Changes in Hemostatic Variables Induced by Estrogen Replacement Therapy: Comparison of Transdermal and Oral Administration in a Crossover-Designed Study

Chronic thromboembolic pulmonary disease: Association with exercise-induced pulmonary hypertension and right ventricle adaptation over time

BACKGROUND AND AIM

Chronic thromboembolic pulmonary disease (CTEPD) is a progressive condition caused by fibrotic thrombi and vascular remodeling in the pulmonary circulation despite prolonged anticoagulation. We evaluated clinical factors associated with CTEPD, as well as its impact on functional capacity, pulmonary haemodynamics at rest and after exercise, and right ventricle (RV) morphology and function.

METHODS

We compared 33 consecutive patients with a history of acute pulmonary embolism and either normal pulmonary vascular imaging (negative Q-scan, group 1, n = 16) or persistent defects on lung perfusion scan (positive Q-scan) despite oral anticoagulation at 4 months (group 2, n = 17). Investigations included thrombotic load, the Pulmonary Embolism Severity Index (PESI) score, functional class, N-terminal prohormone of brain natriuretic peptide (NT-proBNP), cardiopulmonary exercise test (CPET) and echocardiographic parameters at rest and after exercise (ESE), at 4 and at 24 months.

RESULTS

Compared with group 1, group 2 featured a higher PESI score (p = 0.02) and a higher thrombotic load (p = 0.004) at hospital admission. At 4 months, group 2 developed exercise-induced pulmonary hypertension (Ex-PH) at CPET (p < 0.001) and ESE (p < 0.001). At 24 months group 2 showed higher NT-proBNP (p < 0.001), WHO-FC (p < 0.001), systolic (p<0.001) and diastolic (p = 0.037) RV dysfunction and worse RV-arterial coupling (p < 0.001) despite maintaining a low or intermediate echocardiographic probability of PH.

CONCLUSIONS

This is the first "proof of concept" study showing that patients with a positive Q-scan frequently develop Ex-PH and RV functional deterioration as well as reduced functional capacity, generating the hypothesis that Ex-PH could help detect the progression to CTEPD.

Pharmacokinetics of Sublingual vs. Oral Estradiol in Transgender Women

OBJECTIVE

To investigate the pharmacokinetics of 17ß-estradiol administered orally versus sublingually in transgender women.

METHODS

Single doses of 17ß-estradiol were administered orally (1 mg) to ten transgender women, then sublingually (1 mg) after a one-week washout. Blood samples were taken at baseline and T = 1,2,3,4,6,8 hours after dosing. Samples were frozen and analyzed using LC-MS/MS (liquid chromatography mass spectrometry) and immunoassay.

RESULTS

Results demonstrated that sublingual estradiol had a significantly higher peak serum estradiol (E2) concentration at 144 pg/mL by LC-MS/MS compared to oral estradiol at 35 pg/mL by LC-MS/MS (p= 0.003). Sublingual estradiol peaked at hour 1 and oral estradiol peaked at hour 8 when measured by LC-MS/MS. The area under the curve (AUC) 0-8h for sublingual estradiol measured by LC-MS/MS showed a 1.8-fold higher level compared to the AUC 0-8h for oral estradiol measured by LC-MS/MS. Additionally, sublingual E2 was found to have an increased E2 to estrone (E1) ratio at all timepoints (1.1 ± 1.0 v. 0.7 ± 0.4, p= <0.0001), the clinical significance of which is unclear.

CONCLUSION

Oral estradiol administered sublingually has a different pharmacokinetic profile, with higher serum estradiol levels and AUC (0-8h) than traditionally administered oral E2. Multi-daily dosing may be necessary to suppress testosterone levels with sublingual estradiol. The appropriate dosing, efficacy and safety of sublingual estradiol compared to other estradiol preparations is unknown.

Aerobic training abolishes ambulatory blood pressure increase induced by estrogen therapy: a double blind randomized clinical trial

Emerging data reveal that oral estrogen therapy can increase clinic blood pressure (BP) in post-menopausal women; however, it is important to establish its effects on ambulatory BP, which is a better predictor for target-organ damage. Besides estrogen therapy, aerobic training is widely recommended for post-menopausal women, and it can decrease ambulatory BP levels. This study was designed to evaluate the effect of aerobic training and estrogen therapy on the ambulatory BP of post-menopausal women. Forty seven healthy hysterectomized women were randomly divided (in a double-blind manner) into 4 groups: placebo-control (PLA-CO=12), estrogen therapy-control (ET-CO=14), placebo-aerobic training (PLA-AT=12), and estrogen therapy-aerobic training (ET-AT=09). The ET groups received estradiol valerate (1 mg/day) and the AT groups performed cycle ergometer, 3×/week at moderate intensity. Hormonal status (blood analysis), maximal cardiopulmonary exercise test (VO(2) peak) and ambulatory BP (24-h, daytime and nighttime) was evaluated before and 6 months after interventions. A significant increase in VO(2) peak was observed only in women who participated in aerobic training groups (+4.6±1.0 ml kg(-1) min(-1), P=0.00). Follicle-stimulating hormone was a significant decreased in the ET groups (-18.65±5.19 pg/ml, P=0.00), and it was accompanied by an increase in circulating estrogen (56.1±6.6 pg/ml). A significant increase was observed in the ET groups for daytime (P=0.01) and nighttime systolic BP (P=0.01), as well as nighttime diastolic BP (P=0.02). However, daytime diastolic BP was increased only in the ET-CO group (+3.4±1.2 mmHg, P=0.04), and did not change in any other groups. No significant effect was found in ambulatory heart rate. In conclusion, aerobic training abolished the increase of daytime ambulatory BP induced by estrogen therapy in hysterectomized, healthy, normotensive and postmenopausal women.

The effect of estrone on thrombin generation may explain the different thrombotic risk between oral and transdermal hormone replacement therapy

BACKGROUND

The metabolism of estrogen contained within hormone replacement therapy (HRT) is influenced by the route of administration, and this may affect the risk of venous thromboembolism. Thrombin generation, a global coagulation assay, is a marker of hypercoagulability and is of potential use in determining the thrombotic risk associated with particular HRT administration routes.

OBJECTIVES

To determine whether any effect of oral and transdermal HRT on thrombin generation is related to the plasma estrogen profile.

METHODS

We investigated the effects of oral, transdermal and no HRT (controls) in 52, 39 and 52 postmenopausal women, respectively, on thrombin generation, standard markers of thrombophilia, estradiol level and estrone level.

RESULTS

All parameters of thrombin generation were altered in women using oral HRT as compared with controls (P<0.001 for all comparisons). No such differences were found in women using transdermal HRT. Estrone levels correlated with peak thrombin generation (R=0.451, P<0.001) in women using oral HRT, but there was no correlation in women using the transdermal route.

CONCLUSIONS

Thrombin generation is significantly increased in women who use HRT administered by the oral route. This is probably mediated by the hepatic first-pass metabolism of estrone, the main metabolite of oral estradiol, which is avoided by the transdermal route. The effect of estrone on thrombin generation may provide the explanation for the higher thrombotic risk seen in women using oral rather than transdermal HRT.

Low PAI-1 activity in relation to inflammatory parameters, insulin profile and body mass index

BACKGROUND AND OBJECTIVE

High plasminogen activator inhibitor type 1 (PAI-1) activity is associated with inflammatory reactions and insulin resistance, but it is unclear what regulates PAI-1 activity at the low end. The purpose of this study was to investigate if patients with low PAI-1 activity have a lack of inflammatory response or a low insulin level.

DESIGN

Retrospective cohort study with internal controls.

SUBJECTS

Sixty-three patients referred for investigation of bleeding tendency and with low PAI-1 activity were compared with 118 patients with normal or high PAI-1 activity.

OUTCOME

Levels of C-peptide, proinsulin, high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6). Adjustments were made for body mass index (BMI), oral oestrogens and age. Low PAI-1 activity was defined as less than 1 U mL(-1).

RESULTS

Body mass index in the low normal range, oral oestrogens, young age and low C-peptide were significantly associated with low PAI-1 activity and there was a trend for association with IL-6 in univariable analysis. The effect of age disappeared after correction for oral oestrogens and the effect of C-peptide and IL-6 disappeared after further adjustments. Low BMI remained as the strongest predictor of low PAI-1 activity.

CONCLUSION

Patients with bleeding tendency and low PAI-1 activity have inflammatory and insulin profiles similar to those with normal or high PAI-1, whereas BMI seems to be the most important determinant.