Long-term oral contraceptive use does not affect trabecular bone density

Amount of bone loss in relation to time around the final menstrual period and follicle-stimulating hormone staging of the transmenopause

BACKGROUND AND OBJECTIVE

The objective of the study was to describe bone loss rates across the transmenopause related to FSH staging and the final menstrual period (FMP).

DESIGN AND SETTING

This was a population-based cohort of 629 women (baseline age 24-44 yr) with annual data points over 15 yr.

MEASUREMENTS

Measures were bone mineral density (BMD), FSH to define four FSH stages, and menstrual bleeding cessation to define the FMP. Bone loss rates were reported by obesity status.

RESULTS

Annualized rates of lumbar spine bone loss began in FSH stage 3, which occurs approximately 2 yr prior to the FMP (1.67%/yr); bone loss continued into FSH stage 4 (1.21%/yr). Mean spine BMD in FSH stage 4 was 6.4% less than spine BMD value in FSH stage 1. Annualized rates of femoral neck (FN) bone loss began in FSH stage 3 (0.55%/yr) and continued into FSH stage 4 (0.72%/yr). The FN difference between mean values in FSH stage 1 and FSH stage 4 was 5%. Annualized rates of spine bone loss in the 2 yr prior to the FMP were 1.7%/yr, 3.3%/yr in the 2 yr after the FMP, and 1.1%/yr in the 2- to 7-yr period after the FMP. Nonobese women had lower BMD levels and greater bone loss rates.

CONCLUSIONS

Spine and FN bone loss accelerates in FSH stage 3. Bone loss also began to accelerate 2 yr before the FMP with the greatest loss occurring in the 2 yr after the FMP. Bone loss rates in both spine and FN BMD were greater in nonobese women than obese women.

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.

Comparison of the skeletal effects of the progestogens desogestrel and levonorgestrel in oral contraceptive preparations in young women: controlled, open, partly randomized investigation over 13 cycles

AIM

This 12-month study was conducted to evaluate the skeletal effects of two monophasic oral contraceptives containing 20 mug of ethinylestradiol and 100 mug of levonorgestrel (LEVO) or 150 mug of desogestrel (DESO).

METHODS

Fifty-two women (18-24 years) were randomized into the DESO group or the LEVO group; 36 women served as controls. The areal bone mineral density (aBMD) of the femoral neck and the lumbar spine was evaluated by DXA, and parameters of bone geometry and volumetric bone mineral density (vBMD) were assessed by peripheral quantitative computed tomography at the distal radius and the tibia.

RESULTS

The LEVO group did not lose vertebral aBMD, whereas women in the DESO group lost 1.5%. At the distal radius and the tibia (shank level, 14%), LEVO induced an increase in total cross-sectional area, indicating increased periosteal bone formation. Radial trabecular vBMD declined by 1.4+/-1.8% in the DESO group, while it remained unchanged in the LEVO group.

CONCLUSION

Our study suggests that the skeletal effects of OC preparations may be influenced by progestogenic components in young women.

Combined hormonal contraception and bone health: a systematic review

This systematic review examined whether women who use combined hormonal contraception experience changes in risk of fracture or bone mineral density (BMD) that differ from nonusers. We identified 86 articles from PubMed and EMBASE (published 1966 to August 2005) that reported on fracture or BMD outcomes by use of combined hormonal contraceptives. The evidence relating to combined oral contraceptives (COCs) and fracture is inconclusive, as results from the available studies conflict. Studies of adolescent and young adult women generally found lower BMD among COC users than nonusers. Evidence for premenopausal adult women suggested no differences in BMD between COC users and nonusers. COC use in perimenopausal and postmenopausal women preserved bone mass, while nonusers lost BMD, but BMD among former COC users in this age group was the same as for never-users. Evidence for other combined hormonal methods was very limited, with one study indicating no effect of combined hormonal injectable use among premenopausal women on BMD and one study suggesting lower BMD among premenopausal users of the NuvaRing than in nonusers.

Effect of oral contraceptives and hormone replacement therapy on bone mineral density in premenopausal and perimenopausal women: a systematic review

Seventy five articles on the effect of oral contraceptives and other hormone replacement on bone density in premenopausal and perimenopausal women were reviewed. The evidence was appraised using the Oxford Centre for Evidence-Based Medicine levels of evidence. There is good evidence for a positive effect of oral contraceptives on bone density in perimenopausal women, and fair evidence for a positive effect in "hypothalamic" oligo/amenorrhoeic premenopausal women. There is limited evidence for a positive effect in healthy and anorexic premenopausal women. In hypothalamic oligo/amenorrhoeic women, baseline bone density has been shown to be significantly lower than that in healthy controls, therefore the decision to treat is clinically more important. The ideal formulation(s) and duration of treatment remain to be determined by further longitudinal and prospective randomised controlled trials in larger subject populations.

Prior oral contraception and postmenopausal fracture: a Women's Health Initiative observational cohort study

OBJECTIVE

To test for the possible association of past oral contraceptive (OC) use and incident fracture after menopause.

DESIGN

A prospective cohort of 93,725 postmenopausal women.

SETTING

Forty Women's Health Initiative (WHI) clinical centers across the United States.

PATIENT(S)

Ethnically diverse 93,725 volunteer postmenopausal women, 50 to 79 years old.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The main outcome was self-reported incident first fracture assessed prospectively by annual questionnaire.

RESULT(S)

The adjusted relative hazard (HR) for fracture among past OC users was 1.07 (95% CI, 1.01-1.15). Among women without any postmenopausal hormone treatment, past OC use for < or =5 years led to an HR of 1.15 (95% CI, 1.04-1.27) and for past OC use >5 years led to an HR of 1.09 (95% CI, 0.97-1.23) compared with never users.

CONCLUSION(S)

This study does not support the idea that past OC use protects against later fracture.

Oral contraceptive use in young women is associated with lower bone mineral density than that of controls

Osteoporosis is a skeletal disease affecting 44 million Americans. A primary strategy to prevent osteoporosis is to develop a high peak bone mass in youth. Oral contraceptives (OCs) alter hormones in women and could affect bone mass development. Fifty percent of American women between the ages of 20 and 24 years use OCs. However, the interaction between OCs and skeletal mineralization is poorly understood. Our aim was to compare bone mass [bone mineral density (BMD)] of young women who had a history of OC use, with regularly menstruating controls. We recruited 98 women who were 18 to 25 years of age and had a history of OC use (n=44, 3.4+/-1.9 years of OC use) and controls (n=58). BMD at the hip, whole-body, and spine [anterior-posterior (AP) and lateral grams per square centimeter] was measured by dual-energy X-ray absorptiometry (DXA). Physical activity [in metabolic equivalents (METs)] was measured via questionnaire, and grip strength was evaluated with an isometric dynamometer. Groups were similar in body mass index (BMI), fat mass, grip strength, calcium intake and physical activity, but OC users were slightly older than controls (21.3+/-1.9 years vs 20.3+/-1.6 years, P<0.05). In analysis of covariance, controlled for age and BMI, controls had significantly greater BMD than OC users at the AP and lateral spine, femoral neck, greater trochanter, total hip, and whole body (P<0.05). We conclude that, in this cross-sectional analysis, oral contraceptive use by young women may compromise bone health during a time when mineral is still accruing.

Bone mineral density in Norwegian premenopausal women

The aims of this study were: 1) to determine bone mineral density (BMD) in different age groups, 2) to determine the prevalence of low BMD, and 3) to determine the possible association between BMD and a number of risk factors in Norwegian premenopausal women. BMD of the lumbar spine (L(2)-L(4)), total body, and the hip (total femur, femur neck, and trochanter) were measured using dual-energy X-ray absorptiometry (Prodigy, Lunar) in 145 randomly selected women aged 13-39 years. Information on other factors thought to influence BMD was obtained through questionnaire and a clinical interview. The group aged 25-29 years had the highest mean BMD in the total body, lumbar spine, and total femur while the group aged 13-19 years had the highest mean BMD in the femur neck and the trochanter. The mean BMD values of Norwegian premenopausal women were 3.4-5.1% higher than US/European reference data (P<0.05). Five percent of the study sample aged 20-39 years were defined with low BMD (Z-score <-2) using the standard values from this study. Weight-bearing physical activity, body weight, body height, and age were positively associated with BMD, whilst menstrual dysfunction and previous pregnancy were associated with lower BMD in some of the measurement sites. The results show that the factors associated with BMD are extensive, and the strategies to prevent low BMD have to be multifactorial. A follow-up study should be conducted on the study sample to investigate actual mean BMD values and BMD changes through time.

Effects of an Oral Contraceptive Containing Drospirenone on Bone Turnover and Bone Mineral Density

OBJECTIVE

To compare the effects of a new 21-day combined oral contraceptive containing 30 microg ethinyl/estradiol plus 3 mg drospirenone with a 21-day preparation containing 30 microg ethinyl/estradiol plus 75 microg gestodene on bone turnover and bone mineral density in young fertile women.

METHODS

A randomized, controlled trial was conducted with healthy fertile women treated with 30 microg ethinyl/estradiol plus 3 mg drospirenone (group A; n = 24), 30 microg ethinyl/estradiol plus 75 microg gestodene (group B; n = 24) and healthy controls (group C, n = 23). At 3, 6, 9, and 12 months of the study, serum and urinary calcium, osteocalcin, urinary pyridinoline, and deoxypyridinoline were measured. At baseline and after 12 months, lumbar bone mineral density was determined by dual-energy X-ray absorptiometry.

RESULTS

In groups A and B, urinary pyridinoline and deoxypyridinoline at 6, 9, and 12 months were significantly reduced in comparison with basal values and group C (P < .05). Pyridinoline and deoxypyridinoline levels were lower in group A than in group B throughout the study, but not significantly. In group A serum calcium levels were significantly increased after 6 months. At 12 months, no significant difference was detected in lumbar bone mineral density values among the 3 groups and in comparison with basal values.

CONCLUSION

Both combined oral contraceptives exert a similar positive influence on bone turnover and bone-sparing effect in young postadolescent women.

Long-term sensitivity of uterus and hypothalamus/pituitary axis to 17beta-estradiol is higher than that of bone in rats

We examined the long-term sensitivity of uterus and bone to low-dose 17beta-estradiol in a 4-month experiment in OVX rats and found that a dose of estradiol that fully protected against uterine atrophy did not protect against bone loss. Our results suggest higher estrogen sensitivity of the uterus compared with bone.

INTRODUCTION

Estrogen is essential for the function of reproductive tissues and for the normal acquisition and maintenance of bone mass in females. This study was designed to examine the long-term sensitivity of the uterus and bone to low-dose estrogen.

MATERIALS AND METHODS

In preliminary experiments, we determined the lowest subcutaneous dose of 17beta-estradiol able to fully protect against uterine atrophy in ovariectomized (OVX) rats. This dose was found to be 1.5 microg/kg, given five times per week. Subsequently, groups of sham-operated (SHAM) or OVX 6-month-old rats (n = 8 each) were subcutaneously injected with vehicle or 1.5 microg/kg 17beta-estradiol five times per week. All animals were killed 4 months after surgery. Serum osteocalcin and urinary deoxypyridinoline were measured as biochemical markers of bone turnover. Bones were analyzed by bone histomorphometry and pQCT.

RESULTS AND CONCLUSIONS

Our study clearly showed that a dose of estradiol that restores physiological estradiol serum levels, fully maintains uterine weight in OVX rats at the SHAM control level, and suppresses serum follicle-stimulating hormone (FSH) by 67% relative to OVX vehicle controls does not provide significant protection against OVX-induced bone loss at different cancellous and cortical bone sites. We conclude that the long-term sensitivity of the uterus and the hypothalamus/pituitary axis to 17beta-estradiol is higher than that of bone in rats.

Effects of hormonal contraception on bone mineral density after 24 months of use

OBJECTIVE

To measure the effect of 24 months of depot medroxyprogesterone acetate use on bone mineral density compared with oral contraception (pills) and nonhormonal contraception.

METHODS

Women aged 18-33 years self-selected oral contraception, depot medroxyprogesterone acetate, or nonhormonal contraception (controls). Those selecting pills were randomized to formulations containing either 35 microg ethinyl estradiol and norethindrone or 30 microg ethinyl estradiol and desogestrel. Controls were frequency matched on age and race/ethnicity to hormonal contraception users. Dual-energy X-ray absorptiometry of the lumbar spine (L1-L4) was performed at baseline, 12 months, and 24 months. Percent change in bone mineral density was analyzed by using analysis of covariance, adjusting for age, race/ethnicity, weight-bearing exercise, calcium intake, smoking status, and body mass index.

RESULTS

Of the 191 women making up the final sample, 86 used pills, 47 used depot medroxyprogesterone acetate, and 58 used nonhormonal contraception. Women using depot medroxyprogesterone acetate for 24 months experienced, on average, a 5.7% loss in bone mineral density, with a 3.2% loss occurring between months 12 and 24. On average, users of desogestrel pills experienced a 2.6% loss in bone mineral density after 24 months. Bonferroni-adjusted pairwise comparisons demonstrated that bone mineral density changes from baseline to 24 months among depot medroxyprogesterone acetate users differed significantly from changes experienced by either of the pill groups or the control group. Changes in bone mineral density among users of either pill did not significantly differ from each other or from controls.

CONCLUSION

Loss of bone mineral density associated with depot medroxyprogesterone acetate use appears to be linear during the first 2 years of use. Shifts in bone mineral density among pill users were not significant when compared with controls.

Lifestyle factors and the development of bone mass and bone strength in young women

OBJECTIVE

To evaluate the contributions of adolescent calcium intake, oral contraceptive use, and exercise on bone mass and bone strength.Study design Eighty white women participated in 10 years of the Penn State Young Women's Health Study, a longitudinal study of community participants. We measured bone mineral mass (g), density (BMD, g/cm(2)), and body composition from dual energy x-ray absorptiometry and estimated proximal femur section modulus (bone bending strength). Calcium intake was determined from 45 days of prospective food records at regular intervals between the ages of 12 and 22 years. Exercise history and oral contraceptive use were assessed by questionnaire.

RESULTS

Daily calcium intakes between the ages of 12 and 22 years ranged from 500 to 1900 mg/d and were not significantly associated with bone gain or bone strength. Oral contraceptive use during adolescence was not correlated with bone or body composition measurements. Femoral neck BMD did not change from 17 to 22 years of age, but section modulus increased 3% (P <.05). Only exercise during adolescence was significantly associated with increased BMD and bone bending strength.

CONCLUSIONS

Adolescent lifestyle patterns can influence young adult bone strength. Our data suggest that exercise is the predominant lifestyle determinant of bone strength for this cohort.

Predictors of bone mineral density in female workers in Morelos State, Mexico

BACKGROUND

Although several studies have identified factors associated with bone mineral density (BMD), little research is available on Mexican women.

METHODS

A cross-sectional study was conducted in 1,622 female workers between 20 and 80 years of age at the Mexican Social Security Institute (IMSS), an integral part of the Mexican health system. It was carried out in Morelos, a Mexican state that borders Mexico City. Women were recruited to participate in this study from their workplaces. Body mass index (BMI) was measured and BMD was assessed using dual-energy x-ray absorptiometry of dominant forearm. Predictors of BMD (age, reproductive factors, BMI, diet, and physical activity) in pre- and postmenopausal women were assessed by questionnaire and analyzed using generalized additive models.

RESULTS

In premenopausal women, older age, higher BMI, younger age at menarche, and greater vitamin D intake were associated with higher BMD (R(2)=0.06, null deviance reduction=6.9%). In postmenopausal women, determinants of BMD were older age, higher BMI, greater height, later initiation of menopause, longer time of use of hormonal replacement therapy (HRT), and greater calcium intake from dairy products (R(2)=0.39, null deviance reduction=40.7%).

CONCLUSIONS

As observed in other populations, age, BMI, height, age at menopause, time of use of HRT, and calcium intake derived from dairy products in these Mexican women are factors associated with higher forearm BMD during postmenopausal period. Age, BMI, age at menarche, and vitamin D are associated with higher forearm BMD in premenopausal women. Some of these factors are not linearly associated with BMD. This was a limited population study carried out in a large group of female healthcare workers whose reproductive and lifestyle factors potentially agreed with those of female workers from urban areas of Mexico.

Amenorrhea and bone health in adolescents and young women

PURPOSE OF REVIEW

We present an update on amenorrhea in adolescent girls and young women. Amenorrhea may herald the onset of estrogen deficiency, which can adversely affect peak bone mass and ultimate risk of osteoporosis.

RECENT FINDINGS

Adolescence is a critical period for bone accretion. Important modifiable factors that optimize bone accretion during this time are calcium intake, vitamin D, nutrition, and exercise. Another modifiable factor in the hands of the clinician is the prompt recognition and therapy of amenorrhea associated with estrogen deficient states, caused by conditions such as hyperprolactinemia and ovarian failure. An important recent observation is that adolescents with amenorrhea who diet, but who do not meet diagnostic criteria for anorexia nervosa, are nonetheless at significant risk for low bone density. Also, multiple factors contribute to the bone loss experienced by patients with anorexia nervosa, and the associated estrogen deficiency may not be the major contributor. Recent evidence also suggests that the contraceptive depot medroxyprogesterone acetate may contribute to impaired bone accretion. While estrogen/progestin replacement therapy has a clear role in the management of girls and young women with primary ovarian insufficiency, the exact role of this therapy in the amenorrhea associated with anorexia nervosa or exercise remains controversial.

SUMMARY

Increasingly, osteoporosis prevention is recognized as an important role for health care providers of adolescent girls and young women. Viewed from this perspective, there is a need for more aggressive evaluation and management of amenorrhea, and research is needed to define sound and cost effective strategies.

Bone densitometry in premenopausal women: synthesis and review

Bone loss prior to menopause is being increasingly identified in women. Clearly, low bone mineral density (BMD) is a significant risk factor for fracture in the estrogen-deficient female postmenopause. The significance of low bone density prior to menopause needs to be addressed. Low bone density in the premenopausal female may reflect attainment of a lower peak bone mass. It may also be secondary to progressive bone loss following achievement of peak bone density. The etiology of low bone density in the premenopausal female needs to be clarified with meticulous exclusion of secondary causes of bone loss. Menstrual status is an important determinant of peak bone mass as well as the development of bone loss in women prior to the onset of menopause. Subclinical decreases in circulating gonadal steroids may be associated with a lower peak bone mass as well as progressive bone loss in otherwise reproductively normal women. Elevations of follicle-stimulating hormone (FSH) of greater than 20 miu/L are associated with evidence of increased bone turnover marker activity and correlate with progressive bone loss in perimenopausal women. This transitional period requires further study with respect to the magnitude of bone loss experienced and the potential benefits of antiresorptive therapy. Detailed assessment of menstrual status is necessary in the evaluation of low bone density in premenopausal women. The majority of the cross-sectional and longitudinal studies completed evaluating BMD in the premenopausal years suggest that minimal bone loss does occur prior to menopause after attainment of peak bone mass. The magnitude of premenopausal bone loss, however, is controversial and may be site-dependent. More rapid rates of bone loss are seen in the transitional period beginning 2-3 yr prior to the onset of menopause. Prospective data are needed to understand further the relationship between BMD and fracture in the premenopausal period. Women with steroid-induced bone loss as well as other secondary causes of osteoporosis respond to antiresorptive therapy with documented improvements in BMD. Biomarkers can identify perimenopausal women with increased bone turnover. Lifestyle modification can improve BMD in the pre- and the perimenopausal period. Antiresorptive therapy has not been evaluated in pre- or perimenopausal women with low BMD in the absence of secondary causes of osteoporosis. As new treatment options are evaluated and become available, biomarker assessment may be of value in identifying women at risk of fracture.

Longitudinal changes in bone density in relation to oral contraceptive use

The primary aim of this 36-month prospective cohort study was to evaluate the association between use of oral contraceptives (OCs) and bone mineral density in reproductive-age women. The 36-month bone density (g/cm2) at the spine, hip and whole body and percent change from baseline (measured at 6-month intervals) were evaluated among 245 women 18-39 years of age; 89 were using OCs (median duration: 3.7 years at study entry) and 156 were not using any hormonal contraception. Before and after adjustment for covariates (baseline bone density, age, race, ever pregnant, exercise, body mass and calcium intake), women using OCs did not differ significantly from comparison women in percent change in bone density over 36 months or in absolute bone density at 36 months. All p-values for between-group differences were >0.55. In conclusion, within the limitations of this study, OCs did not appear to impact bone density over time in this cohort of reproductive-age women.

Effects of a triphasic combination oral contraceptive containing norgestimate/ethinyl estradiol on biochemical markers of bone metabolism in young women with osteopenia secondary to hypothalamic amenorrhea

This multicenter, double-blind, placebo-controlled, randomized study of 45 patients evaluated the short-term effects of an oral contraceptive [Ortho Tri-Cyclen, 180-250 micro g of norgestimate (NGM) and 35 microg of ethinyl estradiol (EE)] on biochemical markers of bone resorption, formation, and osteoprotegerin in young women (mean age +/- SD, 26.5 +/- 6.3 yr) with hypothalamic amenorrhea and osteopenia. Body fat, endocrine, and cognitive function were evaluated as secondary endpoints. Biomarkers of bone metabolism were measured at baseline and after three cycles of NGM/EE or placebo. There were significant decreases in mean values of N-telopeptide [mean (SD), -13.4 (13.4) vs. 1.2 (23.8) nmol bone collagen equivalents (BCE)/mmol creatinine (Cr); P = 0.001] and deoxypyridinoline [-1.2 (2.9) vs. -0.5 (1.5) nmol deoxypyridinoline/mmol Cr; P = 0.021] as well as significant decreases in bone specific alkaline phosphatase [-5.1 (3.5) vs. 0.4 (3.1) ng/ml; P < 0.001], osteocalcin [-5.9 (3.6) vs. -2.9 (3.7); P = 0.016], and procollagen of type I propeptide [-35.2 (44.6) vs. -0.2 (30.0) ng/ml; P = 0.025], but not osteoprotegerin [0.39 (1.46) vs. -0.2 (0.49) pmol/liter; P = 0.397] in the NGM/EE vs. placebo group. There were no significant differences between groups with respect to changes in cognitive function, mood, body weight, body mass index, body fat, percentage of body fat, and all endocrine levels except FSH, [-3.7 (3.8) vs. -0.6 (2.1) IU/liter; P < 0.001, NGM/EE vs. placebo]. No serious adverse events were reported in either group. These results suggest that NGM/EE decreases bone turnover in osteopenic premenopausal women with hypothalamic amenorrhea. Further studies are needed to determine whether estrogen will increase bone density in this population.

Effects of a low-dose and ultra-low-dose combined oral contraceptive use on bone turnover and bone mineral density in young fertile women: a prospective controlled randomized study

In this prospective, controlled, randomized study, we compared the effect of a low-dose 21-day combined oral contraceptive (COC) containing 20 microg ethinyl estradiol (EE) and 75 microg gestodene (GTD) (Group A; n = 19) with an ultra-low-dose 24-day COC containing 15 microg EE and 60 microg GTD (Group B; n = 18) on bone turnover and bone mineral density (BMD) in young, fertile women. Nineteen healthy fertile women were used as untreated controls (Group C). At 3, 6, 9 and 12 months of the study serum osteocalcin (BGP), urinary pyridinoline (PYD) and deoxypyridinoline (D-PYD) were measured in all subjects. At baseline and after 12 months BMD was determined at lumbar spine by dual-energy X-ray absorptiometry in all patients. In both Groups A and B, urinary levels of PYD and D-PYD at 6, 9 and 12 months, were significantly reduced in comparison with basal values and with control subjects (p < 0.05). No significant differences in urinary PYD and D-PYD levels were observed between Groups A and B during the entire period of treatment. At 12 months, no statistically significant difference in spinal BMD values was detected between the three groups and in comparison with basal values. The present study suggests that the two COCs could exert a similar positive effect on bone turnover in young postadolescent women, without any significant and appreciable modification of BMD.

The effect of estrogen-progestin treatment on bone mineral density in anorexia nervosa

INTRODUCTION

Osteopenia is a serious complication of anorexia nervosa (AN). Although in other states of estrogen deficiency, estrogen replacement therapy increases bone mass, its role in AN remains unresolved.

STUDY OBJECTIVE

To study the effect of estrogen-progestin administration on bone mass in AN.

DESIGN, SETTING, AND PARTICIPANTS

A prospective observational study of 50 adolescents with AN (mean age 16.8 +/- 2.3 yrs) was conducted in a tertiary referral center.

MAIN OUTCOME MEASURES

Bone mineral density (BMD) of the lumbar spine and left hip were prospectively measured using dual-energy x-ray absorptiometry at baseline and annually.

INTERVENTIONS

Twenty-two subjects received estrogen-progestin and 28 standard treatment (Rx) alone. Estrogen-progestin was administered daily as an oral contraceptive containing 20-35 mcg ethinyl estradiol. All subjects received calcium supplementation and the same medical, psychological, and nutritional intervention (standard Rx). Mean length of follow-up was 23.1 +/- 11.4 months.

RESULTS

At presentation, patients were malnourished (79.5% +/- 7.6% IBW), hypoestrogenemic (estradiol 24.7 +/- 10.7 pg/mL), and had reduced bone mass (lumbar spine BMD -2.01 +/- 0.69 SD below the young adult reference mean). Ninety-two percent of subjects were osteopenic and 26% met WHO criteria for osteoporosis. Body weight, and no treatment group, was the major determinant of BMD. At one-year follow-up, there were no significant differences in absolute values or in net change of lumbar spine or femoral neck BMD between those who received estrogen-progestin and those who received standard Rx (80% power of finding a 3% difference in BMD at 1 yr). In those followed for 2-3 yrs, osteopenia was persistent and in some cases progressive.

CONCLUSION

In our study population, estrogen-progestin did not significantly increase BMD compared with standard Rx. These results question the common practice of prescribing hormone replacement therapy to increase bone mass in AN.

Forearm bone density in long-term users of oral combined contraceptives and depot medroxyprogesterone acetate

OBJECTIVE

To compare the bone mineral density of users of combined oral contraceptives (OC) or depot medroxyprogesterone acetate (depot-MPA) with women who have never used a hormonal contraceptive method.

DESIGN

Cross-sectional study.

SETTING

Academic tertiary-care hospital.

PATIENT(S)

A total of 189 women, aged 30 to 34 years old, were allocated to three groups: 63 who had used OC for at least 2 years; 63 who had used depot-MPA for at least 2 years; and 63 control women who had never used hormonal contraceptives.

INTERVENTION(S)

Each woman's bone mineral density (BMD) was evaluated at the distal and ultradistal section of the radius of the nondominant forearm by the use of single x-ray absorptiometry.

MAIN OUTCOME MEASURE(S)

We obtained BMD measurements for each participant.

RESULT(S)

Independent of the period of use and the section of the forearm studied, we found no difference in BMD for OC or depot-MPA users when compared to women who had never used hormonal contraceptive methods. In addition, BMD was similar between OC users and depot-MPA users. The multiple linear regression analysis showed that the variables associated with BMD were weight, number of pregnancies, and the woman's occupation.

CONCLUSION(S)

Women aged 30 to 34 years who have used OC or depot-MPA have similar BMD as control women. These findings suggest that the use of OC or depot-MPA does not affect the BMD of women in this age group.

Exercise and oral contraceptive use suppress the normal age-related increase in bone mass and strength of the femoral neck in women 18-31 years of age

Women who exercise during their second and third decades may increase their peak bone mass and lower their eventual risk for postmenopausal fracture. However, the effects of exercise in younger women can be modulated by the use of oral contraceptives, which may prevent the normal accretion of bone mass that would otherwise occur. We hypothesized that exercise intervention in young adult women would significantly increase both bone mass and the bending rigidity of the femoral neck. We further hypothesized that exercise intervention in the presence of oral contraceptive use would have a negative effect on bone mass and bending rigidity. Women 18-31 years of age (n = 123) were classified by oral contraceptive use (OC, NOC) and age (18-23, 24-31 years), and then randomized into exercise or nonexercise groups. The exercise protocol consisted of three sessions/week of aerobic and nonaerobic exercises, and continued for 2 years. Each 6 months, the femoral neck of each subject was scanned using a Lunar dual-energy X-ray absorptiometry (DEXA) scanner, and bone mineral content, density and geometric information were used to calculate estimated stresses and bending rigidity at the hip. Percent changes from baseline were analyzed using two-way analysis of variance (ANOVA) at 6, 12, 18, and 24 months. Women who neither exercised nor took oral contraceptives (NE/NOC) had the greatest percentage increases in cross-sectional area (4.98 +/- 2.29%), cross-sectional moment of inertia (9.45 +/- 2.37%), total bone mineral density (2.07 +/- 2.09%), fracture index (8.03 +/- 2.03%), and safety factor (20.03 +/- 5.79%) over the 24 month exercise program. Women who exercised and did not take oral contraceptives (E/NOC) declined on most variables related to femoral strength and bone mass, whereas those women who took oral contraceptives were usually intermediate between NE/NOC and E/NOC, whether they exercised or not. These data show that either exercise or OC use is associated with a suppression of the normal increase in bone mass and mechanical strength in the femoral neck in women 18-31 years old, but the combination of exercise and OC use appears to have a less suppressive effect.

The effect of combined oral contraception with or without spironolactone on bone mineral density of hyperandrogenic women

We studied the effect of treatment with combined oral contraception (COC) with or without spironolactone on the bone mineral density (BMD) of hyperandrogenic women. A group of 22 women (group 1) was treated with ethinylestradiol plus desogestrel for 21 days each month for 12 months, while another group of 21 patients (group 2) was treated with ethinylestradiol and desogestrel for 21 days each month plus spironolactone daily for 12 months. There was no statistically significant difference with respect to mean age, body mass index (BMI) and BMD between the two groups of patients before the treatment. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), androstenedione, total testosterone, dehydroepiandrosterone sulfate (DHEAS), sex hormone binding globulin (SHBG), prolactin and estradiol were assessed in both groups and no statistically significant difference was found before treatment. Nor was there any statistically significant difference in bone turnover between the two groups. Statistical analysis was performed using the Student's t test for unpaired data to compare age, BMD and biochemical data, and statistical significance was defined as p < 0.05. The BMD before and after 12 months of treatment showed no statistically significant difference between the patients of group 1 and those of group 2, suggesting that both ethinylestradiol plus desogestrel, and ethinylestradiol and desogestrel plus spironolactone daily for 12 months at the given doses do not affect the BMD of the treated women, while the addition of spironolactone improves the efficacy of hirsutism treatment.

The physiology of the highly trained female endurance runner

Continuing improvements in the performance of female endurance runners and increasing levels of participation have generated the need to know more about the physiology of this group. Specific research is needed in this area, as data referring to male endurance runners cannot legitimately be applied to the female endurance runner because of their markedly different physiological and hormonal profiles. Recent developments in our understanding of an athlete's physiology (mainly in relation to the male endurance runner) have revealed new areas of interest that need to be assessed with specific reference to the female athlete. Relatively little attention has been directed towards identifying the major physiological characteristics of the highly trained/elite female endurance runner in general, and that which has been published on such factors and the effects of the menstrual cycle have produced equivocal results. Moreover, the impact of such training upon the menstrual cycle and endurance running performance is a controversial area, especially when assessing its subsequent impact on health-related issues. Reports of the condition referred to as the 'female athlete triad' have increased in recent years, with a decrease in bone mineral density predisposing the female athlete to increased risks of stress fractures. The aetiology of this triad is multifactorial, with such risk factors including nutrition, menstrual status, training intensity and frequency, body size and composition and psychology/physical stress. However, research limitations and flaws have lead to controversy in the literature regarding the immediate and long term effects of the triad on the female athlete. Likewise, the effects of the oral contraceptive pill on health and endurance performance also remain elusive, with a dearth of research pertaining to how oral contraceptive agents can aid athletic performance and the long term health of the female athlete. The purpose of this paper is to critically appraise the existing literature to provide a current review of the physiological scientific knowledge base in relation to the female athlete, health, training and performance, with suggestions for future areas of research. It is well known that certain menstrual and health-related performance factors of the female athlete, that is, physiological predictors of performance and body fat, have been extensively investigated over the last 30 years. However, a variety of methodological flaws and inconsistencies are present within the research and thus only the most prominent and well controlled studies within this area over the past 30 years will be referred to.

Collagen metabolism markers as a reflection of bone and soft tissue turnover during the menstrual cycle and oral contraceptive use

Two different groups of women, 23 healthy young adults and 13 women with chronic posterior pelvic pain, were studied before and during use of oral contraceptives (OC). Collagen metabolism markers-here, the amino-terminal propeptide of type I procollagen, the carboxy-terminal telopeptide of type I collagen, and the amino-terminal of procollagen type III-as well as hormones and other endocrine factors indicating the balance between androgen expression/anabolism and catabolism of the subjects (testosterone, sex-hormone binding globulin, and insulin-like growth factor I were measured. Type I procollagen, the carboxy-terminal telopeptide of type I collagen, and the amino-terminal of procollagen type III were all significantly decreased during OC use. These findings implicate OC use-induced changes in collagen type I and III turnover. A shift in the anabolic/catabolic balance was also recorded indicating a less anabolic situation during OC use.

Low-dose oral contraceptives and bone mineral density: an evidence-based analysis

We reviewed studies of the association of oral contraceptive (OC) use and bone mineral density (BMD). We limited the review to studies of women using low-dose oral contraceptives and that measured BMD by bone densitometry. A total of 13 studies met the inclusion criteria. Nine of these showed a positive effect of OC use on BMD, and four did not show an association. However, none of the studies showed a decrease in BMD with OC use. We classified the level of evidence from each study according to the guidelines of the US Preventive Services Task Force. The level of evidence supporting a positive association between OC use and increased BMD is II-1. There is fair evidence (Category B) to support the position that OC use has a favorable effect on BMD. We made suggestions for a study design that could yield Level I evidence.

Oral contraceptives and bone mineral density: A population-based study

OBJECTIVE

We sought to test the hypothesis that exposure to oral contraceptives protects the skeleton.

STUDY DESIGN

Multiple regression techniques were used to analyze data for a random sample of 710 Australian women (age range, 20-69 years). Bone mineral density was measured at the lumbar spine, proximal femur, whole body, and distal forearm. Oral contraceptive exposure was assessed by a questionnaire.

RESULTS

Women exposed to oral contraceptives had a 3.3% greater mean bone mineral density adjusted for body mass index and age at the lumbar spine (partial r (2) = 0.009; P =.014). Adjusted mean vertebral bone mineral density was 3.3% greater for premenopausal women (partial r (2) = 0.008; P <.05), but the effect did not reach significance among postmenopausal women. Higher bone mineral density was associated with increased duration of exposure, with a mean increase of 3.2% associated with the first 5 years and a further 0.2% with >/=5 years of exposure. No association was detected at other sites.

CONCLUSION

Exposure to oral contraceptives may be associated with higher lumbar spine bone mineral density.

Effects of hormonal contraceptives on bone mineral density

The clinical research to date on the effects of 3 types of hormonal contraceptives, i.e. depot medroxyprogesterone acetate ('Depo-Provera'), levonorgestrel subdermal implants ('Norplant'), and oral contraceptives, on bone mineral density in premenopausal women is reviewed. The large variance in results across studies for each method is in part due to differences in research design, techniques for measuring bone mineral density, age of the study participants and type of oral contraceptive preparation. However, the balance of the evidence leans toward a positive effect of oral contraceptives on bone mineral density in women of all age. On the other hand, few observations have yet been published on the effects of the new progestin oral contraceptives on bone mineral density. The few extant data suggest a positive impact of levonorgestrel subdermal implants on bone mineral density in women of all ages. Although the findings are preliminary, it appears that depot medroxyprogesterone acetate may exert a negative effect on bone mineral density. More specifically, caution should be exercised in prescribing long term depot medroxyprogesterone acetate (e.g. > 5 years) especially in young adolescents (e.g. < 16 years old) who may not have yet reached peak bone mass.

Effects on bone mass of two oral contraceptives containing ethinylestradiol and cyproterone acetate or desogestrel: results of a 2-year follow-up

BACKGROUND

There are conflicting data about the effects of oral contraceptives on bone mass in young women. Moreover, amenorrheic women may also be affected to varying degrees by osteopenia. Both conditions (oral contraceptive use and amenorrhea) are not infrequent in women during their reproductive years.

AIM

To evaluate the safety for bone mass of two oral contraceptives, one containing cyproterone acetate and the other containing desogestrel.

METHODS

A total of 67 women between 19 and 29 years of age were studied. Of these women, 35 were selected to receive an oral contraceptive containing 35 mg ethinylestradiol and 2 mg cyproterone acetate. A second group of 32 women received an oral contraceptive containing 30 mg ethinylestradiol and 150 mg desogestrel for 2 years. Immediately before and after the 12th and 24th months of therapy, bone mineral density was assessed by dual X-ray absorptiometry, and hormonal profiles and Ferriman-Gallwey scores were evaluated.

RESULTS

After the 2-year follow-up, all subjects showed regular cycles, no pregnancies, and no changes in bone mass density. In addition, hirsute subjects showed a decrease of almost 42% in hirsutism scores.

CONCLUSION

Oral contraceptives containing cyproterone acetate or desogestrel in the studied doses have no deleterious effects on bone marrow.

Oral contraceptives and bone metabolism

In women, the bone metabolism is markedly influenced by gonadal steroids and by their fluctuations. Indeed, estrogens influence bone metabolism by influencing endocrine and paracrine functions involved in bone remodelling. In normally cycling women, the administration of oral contraceptives does not increase bone mineral density and does not induce deleterious effects on bone. In women with ovulatory disturbances, bone turnover is increased and bone mineral density is lower than in normally cycling women. In these cases, administration of oral contraceptives is capable of blocking increased bone loss and of restoring a normal bone mineral density. Similarly, in women treated with gonadotropin releasing hormone (GnRH) analogs, the concomitant administration of oral contraceptives completely antagonizes GnRH analog-induced bone loss. The progestogenic component of oral contraceptives seems to contribute to the protective effect of estrogens on bone. Oral contraceptives are safe for bone maintenance in normal adult women, and are indeed indicated to prevent postmenopausal osteoporosis in women with ovulatory disturbances.

Biochemical aspects of hormonal contraception: effects on bone metabolism

Both trabecular and cortical bone mineral content reduction physiologically occur during the premenopausal period and, overall, at the time of menopause. It is related to plasma estrogen fall. Several studies have examined the relationship between bone density and oral contraceptives (OCs), but their results disagree. The different results may be due to the small number of patients investigated, the different OC formulations, and to the multifactorial nature of the bone loss phenomenon. Furthermore, the use of different techniques and different sites for measuring the bone density may limit the interpretation and reproducibility of the reported findings. Our previous studies evidenced that: (1) in premenopausal (40-45 years) women (n = 26), OCs, over a period of 2 years, do not induce any change either in bone mineral density or in bone metabolism biochemical markers (osteocalcin, alkaline phosphatase, urinary hydroxyproline/creatinine ratio; and (2) independent from the therapy length, the premenopausal use of OCs does not modify the bone mineral loss in postmenopausal patients (n = 40). The present study compared, over a period of 36 months, in perimenopausal (46-53 years; follicle stimulating hormone < or = 35 mU/ml; estradiol < 50 pg/ml) women, the effect of OCs (n = 8) on bone metabolism. The results were compared with those of a matched control group (n = 9). In the treated group, a slight, though not significant, bone mass improvement was observed during the entire therapy period, whereas, in the control group, a continued and progressive bone mass loss was observed and a significant decrease was shown at the end of the observational period. Our data suggest that OCs have no significant effects on bone metabolism in women during their childbearing years. However, OCs may be beneficial in inhibiting bone reabsorption in pre- and postmenopause. Furthermore, the pill, also in virtue of its contraceptive effect, would be the first presidium in hormone therapy in the premenopause.

Oral contraceptive treatment inhibits the normal acquisition of bone mineral in skeletally immature young adult female monkeys

The purpose of the present study was to determine the effects of oral contraceptive therapy on bone density and serum markers of bone metabolism in a prospective, longitudinal study of young adult female cynomolgus monkeys. Two hundred and seven intact cynomolgus monkeys were randomized to two groups, and fed an atherogenic diet containing either no drug (Control) or a triphasic oral contraceptive regimen (Contraceptive). Measurements of bone density were carried out by dual-energy X-ray absorptiometry at 10-month intervals (0, 10, and 20 months) and serum bone biomarkers were determined at 5-month intervals over the 20-month time course. No significant differences in these variables were observed prior to treatment. Both groups of animals gained bone mineral during the study, indicating that peak bone mass had not been reached at baseline. Contraceptive-treated animals gained less spinal (lumbar vertebrae 2-4) bone mineral content and density and less whole-body bone mineral content than Controls over the course of the study. Significant depressive effects of contraceptive treatment on gains in BMC and BMD were observed during each 10-month interval of the study. Bone metabolism was inhibited in the Contraceptive group, as reflected by marked reductions (approximately 40%) in serum osteocalcin and alkaline phosphatase levels along with moderate reductions in serum acid phosphatase and calcium. The results suggest that triphasic oral contraceptive treatment of young adult female monkeys that have not reached peak bone mass inhibits net bone accretion and/or growth by reducing bone metabolism. Thus, prolonged continuous oral contraceptive use in skeletally immature females may lead to a lower peak bone mass--an effect which could increase the risk of fractures in later life.

Influence of hormonal and reproductive factors on the risk of vertebral deformity in European women. European Vertebral Osteoporosis Study Group

The aim of this study was to determine whether variation in the level of selected hormonal and reproductive variables might explain variation in the occurrence of vertebral deformity across Europe. A population-based cross-sectional survey method was used. A total of 7530 women aged 50-79 years and over were recruited from 30 European centres. Subjects were invited to attend for an interviewer-administered questionnaire and lateral spinal radiographs which were taken according to a standard protocol. After adjusting for age, centre, body mass index and smoking, those in the highest quintile of menarche (age > or = 16 years) had an increased risk of vertebral deformity (odds ratio [OR] = 1.48; 95% confidence interval [CI] 1.16, 1.88). Increased menopausal age (> 52.5 years) was associated with a reduced risk of deformity (OR = 0.78; 95% CI 0.60, 1.00), while use of the oral contraceptive pill was also protective (OR = 0.76; 95% CI 0.58, 0.99). There was a smaller protective effect associated with one or more years use of hormone replacement therapy, though the confidence limits clearly embraced unity. There was no apparent effect of parity or breast-feeding on the risk of deformity. We conclude that oestrogen status is an important determinant of vertebral deformity. Ever use of the oral contraceptive pill was associated with a 25% reduction in risk of deformity though the effect may be a result of the higher-dosage oestrogen pills used in the past. Parity and breast-feeding do not appear to be important and would appear to have little potential for identification of women at high risk of vertebral deformity.

A prospective comparison of bone density in adolescent girls receiving depot medroxyprogesterone acetate (Depo-Provera), levonorgestrel (Norplant), or oral contraceptives

OBJECTIVE

To examine bone density among adolescents receiving different forms of hormonal contraception along with that of control subjects.

METHODS

Baseline and 1-year measures of lumbar vertebral bone density were obtained in girls receiving depot medroxyprogesterone acetate (Depo-Provera) (n = 15), levonorgestrel (Norplant) (n = 7), or oral contraceptives (n = 9) and in girls receiving no hormonal treatment (n = 17). In a subsample of Depo-Provera users (n = 8), Norplant users (n = 3), and control subjects (n = 4), bone density measurements were repeated after 2 years. Bone density was measured by dual-energy x-ray absorptiometry.

RESULTS

Body mass indexes, level of pubertal development, substance use, and reproductive histories were not significantly different among the groups. More black girls were represented in the initial Depo-Provera group (p < 0.02), girls in the Norplant group exercised more hours per week (p < 0.02), and control subjects were older (p < 0.01) than those in the other groups. These variables did not significantly affect bone density results. After 1 year, bone density decreased 1.5% in Depo-Provera users, compared with increases of 2.5% in Norplant users, 1.5% in oral contraceptive users, and 2.9% control subjects (p < 0.02). After 2 years, bone density increased a total of 9.3% in Norplant users and 9.5% in control subjects but decreased a total of 3.1% in Depo-Provera users (p < 0.0001).

CONCLUSION

These data suggest that Depo-Provera may, at least temporarily, suppress the expected skeletal bone mineralization in adolescents, whereas Norplant and oral contraceptives are associated with the expected increase in bone density in this population.

Decreased bone turnover in oral contraceptive users

The objective of this study was to determine the effect of oral contraceptive pills on bone turnover. The design consisted of a cross-sectional analysis of a prospective cohort. There were 52 women taking oral contraceptives and 156 nonuser controls from a large cohort of 1039 healthy women, aged 31-89 years (OFELY study). Most users were taking combined oral contraceptives containing 30 micrograms ethinyl estradiol and the mean duration of pill use was 6.7 +/- 6.4 years. Users and nonusers were matched for age [mean age (years): 39.3 +/- 3.5 vs. 40.5 +/- 4.3, range 35-49 years for both]. Main outcome measures included three markers of bone formation (serum osteocalcin, bone-specific alkaline phosphatase, and C-terminal propeptide of type I collagen) and two markers of bone resorption that are pyridinoline crosslinked peptides (Crosslaps and NTX). Users and nonusers did not differ for weight, height, alcohol and tobacco use, dietary calcium intake, parity, exercise activity, body fat and lean composition, and calcium chemistry tests. In pill users all bone formation and resorption markers were decreased compared with controls: osteocalcin, 7.7 +/- 2.7 vs. 10.1 +/- 3.1 ng/mL (-24%, p < 0.001); bone-specific alkaline phosphatase, 7.5 +/- 2.3 vs. 8.8 +/- 2.7 ng/mL (-15%, p < 0.003); C-terminal propeptide of type I collagen, 77.2 +/- 93.1 vs. 93.1 +/- 31.9 ng/mL (-17%, p = 0.001); Crosslaps: 175 +/- 91 vs. 211 +/- 105 micrograms/mmol Cr (-17%, p = 0.03); and NTX, 16.2 +/- 5.9 vs. 22.5 +/- 9.4 nmol of bone collagen equivalent/mmol Cr (-28%, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Bone mass and long-term monophasic oral contraceptive treatment in young women

A prospective study has been designed to investigate bone metabolism in young women taking an oral monophasic contraceptive formulation (ethinylestradiol 20 micrograms + desogestrel 0.150 mg) over 5 years. Healthy women (n = 200) between 19 and 22 years of age were divided into two groups. Group A received oral contraception, Group B did not receive any treatment. All the subjects underwent a bone mass density (BMD) evaluation at spinal level L2-L4 with Dexa (Norland XR-26) and a measurement of the serum alkaline phosphatase levels and urinary excretion of OH-proline at baseline and every 12 months over 5 years. Our results demonstrated that Group A did not show any significant BMD change after 5 years of oral contraceptive treatment, while Group B demonstrated a significant increase (p < 0.01) in the bone mass content at the end of the time of observation (+7.8% after 5 years). No significant changes were found in serum alkaline phosphatase levels and in urinary excretion of OH-proline at the end of the study in comparison with basal levels in both groups. Our data suggested that long-term treatment with an oral monophasic contraceptive formulation (ethinylestradiol 20 micrograms + desogestrel 0.150 mg) did not modify the BMD but prevented the occurrence of the physiologic peak of bone mass in young women.

Hormone replacement therapy in perimenopausal women with a low dose oral contraceptive preparation: effects on bone mineral density and metabolism

In a 2-year longitudinal, calcium-controlled study we evaluated bone density and metabolism in perimenopausal women with initial ovarian failure, and the effects of hormone replacement with a low dose oral contraceptive preparation (OC). In perimenopausal oligomenorrhoic women (n = 16) a significant (P < 0.01) increase in cycle length and plasma FSH levels as well as a parallel decrease in plasma estradiol levels (P < 0.01) were evident. In this group, despite the calcium supplementation (500 mg/day), a significant (P < 0.001) increase in the biochemical markers of bone remodelling paralleled a significant (P < 0.001) decrease (-3.4% after 24 months) in bone density. Conversely, in premenopausal oligomenorrhoic women treated with a low dose oral contraceptive (OC) formulation (30 mcg ethinyl estradiol plus 75 mcg gestodene, n = 16), bone markers showed a significant (P < 0.01) decrease, that paralleled a slight but significant (P < 0.01) increase (+1.71%) in bone density. These data suggest that premenopausal administration of OC can prevent the acceleration of bone turnover and reverse the decrease in bone density that follows the premenopausal impairment of ovarian function.

Bone mineral density and risk factors for osteoporosis--a population-based study of 1600 perimenopausal women

Population-based epidemiological studies on osteoporosis are few. Our study evaluated the effects of menopause and certain putative behavioural risk factors on bone mineral density (BMD). Spinal and femoral neck BMD were measured with dual X-ray absorptiometry (DXA) from 1600 perimenopausal women aged 48-59 years (mean 53.2 years) with no diseases or medications known to affect bone metabolism. These women were a selected sample of the Kuopio Osteoporosis Risk Factor and Prevention Study population (n = 14,220). There was a wide variation of BMD among perimenopausal women. Menopause had a major effect on BMD. Postmenopausal women had significantly lower BMD in both spine (-6.2%) and femoral neck (-3.9%) as compared with premenopausal women. Multiple regression analysis showed that weight, menopausal status, age, and grip strength were significant independent predictors of both spinal and femoral BMD. Additionally, physical activity was found to be a significant predictor of femoral BMD, and alcohol consumption was a significant predictor of spinal BMD. However, current anthropometric and lifestyle factors explained only 18.7-25.4% of the variability of BMD. Therefore, the estimation of the risk factor status at menopause is not an adequate substitute for bone densitometry. However, our results may in part help clinicians to identify the risk groups at which to direct bone density measurements.

Noncontraceptive effects of hormonal contraceptives: bone mass, sexually transmitted disease and pelvic inflammatory disease, cardiovascular disease, menstrual function, and future fertility

Noncontraceptive actions of oral contraceptives (OCs) include hormonal effects on bone mass, sexually transmitted disease, pelvic inflammatory disease, the cardiovascular system, menstrual function, and future fertility. Information about the effects of OCs on bone mass is limited and contradictory. Two recent studies failed to show a positive effect of OC use on bone mass or density compared with the three cross-sectional studies and one longitudinal study that showed favorable effects. A recently completed study of 156 healthy females indicated a significant correlation between OC use and the rate of change in total body bone-mineral content. One study involving depot medroxyprogesterone acetate suggests bone density decreases with long-term use of the drug. The use of OCs does not reduce the risk of gonococcal or chlamydial infection of the lower tract and in fact may enhance spread of lower tract infection. However, OCs may exert a protective effect against some types of pelvic inflammatory disease. Regarding transmission of human immunodeficiency virus, the results of recent studies are conflicting. Research related to newer OC formulations containing 35 micrograms or less of ethinyl estradiol suggests that the risk of a negative cardiovascular effect is substantially reduced. All forms of hormonal contraception alter menstrual function to some degree, but most patterns improve with duration of use. No evidence exists that hormonal contraception permanently affects fertility, although fertility restoration may be delayed with some agents.

Assessment of age and risk factors on bone density and bone turnover in healthy premenopausal women

The influence of age and risk factors on bone density and bone turnover was evaluated in 249 healthy premenopausal women. Risk factors were assessed by standardized questionnaires and included reproductive history and lifestyle factors (intake of calcium and vitamin D supplements, consumption of caffeine, smoking habits and physical activity). Bone mineral density (BMD) measurements were obtained in the distal forearm, the lumbar spine and the proximal femur. Bone turnover were assessed by plasma bone Gla proteins (pBGP) and fasting urinary hydroxyproline corrected for creatinine (fUHPr/Cr). Peak bone density seems to be achieved before the age of 30 years, whereafter we found no appreciable bone loss at any skeletal site. Accordingly, the levels of pBGP and fUHPr/Cr were increased before the age of 30, whereafter the values stabilized at a lower level. A dairy calcium intake above 660 mg/day significantly increased BMD in the spine and proximal femur by 3%-5%. Physical activity alone had no influence on BMD, but in combination with calcium intake an additive effect was observed. Women who had an active lifestyle (corresponding to at least 1 h of daily walking) and a dairy calcium intake above 660 mg/day had a 3%-7% increase in BMD compared with more sedentary women with a calcium intake below this limit. Vitamin D supplements, caffeine, smoking and reproductive history did not consistently influence BMD or bone turnover. Only pBGP was selectively reduced by smoking and current use of oral contraceptives, respectively. We conclude that there is no appreciable change in BMD before the menopause once skeletal maturity has been reached.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of previous oral contraceptive use on bone mineral density in perimenopausal women

The bone mineral density (BMD) of the lumbar vertebrae L2-4 and femoral neck was determined by dual-energy X-ray absorptiometry (DXA) in 3222 perimenopausal women-a random stratified sample of the population-based Kuopio Osteoporosis Study (OSTPRE). The mean age of the women was 53.4 years (range 47.9-59.6 years). Twenty-nine percent of the women were past users of oral contraceptives (OC) containing 50 micrograms or less of ethinyl estradiol and 7.4% (n = 250) of the women reported OC use for more than 6 years. There was a slight but statistically significant difference between OC users (n = 939) and non-users (n = 2283) in lumbar BMD (1.134 +/- 0.155 g/cm2 v 1.123 +/- 0.161 g/cm2, p = 0.014). A statistically significant difference was recorded also after adjustment for years since menopause, duration of hormonal replacement therapy (HRT) and present weight (p = 0.044). When the analysis was performed among women who had never used oestrogen replacement therapy (n = 1427) and among premenopausal women (n = 387), no differences in BMD were found between OC users and non-users. Similarly, femoral neck BMD did not differ between the groups. This population-based study demonstrated a slightly higher lumbar BMD among past OC users. However, OC users and non-users differed from each other in many behavioral characteristics. Thus, the differences in BMD may be accounted for more by other factors than by past OC use itself. The low-dosage estrogen OCs used today would not be expected to have any positive bone effects among future perimenopausal women.

Bone metabolism in young women taking a monophasic pill containing 20 mcg ethinylestradiol: a prospective study

The present one-year prospective study was performed to evaluate the effects of an oral contraceptive containing 20 mcg ethinylestradiol plus 0.150 mg desogestrel on bone metabolism in young women. Nineteen women aged 20 to 30 years completed the trial. Bone density was measured in the distal radius by dual photon absorptiometry before starting pill use and at the 3rd, 6th and 12th cycle. At the same time intervals, urinary hydroxyproline-to-creatinine ratio and serum alkaline phosphatase were evaluated. Bone density showed a slight, but not significant, increase at the end of the trial. Both urinary hydroxyproline-to-creatinine ratio and serum alkaline phosphatase showed a significant decrease. The results suggest that bone resorption is reduced, although bone density in the distal radius is not significantly increased in young women using an oral contraceptive containing only 20 mcg ethinylestradiol for one year.

Influence of the climacteric on the bone mass of the spine and femur

OBJECTIVE

To determine the correlation between the bone mass of the lumbar spine and the neck of the femur in Spanish climacteric women.

METHOD

Bone mass was measured using quantitative digital radiology in 200 climacteric women who had no record of receiving hormone replacement therapy.

RESULT

A statistically significant correlation (P < 0.05) is observed between the bone mineral density and content of the lumbar spine and the femur in all the groups of climacteric women, although only in the postmenopausal women does it approach 70%. A direct relationship is observed between the loss of bone mass and the onset of the menopause, as well as with the patients' body mass index.

CONCLUSION

When the different parameters are analyzed, the results show that measurement of the lumbar spine is essential, and measurement of the femur should not be used as a substitute, but rather in addition to it.

Determinants of lumbar bone mineral density in normal weight, non-smoking women soon after menopause. A study using clinical data and quantitative computed tomography

OBJECTIVES

Is there an influence of oral contraceptive use, parity and lactation on early postmenopausal bone mass? Is assessment of reproductive history, body weight in combination with biochemical markers of bone metabolism suitable to predict lumbar bone mass soon after menopause?

STUDY DESIGN

A cross-sectional study in 94 healthy, normal weight, non-smoking women, 1-3 years after spontaneous menopause. Bone mineral density (BMD) of the lumbar spine was measured with single energy quantitative computed tomography.

RESULTS

Multiple regression analysis showed that only total duration of lactation and alkaline phosphatase (AP) levels are independently related to trabecular BMD (P = 0.001 and P = 0.002 respectively). AP was also associated with cortical BMD (P = 0.003). Assessment of reproductive history, body mass index and biochemical markers of bone metabolism could only account for 17% of the variation of trabecular BMD observed in the study population.

CONCLUSION

This study suggests that total duration of lactation rather than parity is associated with trabecular BMD of the spine. Clinical assessment of risk factors unsuccessfully predicts lumbar BMD in healthy, early postmenopausal women.