Oral contraceptive use and bone mass in women aged 26-36 years

Fracture incidence in women: the impact of reproductive characteristics

BACKGROUND

Although endogenous estrogen exposure, influenced by reproductive factors (RFs), is negatively associated with fracture risk, there is limited and conflicting information on the association between these factors and the incidence of fractures. This study aimed to evaluate the association between RFs and fracture incidence (FXI) separately.

METHODS

This longitudinal study commenced in 1999 and concluded in 2021. It is performed on women without previous fractures and adjusted for confounders. RFs, including age at menarche, parity, abortion, duration of breastfeeding (BF), hormonal contraceptive use, and age at menopause, were exposure variables. The incidence of fractures was the primary outcome. A Cox proportional hazards regression model was used to estimate the associations between RFs and FXI outcomes.

RESULTS

The median (interquartile range) of follow-up time was 15.0 (12.1-17.0) years. A total of 19.9% (1324/6653)of the women were menopausal at baseline, and 13% (865/6653) of the remaining participants reached menopause at the end of follow-up. At the end of the follow-up, 222 (3.3%) participants had fractures. The mean age of participants at the initiation of the study and last follow-up were 35.8 (15.5) and 50.0 (15.3) years, respectively. After adjusting for potential confounders, the HR of FXI increased by 10% per one extra delivery (HR: 1.10,95% CI: (1.03, 1.18); p = 0.01), and by 12% per one-year increase in age at menarche (HR: 1.12, 95% CI: (1.02, 1.23); p = 0.02). The HR of FXI decreased by 3% per month extra exclusive BF (HR: 0.97,95% CI: (0.94, 0.99); p = 0.04).

CONCLUSIONS

The results elucidate that a longer duration of exclusive BF has a protective effect on FXI. In contrast, increasing age at menarche and the number of parities increase the risk of FXI.

Association of hormone preparations with bone mineral density, osteopenia, and osteoporosis in postmenopausal women: data from National Health and Nutrition Examination Survey 1999-2018

OBJECTIVE

This study aimed to evaluate the associations of hormone preparations with lumbar spine bone mineral density (BMD), osteopenia, and osteoporosis in postmenopausal women, and whether these impacts persisted after hormone preparations were discontinued.

METHODS

A total of 6,031 postmenopausal women were enrolled and divided into seven groups based on the types of hormone preparations. Among them, 1,996 participants were further divided into a current users (CU) group and a past users (PU) group. Multivariable linear regression models or logistic regression models were used to evaluate the associations of hormone preparation with lumbar spine BMD, osteopenia, and osteoporosis.

RESULTS

Combined oral contraceptive pills, estrogen-only pills, estrogen/progestin combo pills, estrogen-only patches, or the use of more than two kinds of hormone preparations were positively associated with lumbar spine BMD (all P < 0.05). Except for estrogen-only patches, other hormone preparations also had a protective effect against osteopenia (all OR < 1, all P < 0.05), but none of them were associated with osteoporosis prevalence (all P > 0.05). The BMD increased by 0.10 and 0.04 g/cm 2 in the CU and PU groups, respectively, compared with the nonusers group (all P < 0.05). In both the CU and PU groups, the risk of osteopenia was reduced (OR, 0.34 and 0.57, respectively).

CONCLUSIONS

Hormone preparations increase lumbar spine BMD in postmenopausal women and exert a protective effect against osteopenia. These impacts persisted after hormone preparations were discontinued. Hormone preparations, however, were not associated with osteoporosis prevalence.

Hormonal contraceptive use, bone density and biochemical markers of bone metabolism in British Army recruits

INTRODUCTION

Hormonal contraceptive use might impair bone health and increase the risk of stress fracture by decreasing endogenous oestrogen production, a central regulator of bone metabolism. This cross-sectional study investigated bone density and biochemical markers of bone metabolism in women taking hormonal contraceptives on entry to basic military training.

METHODS

Forty-five female British Army recruits had biochemical markers of bone metabolism, areal bone mineral density (aBMD) and tibial speed of sound (tSOS) measured at the start of basic military training. Participants were compared by their method of hormonal contraception: no hormonal contraception (NONE), combined contraceptive pill (CP) or depot-medroxyprogesterone acetate (DMPA) (20±2.8 years, 1.64±0.63 m, 61.7±6.2 kg).

RESULTS

aBMD was not different between groups (p≥0.204), but tSOS was higher in NONE (3%, p=0.014) when compared with DMPA users. Beta C-terminal telopeptide was higher in NONE (45%, p=0.037) and DMPA users (90%, p=0.003) compared with CP users. Procollagen type 1 N-terminal propeptide was higher in DMPA users compared with NONE (43%, p=0.045) and CP users (127%, p=0.001), and higher in NONE compared with CP users (59%, p=0.014). Bone alkaline phosphatase was higher in DMPA users compared with CP users (56%, p=0.044).

CONCLUSIONS

DMPA use was associated with increased bone turnover and decreased cortical bone integrity of the tibia. Lower cortical bone integrity in DMPA users was possibly mediated by increased intracortical remodelling, but trabecular bone was not affected by contraceptive use.

Association of Female Reproductive Factors With Incidence of Fracture Among Postmenopausal Women in Korea

IMPORTANCE

Although estrogen level is positively associated with bone mineral density, there are limited data on the risk of fractures after menopause.

OBJECTIVE

To investigate whether female reproductive factors are associated with fractures among postmenopausal women.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study used data from the Korean National Health Insurance Service database on 1 272 115 postmenopausal women without previous fracture who underwent both cardiovascular and breast and/or cervical cancer screening from January 1 to December 31, 2009. Outcome data were obtained through December 31, 2018.

EXPOSURES

Information was obtained about reproductive factors (age at menarche, age at menopause, parity, breastfeeding, and exogenous hormone use) by self-administered questionnaire.

MAIN OUTCOMES AND MEASURES

Incidence of any fractures and site-specific fractures (vertebral, hip, and others).

RESULTS

Among the 1 272 115 participants, mean (SD) age was 61.0 (8.1) years. Compared with earlier age at menarche (≤12 years), later age at menarche (≥17 years) was associated with a higher risk of any fracture (adjusted hazard ratio [aHR], 1.24; 95% CI, 1.17-1.31) and vertebral fracture (aHR, 1.42; 95% CI, 1.28-1.58). Compared with earlier age at menopause (<40 years), later age at menopause (≥55 years) was associated with a lower risk of any fracture (aHR, 0.89; 95% CI, 0.86-0.93), vertebral fracture (aHR, 0.77; 95% CI, 0.73-0.81), and hip fracture (aHR, 0.88; 95% CI, 0.78-1.00). Longer reproductive span (≥40 years) was associated with lower risk of fractures compared with shorter reproductive span (<30 years) (any fracture: aHR, 0.86; 95% CI, 0.84-0.88; vertebral fracture: aHR, 0.73; 95% CI, 0.71-0.76; and hip fracture: aHR, 0.87; 95% CI, 0.80-0.95). Parous women had a lower risk of any fracture than nulliparous women (aHR, 0.96; 95% CI, 0.92-0.99). Although breastfeeding for 12 months or longer was associated with a higher risk of any fractures (aHR, 1.05; 95% CI, 1.03-1.08) and vertebral fractures (aHR, 1.22; 95% CI, 1.17-1.27), it was associated with a lower risk of hip fracture (aHR, 0.84; 95% CI, 0.76-0.93). Hormone therapy for 5 years or longer was associated with lower risk of any factures (aHR, 0.85; 95% CI, 0.83-0.88), while use of oral contraceptives for 1 year or longer was associated with a higher risk of any fractures (aHR, 1.03; 95% CI, 1.01-1.05).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that female reproductive factors are independent risk factors for fracture, with a higher risk associated with shorter lifetime endogenous estrogen exposure. Interventions to reduce fracture risk may be needed for women at high risk, including those without osteoporosis.

Negative impact of polycystic ovary syndrome on bone health: a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) has reproductive and metabolic aspects that may affect bone health. Controversial results from different studies regarding the risk of fractures, bone mineral density (BMD) or bone markers led to uncertainty whether PCOS might improve or deteriorate bone health.

OBJECTIVE AND RATIONALE

This study aimed to investigate the impact of PCOS on bone markers, BMD and fracture risk.

SEARCH METHODS

A systematic review and a meta-analysis were carried out. PubMed, EMBASE and Cochrane databases were searched for eligible studies from 1st of January of 1990 to 9th of October of 2018. Eligible studies enrolled women older than 18 years with PCOS, which should be diagnosed according to the Rotterdam Consensus, the Androgen Excess Society, the National Institutes of Health Consensus or the International Classification of Diseases. The studies were grouped according to patient mean BMI: <27 kg/m2 or ≥27 kg/m2. The results were polled as mean difference (MD), standardized MD (SMD) and hazard ratio (HR).

OUTCOMES

Overall, 921 studies were retrieved, and 31 duplicated studies were removed. After screening the titles and abstracts, 80 studies were eligible for full text reading. Of those, 23 studies remained for qualitative synthesis. With the exception of one study, all studies were considered high quality based on the Newcastle-Ottawa scale (NOS; score ≥6). Meta-analysis was performed in 21 studies, with a total of 31 383 women with PCOS and 102 797 controls. Women with PCOS with BMI <27 kg/m2 had lower BMD of the total femur (MD, -0.04; 95% CI, -0.07 to 0.00; I2 = 31%; P = 0.22) and spine (MD, -0.07; 95% CI, -0.13 to -0.01; I2 = 70%; P < 0.01) when compared with the control group, whereas for women with BMI ≥27 kg/m2 no difference was observed (femur: MD, 0.02; 95% CI, -0.02 to 0.05; I2 = 20%, P = 0.29; spine: MD, 0.02; 95% CI, -0.06 to 0.05; I2 = 0%; P = 0.84). Osteocalcin was remarkably reduced in women with PCOS with BMI <27 kg/m2 (SMD, -2.68; 95% CI, -4.70 to -0.67; I2 = 98%; P < 0.01), but in women with BMI ≥27 kg/m2, there were no differences between PCOS and controls. Few studies (n = 3) addressed the incidence of bone fractures in women with PCOS. The HR for total bone fractures did not identify differences between women with PCOS and controls.

WIDER IMPLICATIONS

On the basis of the available evidence, it is possible to assume that PCOS in women with BMI <27 kg/m2 is associated with reduced BMD in the spine and femur, and decreased bone formation, as manifested by lower levels of circulating osteocalcin. These findings suggest that bone parameters in PCOS may be linked, to some extent, to adiposity. These studies included premenopausal women, who have already achieved peak bone mass. Hence, further prospective studies are necessary to clarify the existence of increased risk of fractures in women with PCOS.

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.