hypercortisolism: the 24-hour urinary cortisol test, the low-dose dexamethasone suppression test, or the late-night salivary cortisol test. “We sometimes use 2 or 3 of these tests since 1 may not accurately reflect cortisol production in a particular patient,” Dr Salvatori notes. The next step is to determine the source of the hypercortisolism, which may involve the high-dose dexamethasone suppression test, magnetic resonance imaging, or petrosal sinus sampling.2

Medication is the most common cause of Cushing’s syndrome. These iatrogenic or exogenous cases typically result from corticosteroids administered for conditions such as asthma, allergies, and autoimmune disorders.6 More rarely, the disorder can be caused by the use of medroxyprogesterone. In these cases, corticosteroids should be reduced or discontinued under medical care, if possible.

Endogenous Cushing’s syndrome results from the presence of benign or malignant tumors on the adrenal or pituitary glands or elsewhere in the body. These tumors can interfere with the adrenal glands’ production of cortisol that is usually prompted by the adrenocorticotropic hormone (ACTH) released by the pituitary gland.6 There are 3 different mechanisms by which the process can occur.

  • Pituitary adenomas, which account for approximately 70% of endogenous cases of Cushing’s syndrome, secrete ACTH and stimulate additional cortisol production. Because of the large proportion of cases this condition represents, it is specifically referred to as Cushing’s disease. It is more common in women than men (with a ratio of 3 to 4:1), although in pediatric patients, it occurs more frequently in boys vs girls.5
  • Adrenal tumors (adenomas, malignant tumors, or micronodular hyperplasia) produce cortisol in their own tissue in addition to the amount produced by the adrenal glands. These tumors, which cause approximately 15% of endogenous Cushing’s syndrome cases, are more common in children vs adults and in women vs men.
  • Benign or malignant tumors elsewhere in the body, most often the lungs, thyroid, thymus, and pancreas, secrete ACTH and trigger the excessive release of cortisol. An estimated 15% of endogenous cases are attributed to these types of tumors.

Treatment

Surgery is the first-line treatment for Cushing’s syndrome. “We first want to try to figure out the cause of the disorder,” Dr Salvatori says. “Ideally, treatment involves surgery to remove the tumor that is causing it.”

When surgery is unsuccessful, contraindicated, or delayed, other treatment options include radiation or medications that inhibit cortisol, modulate the release of ACTH, or inhibit steroidogenesis.5 Bilateral adrenalectomy may be indicated for patients who do not respond to medication or other surgery.

If surgical resection of the tumor is successful, then “all of the comorbidities reverse, but if it is unsuccessful or must be delayed, you would treat each comorbidity” with the appropriate medication; for example, antihypertensives for high blood pressure and antidiabetic medications for diabetes, Dr Salvatori advises. In severe cases, prophylactic antibiotics may be indicated for the prevention of severe infections such as pneumonia.

It is also important to inquire about and address psychiatric symptoms related to Cushing’s syndrome, even in patients who are in remission. It has been proposed that the chronic hypercortisolism and dysfunction of the HPA axis may “lead to structural and functional changes in the central nervous system, developing brain atrophy, particularly in the hippocampus, which may determine the high prevalence of psychiatric disorders, such as affective and anxiety disorders or cognitive dysfunctions,” according to a recently published paper on the topic.7 Patients should be screened with self-report questionnaires such as the Beck Depression Inventory and the Hospital Anxiety and Depression Scale, and management of psychiatric symptoms may include patient education, psychotropic medications, and referral to a mental health professional.

Future Directions

Several trials are currently planned or underway, including a phase 2 randomized, double-blind, placebo-controlled study of an oral medication called ATR-101 by Millendo Therapeutics, Inc. (ClinicalTrials.gov identifier: NCT03053271). In addition to the need for novel medical therapies, refined imaging techniques could improve surgical success rates in patients with Cushing’s disease in particular, according to Dr Salvatori. “A significant portion of these patients have tumors too small to be detected by MRI, and the development of more sensitive MRI could improve detection and provide a surgical target” for neurosurgeons treating the patients, he says.

Summary

Milder cases of Cushing’s syndrome present diagnostic challenges are a result overlapping features with various other conditions. Diagnosis may require careful observation as well as biochemical and imaging tests.

References

  1. Loriaux DL. Diagnosis and differential diagnosis of Cushing’s syndromeN Engl J Med. 2017;376:1451-1459. doi:10.1056/NEJMra1505550
  2. American Association of Neurological Surgeons. Cushing’s syndrome/disease. http://www.aans.org/Patients/Neurosurgical-Conditions-and-Treatments/Cushings-Disease. Accessed August 1, 2017.
  3. León-Justel A, Madrazo-Atutxa A, Alvarez-Rios AI, et al. A probabilistic model for cushing’s syndrome screening in at-risk populations: a prospective multicenter studyJ Clin Endocrinol Metab. 2016;101:3747-3754. doi:10.1210/jc.2016-1673
  4. The Pituitary Society. Cushing’s syndrome and disease–symptoms. https://pituitarysociety.org/patient-education/pituitary-disorders/cushings/symptoms-of-cushings-disease-and-cushings-syndrome. Accessed August 1, 2017.
  5. Sharma ST, Nieman LK, Feelders RA. Cushing’s syndrome: epidemiology and developments in disease managementClin Epidemiol. 2015;7:281-293. doi:10.2147/CLEP.S44336
  6. National Institutes of Health: Eunice Kennedy Shriver National Institute of Child Health and Human Development. What causes Cushing’s syndrome?https://www.nichd.nih.gov/health/topics/cushing/conditioninfo/pages/causes.aspx. Accessed August 1, 2017.
  7. Santos A, Resmini E, Pascual JC, Crespo I, Webb SM. Psychiatric symptoms in patients with Cushing’s syndrome: prevalence, diagnosis and management. Drugs. 2017;77:829-842. doi:10.1007/s40265-017-0735-z

From http://www.endocrinologyadvisor.com/adrenal/cushings-syndrome-diagnosis-treatment/article/682302/

Who’s at Risk for Cushing’s?

by Kristen Monaco
Contributing Writer, MedPage Today

Researchers have developed a new method to assess specific populations for Cushing’s syndrome, based on results from a multicenter study.

The prospective cohort study evaluated at-risk patients for Cushing’s syndrome to create a novel type of scoring system in order to better predict the development of disease, stated lead author Antonio León-Justel, PhD,of the Seville Institute of Biomedicine in Spain, and colleagues.

Cushing’s syndrome is identified by an excess of cortisol and/or glucocorticoids in the blood, which can result in myriad negative health outcomes, including an increased risk of death and morbidity, according to the study in The Journal of Clinical Endocrinology & Metabolism.

Because Cushing’s syndrome (CS) is complex and difficult to diagnose, there is a necessity for new methods to assess at-risk populations in order to mitigate the rising prevalence of the disorder, the authors noted.

“The diagnosis of CS might pose a considerable challenge even for experienced endocrinologists since there are no pathognomonic symptoms or signs of CS and most of the symptoms and signs of CS are common in the general population including obesity, hypertension, bone loss, and diabetes,” the senior author, Alfonso Leal Cerro, MD, toldMedPage Today via email. “Routine screening for CS remains impractical due to the estimated low prevalence of the disease. However this prevalence might be higher in at-risk populations.”

The authors screened a total of 353 at-risk patients from 13 different hospitals across Spain between January 2012 and July 2013 to measure cortisol variability from saliva samples.

At-risk populations, which the authors note have a higher prevalence of Cushing’s syndrome, included individuals with type 2 diabetes, hypertension, and osteoporosis.

The patients screened in the study were each identified as having at least two of the risk factors for Cushing’s syndrome: high blood pressure (defined as taking two or more drugs and having a systolic blood pressure over 140 mmHg and/or a diastolic blood pressure over 90 mmHg), obesity (body mass index >30), uncontrolled diabetes (HbA1c>7.0%), osteoporosis (T-score ≥ -2.5 SD), and virilization syndrome (hirsutism) with menstrual disorders.

The researchers used clinical and biochemical methods of assessment. Clinical methods included inspection of physical characteristics, such as muscle atrophy, purple striae, and/or facial plethora. Biochemical methods included collecting saliva and blood samples from participants to test cortisol levels using a chemiluminescence method. Each individual was identified as either negative for hypercortisolism (late-night salivary cortisol [LNSC] ≤ 7.5 nmol/L and dexamethasone suppression test [DST] ≤ 50 nmol/L) or positive for hypercortisolism (LNSC > 7.5 nmol/L and DST > 50 nmol/L).

Univariate testing indicated the following significant characteristics to be positively correlated with the development of Cushing’s syndrome:

  • Muscular atrophy (15.2, CI 95% 4.48-51.25);
  • Osteoporosis (4.60, 1.66-12.75); and
  • Dorsocervical fat pad (3.32, 1.48-7.5).

A logistic regression analysis of LNSC values also showed significant correlation between Cushing’s syndrome and the following top three characteristics:

  • Muscular atrophy (9.04, CI 95% 2.36-34.65);
  • Osteoporosis (3.62, CI 95% 1.16-11.35); and
  • Dorsocervical fat pad (3.3, CI 95% 1.52-7.17).

Roberto Salvatori, MD, professor and medical director of the Johns Hopkins Pituitary Center, who was not involved with the study, commented to MedPage Today in an email: “Any endocrinologist would proceed with careful Cushing biochemical evaluation in the presence of the clinical features (muscular atrophy, osteoporosis, and dorsocervical fat pad) that are well known to be associated with hypercortisolism. Of notice, the odds ratio is further increased by an abnormal late-night salivary cortisol, which is already a screening test for hypercortisolism.”

The researchers used their results to develop an equation to determine the level of risk a patient has for developing Cushing’s syndrome, taking into account factors for osteoporosis, dorsocervical fat pads, muscular atrophy, and LNSC levels.

Although the study was able to develop a comprehensive risk model for the syndrome, when tested against the prevalence for Cushing’s syndrome in the subject group, the equation generated a total of 56 false-positive and 25 true-positive results. Overall, the researchers wrote, 83% of patients were accurately classified as belonging to the at-risk population when using the equation.

Because the newly developed equation for identifying at-risk individuals involved factors that are relatively easy to test for, the authors noted that clinical application is broad and cost-effective in a primary care setting.

“We would like to test the scoring system in different clinical settings such as primary care or hypertension clinics,” Leal Cerro said. “Primary care would be a particularly interesting setting since it might significantly decrease the time to diagnosis, something critical to avoid an excessive exposure to glucocorticoid excess and consequent deleterious effects.”

Salvatori said that while the study was a good start at shedding light on some of the unknowns about Cushing’s syndrome, more research is required. “The real question in my mind is when does a non-endocrinologist need to suspect Cushing in a general medicine, orthopedic, or other clinic? When the internal medicine residents ask me about guidelines for ‘who to screen for hypercortisolism in my clinic,’ I am unable to provide an evidence-based answer.”

The study was funded by a grant from Novartis Oncology, Spain.

León-Justel and Leal Cerro disclosed financial relationships with Novartis Oncology, Spain.

  • Reviewed by F. Perry Wilson, MD, MSCEAssistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner

LAST UPDATED 08.15.2016

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