Steroidal contraceptives: effect on bone fractures in women

Medically induced amenorrhea in female astronauts

Medically induced amenorrhea can be achieved through alterations in the normal regulatory hormones via the adoption of a therapeutic agent, which prevents menstrual flow. Spaceflight-related advantages for medically induced amenorrhea differ according to the time point in the astronaut's training schedule. Pregnancy is contraindicated for many pre-flight training activities as well as spaceflight, therefore effective contraception is essential. In addition, the practicalities of menstruating during pre-flight training or spaceflight can be challenging. During long-duration missions, female astronauts have often continuously taken the combined oral contraceptive pill to induce amenorrhea. Long-acting reversible contraceptives (LARCs) are safe and reliable methods used to medically induce amenorrhea terrestrially but as of yet, not extensively used by female astronauts. If LARCs were used, daily compliance with an oral pill is not required and no upmass or trash would need disposal. Military studies have shown that high proportions of female personnel desire amenorrhea during deployment; better education has been recommended at recruitment to improve uptake and autonomous decision-making. Astronauts are exposed to similar austere conditions as military personnel and parallels can be drawn with these results. Offering female astronauts up-to-date, evidence-based, comprehensive education, in view of the environment in which they work, would empower them to make informed decisions regarding menstrual suppression while respecting their autonomy.

Oral contraceptive use and fracture risk around the menopausal transition

OBJECTIVE

The effect of oral contraceptive (OC) use on risk of fracture remains unclear, and use during later reproductive life may be increasing. To determine the association between OC use during later reproductive life and risk of fracture across the menopausal transition, we conducted a population-based case-control study in a Pacific Northwest HMO, Group Health Cooperative.

METHODS

For the January 2008 to March 2013 interval, 1,204 case women aged 45 to 59 years with incident fractures, and 2,275 control women were enrolled. Potential cases with fracture codes in automated data were adjudicated by electronic health record review. Potential control women without fracture codes were selected concurrently, sampling based on age. Participants received a structured study interview. Using logistic regression, associations between OC use and fracture risk were calculated as odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Participation was 69% for cases and 64% for controls. The study sample was 82% white; mean age was 54 years. The most common fracture site for cases was the wrist/forearm (32%). Adjusted fracture risk did not differ between cases versus controls for OC use in the 10 years before menopause (OR 0.90, 95% CI 0.74, 1.11); for OC use after age 38 (OR 0.94, 95% CI 0.78, 1.14); for duration of use, or for other OC exposures.

CONCLUSIONS

The current study does not show an association between fractures near the menopausal transition and OC use in the decade before menopause or after age 38. For women considering OC use at these times, fracture risk does not seem to be either reduced or-reassuringly-increased.

The state of hormonal contraception today: established and emerging noncontraceptive health benefits

In the 50 years since the advent of combined oral contraceptives the amount of estrogen in oral contraceptives dropped from over 100 mcg to less than 30 mcg. Many noncontraceptive health benefits have emerged that decrease mortality and improve quality of life. Some of the immediate benefits include improvement of menorrhagia and dysmenorrhea, reduction in premenstrual dysphoric disorder symptoms, and decreased acne. As an effective birth control method oral contraceptives also decrease pregnancy-related deaths by preventing pregnancy. After the reproductive years, previous use of oral contraceptives continues to be beneficial, reducing the risk of death from ovarian and endometrial cancer. All these benefits have held up over time whereas cardiovascular risks have lessened because of the decrease in oral contraceptive pill dosage. Decreased ovarian cyst formation is an example of benefit with higher-dose oral contraceptive formulations that no longer holds true with low-dose pills.

[Analgesic interventions for spinal diseases]

As a rule vertebroplasty and kyphoplasty can prevent further collapse of a previously broken vertebra. Pain is probably caused by collapse of the porous bone resulting in instability of the vertebra. Stabilization of the vertebra by injecting cement results in a clear improvement in the complaint and a clear reduction in pain resulting in better mobilization. Recent results have, however, cast doubt on the effectiveness of this therapy. Diagnostic nerve blocks on the spinal column are important because the pain is mostly clinically uncharacteristic, the innervation is complex and the pain is subjective. An exact classification can be made using special nerve blocks. Prerequisites for the use of diagnostic nerve blocks are an extensive clinical history and examination of the patient before nerve blocks are carried out. In approximately 15-45% of patients the zygapophyseal joint is the cause of the back pain. Anesthesia of the zygapophyseal joint can be carried out by direct intra-articular application of a local anesthetic or by a block of the medial branch of the posterior branch of each of two spinal nerves. The simplest method is by computed tomography-guided zygapophyseal block.

Oral contraceptive use and bone

Sex hormones play a key role in bone homeostasis, and oral contraceptive (OC) use may affect bone mass in women. However, the nature of the association between OC use and bone remains controversial. This paper critically reviews studies on OC use and bone published between January 2009 and August 2010. Studies of OC use and bone mass mainly focus on adolescents or young adults and showed mixed results. Weak evidence suggests that OC use has no effect or a beneficial effect on bone mass, except in women commencing OCs shortly after menarche, and a consistently negative effect on bone turnover markers. A limited number of studies have examined the effect of ultra-low-dose OC (20 μg ethinyl estradiol) on bone mass in adolescents or young adults, and present conflicting results. The lack of randomized trials indicates that further high-quality prospective studies are required to investigate the effect of OC use on bone mass, particularly the optimal dose and timing of initiation of OC use in adolescents requiring contraception.

Oral contraceptive use and bone density in adolescent and young adult women

BACKGROUND

Most of the millions of oral contraceptive (OC) users are under 30 years of age and in the critical period for bone mass accrual.

STUDY DESIGN

This cross-sectional study of 606 women aged 14-30 years examined both OC duration and estrogen dose and their association with bone mineral density (BMD) at the hip, spine, and whole body (dual-energy X-ray absorptiometry).

RESULTS

Of 389 OC users and 217 nonusers enrolled, 50% were adolescents (14-18 years). Of OC users, 38% used "low-dose" OCs [<30 mcg ethinyl estradiol (EE)]. In adolescents, mean BMD differed by neither OC duration nor EE dose. However, 19- to 30-year-old women's mean BMD was lower with longer OC use for spine and whole body (p=.004 and p=.02, respectively) and lowest for >12 months of low-dose OCs for the hip, spine and whole body (p=.02, .003 and .002, respectively).

CONCLUSIONS

Prolonged use of today's OCs, particularly <30 mcg EE, may adversely impact young adult women's bone density while using these agents.