Combined hormonal contraception and bone health: a systematic review

The Impact of Progesterone and Estrogen on the Tooth Mobility

Background and Objectives: Progesterone and estrogen modify the bone metabolism directly related to the periodontium, this study aimed at answering the question whether fluctuations in the levels of these hormones or the use of their synthetic equivalents in modern contraceptives have a significant impact on the natural tooth mobility (TM) in its alveolus. Materials and Methods: Sixty healthy women who had never been pregnant and when interviewed reported either (1) having regular menstruations every 28-30 days or (2) taking oral two-phase two-ingredient hormonal contraceptives formed, respectively, groups M and S in the study. TM evaluated as the Periotest value (PTV) was checked in the menstruation, ovulation, and luteal phases of the menstrual cycle (group M) and on the days corresponding to the moment of the menstrual cycle in group S. Results: Although the PTV-s were within the limits of norm, the canines and the molars were always more stable than the other teeth. In group M, the TM was statistically comparable (p > 0.05) in the menstrual and ovulation phases, thus significantly increased (p < 0.001) in the luteal phase. The TM remained constant (p = 0.758) in all studies in group S. The results demonstrated that the canines and the molars in the luteal phase were significantly more mobile in group M than in group S (p < 0.001), although increased mobility of the teeth in group M affected the canines and the first molars to a significantly lesser degree than the other teeth. Conclusions: However, since women between 20 and 30 years old constitute the majority of ortho-dontic patients, possible determination of the optimum moment of force application in relation to the sex hormones cycle, namely, to its luteal phase, is clinically very promising.

Bone health and hormonal contraception

INTRODUCTION

Short-term and long-term steroid contraceptive systems are widely employed in adolescents and premenopausal women; they could induce variation in bone metabolism, but whether these changes increase the overall fracture risk is not yet clear.

EVIDENCE ACQUISITION

A systematic search of scientific publications about "hormonal contraceptives" and "bone metabolism" in reproductive age women was conducted.

EVIDENCE SYNTHESIS

In adolescent girl, combined oral contraceptives could have a deleterious effect on bone health when their onset is within three years after menarche and when they contain ethinyl estradiol at the dose of 20 mcg. In perimenopausal women, steroid contraceptives seem not influence bone health nor increase osteoporotic fractures risk in menopause. The oral progestogens intake is not related to negative effects on skeletal health. Depot medroxyprogesterone acetate (DMPA) induce a prolonged hypoestrogenism with secondary detrimental effect on healthy bone; the higher bone loss was observed at the DMPA dose of 150 mg intramuscular such as after long-term DMPA-users. Progestin-based implants and intrauterine devices have not negative effect on bone health.

CONCLUSIONS

Since sex-steroid drugs induce variations in hormonal circulating concentrations, they may negatively affect bone metabolism. Contraceptive choice should be tailored evaluating any possible effect on bone health. Clinicians should always perform a precontraceptive counselling to identify any coexisting condition that may affect bone health. Further randomized studies are needed to confirm these results.

Physiological Characteristics of Female Soccer Players and Health and Performance Considerations: A Narrative Review

Female soccer has seen a substantial rise in participation, as well as increased financial support from governing bodies over the last decade. Thus, there is an onus on researchers and medical departments to develop a better understanding of the physical characteristics and demands, and the health and performance needs of female soccer players. In this review, we discuss the current research, as well as the knowledge gaps, of six major topics: physical demands, talent identification, body composition, injury risk and prevention, health and nutrition. Data on female talent identification are scarce, and future studies need to elucidate the influence of relative age and maturation selection across age groups. Regarding the physical demands, more research is needed on the pattern of high-intensity sprinting during matches and the contribution of soccer-specific movements. Injuries are not uncommon in female soccer players, but targeting intrinsically modifiable factors with injury prevention programmes can reduce injury rates. The anthropometric and physical characteristics of female players are heterogeneous and setting specific targets should be discouraged in youth and sub-elite players. Menstrual cycle phase may influence performance and injury risk; however, there are few studies in soccer players. Nutrition plays a critical role in health and performance and ensuring adequate energy intake remains a priority. Despite recent progress, there is considerably less research in female than male soccer players. Many gaps in our understanding of how best to develop and manage the health and performance of female soccer players remain.

Depot Medroxyprogesterone Acetate Use and Blood Lead Levels in a Cohort of Young Women

BACKGROUND

Injectable contraceptive use is common, with 74 million users worldwide. Use of the injectable contraceptive depot medroxyprogesterone acetate (DMPA) is associated with bone mineral density loss. We hypothesize that increased bone resorption with DMPA use allows for mobilization of the toxic metal lead stored in bone to blood, presenting users with increased systemic exposure to lead.

OBJECTIVE

The objective of our study was to investigate the association between current DMPA use and blood lead concentrations.

METHODS

We conducted a cross-sectional analysis using enrollment data from the Study of Environment, Lifestyle & Fibroids (SELF), a cohort of 1,693 African-American women who were 23-35 years of age. Data on DMPA use were collected by computer-assisted telephone interview. Blood lead concentrations were measured in whole blood samples among 1,548 participants (91% of cohort). We estimated the adjusted percent difference in blood lead concentrations and 95% confidence intervals (CI) between current DMPA users and nonusers using multivariable linear regression.

RESULTS

Geometric mean blood lead concentration was 0.69 μ g / dL (95% CI: 0.67, 0.71). After adjustment, current DMPA users (7% of cohort) had blood lead concentrations that were 18% higher than those of nonusers (95% CI: 8%, 29%). Similar associations were observed with additional analyses to assess for potential bias from smoking, DMPA-induced amenorrhea, use of estrogen-containing contraceptives, having given birth in the prior year, and history of medical conditions or current medication use associated with bone loss.

DISCUSSION

Our results indicate that current DMPA use is associated with increased blood lead concentrations. Further research, particularly in populations highly exposed to lead, is warranted to consider tradeoffs between the adverse effects of lead on human health and the importance of DMPA as a contraceptive option to prevent unintended pregnancy. https://doi.org/10.1289/EHP7017.

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.

Steroidal contraceptives and bone fractures in women: evidence from observational studies

BACKGROUND

Age-related decline in bone mass increases the risk of skeletal fractures, especially those of the hip, spine, and wrist. Steroidal contraceptives have been associated with changes in bone mineral density in women. Whether such changes affect the risk of fractures later in life is unclear. Hormonal contraceptives are among the most effective and most widely-used contraceptives. Concern about fractures may limit the use of these effective contraceptives. Observational studies can collect data on premenopausal contraceptive use as well as fracture incidence later in life.

OBJECTIVES

We systematically reviewed the evidence from observational studies of hormonal contraceptive use for contraception and the risk of fracture in women.

SEARCH METHODS

Through June 2015, we searched for observational studies. The databases included PubMed, POPLINE, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS, EMBASE, CINAHL, and Web of Science. We also searched for recent clinical trials through ClinicalTrials.gov and the ICTRP. For other studies, we examined reference lists of relevant articles and wrote to investigators for additional reports.

SELECTION CRITERIA

We included cohort and case-control studies of hormonal contraceptive use. Interventions included comparisons of a hormonal contraceptive with a non-hormonal contraceptive, no contraceptive, or another hormonal contraceptive. The primary outcome was the risk of fracture.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. One author entered the data into RevMan, and a second author verified accuracy. We examined the quality of evidence using the Newcastle-Ottawa Quality Assessment Scale (NOS), developed for case-control and cohort studies. Sensitivity analysis included studies of moderate or high quality based on our assessment with the NOS.Given the need to control for confounding factors in observational studies, we used adjusted estimates from the models as reported by the authors. Where we did not have adjusted analyses, we calculated the odds ratio (OR) with 95% confidence interval (CI). Due to varied study designs, we did not conduct meta-analysis.

MAIN RESULTS

We included 14 studies (7 case-control and 7 cohort studies). These examined oral contraceptives (OCs), depot medroxyprogesterone acetate (DMPA), and the hormonal intrauterine device (IUD). This section focuses on the sensitivity analysis with six studies that provided moderate or high quality evidence.All six studies examined oral contraceptive use. We noted few associations with fracture risk. One cohort study reported OC ever-users had increased risk for all fractures (RR 1.20, 95% CI 1.08 to 1.34). However, a case-control study with later data from a subset reported no association except for those with 10 years or more since use (OR 1.55, 95% CI 1.03 to 2.33). Another case-control study reported increased risk only for those who had 10 or more prescriptions (OR 1.09, 95% CI 1.03 to 1.16). A cohort study of postmenopausal women found no increased fracture risk for OC use after excluding women with prior fracture. Two other studies found little evidence of association between OC use and fracture risk. A cohort study noted increased risk for subgroups, such as those with longer use or specific intervals since use. A case-control study reported increased risk for any fracture only among young women with less than average use.Two case-control studies also examined progestin-only contraceptives. One reported increased fracture risk for DMPA ever-use (OR 1.44, 95% CI 1.01 to 2.06), more than four years of use (OR 2.16, 95% CI 1.32 to 3.53), and women over 50 years old. The other reported increased risk for any past use, including one or two prescriptions (OR 1.17, 95% CI 1.07 to 1.29) and for current use of 3 to 9 prescriptions (OR 1.36, 95% CI 1.15 to 1.60) or 10 or more (OR 1.54, 95% CI 1.33 to 1.78). For the levonorgestrel-releasing IUD, one study reported reduced fracture risk for ever-use (OR 0.75, 95% CI 0.64 to 0.87) and for longer use.

AUTHORS' CONCLUSIONS

Observational studies do not indicate an overall association between oral contraceptive use and fracture risk. Some reported increased risk for specific user subgroups. DMPA users may have an increased fracture risk. One study indicated hormonal IUD use may be associated with decreased risk. Observational studies need adjusted analysis because the comparison groups usually differ. Investigators should be clear about the variables examined in multivariate analysis.

The associations of exposure to combined hormonal contraceptive use on bone mineral content and areal bone mineral density accrual from adolescence to young adulthood: A longitudinal study

Background

The association of long term combined hormone based contraceptives (CHC) use on bone mineral content (BMC) and areal bone mineral density (aBMD) development remains controversial, as it appears that the relationship may be age-dependent. The purpose of this study was to investigate the long-term associations of CHC exposure on the accrual of bone parameters from adolescence into young-adulthood.

Methods

110 women (67 exposed to CHC) were drawn from the Pediatric Bone Mineral Accrual Study (PBMAS). Serial measures of total body (TB), lumbar spine (LS) and femoral neck (FN) BMC and aBMD were assessed by DXA (a total of 950 scans) and aligned by biological age (BA, years from peak height velocity [PHV]). Multilevel random effects models were constructed to assess the time dependent associations between annual CHC exposure and the development of bone parameters.

Results

After BA, height, lean tissue mass, fat mass, calcium and vitamin D intake, and physical activity were controlled, it was observed that those individuals exposed to CHC 6-years post PHV developed significantly less (−0.00986 ± 0.00422 g/cm²) TB aBMD than their non CHC exposed peers. Additionally, there were significant BA by CHC exposure interactions, where CHC exposure 6-years or more post PHV resulted in developing less TB BMC (−4.94 ± 2.41 g), LS BMC (−0.29 ± 0.11 g) and LS aBMD (−0.00307 ± 0.00109 g/cm²). One year after the attainment of PHV, CHC users were predicted to have 1.2% more TB BMC, 3.8% more LS BMC and 1.7% more LS aBMD than non-users. At 9-years post PHV the predicted differences showed that CHC users had 0.9% less TB BMC and 2.7% less LS BMC and 1.6% less LS BMD than those not exposed to CHC.

Conclusions

CHC may not hinder the development of BMC or aBMD during adolescence; however, exposure 6-years or more after PHV may be detrimental.

•

The effects of combined hormone contraceptive (CHC) exposure on bone mass were assessed.

•

CHC exposure resulted in developing significantly less (− 9.86 ± 4.22 g/cm²) TB aBMD.

•

CHC exposure 6-years after PHV resulted in significantly less BMC and aBMD.

•

CHC may not hinder adolescent bone development, but may be detrimental after growth.

Low-dose combined oral contraceptive use is associated with lower bone mineral content variation in adolescents over a 1-year period

BACKGROUND

Low-dose combined oral contraceptives (COCs) can interfere with bone mass acquisition during adolescence. This study aimed to evaluate bone mineral density (BMD) and bone mineral content (BMC) in female adolescents taking a standard low-dose COC (ethinylestradiol 20 μg/desogestrel 150 μg) over a 1-year period and to compare their data with those of healthy adolescents from the same age group not taking COCs.

METHODS

This was a non-randomized parallel-control study with a 1-year follow-up. Sixty-seven adolescents aged from 12 to 19 years, divided into COC users (n = 41) taking 20 μg ethinylestradiol/150 μg desogestrel and COC non-user controls (n = 26), were evaluated by bone densitometry examinations at baseline and after 12 months. Comparisons between the groups at the study onset were performed using the Mann-Whitney test with the significance level fixed at 5% or p < 0.05. Comparisons between the groups at the study onset and after 12 months were based on variations in the median percentages for bone mass variables.

RESULTS

The COC users presented with low bone mass acquisition in the lumbar spine, and had BMD and BMC median variations of 2.07% and +1.57%, respectively, between the measurements at baseline and 12 months. The control group had median variations of +12.16% and +16.84% for BMD and BMC, respectively, over the same period. The total body BMD and BMC showed similar evolutions during the study in both groups. Statistical significance (p < 0.05) was seen for the BMC percentage variation between COC users and non-users.

CONCLUSIONS

Use of a low-dose COC (ethinylestradiol 20 μg/desogestrel 150 μg) was associated with lower bone mass acquisition in adolescents during the study period.

TRIAL REGISTRATION

Registry Number, RBR-5h9b3c.

Disordered eating, menstrual irregularity, and musculoskeletal injury in high school athletes: a comparison of oral contraceptive pill users and nonusers

BACKGROUND

The female athlete triad is the interrelatedness of energy availability, menstrual function, and bone density. Currently, limited information about triad components and their relationship to musculoskeletal injury in the high school population exists. In addition, no study has specifically examined triad components and injury rate in high school oral contraceptive pill (OCP) users.

HYPOTHESIS

To compare the prevalence of disordered eating (DE), menstrual irregularity (MI), and musculoskeletal injury (INJ) among high school female athletes in OCP users and non-OCP users.

STUDY DESIGN

Retrospective cohort study.

LEVEL OF EVIDENCE

Level 2.

METHODS

The subject sample completed the Eating Disorder Examination-Questionnaire (EDE-Q) and Healthy Wisconsin High School Female Athletes Survey (HWHSFAS). Athletes were classified by OCP use and sport type.

RESULTS

Of the participants, 14.8% reported OCP use. There was no difference in MI and INJ among groups. The prevalence of DE was significantly higher among OCP users as compared with non-OCP users; OCP users were twice as likely to meet the criteria for DE (odds ratio [OR], 2.47; 95% confidence interval [CI], 1.20-5.09). OCP users were over 5 times more likely to have a global score that met criteria for DE as compared with non-OCP users (OR, 5.36; 95% CI, 1.92-14.89).

CONCLUSION

Although MI and INJ rates are similar among groups, there is a higher prevalence of DE among high school female athletes using OCPs as compared with non-OCP users.

CLINICAL RELEVANCE

Because OCP users may be menstruating, clinicians may fail to recognize the other triad components. However, DE exists in the menstruating OCP user. As such, clinicians should be vigilant when screening for triad components in high school OCP users, particularly DE.

The combined oral contraceptive pill -- recent developments, risks and benefits

The introduction of the birth control pill as an effective, coitally-independent method of contraception was a public health milestone of the last century. Over time, combined oral contraception (COC) formulations and pill-taking regimens have evolved with improved safety and tolerability while maintaining contraceptive efficacy. In addition to protection against pregnancy, use of combined oral contraception confers a number of significant non-contraceptive benefits to users. COC use is also associated with well-studied risks. Common side effects are generally self-limiting and improve with increasing duration of use while serious adverse events, including venous thromboembolism, are rare among healthy COC users. Contraceptive decision-making should include consideration of both the risks and benefits of a given method versus the real consequences of unintended pregnancy.

Steroidal contraceptives: effect on bone fractures in women

BACKGROUND

Steroidal contraceptive use has been associated with changes in bone mineral density in women. Whether such changes increase the risk of fractures later in life is not clear. Osteoporosis is a major public health concern. Age-related decline in bone mass increases the risk of fracture, especially of the spine, hip, and wrist. Concern about bone health influences the recommendation and use of these effective contraceptives globally.

OBJECTIVES

Our aim was to evaluate the effect of using hormonal contraceptives before menopause on the risk of fracture in women.

SEARCH METHODS

Through April 2014, we searched for studies of fracture or bone health and hormonal contraceptives in MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS, as well as ClinicalTrials.gov and ICTRP. We examined reference lists of relevant articles for other trials. For the initial review, we wrote to investigators to find additional trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) were considered if they examined fractures, bone mineral density (BMD), or bone turnover markers in women with hormonal contraceptive use prior to menopause. Eligible interventions included comparisons of a hormonal contraceptive with a placebo or with another hormonal contraceptive that differed in terms of drug, dosage, or regimen. They also included providing a supplement to one group.

DATA COLLECTION AND ANALYSIS

We assessed all titles and abstracts identified through the literature searches. Mean differences were computed using the inverse variance approach. For dichotomous outcomes, the Mantel-Haenszel odds ratio (OR) was calculated. Both included the 95% confidence interval (CI) and used a fixed-effect model. Due to differing interventions, no trials could be combined for meta-analysis. We applied principles from GRADE to assess the evidence quality and address confidence in the effect estimates. In addition, a sensitivity analysis included trials that provided sufficient data for this review and evidence of at least moderate quality.

MAIN RESULTS

We found 19 RCTs that met our eligibility criteria. Eleven trials compared different combined oral contraceptives (COCs) or regimens of COCs; five examined an injectable versus another injectable, implant, or IUD; two studied implants, and one compared the transdermal patch versus the vaginal ring. No trial had fracture as an outcome. BMD was measured in 17 studies and 12 trials assessed biochemical markers of bone turnover. Depot medroxyprogesterone acetate (DMPA) was associated with decreased bone mineral density (BMD). The placebo-controlled trials showed BMD increases for DMPA plus estrogen supplement and decreases for DMPA plus placebo supplement. COCs did not appear to negatively affect BMD, and some formulations had more positive effects than others. However, no COC trial was placebo-controlled. Where studies showed differences between groups in bone turnover markers, the results were generally consistent with those for BMD. For implants, the single-rod etonogestrel group showed a greater BMD decrease versus the two-rod levonorgestrel group but results were not consistent across all implant comparisons.The sensitivity analysis included 11 trials providing evidence of moderate or high quality. Four trials involving DMPA showed some positive effects of an estrogen supplement on BMD, a negative effect of DMPA-subcutaneous on lumbar spine BMD, and a negative effect of DMPA on a bone formation marker. Of the three COC trials, one had a BMD decrease for the group with gestodene plus EE 15 μg. Another indicated less bone resorption in the group with gestodene plus EE 30 μg versus EE 20 μg.

AUTHORS' CONCLUSIONS

Whether steroidal contraceptives influence fracture risk cannot be determined from existing information. The evidence quality was considered moderate overall, largely due to the trials of DMPA, implants, and the patch versus ring. The COC evidence varied in quality but was low overall. Many trials had small numbers of participants and some had large losses. Health care providers and women should consider the costs and benefits of these effective contraceptives. For example, injectable contraceptives and implants provide effective, long-term birth control yet do not involve a daily regimen. Progestin-only contraceptives are considered appropriate for women who should avoid estrogen due to medical conditions.

Menstrual suppression in the adolescent

Menstrual suppression, the use of contraceptive methods to eliminate or decrease the frequency of menses, is often prescribed for adolescents to treat menstrual disorders or to accommodate patient preference. For young women using hormonal contraceptives, there is no medical indication for menstruation to occur monthly, and various hormonal contraceptives can be used to decrease the frequency of menstruation with different side effect profiles and rates of amenorrhea. This article reviews the different modalities for menstrual suppression, common conditions in adolescents which may improve with menstrual suppression, and strategies for managing common side effects.

PCOS: perspectives from a pediatric endocrinologist and a pediatric gynecologist

Polycystic ovary syndrome is the most common endocrinopathy recognized in women of childbearing age with a prevalence of 4-12%. The prevalence of the disorder in adolescent population is poorly defined. The pathogenesis as well as the management of this disorder is widely debated.

Steroidal contraceptives and bone fractures in women: evidence from observational studies

BACKGROUND

Age-related decline in bone mass increases the risk of skeletal fractures, especially those of the hip, spine, and wrist. Steroidal contraceptives have been associated with changes in bone mineral density in women. Whether such changes affect the risk of fractures later in life is unclear. Hormonal contraceptives are among the most effective and most widely-used contraceptives. Concern about fractures may limit the use of these effective contraceptives. Observational studies can collect data on premenopausal contraceptive use as well as fracture incidence later in life.

OBJECTIVES

We systematically reviewed the evidence from observational studies of hormonal contraceptive use for contraception and the risk of fracture in women.

SEARCH METHODS

In May 2012, we searched for observational studies. The databases included MEDLINE, POPLINE, Cochrane Central Register of Controlled Trials (CENTRAL), LILACS, EMBASE, CINAHL, and Web of Science. We also searched for recent clinical trials through ClinicalTrials.gov and the ICTRP. For other studies, we examined reference lists of relevant articles and wrote to investigators for additional reports.

SELECTION CRITERIA

We included cohort and case-control studies of hormonal contraceptive use. Interventions included comparisons of a hormonal contraceptive with a nonhormonal contraceptive, no contraceptive, or another hormonal contraceptive. The primary outcome was the risk of fracture.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data. One author entered the data into RevMan, and a second author verified accuracy. We examined the quality of evidence using the Newcastle-Ottawa Quality Assessment Scale (NOS), developed for case-control and cohort studies. Sensitivity analysis included studies of moderate or high quality based on our assessment with the NOS.Given the need to control for confounding factors in observational studies, we used adjusted estimates from the models as reported by the authors. Where we did not have adjusted analyses, we calculated the odds ratio (OR) with 95% confidence interval (CI). Due to varied study designs, we did not conduct meta-analysis.

MAIN RESULTS

We included 14 studies (7 case-control and 7 cohort studies). These examined oral contraceptives (OCs) (N=12), depot medroxyprogesterone acetate (DMPA) (N=4), and the hormonal intrauterine device (IUD) (N=1). This section focuses on evidence from the six studies with moderate or high quality evidence that we included in the sensitivity analysis.All six studies examined oral contraceptive use. We noted few associations with fracture risk. One cohort study found OC ever-users had increased risk for all fractures (reported RR 1.20; 95% CI 1.08 to 1.34). However, a case-control study with later data from a subset reported no association except for those with 10 years or more since use (reported OR 1.55; 95% CI 1.03 to 2.33). Another case-control study reported increased risk only for those who had 10 or more prescriptions (reported OR 1.09; 95% CI 1.03 to 1.16). A cohort study of postmenopausal women found no increased fracture risk for OC use after excluding women with prior fracture. Two other studies found little evidence of association between OC use and fracture risk. A cohort study noted increased risk for subgroups, such as those with longer use or specific intervals since use. A case-control study reported increased risk for any fracture only among young women with less than average use.Two case-control studies in the sensitivity analysis also examined progestin-only contraceptives. One reported increased fracture risk for DMPA ever-use (reported OR 1.44 (95% CI 1.01 to 2.06), more than four years of use (reported OR 2.16; 95% CI 1.32 to 3.53), and women over 50 years old. The other noted increased risk for any past use, including one or two prescriptions (reported OR 1.17; 95% CI 1.07 to 1.29), and for current use of 3 to 9 or 10 or more prescriptions. In addition, one study reported reduced fracture risk for ever-use of the hormonal IUD (reported OR 0.75; 95% CI 0.64 to 0.87) and longer use of that IUD.

AUTHORS' CONCLUSIONS

Observational studies do not indicate an overall association between OC use and fracture risk. Some reported increased risk for specific user subgroups. DMPA users may have an increased fracture risk. One study indicated hormonal IUD use may be associated with decreased risk. Observational studies need adjusted analysis because the comparison groups usually differ. Researchers should be clear about the variables examined in multivariate analysis.

Combined oral contraceptives' influence on weight, body composition, height, and bone mineral density in girls younger than 18 years: a systematic review

OBJECTIVE

Combined oral contraceptives (COCs) are increasingly used by adolescents. The aim of this review is to investigate the evidence regarding COCs' influence on weight, height and bone mineral density (BMD) in girls younger than 18 years.

METHOD

Systematic literature search using PubMed/Medline and Scopus (January 1990-February 2012) on COCs for girls under 18 years of age and the possible influence on body parameters. MeSH terms: Oral contraception; Adolescent; Weight; Body composition; Height; Bone mineral density.

RESULTS

There is no evidence that COCs induce weight gain in girls younger than 18 years. Obese girls are not at higher risk of gaining weight. COCs do not cause changes in body fat and lean mass beyond the changes caused by natural development. Moreover, growth and stature are unaffected. Few studies indicate that COCs have a negative impact on BMD, but the evidence is presently too limited for definite conclusions.

CONCLUSION

Studies in young users are few. Presently, there are no indications of a negative impact of COCs on weight, body composition or height. Lesser increases in BMD cannot be excluded. As the demand for COCs is increasing among the youngest girls, there is a need for prospective studies addressing this issue.

Effect of two kinds of different combined oral contraceptives use on bone mineral density in adolescent women

BACKGROUND

Steroid hormonal contraceptives are highly effective and widely used. Most studies have shown a negative effect of combined oral contraceptives (COCs) on the bone mineral density (BMD) of adolescents. The study was conducted to compare BMD among users of ethinylestradiol/desogestrel, users of ethinylestradiol/cyproterone acetate and nonhormonal control subjects in women aged 16-18 years.

STUDY DESIGN

The study included 450 women 16-18 years of age. One hundred fifty women were using ethinylestradiol/desogestrel, 150 women were using ethinylestradiol/cyproterone acetate, and 150 women were using nonhormonal contraception as control subjects. BMD ofthe lumbar spine and femoral neck was obtained using dual-energy X-ray absorptiometry, and mean BMD changes in COCs users and nonusers were compared.

RESULTS

At 24 months of treatment, lumbar spine and femoral neck mean BMD values in women (n=127) who used ethinylestradiol/desogestrel were slightly lower compared with baseline, but these effects did not reach statistical significance (p=.837 and p=.630, respectively). The mean lumbar spine and femoral neck BMD values in women (n=134) who used ethinylestradiol/cyproterone acetate were slightly higher compared with baseline, but there was no statistical significance (p=.789 and p=.756, respectively). The increases in mean percent change in lumbar spine and femoral neck BMD in the ethinylestradiol/cyproterone acetate group were less than those in the control group (1.88% vs. 0.30% and 0.98% vs. 0.49%, respectively). There were no significant differences in mean BMD of the lumbar spine and femoral neck between the users of ethinylestradiol/desogestrel or ethinylestradiol/cyproterone acetate and nonusers (p>.05).

CONCLUSION

Our study indicates that 2 years of COCs therapy had no significant effect on bone density in adolescents, but it remains unknown whether therapy longer than 2 years has a significant adverse effect on the attainment of peak bone mass.

Noncontraceptive uses of hormonal contraception

Hormonal contraceptives are not only effective methods of birth control but also are effective at treating and/or preventing a variety of gynecologic and general disorders. Hormonal contraceptives can decrease the severity of acne, correct menstrual irregularities, treat endometriosis-associated pain, decrease bleeding associated with uterine myomas, decrease pain associated with menstrual periods, moderate symptoms associated with premenstrual syndrome, reduce menstrual migraine frequency, and increase bone mineral density as well as decrease the risk of specific cancers such as endometrial and ovarian cancer. Women need to receive this information to guide them in their decisions regarding choice of contraception as well as treatment options for gynecologic disorders.

Steroidal contraceptives: effect on bone fractures in women

BACKGROUND

Steroidal contraceptive use has been associated with changes in bone mineral density in women. Whether such changes increase the risk of fractures later in life is not clear. Osteoporosis is a major public health concern. Age-related decline in bone mass increases the risk of fracture, especially of the spine, hip, and wrist. Concern about bone health influences the recommendation and use of these effective contraceptives globally.

OBJECTIVES

To evaluate the effect of using hormonal contraceptives before menopause on the risk of fracture in women

SEARCH STRATEGY

We searched for studies of fracture or bone health and hormonal contraceptives in MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS, as well as ClinicalTrials.gov and ICTRP. We wrote to investigators to find additional trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) were considered if they examined fractures, bone mineral density (BMD), or bone turnover in women with hormonal contraceptive use prior to menopause. Interventions could include comparing a hormonal contraceptive with a placebo or another hormonal contraceptive or could compare providing a supplement versus a placebo.

DATA COLLECTION AND ANALYSIS

We assessed all titles and abstracts identified through the literature searches. Mean differences were computed using the inverse variance approach. For dichotomous outcomes, the Mantel-Haenszel odds ratio (OR) was calculated. Both included the 95% confidence interval (CI) and used a fixed-effect model. Due to different interventions, no trials could be combined for meta-analysis.

MAIN RESULTS

Of the 16 RCTs we found, 2 used a placebo and 1 used a non-hormonal method as the comparison, while 13 compared two hormonal contraceptives. No trial had fracture as an outcome. Most measured BMD and several assessed bone turnover. Depot medroxyprogesterone acetate (DMPA) was associated with decreased bone mineral density. The placebo-controlled trials showed BMD increases for DMPA plus estrogen supplement and decreases for DMPA plus placebo. Combination contraceptives did not appear to negatively affect bone health, but none were placebo-controlled. For implants, the single-rod etonogestrel group showed a greater BMD decrease versus the two-rod levonorgestrel group. However, results were not consistent across all implant comparisons.

AUTHORS' CONCLUSIONS

Whether steroidal contraceptives influence fracture risk cannot be determined from existing information. Many trials had small numbers of participants and some had large losses to follow up. Health care providers and women should consider the costs and benefits of these effective contraceptives. For example, injectable contraceptives and implants provide effective, long-term birth control yet do not involve a daily regimen. Progestin-only contraceptives are considered appropriate for women who should avoid estrogen due to medical conditions.

Update on hormonal contraception and bone density

Combination hormonal contraception and progestin-only contraception (including depot medroxyprogesterone acetate [DMPA]) are effective and convenient forms of reversible contraception that millions of women use worldwide. In recent years, observations of reduced bone mineral density in current users of these methods have led to concerns that this hormone-induced bone loss might translate into long-term increased fracture risk. Special focus has been placed on adolescent users who have not yet attained their peak bone mass as well as perimenopausal users. In 2004, the FDA added a black box warning to DMPA package labeling warning of the risk of significant bone loss and cautioning against long-term use (> 2 years). This article reviews evidence on the use of hormonal contraception and its effect on bone density in adolescent, premenopausal, and perimenopausal populations. Recommendations from reproductive healthcare organizations are reviewed and clinical recommendations are provided.

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 mass in women aged 26-36 years

INTRODUCTION

The association between hormonal contraceptive use and bone mineral density remains controversial.

HYPOTHESIS

Hormonal contraceptive use is positively associated with bone mass in young premenopausal women.

METHODS

Cross-sectional analysis of data collected from women aged 26-36 years (n = 687) in the Childhood Determinants of Adult Health study-a longitudinal study investigating childhood determinants of cardiovascular disease, diabetes, and other chronic diseases in adulthood. Participants were not currently pregnant or breast-feeding. Contraceptive use was obtained by self-administered questionnaire. Women were categorized as combined oral contraceptive users (n = 219), progestogen-only contraceptive users (n = 43), and non-users of hormonal contraceptives (n = 425). Bone mass was measured by quantitative ultrasound.

RESULTS

Compared with women who were not using any hormonal contraceptives, women using combined oral contraceptives had significantly higher values of broadband ultrasound attenuation (BUA), speed of sound, and quantitative ultrasound index. These associations remained after adjustment for confounders. Progestogen-only contraceptive users had higher BUA than non-users, but the differences were not statistically significant in this small group.

CONCLUSION

Combined oral contraceptive use was associated with higher bone mass measured by quantitative ultrasound in this population-based sample of premenopausal women aged 26-36 while progestogen-only contraceptives appeared to have no deleterious effect on bone mass.

Examining the efficacy, safety, and patient acceptability of the combined contraceptive vaginal ring (NuvaRing)

The contraceptive vaginal ring is a novel contraceptive method that offers unique advantages. Intravaginal delivery of both estrogen and progesterone allows continuous release of medication, resulting in lower systemic levels. The use of long-term combined hormonal contraception enables improved cycle control compared with progesterone-only methods. The indications and usage of the NuvaRing^® are described along with the efficacy, tolerability, and safety. Overall, the contraceptive vaginal ring appears to be very effective, with a favorable side-effect profile, and is highly acceptable to most patients.

Recent advances in hormonal contraception

This report reviews some of the new studies regarding new hormonal contraceptive formulations (e.g., Yaz, Qlaira^®, extended-cycle or continuous combined contraceptives, subcutaneous depot medroxyprogesterone acetate, and ulipristal acetate as an emergency contraceptive). Recent data on the relationship between hormonal contraceptive use and bone health are also reviewed.

The effects of hormonal contraceptives on bone turnover markers and bone health

Sex hormones are important regulators of bone metabolism. As hormonal contraceptives contain either oestrogens or progestins, or a combination thereof, it is conceivable that these widely used agents have an effect on bone metabolism and bone health. The main users of hormonal contraceptives, adolescent girls and young women, are still building bone and accruing bone mass and may therefore be particularly susceptible to the effects of hormonal contraceptives on bone. Despite these concerns, the effects of hormonal contraceptives on bone health are still poorly understood. As biochemical markers of bone turnover have been proven useful tools in the assessment and monitoring of bone metabolism, we reviewed the effects of combined and gestagen-only hormonal contraceptives on bone turnover markers and related effects on bone mineral density and fracture risk in premenopausal women, as documented in the literature until January 2009.

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.

Steroidal contraceptives: effect on bone fractures in women

BACKGROUND

Steroidal contraceptive use has been associated with changes in bone mineral density in women. Whether such changes increase the risk of fractures later in life is not clear. However, osteoporosis is a major public health concern. Age-related decline in bone mass increases the risk of fracture, especially of the spine, hip, and wrist. Concern about bone health influences the recommendation and use of these effective contraceptives globally.

OBJECTIVES

To evaluate the effect of using hormonal contraceptives before menopause on the risk of fracture in women

SEARCH STRATEGY

We searched for studies of fracture or bone health and hormonal contraceptives in MEDLINE, POPLINE, CENTRAL, EMBASE, and LILACS, as well as in clinical trials databases (ClinicalTrials.gov and ICTRP). We wrote to investigators to find additional trials.

SELECTION CRITERIA

Randomized controlled trials were considered if they examined fractures, bone mineral density (BMD), or bone turnover in women with hormonal contraceptive use prior to menopause. Studies were excluded if hormones were provided for treatment of a specific condition rather than for contraception. Interventions could include comparisons of a hormonal contraceptive with a placebo or with another hormonal contraceptive. Interventions could also include the provision of a supplement versus a placebo.

DATA COLLECTION AND ANALYSIS

We assessed for inclusion all titles and abstracts identified through the literature searches with no language limitation. The mean difference was computed with 95% confidence interval (CI) using a fixed-effect model.

MAIN RESULTS

We found 13 RCTs, 2 of which used a placebo. No trial had fracture as an outcome but most measured BMD. Combination contraceptives did not appear to affect bone health. Of progestin-only methods, depot medroxyprogesterone acetate (DMPA) was associated with decreased bone mineral density, while results were inconsistent for implants. The two placebo-controlled trials showed BMD increases for DMPA plus estrogen supplement and decreases for DMPA plus placebo.

AUTHORS' CONCLUSIONS

Whether steroidal contraceptives influence fracture risk cannot be determined from existing information. Due to different interventions, no trials could be combined for meta-analysis. Many trials had small numbers of participants and some had large losses to follow up. Health care providers and women should consider the costs and benefits of these effective contraceptives. For example, injectable contraceptives and implants provide effective, long-term birth control yet do not involve a daily regimen. Progestin-only contraceptives are considered appropriate for women who should avoid estrogen due to medical conditions.

Bone mineral density in young women aged 19-24 after 4-5 years of exclusive and mixed use of hormonal contraception

BACKGROUND

Use of depot-medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN) and low-dose combined oral contraceptives (COCs) has been associated with loss of bone mineral density (BMD) in adolescents. However, the effect of using a combination of these methods over time in this age group is limited. The aim of this cross-sectional study was to investigate BMD in young women (aged 19-24 years) with a history of mixed hormonal contraceptive use.

STUDY DESIGN

BMD was measured at the spine, hip and femoral neck using dual X-ray absorptiometry. Women were classified into three groups: (1) injectable users (DMPA, NET-EN or both) (n=40), (2) mixed COC and injectable users (n=13) and (3) non-user control (n=41).

RESULTS

Women in the injectables-only user group were found to have lower BMDs compared to the non-user group at all three sites, and there was evidence of a difference in BMD between these two groups at the spine after adjusting for body mass index (p=.042), hip (p=.025) and femoral neck (p=.023). The mixed COC/injectable user group BMD values were lower than those for controls; however, there was no evidence of a significant difference between this group and the non-user group at any of the three sites.

CONCLUSION

This study suggests that BMD is lower in long-term injectable users but not when women have mixed injectable and COC use.

Bone mineral density in a cohort of adolescents during use of norethisterone enanthate, depot-medroxyprogesterone acetate or combined oral contraceptives and after discontinuation of norethisterone enanthate

BACKGROUND

Depot medroxyprogesterone acetate (DMPA), norethisterone enanthate (NET-EN) and combined oral contraceptives (COCs) have been shown to have a negative effect on bone mineral density (BMD) in adolescents. The aim of this study was to investigate BMD in 15- to 19-year-old new users of DMPA, NET-EN and COCs.

STUDY DESIGN

This 5-year longitudinal study followed up new users of DMPA (n=115), NET-EN (n=115) and COCs (n=116) and 144 nonuser controls. BMD was measured at the distal radius using dual-energy X-ray absorptiometry.

RESULTS

BMD increased in all groups (annual percent increase: nonusers, 1.49%; DMPA, 1.39%; NET-EN, 1.03%; COCs, 0.84%) during follow-up (p<.001). There was evidence for lower BMD increases per annum in NET-EN (p=.050) and COC (p=.010) users compared to nonusers but no difference between DMPA and nonusers (p=.76). In 14 NET-EN discontinuers, an overall reduction of 0.61% per year BMD was followed upon cessation by an increase of 0.69% per year (p=.066).

CONCLUSION

This study suggests that BMD increases in adolescents may be less in NET-EN and COC users; however, recovery of BMD in NET-EN users was found in the small sample of adolescents followed post-discontinuation.

Bone mineral density in young adult survivors of acute lymphoblastic leukemia

BACKGROUND

The purpose of the current study was to determine the prevalence of low bone mineral density (BMD) (ie, osteopenia) and identify factors associated with low BMD in young adult survivors of childhood acute lymphoblastic leukemia (ALL).

METHODS

Dual energy x-ray absorptiometry was used to evaluate BMD in 74 randomly selected, long-term childhood ALL survivors initially treated in Minneapolis/St. Paul, Minnesota. Growth hormone (GH)-releasing hormone-arginine stimulation testing was conducted to evaluate peak GH level, and insulin-like growth factor I (IGF-I) and other markers of endocrine functioning were also evaluated in relation to BMD.

RESULTS

The mean age at the time of interview was 30 years, and the mean time since diagnosis was 24 years. Low BMD (Z-score, < or = -1) was present in 24% of subjects, including 1 with osteoporosis. Low BMD was substantially more prevalent in men than in women and was strongly associated with short height. The mean height Z-score for those with low BMD was -1.44, compared with a height Z-score of -0.39 (P < .01) for those with normal BMD. GH insufficiency, low IGF-I Z-score, and current smoking were also suggestive risk factors for low BMD.

CONCLUSIONS

In this long-term follow-up study of childhood ALL survivors, low BMD was found to be more prevalent than expected based on population normative data, specifically in men. The health consequences of early-onset BMD problems in childhood ALL survivors need to be carefully monitored.

Effect of administration of oral contraceptives in vivo on collagen synthesis in tendon and muscle connective tissue in young women

Women are at greater risk than men for certain kinds of diseases and injuries, which may at least partly be caused by sex hormonal differences. We aimed to test the influence of estradiol in vivo on collagen synthesis in tendon, bone, and muscle. Two groups of young, healthy women similar in age, body composition, and exercise-training status were included. The two groups were either habitual users of oral contraceptives exposed to a high concentration of synthetic estradiol and progestogens (OC, n = 11), or non-OC-users tested in the follicular phase of the menstrual cycle characterized by low concentrations of estradiol and progesterone (control, n = 12). Subjects performed 1 h of one-legged kicking exercise. The next day collagen fractional synthesis rates (FSR) in tendon and muscle connective tissue were measured after a flooding dose of [(13)C]proline followed by biopsies from the patellar tendon and vastus lateralis in both legs. Simultaneously, microdialysis catheters were inserted in vastus lateralis and in front of the patellar tendon for measurement of insulin-like growth factor I (IGF-I) and its binding proteins. Serum NH(2)-terminal propeptide of type I collagen (PINP) and urine COOH-terminal telopeptides of type-I collagen (CTX-I) were measured as markers for bone synthesis and breakdown, respectively. Tendon FSR and PINP were lower in OC compared with control. An increase in muscle collagen FSR postexercise was only observed in control (P < 0.05). Furthermore, the results indicate a lower bioavailability of IGF-I in OC. In conclusion, synthetic female sex hormones administered as OC had an inhibiting effect on collagen synthesis in tendon, bone, and muscle connective tissue, which may be related to a lower bioavailability of IGF-I.

Controversies in contraception

PURPOSE OF REVIEW

New research is constantly being published regarding hormonal contraceptives and bone health, migraine headaches, thrombosis risk, hypertension, weight gain, and obesity, as well as emergency contraception. At times, these studies can be clarifying, but they can also raise new controversies and questions. It is important for providers to be aware of the emerging issues regarding contraceptive care for adolescent patients.

RECENT FINDINGS

Research suggests that Depo-Provera (depot medroxyprogesterone acetate; Pfizer, New York City, New York, USA) and, perhaps, low-dose oral contraceptive pills can have adverse effects on adolescent bone health, although the data demonstrating reversibility of bone loss after discontinuation of these contraceptives are reassuring. Additionally, estrogen-containing contraceptives pose risks for patients, including the onset of or exacerbation of migraine headaches, venous thromboembolism, and hypertension. Depo-Provera has been implicated in weight gain, especially in girls who are already overweight. Obesity may decrease the efficacy of some hormonal contraceptives. Finally, the mechanism of action of emergency contraception is still unknown, although studies continue to suggest that it has primarily preovulatory, not postovulatory, effects.

SUMMARY

Adolescent health providers need to be aware of the new research and controversies in contraceptive care in order to counsel and care for patients effectively.

Trabecular bone microarchitecture in female collegiate gymnasts

Using high-resolution magnetic resonance imaging, we observed more developed trabecular bone microarchitecture in the proximal tibia of female collegiate gymnasts vs. matched controls. This suggests that high-load physical activity may have a positive effect on the trabecular microarchitecture in weight-bearing bone.

INTRODUCTION

Participation in physical activities that overload the skeleton, such as artistic gymnastics, is associated with increased areal bone mineral density (aBMD); however, the status of trabecular microarchitecture in the weight-bearing bone of gymnasts is unknown.

METHODS

Eight female collegiate artistic gymnasts and eight controls matched for age, height, body mass, gender and race were recruited for the study. Apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), thickness (appTb.Th) and trabecular separation (appTb.Sp) were determined using high resolution magnetic resonance imaging. Areal bone mineral density, bone mineral content (BMC) and bone area in the proximal tibia were determined using dual-energy X-ray absorptiometry. Group differences were determined using t-tests. The magnitude of group differences was expressed using Cohen's d (d).

RESULTS

Gymnasts had higher appBV/TV (13.6%, d = 1.22) and appTb.N (8.4%, d = 1.45), and lower appTb.Sp (13.7%, d = 1.33) than controls (p < 0.05). Gymnasts had higher aBMD and BMC in the proximal tibia, although the differences were smaller in magnitude (d = 0.75 and 0.74, respectively) and not statistically significant (p > 0.05).

CONCLUSION

The findings suggest that high-load physical activity, such as performed during gymnastics training, may enhance the trabecular microarchitecture of weight-bearing bone.

Estrogen-progestin contraceptive use during adolescence prevents bone mass acquisition: a 4-year follow-up study

BACKGROUND

Estrogen-progestin contraception may affect estrogen production and alter the development of peak bone mass.

STUDY DESIGN

A 4-year follow-up with 122 adolescent women aged 12-19 years. The data were divided into three groups based on estrogen-progestin contraceptive (EPC) use: (i) nonusers (n=52), (ii) 1-2 years of use (n=24) and (iii) use for more than 2 years (n=46). The estrogen dose of the preparations was < or =35 mcg. Height, weight, and the amount of exercise (ratio of work metabolic rate, h/week) as well as bone mineral content (BMC) of lumbar spine and femoral neck were measured repeatedly.

RESULTS

There was a significant trend showing less of an increase in the mean adjusted BMC of lumbar spine in the group of adolescent women who had used EPC for more than 2 years compared with the two other groups. In the mean adjusted BMC of the femoral neck, there was a significant trend of a smaller increase in EPC users for more than 2 years compared with 1-2 years of use.

CONCLUSIONS

Long-term EPC with low-dose estrogen preparations seems to suppress normal bone mineral accrual in adolescent women.

Long-term effects of progestins on bone quality and fractures

The effects of progestins on the quality of bone and their influence on the risk of fractures are reviewed. Data discussed are based on experimental studies in vivo that generally lasted for longer than one year. Information is given on the background of osteoporosis and on several means of inducing changes in bone quality. In young women who start using oral contraceptives based on progestins alone shortly after pubertal development, a significant decrease in bone quality has been documented. World Health Organization experts have concluded that this is not a real argument for restrictions on the use of these contraceptives. In postmenopausal women, no evidence has been found for a bone-protective or an estrogen-antagonistic effect of progestins. A wide range of estrogens have been used that have shown positive effects on bone, which are not antagonized by progestins. The therapeutic use of high-dose megestrol acetate may result in marked negative effects on bone, leading to severe osteoporosis, possibly due to the inherent glucocorticoid activity of this progestin. Other pharmacotherapeutic agents that can be used in postmenopausal therapy, and that clearly have beneficial effects on bone, are discussed.

Modifiable lifestyle factors affecting bone health using calcaneus quantitative ultrasound in adolescent girls

One hundred and fourteen girls were measured for calcaneus QUS (stiffness index score), calcium intake, weight, and total hours spent in physical activity (moderate to high-impact activities and low to no-impact activities). Multiple regression analysis indicated that hours spent in moderate to high-impact activities, current calcium intake, and weight significantly predicted SI.

INTRODUCTION

To determine the influence of modifiable lifestyle factors on adolescent girls' bone health measured by calcaneus quantitative ultrasound (QUS).

METHODS

One hundred and fourteen girls, ages 14-18 (15.97 +/- .7), enrolled in high school physical education classes, were measured for calcaneus QUS (stiffness index score), height, weight, current calcium intake from 2-3 day food records, and estimated total hours spent in physical activity from kindergarten to present. Cumulative physical activity hours were separated into two classifications (according to their estimated strain from ground reaction force): moderate to high-impact activities and low to no-impact activities.

RESULTS

Pearson correlations between stiffness index (SI) and age, height, weight, current calcium intake, and hours spent in moderate to high-impact versus low to no-impact activities indicated a positive relationships between SI and weight (r = .259, p = .005), current calcium intake (r = .286, p = .002), and hours spent in moderate to high-impact activities (r = .451, p < .001). Multiple regression between SI and the above independent variables indicated that collectively, hours spent in moderate to high-impact activities, current calcium intake, and weight (r (2) = .363, p = <.001) significantly predicted SI.

CONCLUSION

Our data indicate that moderate to high-impact activities, current calcium intake, and weight positively influence bone properties of the calcaneus in adolescent girls.