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Background Recently, endogenous glucocorticoid excess has been identified as a risk factor for VTE. Whether exogenous use of glucocorticoids is associated with an increased risk of VTE is unclear. We aimed to quantify the risk of symptomatic pulmonary embolism (PE) in patients using corticosteroids. Methods A case-control study using the PHARMO Record Linkage System, a Dutch population-based pharmacy registry, was conducted. Cases were 4,495 patients with a first hospital admission for PE between 1998 and 2008. Control subjects were 16,802 sex- and age-matched subjects without a history of PE. International Classification of Diseases codes for hospitalization were used to retrieve information on underlying conditions. Results The risk of PE was highest in the first 30 days of glucocorticoid exposure (adjusted OR, 5.9; 95% CI, 2.3-3.9) and gradually decreased with increasing duration of use (OR, 1.9; 95% CI, 1.3-2.9) for long-term users (> 1 year). Low-dose glucocorticoid use (prednisolone daily dose equivalent 30 mg) (OR, 9.6; 95% CI, 4.3-20.5). Stratification for both duration and dose of glucocorticoid showed the highest risk of PE in recently started users compared with long-term users at the time of PE, irrespective of the dose. Conclusion Patients treated with oral glucocorticoids may be at an increased risk of PE, especially during the first month of exposure. This hypothesis requires confirmation in future studies.

SummaryEndocrine disorders affect both the coagulation and fibrinolytic systems, and have been associated with the development of cardiovascular diseases. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a link between coagulation and the fibrinolytic system. The aim of this study was to determine the effect of thyroid hormone excess and deficiency on TAFI levels and function. The effect of hyperthyroxinemia on TAFI was studied in healthy volunteers who were randomised to receive levothyroxine or no medication for 14 days in a crossover design. The effect of hypothyroidism on TAFI was studied in a multicentre observational cohort study. Blood was drawn before treatment of patients with newly diagnosed hypothyroidism and when euthyroidism was achieved. Plasma clot-lysis times, activated TAFI (TAFIa)-dependent prolongation of clot-lysis and TAFI levels were measured. Thyroid hormone excess resulted in a hypofibrinolytic condition and in an enhanced TAFIa-dependent prolongation of clot lysis. A trend towards decreased plasma TAFI levels was observed in healthy volunteers who used levothyroxine. Hypothyroidism resulted in hyperfibrinolysis and a reduced TAFIa-dependent prolongation of clot lysis. In conclusion, alterations of TAFIa-dependent prolongation of clot lysis in patients with thyroid disorders may cause an impaired haemostatic balance. The disturbed haemostatic balance in patients with hyperthyroidism might make them prone to thrombosis, while the risk for bleeding may increase in patients with hypothyroidism.

Atherothrombosis is a multifactorial process, governed by an interaction between the vessel wall, hemodynamic factors and systemic atherothrombotic risk factors. Recent in vitro, human ex vivo and animal studies have implicated the hormone prolactin as an atherothrombotic mediator. To address this issue, we evaluated the anatomy and function of various microvascular beds as well as plasma atherothrombosis markers in patients with elevated prolactin levels. In this pilot study, involving 10 prolactinoma patients and 10 control subjects, sidestream dark field (SDF) imaging revealed a marked perturbation of the sublingual microcirculation in prolactinoma patients compared to control subjects, as attested to by significant changes in microvascular flow index (2.74 +/- A 0.12 vs. 2.91 +/- A 0.05, respectively; P = 0.0006), in heterogeneity index (0.28 [IQR 0.18-0.31] vs. 0.09 [IQR 0.08-0.17], respectively; P = 0.002) and lower proportion of perfused vessels (90 +/- A 4.0% vs. 95 +/- A 3.0%, respectively; P = 0.016). In the retina, fluorescein angiography (FAG) confirmed these data, since prolactinoma patients more often have dilatated perifoveal capillaries. In plasma, prolactinoma patients displayed several pro-atherogenic disturbances, including a higher endogenous thrombin potential and prothrombin levels as well as decreased HDL-cholesterol levels. Prolactinoma patients are characterized by microvascular dysfunction as well as plasma markers indicating a pro-atherothrombotic state. Further studies are required to assess if prolactin is causally involved in atherothrombotic disease.

Endocrine diseases have been associated with cardiovascular events. Both altered coagulation and fibrinolysis markers and thrombotic disorders have been described in several endocrine diseases. This review summarizes the evidence on the influence of thyroid diseases, cortisol excess and deficiency, pheochromocytoma, hyperparathyroidism, hyperaldosteronism, hyperprolactinemia, and growth hormone excess and deficiency; on parameters of hemostasis; and on arterial and venous thrombotic events. All these endocrine diseases do have, or may have, influence either on hemostasis or on the risk of thrombotic events. Future studies are needed to establish the clinical relevance of these associations.

Contains fulltext : 108512.pdf (Publisher’s version ) (Closed access) The pituitary hormone prolactin is thought to influence coagulation. We aimed to study the relation between prolactin levels, coagulation factors and risk of venous thrombosis (VT). We used data from a large population based case-control study into aetiology of first VT (MEGA-study). Prolactin levels were determined in 2,068 patients with VT and 2,785 age- and sex matched control subjects. The relation between levels of coagulation factors and prolactin was studied among the controls. In addition, odds ratios (OR) and 95% confidence intervals (95%CI) were calculated for the risk of VT for different cut-off points of prolactin levels based on percentiles determined in the controls. Restricted analysis was performed among cases in whom blood was sampled within six months after VT. We found a rise in factor VIII and von Willebrand factor with increasing levels of prolactin in the controls. An increased risk of VT was observed when blood was sampled within six months after thrombosis (OR 2.9, 95%CI 1.1-8.1) for prolactin levels above the 99th percentile (42.6 mug/l) relative to levels between the 20th to 80th percentile. When blood was sampled more than six months after VT no clear association could be observed (OR 1.3, 95%CI 0.7-2.3). In conclusion, we found a modest association between prolactin and symptomatic venous thromboembolism, particularly when blood was sampled close to the event. This may be explained by a causal relation or by prolactin being a marker of stress due to the thrombotic event.

Context: Hyperthyroidism is associated with increased thrombosis risk, and fibrin clot structure determines susceptibility to vascular thrombotic events. Objective: Our objective was to investigate clot formation and lysis in hyperthyroidism using observational and interventional studies. Design: Ex vivo fibrin clot structure/fibrinolysis and plasma levels of thrombotic/inflammatory markers were investigated in hyperthyroid individuals (n = 24) and matched controls (n = 19), using turbidimetric assays, ELISA, and confocal and electron microscopy. The effects of normalizing thyroid function were analyzed (n = 19) and the role of short-term exogenous hyperthyroidism in healthy volunteers studied (n = 16). Results: Hyperthyroid subjects displayed higher clot maximum absorbance compared with controls (0.41 +/- 0.03 and 0.27 +/- 0.01 arbitrary units, respectively; P

Contains fulltext : 97999.pdf (Publisher’s version ) (Closed access) Context: Venous thrombosis has frequently been reported in patients with endogenous Cushing's syndrome (CS). Objective: The aim of this study was to evaluate the incidence of venous thromboembolism (VTE) in patients with CS prior to treatment and after surgery. Design and Setting: We conducted a multicenter cohort study at all university medical centers in The Netherlands. Patients: Consecutive patients diagnosed with endogenous CS of benign origin between January 1990 and June 2010 were eligible for inclusion. Patients surgically treated for nonfunctioning pituitary adenoma served as controls for the incidence of postoperative VTE in ACTH-dependent CS. Main Outcome Measures: We documented all objectively confirmed VTE during 3 yr prior to, and 3 yr after treatment onset. The incidences of VTE were expressed as incidence rates. Results: A total of 473 patients (mean age 42 yr, 363 women) were included (360 ACTH-dependent pituitary CS). The total number of person-years was 2526. Thirty-seven patients experienced VTE during the study period, resulting in an incidence rate of 14.6 [95% confidence interval (CI) 10.3-20.1] per 1000 person-years. The incidence rate for first-ever VTE prior to treatment was 12.9 (95% CI 7.5-12.6) per 1000 person-years (17 events). The risk of postoperative VTE, defined as risk within 3 months after surgery, was 0% for ACTH-independent and 3.4% (95% CI 2.0-5.9) for ACTH-dependent CS (12 events in 350 patients); most events occurred between 1 wk and 2 months after surgery. Compared with the controls, the risk of postoperative VTE in patients undergoing transsphenoidal surgery was significantly greater (P = 0.01). Conclusions: Patients with CS are at high risk of VTE, especially during active disease and after pituitary surgery. Guidelines on thromboprophylaxis are urgently needed.

Background There is accumulating evidence that rheumatoid arthritis (RA) should be considered as prothrombotic state, explaining the increased risk of thromboembolic events. Suppressing inflammation could reduce this hypercoagulability. COBRA, the combination of step-down prednisolone, methotrexate and sulfasalazine (SSZ) is an effective antirheumatic therapy. Whether glucocorticoids induce a procoagulant state is controversial and depends on the population, thus the effect of prednisolone in RA is unknown. Objectives To evaluate the course of haemostatic markers in RA patients during anti-inflammatory therapy and the dose-dependent effect of prednisolone on coagulation and fibrinolysis. Methods 22 patients diagnosed with early RA, were randomised to either COBRA therapy or an attenuated form (COBRA-light) with halved initial prednisolone dose and without SSZ. At baseline and after 1, 4 and 26 weeks of treatment, 10 ml of citrated blood was collected for measurement of prothrombin time (PT), activated partial thromboplastin time (aPTT) and five haemostatic markers: prothrombin fragment 1+2 (F1+2), factor VIII (FVIII), von Willebrand factor (vWF), plasminogen activator inhibitor (PAI-1) and D-dimer. For statistical analyses t-tests and linear regression were used. Results Baseline characteristics were not significantly different between the 2 groups (each 11 patients). DAS44, CRP, ESR, aPTT, D-dimer and F1+2 decreased during treatment in all patients (table). There was a significant positive association between decrease in CRP and BSE with D-dimer and decrease in CRP, BSE and DAS44 with F1+2 at all time points. There was no difference in the markers between the two groups, except for a stronger decrease in aPTT after 2 weeks (p=0.03) in the COBRA group. This difference was no longer seen at 4 weeks. Conclusions Overall, both COBRA and COBRA-light therapy induced an improvement of inflammatory and procoagulant factors in RA. There were no remarkable differences in the haemostatic markers between the two groups, indicating that doses higher than 30 mg of prednisolone have no attributable effect on the procoagulant state in RA. Disclosure of Interest None Declared

An excess of thyroid hormone leads to a prothrombotic state; however, the underlying pathophysiological mechanisms remain unknown. As evidence points towards an extensive “cross-talk” between the inflammatory and coagulation cascade, inflammation has been claimed as a possible mechanism through which different risk factors trigger venous thrombus formation. We aimed to study changes in expression of inflammation-related genes of the leukocyte RNA expression profile in healthy subjects in response to supraphysiological doses of levothyroxine. In a randomized single-blinded crossover design, 12 healthy volunteers (aged 18–40 years) received levothyroxine and no medication, both for 14 days with a wash-out period of at least 28 days between the periods. Blood was sampled at baseline and day 14 of each study period. MRNA was isolated from whole blood and used for multiplex ligation-dependent probe amplification to study the expression of inflammation-related genes. Compared to the control situation no significant changes were found in the expression of proinflammatory cytokines and mediators after the intake of levothyroxine. The results of this study show that high thyroid hormone levels do not lead to an altered inflammatory profile. This provides evidence against a major role of the inflammatory system as mediator in the effect of thyroid hormone on the coagulation system. The mechanisms by which thyroid hormone may influence coagulation proteins remain to be elucidated.