Combined oral contraceptives: venous thrombosis

Estimating systemic exposure to levonorgestrel from an oral contraceptive

OBJECTIVE

The gold standard for measuring oral contraceptive (OC) pharmacokinetics is the 24-h steady-state area under the curve (AUC). We conducted this study to assess whether limited sampling at steady state or measurements following use of one or two OCs could provide an adequate proxy in epidemiological studies for the progestin 24-h steady-state AUC of a particular OC.

STUDY DESIGN

We conducted a 13-sample, 24-h pharmacokinetic study on both day 1 and day 21 of the first cycle of a monophasic OC containing 30-mcg ethinyl estradiol and 150-mcg levonorgestrel (LNG) in 17 normal-weight healthy White women and a single-dose 9-sample study of the same OC after a 1-month washout. We compared the 13-sample steady-state results with several steady-state and single-dose results calculated using parsimonious sampling schemes.

RESULTS

The 13-sample steady-state 24-h LNG AUC was highly correlated with the steady-state 24-h trough value [r=0.95; 95% confidence interval (0.85, 0.98)] and with the steady-state 6-, 8-, 12- and 16-h values (0.92≤r≤0.95). The trough values after one or two doses were moderately correlated with the steady-state 24-h AUC value [r=0.70; 95% CI (0.27, 0.90) and 0.77; 95% CI (0.40, 0.92), respectively].

CONCLUSIONS

Single time-point concentrations at steady state and after administration of one or two OCs gave highly to moderately correlated estimates of steady-state LNG AUC. Using such measures could facilitate prospective pharmaco-epidemiologic studies of the OC and its side effects.

IMPLICATIONS

A single time-point LNG concentration at steady state is an excellent proxy for complete and resource-intensive steady-state AUC measurement. The trough level after two single doses is a fair proxy for steady-state AUC. These results provide practical tools to facilitate large studies to investigate the relationship between systemic LNG exposure and side effects in a real-life setting.

Sex differences in the epidemiology, clinical features, and pathophysiology of migraine

Migraine is two to three times more prevalent in women than men, and women report a longer attack duration, increased risk of headache recurrence, greater disability, and a longer period of time required to recover. Conditions recognised to be comorbid with migraine include asthma, anxiety, depression, and other chronic pain conditions, and these comorbidities add to the amount of disability in both sexes. Migraine-specifically migraine with aura-has been identified as a risk factor for vascular disorders, particularly in women, but because of the scarcity of data, the comparative risk in men has yet to be established. There is evidence implicating the role of female sex hormones as a major factor in determining migraine risk and characteristics, which accounts for sex differences, but there is also evidence to support underlying genetic variance. Although migraine is often recognised in women, it is underdiagnosed in men, resulting in suboptimal management and less participation of men in clinical trials.

Combined hormonal contraception and the risk of venous thromboembolism: a guideline

While venous thromboembolism (VTE) is rare in young women of reproductive age, combined oral contraceptives increase the risk of VTE. In the patient in whom combined hormonal contraception is appropriate, it is reasonable to use any currently available preparation.

Environmental and Genetic Risk Factors Associated with Venous Thromboembolism

Venous thromboembolism (VTE) includes deep vein thrombosis and pulmonary embolism, and a combination of environmental and genetic risk factors contributes to VTE risk. Within environmental risk factors, some are provoking (e.g., cancer, surgery, trauma or fracture, immobilization, pregnancy and the postpartum period, long-distance travel, hospitalization, catheterization, and acute infection) and others are nonprovoking (e.g., age, sex, race/ethnicity, body mass index and obesity, oral contraceptive or hormone therapy use, corticosteroid use, statin use, diet, physical activity, sedentary time, and air pollution). Additionally, VTE has a strong genetic basis, with approximately 50 to 60% of the variance in VTE incidence attributed to genetic effects. Some genetic susceptibility variants that contribute to risk have been identified in candidate genes, mostly related to the clotting system and responsible for inherited hypercoagulable states (e.g., factor V Leiden, prothrombin, fibrinogen gamma, or blood group non-O). Other susceptibility single-nucleotide polymorphisms have been identified from genome-wide association studies, such as the two new loci in TSPAN15 (rs78707713) and SCL44A2 (rs2288904) genes. Risk factors are not always associated with VTE in isolation; however, and an understanding of how environmental and genetic factors interact may provide insight into the pathophysiology of VTE, possibly identifying opportunities for targeted prevention and treatment.

Oxidative Stress in Female Athletes Using Combined Oral Contraceptives

Background

Oxidative stress in female athletes is understudied. We investigated oxidative stress in sportswomen of different disciplines according to combined oral contraceptive (OC) use and lifestyle/alimentary habits.

Methods

Italian sportswomen (n = 144; mean age 23.4 ± 4.2 years; body mass index 21.2 ± 2.2 kg m⁻²; sport activity 9.2 ± 4.1 h week⁻¹) were analyzed; 48 % were volleyball players, 12.5 % soccer players, 10.4 % track-and-field sports, and followed by other disciplines’ athletes. Oxidative stress was evaluated by free oxygen radical test (FORT) assessing blood hydroperoxides and free oxygen radical defense (FORD) assay evaluating antioxidant capacity in OC users (n = 42) compared to non-OC users.

Results

Elevated oxidative stress levels (≥310 FORT units) were found in 92.9 % of OC users and in 23.5 % of non-OC users (crude OR = 42, 95 % CI 12–149, p < 0.001; adjusted OR = 60, 95 % CI 11–322, p < 0.001). Continuous values of hydroperoxides were twofold higher in OC users versus non-OC users (median 484 versus 270 FORT units, p < 0.001) and were inversely related to FORD units in OC users (p = 0.01). Hydroperoxides were not associated with weekly hours of exercise. In OC users, lifestyle/alimentary habits were not correlated to hydroperoxides. In non-OC users only, hydroperoxide values were positively correlated with weight and BMI and inversely correlated with chocolate and fish consumption.

Conclusions

The markedly elevated oxidative stress we revealed in OC-user athletes could be detrimental to physical activity and elevate cardiovascular risk (as thromboembolism). Further research is needed to extend our results, to clarify the biochemical pathways leading to increased hydroperoxides (mainly lipid peroxides) and reduced antioxidant defense, and to elucidate the potential effects on athletic performance. OC use should be considered when developing gender-focused strategies against oxidative stress.

Retrospective analysis of the impact of increasing access to long acting reversible contraceptives in a commercially insured population

Background

Unintended pregnancies have been shown to be associated with high costs for the healthcare system, among other adverse impacts, but could still account for up to 51 % of pregnancies in the US. Improvements in contraception among women are needed. Long acting reversible contraceptives (LARCs), which have proved their safety and efficacy, have been found to significantly decrease the risk of unintended pregnancy. Yet they are still marginally employed. This study aims at investigating the evolution of LARC use over 15 years and at assessing the impact of the introduction of newer LARCs on LARC use relative to all contraceptive use.

Methods

This retrospective study identified women with LARC or short acting reversible contraceptive (SARC) claims from a US insurance claims database (01/1999-03/2014). Yearly proportions of LARC users relative to all contraceptive users were reported. Generalized estimating equation models were used to assess the impact of user characteristics, such as age group (15–17, 18–24, 25–34, and 35–44), and of time periods related to the introduction of new LARCs (01/2001: Mirena, 07/2006: Implanon, 01/2013: Skyla) on LARC use.

Results

A total of 1,040,978 women were selected. LARC use increased yearly from 0.6 % (1999) to 16.6 % (2013) among contraceptive users. Time periods associated with the introduction of a newer LARC were significant predictors of LARC use; women in 2006-2012 and 2013-2014 were respectively 3.7-fold (95 % CI:3.57–3.74) and 6.6-fold (95 % CI:6.43–6.80) more likely to use LARCs over SARCs relative to women in 2001-2006. The increase in LARC use was especially pronounced in young women. Compared to women aged 18–24 in 2001-2006, women aged 18–24 in 2006-2012 and 2013-2014 were respectively 6.4-fold (95 % CI:5.91–6.86) and 14.7-fold (95 % CI:13.59–15.89) more likely to use LARCs over SARCs.

Conclusions

This broadly representative commercial claim-based study showed that the proportion of privately insured women of childbearing age using LARCs increased over time and that the introduction of newer LARCs corresponded with significant increases in overall LARC use. Future research is needed to assess LARC use in uninsured or publicly-insured populations.

Pharmacologic Therapies in Women's Health: Contraception and Menopause Treatment

Female hormones play a significant role in the etiology and treatment of many women's health conditions. This article focuses on the common uses of hormonal therapy. When prescribing estrogen-containing regimens throughout the span of a woman's life, the risks are similar (ie, cardiovascular risk and venous thromboembolism), but the degree of risk varies significantly depending on a woman's particular set of risk factors and the details of the hormone regimen. In addition to estrogens and progestogens, this article also touches on the use of selective steroid receptor modulators in emergency contraception and in treatment of menopause symptoms.

Combined oral contraceptives, thrombophilia and the risk of venous thromboembolism: a systematic review and meta-analysis

Essentials We performed a meta-analysis on thrombosis risk in thrombophilic oral contraceptive (COC)-users. The results support discouraging COC-use in women with a natural anticoagulant deficiency. Contrary, additive risk of factor V Leiden (FVL) or prothrombin-G20210A (PT) mutation is modest. Women with a FVL/PT-mutation as single risk factor can use COCs if alternatives are not tolerated.

SUMMARY

Background Combined oral contraceptives (COCs) are associated with an increased risk of venous thromboembolism (VTE), which is shown to be more pronounced in women with hereditary thrombophilia. Currently, WHO recommendations state that COC-use in women with hereditary thrombophilias (antithrombin deficiency, protein C deficiency, protein S deficiency, factor V Leiden and prothrombin-G20210A mutation) is associated with an unacceptable health risk. Objective To perform a meta-analysis evaluating the additional risk of VTE in COC-users with thrombophilia. Methods The MEDLINE and EMBASE databases were searched on 10 February 2015 for potential eligible studies. A distinction was made between 'mild' (factor V Leiden and prothrombin-G20210A mutation) and 'severe' thrombophilia (antithrombin deficiency, protein C deficiency, protein S deficiency, double heterozygosity or homozygosity of factor V Leiden and prothrombin-G20210A mutation). Results We identified 12 case-control and three cohort studies. In COC-users, mild and severe thrombophilia increased the risk of VTE almost 6-fold (rate ratio [RR], 5.89; 95% confidence interval [CI], 4.21-8.23) and 7-fold (RR, 7.15; 95% CI, 2.93-17.45), respectively. The cohort studies showed that absolute VTE risk was far higher in COC-users with severe thrombophilia than in those with mild thrombophilia (4.3 to 4.6 vs. 0.49 to 2.0 per 100 pill-years, respectively), and these differences in absolute risks were also noted in non-affected women (0.48 to 0.7 vs. 0.19 to 0.0), but with the caveat that absolute risks were estimated in relatives of thrombophilic patients with VTE (i.e. with a positive family history). Conclusion These results support discouraging COC-use in women with severe hereditary thrombophilia. By contrast, additive VTE risk of mild thrombophilia is modest. When no other risk factors are present, (e.g. family history) COCs can be offered to these women when reliable alternative contraceptives are not tolerated.

Combined hormonal contraceptive use among obese women and risk for cardiovascular events: A systematic review

CONTEXT

Combined hormonal contraceptive (CHC) use may modify the risk of cardiovascular events in obese [body mass index (BMI) ≥30kg/m²] women.

OBJECTIVE

The objective was to evaluate from the literature whether CHC use modifies the risk of acute myocardial infarction (AMI), stroke, cerebral venous thrombosis (CVT) and venous thromboembolism (VTE) in obese women and to evaluate evidence for a dose-response relationship between BMI and VTE.

METHODS

We searched PubMed for all articles published between database inception and February 2016 providing direct evidence on BMI, CHCs, and cardiovascular outcomes. We also searched for indirect evidence related to a dose-response relationship between BMI and risk of VTE in the general population, as these data were lacking for CHC users. The quality of each individual study was assessed using the system for grading evidence developed by the United States Preventive Services Task Force.

RESULTS

The direct evidence search yielded 3 pooled analyses, 11 case-control studies and 1 cohort study. There was conflicting evidence about the risk of AMI or stroke among obese combined oral contraceptive (COC) users compared to obese nonusers, with one study finding no increased risk for AMI or stroke for COC users overall or stratified by BMI. A second study found significantly increased risk of AMI and stroke for COC users, with the highest risk estimates for high-BMI COC users. A single study suggested that obese COC users may be at higher risk for CVT compared with normal-weight nonusers. For VTE, obese COC users consistently had a risk that was 5 to 8 times that of obese nonusers and approximately 10 times that of nonobese nonusers. Five prospective cohort studies were identified as indirect evidence, and all found increased risk for VTE as BMI increased, suggesting a dose-response relationship between BMI and risk for VTE. No studies on the contraceptive patch or vaginal ring were identified that met the inclusion criteria.

CONCLUSION

Limited evidence of Level II-2, fair quality, concerning whether CHC use modifies the risk of AMI and stroke in obese women is inconclusive, while a single study of Level II-2, poor quality, found that obese COC users may be at higher risk for CVT compared with normal-weight nonusers. Both COC use and higher BMI increase risk for VTE, and the greatest relative risks are for those with both risk factors based on a body of evidence graded as Level II-2, fair to poor quality. It is not possible to estimate absolute risk of VTE among women with both of these risk factors; however, the absolute risk of VTE in healthy women of reproductive age is small.

Family history of venous thromboembolism is a risk factor for venous thromboembolism in combined oral contraceptive users: a nationwide case-control study

BACKGROUND

The aim was to assess the risk of venous thromboembolism (VTE) associated with use of combined oral contraceptives (COCs) in women with a family history of VTE.

METHODS

The study is a Swedish nationwide case-control study based on the Multigeneration register, the Swedish Hospital Discharge Register, the Outpatient Care Register, and the Swedish Prescribed Drug Register. Cases (n = 2,311) were non-pregnant Swedish women aged 15-49 with first VTE diagnoses between January 2006 and December 2010. Five controls without VTE were matched to each case on age and education level. Conditional logistic regression examined the associations with VTE with determination of odds ratio (OR) for first VTE diagnosis. Effect modification was assessed by interaction testing.

RESULTS

Both among controls (14.6 % vs. 4.5 %; p < 0.0001) and cases (27.2 % vs. 8.8 %; p < 0.0001) COC use was more common in women without a family history of VTE compared with women with a family history of VTE. In a multivariate conditional logistic regression model the OR for VTE was 2.53 (95 % CI 2.23-2.87) for COC users and 2.38 (2.09-2.71) for individuals with a family history of VTE. The OR for VTE for COC users with a family history of VTE was 6.02 (5.02-7.22). There was no significant interaction between family history of VTE and COC use (OR 0.92, 0.57-1.46).

CONCLUSIONS

Family history of VTE is a risk factor for VTE in women using COCs. The low prevalence of COC use among women with a family history of VTE suggests that family history of VTE is considered when COCs are prescribed in Sweden. The present study may therefore even underestimate the importance of family history of VTE. The lack of interaction indicates that the risk of COC use in women with family history of VTE is determined by the product of the ORs for family history and COC use.

Risk Factors for Venous Thromboembolism Among Reproductive Age Women

BACKGROUND

Venous thromboembolism (VTE) is rare among young women and is often presumed to occur in the setting of a genetic predisposition or during the use of estrogen-containing combined hormonal contraceptive or to have an unknown cause. This study aims to describe the distribution of VTE risk factors among women with a confirmed VTE.

METHODS

We identified all women aged 15-46 years with a VTE diagnosis at Columbia University Medical Center from 2005 to 2012 using medical center databases. We then reviewed all electronic medical records to validate the diagnoses and identify risk factors associated with each confirmed case.

RESULTS

We identified 315 cases and confirmed 186 (59%). The proportion of unconfirmed cases increased over time. Forty percent of confirmed cases were associated with hormonal contraceptives or pregnancy. Ninety-five percent of confirmed cases had identifiable major risk factors including a personal history, family history, malignancy or other predisposing illness, recent long-haul travel, trauma, hospitalization, and obesity; many had multiple simultaneous risk factors. None of the confirmed cases was associated with a previously known genetic predisposition, but in 10 confirmed cases a genetic predisposition was identified during evaluation. In only 10 of the 186 confirmed cases could we not identify any acquired risk factor, and only 2 of those 10 women had a genetic predisposition.

CONCLUSIONS

Many reproductive age women experiencing a VTE have risk factors unique to this group, and most have multiple risk factors, confirming that this is a multifactorial disease. The large proportion of unconfirmed cases suggests the need for great caution in using administrative databases for research due to poor diagnostic specificity and due to lack of information about additional risk factors.

Combined oral contraceptives: the risk of myocardial infarction and ischemic stroke

BACKGROUND

Combined oral contraceptives (COCs) have been associated with an increased risk of arterial thrombosis, i.e. myocardial infarction or ischemic stroke. However, as these diseases are rare in young women and as many types of combined oral contraception exist, the magnitude of the risk and the effect of different hormonal contents of COC preparations remain unclear.

OBJECTIVES

To estimate the risk of myocardial infarction or ischemic stroke in users compared with non-users of different types, doses and generations of combined oral contraception.

SEARCH METHODS

We searched electronic databases (MEDLINE (1966 to July 08, 2015), EMBASE (1980 to July 08, 2015), Popline (1970 to July 08, 2015) and LILACS (1985 to July 08, 2015) for eligible studies, without language restrictions.

SELECTION CRITERIA

We included observational studies that recruited women in the reproductive age group (18 to 50 years) and compared the risk of myocardial infarction or ischemic stroke between users and non-users of COCs.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected relevant studies and extracted data. We pooled relative risks ()(combined odds ratios and one incidence rate ratio) and 95% confidence intervals (CIs) for myocardial infarction or ischemic stroke in users versus non-users of COCs.We combined the outcomes of myocardial infarction and ischemic stroke and also analysed these outcomes separately. Analyses were stratified according to estrogen dose and progestagen type.

MAIN RESULTS

In total, we identified 1298 publications through the search strategy. We included 28 publications reporting on 24 studies. COC users were at increased risk of myocardial infarction or ischemic stroke compared with non-users: relative risk (RR) 1.6 (95% CI 1.3-1.9).These RRs were similar for myocardial infarction (1.6, 95% CI 1.2 to 2.1) and ischemic stroke (1.7, 95% CI 1.5 to 1.9). The risks did not vary clearly according to the generation of progestagen or according to progestagen type. When we stratified preparations according to estrogen dose, the risk of myocardial infarction or ischemic stroke seemed to increase with higher doses of estrogen.

AUTHORS' CONCLUSIONS

This meta-analysis showed that the risk of myocardial infarction or ischemic stroke was 1.6-fold increased in women using COCs . The risk was highest for pills with > 50 microgram estrogen. When combined with the results of studies on the risk of venous thrombosis in COC users, it seems that the COC pill containing levonorgestrel and 30 μg of estrogen is the safest oral form of hormonal contraception.

Oral contraception

Oral contraception (OC) remains a popular noninvasive, readily reversible approach for pregnancy prevention and, largely off label, for control of acne, hirsutism, dysmenorrhea, irregular menstruation, menorrhagia, and other menstrual-related symptoms. Many OC formulations exist, with generics offering lower cost and comparable efficacy. Certain medical conditions, including hypertension, migraine, breast cancer, and risk of venous thromboembolism (VTE), present contraindications. Blood pressure measurement is the only physical examination or testing needed before prescription. Although no OC is clearly superior to others, OCs containing the second-generation progestin levonorgestrel have been associated with lower VTE risk than those containing other progestins.

Sickle cell disease and venous thromboembolism in pregnancy and the puerperium

Recent data strongly suggest an increased risk of venous thromboembolism in subjects with sickle cell disease and to a lesser extent, sickle cell trait. However, most studies have been retrospective, case-control or cross-sectional based on data obtained from administrative databases. More data from adequately powered prospective studies that include matched controls are needed to definitely establish the link between venous thromboembolism during pregnancy and sickle hemoglobin disorders. Similarly, there remains a need for properly designed randomized control trials to establish the safety of various hormonal contraceptive methods in women with sickle cell disorders.

Oral contraceptives and menopausal hormone therapy: relative and attributable risks of cardiovascular disease, cancer, and other health outcomes

PURPOSE

To summarize the relative risks (RRs) and attributable risks (ARs) of major health outcomes associated with use of combined oral contraceptives (OCs) and menopausal hormone therapy (HT).

METHODS

For OCs, measures of association are from meta-analyses of observational studies. For HT, these measures are from the Women's Health Initiative, a large randomized trial of HT for chronic disease prevention in postmenopausal women aged 50 to 79 years.

RESULTS

Current OC use increases risks of venous thromboembolism and ischemic stroke. However, women of reproductive age are at low baseline risk, so the ARs are small. OC use also increases risk of breast and liver cancer and reduces risk of ovarian, endometrial, and colorectal cancer; the net effect is a modest reduction in total cancer. The Women's Health Initiative results show that HT does not prevent coronary events or overall chronic disease in postmenopausal women as a whole. Subgroup analyses suggest that timing of HT initiation influences the relation between such therapy and coronary risk, and its overall risk-benefit balance, with more favorable effects (on a relative scale) in younger or recently menopausal women than in older women or those further past the menopausal transition. However, even if the RR do not vary by these characteristics, the low absolute baseline risks of younger or recently menopausal women translate into low ARs in this group.

CONCLUSIONS

OC and HT can safely be used for contraception and treatment of vasomotor symptoms, respectively, by healthy women at low baseline risk for cardiovascular disease and breast cancer.

Oral contraceptives and menopausal hormone therapy: relative and attributable risks of cardiovascular disease, cancer, and other health outcomes

PURPOSE

To summarize the relative risks (RRs) and attributable risks (ARs) of major health outcomes associated with use of combined oral contraceptives (OCs) and menopausal hormone therapy (HT).

METHODS

For OCs, measures of association are from meta-analyses of observational studies. For HT, these measures are from the Women's Health Initiative, a large randomized trial of HT for chronic disease prevention in postmenopausal women aged 50 to 79 years.

RESULTS

Current OC use increases risks of venous thromboembolism and ischemic stroke. However, women of reproductive age are at low baseline risk, so the ARs are small. OC use also increases risk of breast and liver cancer and reduces risk of ovarian, endometrial, and colorectal cancer; the net effect is a modest reduction in total cancer. The Women's Health Initiative results show that HT does not prevent coronary events or overall chronic disease in postmenopausal women as a whole. Subgroup analyses suggest that timing of HT initiation influences the relation between such therapy and coronary risk, and its overall risk-benefit balance, with more favorable effects (on a relative scale) in younger or recently menopausal women than in older women or those further past the menopausal transition. However, even if the RR do not vary by these characteristics, the low absolute baseline risks of younger or recently menopausal women translate into low ARs in this group.

CONCLUSIONS

OC and HT can safely be used for contraception and treatment of vasomotor symptoms, respectively, by healthy women at low baseline risk for cardiovascular disease and breast cancer.

Impact of hormone-associated resistance to activated protein C on the thrombotic potential of oral contraceptives: a prospective observational study

INTRODUCTION

The increased thrombotic risk of oral contraceptives (OC) has been attributed to various alterations of the hemostatic system, including acquired resistance to activated protein C (APC). To evaluate to what extent OC-associated APC resistance induces a prothrombotic state we monitored plasma levels of thrombin and molecular markers specific for thrombin formation in women starting OC use. Elevated plasma levels of thrombin have been reported to characterize situations of high thrombotic risk such as trauma-induced hypercoagulability, but have not yet been studied during OC use.

PATIENTS AND METHODS

Blood samples were collected prospectively from healthy women (n = 21) before and during three menstruation cycles after start of OC. APC resistance was evaluated using a thrombin generation-based assay. Plasma levels of thrombin and APC were directly measured using highly sensitive oligonucleotide-based enzyme capture assay (OECA) technology. Thrombin generation markers and other hemostasis parameters were measured additionally.

RESULTS

All women developed APC resistance as indicated by an increased APC sensitivity ratio compared with baseline after start of OC (p = 0.0003). Simultaneously, plasma levels of thrombin, prothrombin fragment 1+2, and of thrombin-antithrombin complexes did not change, ruling out increased thrombin formation. APC plasma levels were also not influenced by OC use, giving further evidence that increased thrombin formation did not occur.

CONCLUSIONS

In the majority of OC users no enhanced thrombin formation occurs despite the development of APC resistance. It cannot be ruled out, however, that thrombin formation might occur to a greater extent in the presence of additional risk factors. If this were the case, endogenous thrombin levels might be a potential biomarker candidate to identify women at high thrombotic risk during OC treatment. Large-scale studies are required to assess the value of plasma levels of thrombin as predictors of OC-associated thrombotic risk.