Hormonal contraception among electronic cigarette users and cardiovascular risk: a systematic review.
Topic: Hormone Therapy

Women who use combined hormonal contraceptives and cigarettes have an increased risk for cardiovascular (CV) events. We reviewed the literature to determine whether women who use hormonal contraceptives (HC) and electronic cigarettes (e-cigarettes) also have an increased risk.

PICO
Population: Women who use hormonal contraceptives and electronic cigarettes
Intervention: Use of hormonal contraceptives and electronic cigarettes
Comparison: Women who use hormonal contraceptives and traditional cigarettes
Outcomes: Risk of cardiovascular events

Included studies:
title: Cardiovascular effects of nasal and transdermal nicotine and cigarette smoking.
abstract: The purpose of this study was to compare circadian blood pressure and heart rate patterns and other cardiovascular effects of nicotine delivered rapidly (via nasal spray, NNS), slowly (transdermal nicotine, TDN), by cigarette smoking (rapid delivery of nicotine plus other smoke toxins), and placebo NNS. Twelve healthy cigarette smokers were studied on a research ward when they smoked cigarettes (16 per day) or used TDN (15 mg/16 h), NNS (24 1-mg doses per day), or placebo NNS, each for 5 days. There were no significant differences in systolic blood pressure, but diastolic blood pressure was slightly increased during cigarette smoking. Plasma epinephrine, beta-thromboglobulin, and fibrinogen levels were higher during cigarette smoking than with TDN. For most measurements, NNS values were intermediate between and not significantly different from those of cigarette smoking and TDN. We conclude that, at recommended doses, TDN and NNS have fewer effects on biomarkers of cardiovascular risk than does cigarette smoking.
title: Influence of inhaled nicotine source on arterial stiffness.
abstract: Tobacco smoking leads to changes in hemodynamic parameters such as heart rate and systolic or diastolic blood pressure. It has a direct influence on the elasticity of blood vessels and increases arterial stiffness, which can result in development of atherosclerosis. Data show that the nicotine in tobacco smoke probably is responsible for these changes. Electronic cigarettes (e-cigarettes) were supposedly a healthier alternative to combustible cigarettes because they imitate a process of cigarettes smoking but generate nicotine aerosol without the toxic substances from tobacco combustion. However, the use of e-cigarettes is still controversial because their toxicity, safety and long term use health impact have not been sufficiently studied.
title: Effect of vitamin A and zinc on wound healing in steroid-treated mice.
title: Maternal smokeless tobacco use in Alaska Native women and singleton infant birth size.
abstract: To examine the effects of maternal prenatal smokeless tobacco use on infant birth size.
title: [Lesion of the urinary tracts in epidemic parotitis in children].
title: Oral contraceptive use and venous thromboembolism: absence of an effect of smoking.
abstract: We conducted a case-control study to test the hypothesis that women smokers who use oral contraceptives have an increased risk of developing venous thrombosis. Patients and controls were drawn from two sets of hospital patients already included in the Boston Collaborative Drug Surveillance Programme. Sixty patients with uncomplicated thromboembolism were matched with 180 controls with other diagnoses; all were premenopausal women taking oral contraceptives. Patients with conditions that might predispose to thromboembolism or be related to smoking were excluded. We found no association between smoking habits and thromboembolism. Similarly, we found no association between thromboembolism, smoking, and duration of oral contraceptive use. Thus we conclude that differences in fibrinolytic activity between smokers and non-smokers are not major factors in the aetiology of uncomplicated thromboembolism in women using oral contraceptives.
title: Prevention of growth of transplanted sarcoma in mice by vitamin C.
title: Screening practices and attitudes of obstetricians-gynecologists toward new and emerging tobacco products.
abstract: We examined screening practices and attitudes of obstetricians-gynecologists toward the use of noncombustible tobacco products (chewing tobacco, snuff/snus, electronic cigarettes, and dissolvables) during pregnancy.
title: Smoking status and nicotine administration differentially modify hemodynamic stress reactivity in men and women.
abstract: To investigate the impact of cigarette smoking and oral contraceptive (OC) use on hemodynamic stress responses of women. Also, to examine gender differences in stress reactivity as a function of smoking status and acute nicotine administration.
title: Clinical laboratory assessment of the abuse liability of an electronic cigarette.
abstract:   To provide an initial abuse liability assessment of an electronic cigarette (EC) in current tobacco cigarette smokers.
title: Adverse pregnancy outcomes in snuff users.
abstract: The purpose of the study was to evaluate the effects of smokeless tobacco use during pregnancy.
title: The RATIO study: oral contraceptives and the risk of peripheral arterial disease in young women.
abstract: With regard to oral contraceptives, much research has concentrated on venous thrombosis and on the coronary and cerebral forms of atherosclerotic disease, while peripheral arterial disease (PAD) has received little attention. In this case-control study, we assessed oral contraceptive use and the risk of PAD in young women using a population-based case-control study. The women were 18-49 years of age, and had been admitted to a collaborating hospital between January 1990 and October 1995, and had a diagnosis of PAD. Participants were patients with PAD (n = 152), and control women (n = 925), identified by random digit dialing. The diagnosis of PAD was based almost exclusively on intra-arterial angiography. Patients and control subjects filled out the same structured questionnaire, which included questions on medical history, cardiovascular risk factors, and contraceptive use. The adjusted odds ratio for PAD in women using any type of oral contraceptives vs. no use, was 3.8 (95% CI 2.4-5.8). When first generation oral contraceptive use was compared with no use, the odds ratio was 8.7 (95% CI 3.6-21.3). For second and third generation oral contraceptives, the adjusted odds ratios (compared with non-users) were 2.6 (95% CI 1.4-4.9) and 3.0 (95% CI 1.4-6.6), respectively. This is the first study on oral contraceptive use and PAD in humans. All types of oral contraceptives were associated with an increased risk of PAD.
title: Electronic cigarettes: effective nicotine delivery after acute administration.
abstract: Electronic cigarettes (ECs) are marketed as nicotine delivery devices. Two studies with EC-naïve participants suggest that ECs deliver little or no nicotine. In those studies, standard-sized ECs were used, though experienced EC users often use larger devices that house higher voltage and/or longer lasting batteries. Whether user experience and device characteristics influence EC nicotine delivery is uncertain. The purpose of the present study was to examine the effects of ECs in experienced users who were using their preferred devices.
title: Nicotine concentrations with electronic cigarette use: effects of sex and flavor.
abstract: This study examined overall changes in nicotine concentrations when using a popular e-cigarette and 18 mg/mL nicotine e-Juice, and it further explored effects of sex and flavorings on these concentrations.
title: Effects of using electronic cigarettes on nicotine delivery and cardiovascular function in comparison with regular cigarettes.
abstract: The development of electronic cigarettes (e-cigs) has the potential to offer a less harmful alternative for tobacco users. This clinical study was designed to characterize e-cig users' exposure to nicotine, and to investigate the acute effects of e-cigs on the hemodynamic measurements (blood pressure and heart rate) in comparison with the effects of regular smoking. Five e-cigs and one Marlboro® cigarette were randomized for twenty-three participants under two exposure scenarios from Day 1 to Day 11: half-hour controlled administration and one hour ad lib use. The nicotine plasma concentrations after 1.5h of product use (C90) were significantly lower in the users of e-cigs than of Marlboro® cigarettes. The combination of glycerin and propylene glycol as the vehicle facilitated delivery of more nicotine than glycerin alone. The heart rate, systolic and diastolic blood pressure were significantly elevated after use of Marlboro® cigarettes, but the elevation was less after use of most of the e-cigs. Use of e-cigs had no impact on the exhaled CO levels, whereas the Marlboro® cigarette significantly increased the exhaled CO more than 8 times above the baseline. In conclusion, e-cigs could be a less harmful alternative for tobacco users.