The length of perimenopausal menstrual cycles increases later and to a greater degree than previously reported

Patterns of menstrual cycle length over the menopause transition are associated with subclinical atherosclerosis after menopause

OBJECTIVE

Longer menstrual cycles have been associated with greater risk of cardiovascular disease, supporting a contribution of abnormal ovarian function. We aimed to characterize trajectories of menstrual cycle length over the menopause transition (MT) and test whether these trajectories are associated with postmenopausal markers of subclinical atherosclerosis.

METHODS

Women from the Study of Women's Health Across the Nation Daily Hormone Study were included if they had an observed date of the final menstrual period (FMP), recorded cycle lengths from ≥2 annual menstrual cycles (mean±SD: 4.22 ± 1.91 cycles), and had measurements of postmenopausal carotid intima-media thickness (cIMT) and/or brachial-ankle pulse wave velocity (baPWV). Trajectories of cycle length over the MT were identified using group-based trajectory modeling and linked with cIMT and baPWV using linear regression.

RESULTS

We studied 428 women who had 1,808 cycles over the MT (45.1 ± 2.3 y old at baseline visit), and of whom 263 had cIMT, and 213 had baPWV measured postmenopausally (after 13.88 ± 0.42 and 15.25 ± 0.70 y since baseline visit, respectively). Three distinct trajectories of cycle length were identified: stable (no changes in cycle length over the MT among 62.1% of women), late increase (a late increase 2 y before the FMP among 21.8%), and early-increase (an early increase 5 y before the FMP among 16.2%). Women with the late-increase pattern had significantly lower postmenopausal cIMT (0.72 mm) and baPWV (1392 cm/s) levels than the stable group (0.77 mm and 1508 cm/s, respectively) adjusting for race, concurrent age, socioeconomic status, physical activity level, and premenopausal cardiovascular risk profile.

CONCLUSIONS

Patterns of cycle length over the MT seem to be a marker of future vascular health that may help identify groups at greater or lesser risk of atherosclerosis after menopause.

Characterizing physiological and symptomatic variation in menstrual cycles using self-tracked mobile-health data

The menstrual cycle is a key indicator of overall health for women of reproductive age. Previously, menstruation was primarily studied through survey results; however, as menstrual tracking mobile apps become more widely adopted, they provide an increasingly large, content-rich source of menstrual health experiences and behaviors over time. By exploring a database of user-tracked observations from the Clue app by BioWink GmbH of over 378,000 users and 4.9 million natural cycles, we show that self-reported menstrual tracker data can reveal statistically significant relationships between per-person cycle length variability and self-reported qualitative symptoms. A concern for self-tracked data is that they reflect not only physiological behaviors, but also the engagement dynamics of app users. To mitigate such potential artifacts, we develop a procedure to exclude cycles lacking user engagement, thereby allowing us to better distinguish true menstrual patterns from tracking anomalies. We uncover that women located at different ends of the menstrual variability spectrum, based on the consistency of their cycle length statistics, exhibit statistically significant differences in their cycle characteristics and symptom tracking patterns. We also find that cycle and period length statistics are stationary over the app usage timeline across the variability spectrum. The symptoms that we identify as showing statistically significant association with timing data can be useful to clinicians and users for predicting cycle variability from symptoms, or as potential health indicators for conditions like endometriosis. Our findings showcase the potential of longitudinal, high-resolution self-tracked data to improve understanding of menstruation and women's health as a whole.

Quantitative bias analysis for epidemiological associations of perfluoroalkyl substance serum concentrations and early onset of menopause

An association between increased serum concentrations of perfluoroalkyl substances (PFAS) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) and early menopause has been reported (Knox et al., 2011; Taylor et al., 2014). This association may be explained by the fact that women who underwent menopause no longer excrete PFAS through menstruation. Our objective was to assess how much of the epidemiologic association between PFAS and altered timing of menopause might be explained by reverse causality. We extended a published population life-stage physiologically-based pharmacokinetic (PBPK) model of PFOS and PFOA characterized by realistic distributions of physiological parameters including age at menopause. We then conducted Monte Carlo simulations to replicate the Taylor population (Taylor et al., 2014) and the Knox population (Knox et al., 2011). The analysis of the simulated data overall showed a pattern of results that was comparable to those reported in epidemiological studies. For example, in the simulated Knox population (ages 42-51) the odds ratio (OR) for menopause in the fifth quintile of PFOA compared to those in the first quintile was 1.33 (95% CI 1.26-1.40), whereas the reported OR was 1.4 (95% CI 1.1-1.8). Using our model structure, a substantial portion of the associations reported can be explained by pharmacokinetics.

Influence of race/ethnicity, body mass index, and proximity of menopause on menstrual cycle patterns in the menopausal transition: the Study of Women's Health Across the Nation

OBJECTIVE

Few studies have evaluated factors that influence menstrual cycle length (MCL) during the menopausal transition (MT), a life stage during which very long cycles become more likely to occur. The objective of this article was to assess how body mass index and race/ethnicity--factors associated with MCL in young women--influence MCL during the MT.

METHODS

Study of Women's Health Across the Nation menstrual calendar substudy data of African-American, white, Chinese, and Japanese women were available for three sites (southeastern Michigan, Los Angeles, and northern California). Self-recorded monthly menstrual calendars with end-of-the-month questions on hormone therapy use and smoking were collected from 1996 to 2006. Height and weight were measured at annual study visits. We used quantile regression to model MCL at the 25th, 50th, 75th, and 90th percentiles with bootstrap sampling to construct 95% CIs. Models evaluated MCL with time indexed to the start of the MT (n = 963) and to the final menstrual period (n = 431).

RESULTS

During the MT, increases in MCL occurred mostly at the right tail of the distribution, reflecting a lengthening of long menstrual cycles, not of the median MCL. After adjustment for smoking, education, physical activity, and time, Chinese and Japanese women had 1 day to 6 days longer MCLs compared with white women. Obese women had 1 day to 5 days longer MCLs compared with nonobese women.

CONCLUSIONS

As occurs in younger women, menstrual characteristics during the MT are influenced by race/ethnicity and obesity. The long menstrual cycles characteristic of the MT are longer in obese women and in Chinese and Japanese women.

Oral contraception

Oral contraception (OC) remains a popular noninvasive, readily reversible approach for pregnancy prevention and, largely off label, for control of acne, hirsutism, dysmenorrhea, irregular menstruation, menorrhagia, and other menstrual-related symptoms. Many OC formulations exist, with generics offering lower cost and comparable efficacy. Certain medical conditions, including hypertension, migraine, breast cancer, and risk of venous thromboembolism (VTE), present contraindications. Blood pressure measurement is the only physical examination or testing needed before prescription. Although no OC is clearly superior to others, OCs containing the second-generation progestin levonorgestrel have been associated with lower VTE risk than those containing other progestins.

In the clinic. Perimenopause

This issue provides a clinical overview of Perimenopause focusing on prevention, diagnosis, treatment, practice improvement, and patient information. The content of In the Clinic is drawn from the clinical information and education resources of the American College of Physicians (ACP), including ACP Smart Medicine and MKSAP (Medical Knowledge and Self-Assessment Program). Annals of Internal Medicine editors develop In the Clinic from these primary sources in collaboration with the ACP's Medical Education and Publishing divisions and with the assistance of science writers and physician writers. Editorial consultants from ACP Smart Medicine and MKSAP provide expert review of the content. Readers who are interested in these primary resources for more detail can consult http://smartmedicine.acponline.org, http://mksap.acponline.org, and other resources referenced in each issue of In the Clinic.

Cohort efficacy study of natural family planning among perimenopause age women

OBJECTIVE

To determine the efficacy of using natural family planning (NFP) methods to avoid unintended pregnancy among women of perimenopause age (i.e., age 40-55 years).

DESIGN

A secondary analysis of subset data from two prospective observational cohort studies.

SETTING

A university based in-person and online NFP service program.

PARTICIPANTS

One hundred and sixty couples who used either a website or an in-person NFP service to learn how to avoid pregnancy from January 2001 to November 2012.

METHODS

A prospective 12-month effectiveness study among 160 women (between ages 40-55) who used NFP to avoid pregnancy. The women used either a hormonal fertility monitor, cervical mucus monitoring, or both to estimate the fertile phase of their menstrual cycles. Survival analysis was used to determine the pregnancy rate over 12 months of use.

RESULTS

There were a total of five unintended pregnancies among the participants. The typical use pregnancy rate was six per 100 women over 12 months. The monitor alone participants (n = 35) had a 12-month pregnancy rate of three, the participants (n = 73) who used mucus alone had a pregnancy rate of four, and the participants (n = 42) who used the fertility monitor plus mucus had a pregnancy rate of six.

CONCLUSION

Natural family planning methods can be effective for older women to avoid an unintended pregnancy with correct use and adequate instructions. The pregnancy rate most likely was affected by diminished fertility and motivation to limit family size.

Autoimmune diseases and reproductive aging

As the population ages, more individuals with autoimmune diseases are experiencing reproductive senescence. Understanding the impact of menopause and age-related androgen decline on disease onset and course, as well as the potential for hormonal interventions, is critically important. In men, lupus erythematosis (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS) are associated with lower androgen levels. However, the impact of age-related declines in testosterone, as well as of testosterone replacement, on disease course remains underexplored. In women, the course of all three diseases with onset after the age of menopause differs from that with onset before menopause. Early age at menopause is associated with increased disease risk, and after menopause, disease course changes in SLE and RA. Less is known about MS. This article summarizes what is known about the relationship between reproductive aging and autoimmune diseases in men and women, and highlights areas for further investigation.

Hypoestrogenic "inactive phases" at the start of the menstrual cycle: changes with age and reproductive stage, and relationship to follicular depletion

OBJECTIVE

To investigate hypoestrogenic "inactive phases" (IP) in the follicular phase of the menstrual cycle, with respect to age, reproductive stage, and follicular depletion.

DESIGN

Analysis of prospectively collected menstrual bleed and estrone-3-glucuronide data.

SETTING

Center for Population and Health, Georgetown University.

PATIENT(S)

White women (n = 88, aged 25-59 years, mean = 44.7 years) from the population-based Biodemographic Models of Reproductive Aging (BIMORA) project.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The IP durations by age and reproductive stage. Estimated follicular depletion rate based on IP durations.

RESULT(S)

Mean IP duration and variability decreased and then increased with age/reproductive stage. The proportion of very short (≤ 1 day) IP durations increased and then decreased with age/stage. Long IPs occurred most, but not exclusively, in the oldest age/latest stage. Follicular depletion rate estimates were a plausible 2%-4% per year of age, but these models were a poor fit because IP durations did not consistently increase across ages/stages.

CONCLUSION(S)

Follicular depletion models alone do not explain the observed pattern of IPs. Our data suggest that IPs reflect both follicular depletion and hyperstimulation in premenopausal and perimenopausal women. Knowledge of underlying IP patterns in the menstrual cycle could inform decisions about hormone sampling and contraception during the perimenopause.

Reproductive aging, sex steroids, and mood disorders

Epidemiologic studies have documented that the majority of women do not become depressed during the menopause transition. However, recent longitudinal studies suggest that in some women, the events related to the menopause transition could play a role in the onset of depression. In this article we review evidence suggesting a relationship between the menopause transition and depression. Additionally, we describe several findings that suggest a role of ovarian hormones in the onset of these depressions, including the clustering of episodes of depression during the stage of the menopause transition that is accompanied by estradiol withdrawal, and the therapeutic effects of short-term estradiol in depressed perimenopausal women. Finally, we discuss possible causes of affective disturbances during the menopause transition.

The influence of stress on the menstrual cycle among newly incarcerated women

OBJECTIVE

We sought to estimate the association of stressful life events on menstrual function in incarcerated women.

METHODS

Project CONNECT is a study of reproductive health needs of incarcerated women conducted between June 2002 and December 2003. This analysis examines menstrual function in 446 women from this cohort who were under the age of 45. Regularity was defined as menses between 26 and 35 days long. Amenorrhea was defined as > or =90 days since last menstruation. Measures included stressful experiences and deprivation (e.g., physical or sexual abuse, stressful living conditions, exchanging sex for drugs or money, or having had an incarcerated parent).

RESULTS

Menstrual dysfunction was common in this population. Nine percent reported amenorrhea, and 33% reported menstrual irregularity. A number of stressors were associated with menstrual irregularity, including having a parent with history of alcohol or drug problems (relative risk [RR] = 1.34; 95% confidence interval [CI], 1.00-1.80), childhood physical or sexual abuse (RR = 1.48; 95% CI, 1.03-2.13), or any sexual abuse (RR = 1.49; 95% CI, 1.03-2.14) after adjusting for age, race/ethnicity, smoking status, and recent drug use. These effects were attenuated somewhat when excluding women who had reported any hormonal contraceptive use in the past 3 months.

CONCLUSION

Incarcerated women have high rates of amenorrhea and menstrual irregularity and the prevalence may be associated with certain stresses. Further research on the causes and consequences of menstrual dysfunction in this underserved population is needed.