Haemostatic parameters in Cushing's syndrome

The thrombotic risk in Cushing's syndrome-questions, answers, and the algorithm to consider in its assessment: part I-thrombotic risk not related to surgery

Introduction

Recently, it has been reported that there is a great diversity in strategies used for thromboprophylaxis in patients with Cushing's syndrome (CS). An aim of this review was to discuss these practices in light of the existing data on the thrombotic risk in patients with CS and guidelines for medically ill patients.

Methods

The four relevant topics and questions on thrombotic risk in CS were identified. The current guidelines on prevention and diagnosis of venous thromboembolism (VTE) were reviewed for the answers. An algorithm to consider in the assessment of the thrombotic risk in patients with CS was proposed.

Results

To address both generic and CS-specific risk factors for VTE, the algorithm includes the stepwise approach consisting of Padua Score, urine free cortisol, and CS-VTE score, with no indication for routine thrombophilia testing in the prediction of an index VTE episode. Having confirmed VTE, selected patients require thrombophilia testing to aid the duration of anticoagulant treatment. The separate part of the algorithm is devoted to patients with ectopic adrenocorticotropic hormone syndrome in whom exclusion of VTE precedes introducing routine thromboprophylaxis to prevent VTE. The cancer-related VTE also prompts thromboprophylaxis, with the possible vessel invasion. The algorithm presents a unifactorial and multifactorial approach to exclude high-bleeding risks and safely introduce thromboprophylaxis with low-molecular-weight heparin.

Summary

Our article is the first to present an algorithm to consider in the thrombotic risk assessment among patients with Cushing's syndrome as a starting point for a broader discussion in the environment. A plethora of factors affect the VTE risk in patients with CS, but no studies have conclusively evaluated the best thromboprophylaxis strategy so far. Future studies are needed to set standards of care.

Regression of venous thrombus after trans-sphenoidal hypophysectomy for pituitary-dependent hyperadrenocorticism in a dog

An 8.0-kg 8-year-old male dachshund was presented for surgical treatment of suspected pituitary-dependent hyperadrenocorticism with portal vein thrombosis. Advanced diagnostic imaging revealed a thrombus in the splenic and portal veins. For the portal vein thrombus, CT angiography showed an enhanced timing delay in the lateral right and caudate liver lobes. Blood tests showed a marked increase in the liver panel, including total bile acid. Brain MRI revealed a pituitary mass, suggesting pituitary-dependent hyperadrenocorticism. The mass was completely resected. The preoperative antithrombotic therapy of rivaroxaban (0.66 mg/kg, PO, once per day) and clopidogrel sulphate (1.66 mg/kg, PO, once per day) was continued postoperatively. Six months after resection of the pituitary mass, the thrombus had disappeared. Further studies are required to prove a causal association between the disappearance of the thrombus and the treatments provided.

Use of Glucocorticoids and Risk of Venous Thromboembolism: A Narrative Review

Glucocorticoids are potent anti-inflammatory agents that are widely used for the treatment of many inflammatory, autoimmune, and neoplastic disorders. However, their beneficial effect is associated with several side effects, including an increased risk of cardiovascular complications, such as myocardial infarction and stroke. Whether their use also contributes to a procoagulant state, and therefore increases the risk of venous thromboembolism (VTE), is still a matter of debate. As an increased risk of venous thrombotic events is described in patients with Cushing's syndrome, which is characterized by endogenous hypercortisolism, it is reasonable to speculate that the chronic administration of glucocorticoids may induce a hypercoagulable state. However, it seems virtually impossible to separate the role of the drug from the underlying condition, which itself predisposes to the development of VTE. Actually, some evidence suggests that the use of exogenous glucocorticoids for the treatment of underlying disease and its exacerbations may further amplify the risk of VTE. Moreover, a procoagulant state has also been reported in healthy participants receiving oral glucocorticoids versus placebo. We have performed a concise narrative review on available data on the influence of exogenous glucocorticoids on hemostasis and their clinical impact on the risk of VTE.

Impact of Adrenal Function on Hemostasis/Endothelial Function in Patients Undergoing Surgery

Context

Glucocorticoids regulate hemostatic and endothelial function, and they are critical for adaptive functions during surgery. No data regarding the impact of adrenal function on hemostasis and endothelial function in the perioperative setting are available.

Objective

We assessed the association of adrenal response to adrenocorticotropic hormone (ACTH) and markers of endothelial/hemostatic function in surgical patients.

Methods

This prospective observational study, conducted at a tertiary care hospital, included 60 patients (35 male/25 female) undergoing abdominal surgery. Adrenal function was evaluated by low-dose ACTH stimulation test on the day before, during, and the day after surgery. According to their stimulated cortisol level (cutoff ≥ 500 nmol/L), patients were classified as having normal hypothalamic-pituitary-adrenal (HPA)-axis function (nHPA) or deficient HPA-axis function (dHPA). Parameters of endothelial function (soluble vascular cell adhesion molecule-1, thrombomodulin) and hemostasis (fibrinogen, von Willebrand factor antigen, factor VIII [FVIII]) were measured during surgery.

Results

Twenty-one patients had dHPA and 39 had nHPA. Compared with nHPA, patients with dHPA had significantly lower peak cortisol before (median 568 vs 425 nmol/L, P < 0.001) and during (693 vs 544 nmol/L, P < 0.001) surgery and lower postoperative hemoglobin levels (116 g/L vs 105 g/L, P = 0.049). FVIII was significantly reduced in patients with dHPA in uni- and multivariable analyses; other factors displayed no significant differences. Coagulation factors/endothelial markers changed progressively in relation to stimulated cortisol levels and showed a turning point at cortisol levels between 500 and 600 nmol/L.

Conclusions

Patients with dHPA undergoing abdominal surgery demonstrate impaired hemostasis which can translate into excessive blood loss.

Hypercoagulability in Cushing's syndrome: From arterial to venous disease

Cushing's syndrome (CS) is associated with multisystemic complications; the hematological system is not spared. Alteration in hemostatic parameters and in vivo endothelial dysfunction lead to increased thrombotic events. Arterial and venous thrombotic events carry significant morbidity and mortality. Death from cardiovascular and pulmonary embolism account for more than 50% of mortality. Surgery is a critical period; close to 50% of events occur in the 1-2 months after intervention. The evaluation and risk stratification of patients with CS is key to prevent events, balancing the risk-benefit of anticoagulation in this population. This current review will focus on up-to-date data on epidemiology, pathophysiology and management of hypercoagulability in CS.

Hypercoagulability and Risk of Venous Thromboembolic Events in Endogenous Cushing's Syndrome: A Systematic Meta-Analysis

Background: Hypercortisolism has been implicated in the development of venous thromboembolic events (VTE). We aimed to characterize VTE risk in endogenous Cushing's syndrome (CS) patients, compare that risk to other pathologies, and determine if there are any associated coagulation factor changes. Methods: Medline and Scopus search for "hypercortisolism" and "thromboembolic disease" from January 1980 to April 2017 to include studies that reported VTE rates and/or coagulation profile of CS patients. A systematic review and meta-analysis were performed. Results: Forty-eight studies met inclusion criteria. There were 7,142 CS patients, average age was 42 years and 77.7% female. Odds ratio of spontaneous VTE in CS is 17.82 (95%CI 15.24-20.85, p < 0.00001) when comparing to a healthy population. For CS patients undergoing surgery, the odds ratio (both with / without anticoagulation) of spontaneous VTE is 0.26 (95%CI 0.07-0.11, p < 0.00001)/0.34 (0.19-0.36, p < 0.00001) when compared to patients undergoing hip fracture surgery who were not treated with anticoagulants. Coagulation profiles in patients with CS showed statistically significant differences compared to controls, as reflected by increases in von Willebrand factor (180.11 vs. 112.53 IU/dL, p < 0.01), as well as decreases in activated partial thromboplastin time (aPTT; 26.91 vs. 30.65, p < 0.001) and increases in factor VIII (169 vs. 137 IU/dL, p < 0.05). Conclusion: CS is associated with significantly increased VTE odds vs. general population, but lower than in patients undergoing major orthopedic surgery. Although exact timing, type, and dose of anticoagulation medication remains to be established, clinicians might consider monitoring vWF, PTT, and factor VIII when evaluating CS patients and balance advantages of thromboprophylaxis with risk of bleeding.

Adverse effects of glucocorticoids: coagulopathy

Hypercortisolism is associated with various systemic manifestations, including central obesity, arterial hypertension, glucose intolerance/diabetes mellitus, dyslipidemia, nephrolithiasis, osteoporosis, gonadal dysfunction, susceptibility to infections, psychiatric disorders, and hypercoagulability. The activation of the hemostatic system contributes to the development of atherosclerosis and subsequent cardiovascular morbidity and mortality. Previous studies have identified an increased risk of both unprovoked and postoperative thromboembolic events in patients with endogenous and exogenous Cushing's syndrome (CS). The risk for postoperative venous thromboembolism in endogenous CS is comparable to the risk after total hip or knee replacement under short-term prophylaxis. The mechanisms that are involved in the thromboembolic complications in hypercortisolism include endothelial dysfunction, hypercoagulability, and stasis (Virchow's triad). It seems that at least two factors from Virchow's triad must be present for the occurrence of a thrombotic event in these patients. Most studies have demonstrated that this hypercoagulable state is explained by increased levels of procoagulant factors, mainly factors VIII, IX, and von Willebrand factor, and also by an impaired fibrinolytic capacity, which mainly results from an elevation in plasminogen activator inhibitor 1. Consequently, there is a shortening of activated partial thromboplastin time and increased thrombin generation. For these reasons, anticoagulant prophylaxis might be considered in patients with CS whenever they have concomitant prothrombotic risk factors. However, multicenter studies are needed to determine which patients will benefit from anticoagulant therapy and the dose and time of anticoagulation.

Mechanisms in endocrinology: The spectrum of haemostatic abnormalities in glucocorticoid excess and defect

Glucocorticoids (GCs) target several components of the integrated system that preserves vascular integrity and free blood flow. Cohort studies on Cushing's syndrome (CS) have revealed increased thromboembolism, but the pathogenesis remains unclear. Lessons from epidemiological data and post-treatment normalisation time suggest a bimodal action with a rapid and reversible effect on coagulation factors and an indirect sustained effect on the vessel wall. The redundancy of the steps that are potentially involved requires a systematic comparison of data from patients with endogenous or exogenous hypercortisolism in the context of either inflammatory or non-inflammatory disorders. A predominant alteration in the intrinsic pathway that includes a remarkable rise in factor VIII and von Willebrand factor (vWF) levels and a reduction in activated partial thromboplastin time appears in the majority of studies on endogenous CS. There may also be a rise in platelets, thromboxane B2, thrombin-antithrombin complexes and fibrinogen (FBG) levels and, above all, impaired fibrinolytic capacity. The increased activation of coagulation inhibitors seems to be compensatory in order to counteract disseminated coagulation, but there remains a net change towards an increased risk of venous thromboembolism (VTE). Conversely, GC administered in the presence of inflammation lowers vWF and FBG, but fibrinolytic activity is also reduced. As a result, the overall risk of VTE is increased in long-term users. Finally, no studies have assessed haemostatic abnormalities in patients with Addison's disease, although these may present as a consequence of bilateral adrenal haemorrhage, especially in the presence of antiphospholipid antibodies or anticoagulant treatments. The present review aimed to provide a comprehensive overview of the complex alterations produced by GCs in order to develop better screening and prevention strategies against bleeding and thrombosis.

Hypercoagulability in Cushing's syndrome: prevalence, pathogenesis and treatment

Cushing's syndrome is not only accompanied by an increased prevalence of cardiovascular disease but also by a hypercoagulable state that is reflected by an increased incidence of venous thromboembolism. Overall, patients with CS have been reported to have a more than 10-fold increased risk of developing venous thromboembolism. Moreover, the incidence of postoperative thrombosis has been shown to be comparable to the risk after major orthopaedic surgery. Hypercoagulability in CS is due to both increased production of procoagulant factors with activation of the coagulation cascade and an impaired fibrinolytic capacity, resulting in a shortened activated partial thromboplastin time and an increased clot lysis time respectively. Although these abnormalities seem to improve 1 year following successful surgery, they do not yet normalize. Therefore, sustained biochemical remission might be required to fully resolve the hypercoagulable state in CS. Considering the risk of venous thromboembolism in uncontrolled CS there may be a rationale to give patients with active CS thromboprophylaxis. So far this seems warranted following surgical interventions. However, further studies are needed to determine the optimal dosage and duration of thromboprophylaxis.

Pathogenesis of vascular complications in Cushing's syndrome

Chronic exposure to high glucocorticoid levels in Cushing's syndrome (CS) is often associated with alterations in the hemostatic system and the expression of prothrombotic phenotypes. Increased frequency of both atherothrombotic and venous thromboembolic events (VTE) has been reported in patients with CS. In general, cardiovascular complications in these patients cause a five-fold increase in mortality compared to the normal population. Although numerous abnormalities in the hemostatic system have been detected in patients with CS, the underlying mechanisms of the prothrombotic state are not fully elucidated. High levels of factor VIII and von Willebrand factor, with evidence of enhanced thrombin generation and decreased fibrinolytic activity, have been documented in several studies. However, it is not clear to what extent these changes contribute to the shift of hemostatic balance towards the hypercoagulable state and expression of thrombophilic phenotypes. Thrombosis is usually a multicausal disease, and all three components of the so-called Virchow triad, namely 1) vascular abnormalities and endothelial dysfunction, 2) hypercoagulability and 3) stasis, may play a variable role in the pathogenesis of the prothrombotic state in CS patients. Larger studies are needed to establish strategies for prevention of cardiovascular complications in patients with Cushing's syndrome.

The estimation of selected endogenous anticoagulation system parameters in patients with subclinical Cushing's syndrome

OBJECTIVE

An increased tendency towards thromboembolic events is observed in patients with Cushing's syndrome. There are much fewer publications available about thromboembolic complications in patients with subclinical Cushing's syndrome (SCS). Therefore, a question arises whether hemostatic disturbances appear in this particular disease phase.

AIM OF STUDY

Estimation of protein C (PC), free protein S (FPS), antithrombin (AT) activity, thrombomodulin (TM) concentration and activated PC resistance (APCR) in patients with SCS.

MATERIALS AND METHODS

We studied 35 patients with SCS. The control group consisted of 33 healthy volunteers. The activity of PC, AT, FPS, APCR and the concentration of TM was estimated in all representatives.

RESULTS

The comparison of the examined coagulation parameters between the patients with SCS and the healthy individuals revealed significantly higher mean PC activity and mean FPS activity in the SCS group. Mean TM concentration was significantly lower in patients with SCS compared with the control group. The differences in APCR and AT activity were not significant. We did not prove any statistically significant correlations between the examined coagulation parameters and hormonal parameters. We did not find any correlation between the concentration of cortisol and basic coagulation parameters such as international normalized ratio, activated partial thromboplastin time or fibrinogen in the group with SCS either.

CONCLUSIONS

The patients with SCS present disturbances in endogenous anticoagulation system defined as PC, FPS activity and TM concentration. This finding suggests an impact of mild autonomic cortisol overproduction on coagulation system.

Changes in coagulation indexes and occurrence of venous thromboembolism in patients with Cushing's syndrome: results from a prospective study before and after surgery

OBJECTIVES

To evaluate whether patients with Cushing's syndrome (CS) had i) changes in coagulative and fibrinolytic parameters associated with CS activity and ii) higher prevalence of venous thromboembolic events (VTE).

DESIGN

Prospective study conducted on patients with CS evaluated at diagnosis and 12 months after surgery.

PATIENTS AND METHODS

Forty patients with active CS (36 with Cushing's disease (CD) and 4 with an adrenal adenoma) were evaluated. Forty normal subjects and 70 patients with non-ACTH-secreting pituitary adenomas served as controls. All patients and controls underwent an assessment of coagulation and fibrinolysis indexes before and after surgery.

RESULTS

CS patients at baseline had a hypercoagulative phenotype when compared with normal subjects (activated partial thromboplastin time (aPTT), fibrinogen, D-Dimer, von Willebrand factor (VWF), plasminogen activator inhibitor 1 (PAI-1 or SERPINE1), antithrombin III (ATIII or SERPINC1), P<0.0001, α(2) antiplasmin, P=0.0004, thrombin-antithrombin complex (TAT), P=0.01, factor IX (F9), P=0.03). Patients with still active disease after surgery had higher coagulative parameters than those in remission (VWF (P<0.0001), PAI-1 (P=0.004), TAT (P=0.0001), ATIII (P=0.0002) and α(2) antiplasmin (or SERPINF2; P=0.006)), whereas aPTT levels (P=0.007) were significantly reduced. VTE occurred in three patients with CD (7.5%): one had a pulmonary embolism and two patients had a deep venous thrombosis; no patients submitted to transsphenoidal surgery for non-Cushing's pituitary adenoma had VTE (P=0.04).

CONCLUSIONS

Patients with CS have a procoagulative phenotype due to cortisol-associated changes in haemostatic and fibrinolytic markers, leading to increased incidence of VTE. Thromboprophylaxis seems to be appropriated in patients with active disease, particularly in the postoperative period.

Hypercoagulable state in Cushing's syndrome: a systematic review

CONTEXT

It has been debated whether an increased risk of venous thromboembolism (VTE) exists in patients with Cushing's syndrome.

OBJECTIVE

We aimed to summarize published literature on the effects of endogenous hypercortisolism on coagulation and fibrinolysis, as well as on the clinical outcome of VTE.

DATA SOURCES

We searched the MEDLINE and EMBASE databases up to July 2008. Review of reference lists further identified candidate studies.

STUDY SELECTION

Two investigators independently performed study selection and data extraction. Eligible studies had to include Cushing's syndrome patients and either evaluate hemostatic parameters in comparison with control persons or posttreatment levels or describe the occurrence of VTE.

DATA EXTRACTION

The Newcastle-Ottawa Scale was used to assess study quality. A scoring system divided studies into categories of low, medium and high quality.

DATA SYNTHESIS

Of 441 identified publications, 15 reports were included. They contained information on eight cross-sectionals, two intervention, and eight cohort studies. No high-quality studies were identified. Hypercoagulability was suggested by high levels of factor VIII, factor IX, and von Willebrand factor and by evidence of enhanced thrombin generation. A risk of 1.9 and 2.5% was reported for VTE not provoked by surgery, whereas risk of postoperative VTE varied between 0 and 5.6%, with one outlier of 20%. VTE was reported as the cause of death in 0-1.9% of Cushing's syndrome patients.

CONCLUSIONS

Available studies suggest a high risk of venous thrombosis in patients with Cushing's syndrome. Glucocorticoid-induced hypercoagulability as well as surgery and obesity almost certainly contribute to this thrombotic tendency.

Influencing factors of ADP-induced, epinephrine-induced and ristomycin-induced platelet aggregation in dogs

Functional defects of platelets are often studied by in-vitro aggregation tests with chemical compounds such as ADP, epinephrine and ristomycin (ristocetin). The aim of the present work was to investigate the effect of some diseases and that of nonsteroidal anti-inflammatory drug treatment on platelet aggregation in dogs. The examination had been carried out on 115 dogs by a Carat TX4 optical aggregometer (Entec GmbH, Ilmenau, Germany) first used in veterinary practice. The dogs were divided in three groups: healthy (control) dogs (n = 43), diseased dogs with normal haemostasis profile (n = 44), and dogs suffering from arthropathies with normal haemostasis profile treated with the nonsteroidal anti-inflammatory drugs ketoprofen or carprofen (n = 21). Following establishment of normal platelet aggregation curves in healthy dogs we found that some diseases such as diabetes mellitus, Cushing's disease, mastocytoma and lymphoma increased or decreased the aggregation maximum of platelets or caused changes in the feature of the aggregation curve. Carprofen treatment had no effect on platelet aggregation while ketoprofen decreased the aggregation maximum. These results showed that Carat TX4 aggregometer proved a useful instrument in studying platelet aggregation in platelet-rich plasma of dogs. For clinical pathologists it is important to know that the effects of some diseases and nonsteroidal anti-inflammatory drug treatments have to be taken into account when in-vitro platelet aggregation is evaluated. Based on our results and on those of other studies, we think standardization in aggregation methodology is highly recommended in veterinary laboratories.

Acute Effects of Glucocorticoids on Endothelial Fibrinolytic and Vasodilator Function in Humans

Acute coronary events occur most commonly in the morning, when circadian variations dictate that endogenous fibrinolytic activity is low and cortisol levels are high. We hypothesized that glucocorticoids would impair the acute fibrinolytic capacity of the endothelium because chronic glucocorticoid excess is associated with a prothrombotic state and endothelial vasomotor dysfunction. Twelve healthy subjects attended on 3 occasions and received oral metyrapone followed by intravenous saline or low-dose or high-dose hydrocortisone. Forearm blood flow and fibrinolytic indices were measured using venous occlusion plethysmography during intrabrachial bradykinin, acetylcholine, and sodium nitroprusside infusion. Hydrocortisone infusion had no effect on systemic concentrations of plasminogen activator inhibitor type 1 (PAI-1) or tissue plasminogen activator (t-PA; P = 0.10 and 0.95, respectively). Bradykinin caused a dose-dependent increase in plasma t-PA concentrations (P < 0.0001) that was unaffected by systemic hydrocortisone administration. Intrabrachial infusions of bradykinin, acetylcholine, and sodium nitroprusside all caused dose-dependent increases in forearm blood flow (P < 0.05) that were unaltered by hydrocortisone infusions.Short-term variations in plasma cortisol concentrations within the physiological range do not affect endothelial fibrinolytic or vasomotor function in healthy volunteers. These findings suggest that glucocorticoids do not exert acute effects on endothelial function in vivo in humans.

Effects of short-term glucocorticoids on hemostatic factors in healthy volunteers

OBJECTIVE

Increased circulating levels of hemostatic factors have been associated with arterial and venous thrombosis. Although in vitro evidence suggests that glucocorticoids may activate hemostasis and inhibit thrombolysis, no controlled in vivo studies have examined the effects of glucocorticoids on hemostatic factors. We hypothesized that a 5-day treatment course of dexamethasone would increase circulating levels of hemostatic and anti-fibrinolytic factors.

METHODS

We randomized 24 healthy men ages 19-39 to receive either dexamethasone 3 mg twice daily versus placebo for 5 days. Parameters examined before and after the intervention included: clotting factors VII, VIII, and XI, von Willebrand factor (vWF), D-dimer, PAI-1, soluble CD40-ligand (sCD40-ligand), and fibrinogen.

RESULTS

Dexamethasone tended to modestly increase clotting factors levels and fibrinogen without significantly affecting PAI-1, D-dimer or sCD40-ligand. Factor VII increased by a mean of 13% (p = 0.04 versus placebo), factor VIII by 27% (p = 0.0008), factor XI by 6% (p = 0.01), and fibrinogen by 13% (p = 0.05).

CONCLUSIONS

Glucocorticoids may increase the activity of clotting factors in vivo. This may contribute to the reported increased risk of thrombosis in patients with sustained exposure to glucocorticoids.

Diagnosis and Management of Mild Bleeding Disorders

Mild bleeding disorders are a common reason for a referral to a hematologist and these conditions can be challenging to evaluate. Recent research has highlighted that some bleeding symptoms are quite common in the general population and that there is clinical variability in symptom expression among individuals with defined bleeding problems. Moreover, bleeding risks for many bleeding disorders are unknown. This article reviews symptoms and problems that can be considered suspicious of a mild form of bleeding disorder and the diagnostic investigations useful to evaluate these problems. A stepwise approach is presented for the diagnostic evaluation, to allow detection of common and rare coagulation and fibrinolytic defects, and adequate assessments of potential von Willebrand factor and platelet problems. Some common problems in the diagnosis and management of mild bleeding problems are reviewed, including the common failure to establish a diagnosis with testing. An approach is proposed for translation of knowledge to patients who are challenged by mild bleeding problems.

Markers of activation of coagulation and fibrinolysis in patients with Cushing's syndrome

Patients with active Cushing's syndrome have an increased thrombotic tendency. We chose to reassess the mechanism underlying the thrombophilic state associated with this clinical condition using sensitive markers of coagulation and fibrinolysis activation in 17 patients with active disease. The results were compared with those obtained in 12 Cushing's patients successfully treated by surgery and in 20 normal individuals. The general pattern of results in patients with active disease was the finding of increased levels of von Willebrand factor (VWF: Ag), a marker of enhanced metabolic function of endothelial cells (VWF:Ag 181 +/- 42 vs 110 +/- 43, p<0.001 in normal subjects), accompanied by signs of heightened thrombin and plasmin generation, expressed by high levels of thrombin-antithrombin (TAT 5.59+/-3.6 vs 3.06+/-0.92 ng/ml in controls, p<0.01) and plasmin-antiplasmin complexes (PAP 407+/-176 vs 245+/-67 ng/ml in controls, p<0.01). VWF:Ag and TAT values were significantly higher in hypertensive than in normotensive patients with active disease (205+/-40 vs 155+/-26 U/dl, p<0.05 and 7.49+/-3.7 vs 3.45+/-1.8, p<0.01, respectively). Plasma levels of plasminogen activator inhibitor type 1 were higher, though not to a statistically significant extent, in patients with active disease compared to controls (12.8+/-12.3 vs 5.6+/-7.4 IU/ml, NS) and positively correlated with body mass index (r=0.66, p<0.01). After surgical control of Cushing's syndrome, there was a partial or complete reversal of the abnormalities to values similar to those found in normal individuals. Our data suggest that the thrombophilic state present in patients with active Cushing's syndrome is related to an enhanced metabolic function of endothelial cells; this in turn may be caused by an heightened production of thrombin with secondary hyperfibrinolysis. Primary prophylaxis with anticoagulants is recommended in these patients when they are exposed to a thrombophilic condition such as surgery.

Recurrent thromboembolism as a hallmark of Cushing's syndrome

The present report describes a 54-year-old woman with a history of recurrent thromboembolic events. The clinical and physical examination led to suspect Cushing's syndrome. Screening tests (urinary free cortisol excretion and 1 mg dexamethasone) were inconclusive, but a detailed endocrine work up confirmed the presence of ACTH-dependent hypercortisolism. The patient was cured by the removal of a ACTH-secreting microadenoma by transsphenoidal route. The present case provides a clinical demonstration of a previous experimental evidence that a hypercoagulable state is present in Cushing's syndrome.