Longitudinal Changes in Sex Hormone Binding Globulin (SHBG) and Risk of Incident Diabetes: The Study of Women's Health Across the Nation (SWAN)

OBJECTIVE

To investigate the associations of longitudinal changes in sex hormone binding globulin (SHBG) and testosterone (T) over the menopause transition with the risk of diabetes.

RESEARCH DESIGN AND METHODS

We followed 2,952 participants in the Study of Women's Health Across the Nation (SWAN) who were premenopausal or early perimenopausal and diabetes-free at baseline. SHBG,T, and estradiol (E2) levels were measured at up to 13 follow-up visits (over up to 17 years). We used complementary log-log-based discrete-time survival models anchored at baseline.

RESULTS

Diabetes developed in 376 women. A 5-unit increase in time-varying SHBG was associated with a 10% reduced risk of diabetes (hazard ratio [HR] 0.91, 95% CI 0.87-0.95), adjusting for covariates, and baseline SHBG,T, and E2 levels. Time-varying T was not associated with diabetes risk. Compared with the lowest quartile for annual rate of change of SHBG since baseline (quartile 1 [Q1] -92.3 to -1.5 nmol/L), all other quartiles were associated with a decreased risk of diabetes adjusting for covariates and baseline SHBG; associations persisted after adjusting for rate of change of T and E2 (Q2 [> -1.5 to -0.2 nmol/L] HR 0.33, 95% CI 0.23-0.48; Q3 [> -0.2 to 1.3 nmol/L] HR 0.37, 95% CI 0.25-0.55; Q4 [>1.3 to 82.0 nmol/L] HR 0.43, 95% CI 0.30-0.63).

CONCLUSIONS

Increasing levels of SHBG over the menopause transition were associated with a decreased risk of incident diabetes. Stable to increasing rates of change in SHBG were also independently associated with a decreased risk of diabetes compared with decreasing rates of change, suggesting SHBG may affect glucose through a mechanism beyond androgenicity.

Heavy Metals and Trajectories of Anti-Müllerian Hormone During the Menopausal Transition

BACKGROUND

Experimental and epidemiological studies have linked metals with women's reproductive aging, but the mechanisms are not well understood. Disrupted ovarian folliculogenesis and diminished ovarian reserve could be a pathway through which metals impact reproductive hormones and outcomes.

OBJECTIVE

The study aimed to evaluate the associations of heavy metals with anti-Müllerian hormone (AMH), a marker of ovarian reserve.

METHODS

The study included 549 women from the Study of Women's Health Across the Nation with 2252 repeated AMH measurements from 10 to 0 years before the final menstrual period (FMP). Serum AMH concentrations were measured using picoAMH ELISA. Urinary concentrations of arsenic, cadmium, mercury, and lead were measured using high-resolution inductively coupled plasma mass spectrometry. Multivariable linear mixed regressions modeled AMH as a function of time before the FMP interaction terms between metals and time to the FMP were also included.

RESULTS

Adjusting for confounders, compared with those in the lowest tertile, women in the highest tertile of urinary arsenic or mercury concentrations had lower AMH concentrations at the FMP (percent change: -32.1%; 95% CI, -52.9 to -2.2, P-trend = .03 for arsenic; percent change: -40.7%; 95% CI, -58.9 to -14.5, P-trend = .005 for mercury). Higher cadmium and mercury were also associated with accelerated rates of decline in AMH over time (percent change per year: -9.0%; 95% CI, -15.5 to -1.9, P-trend = .01 for cadmium; -7.3%; 95% CI, -14.0 to -0.1, P-trend = .04 for mercury).

CONCLUSION

Heavy metals including arsenic, cadmium, and mercury may act as ovarian toxicants by diminishing ovarian reserve in women approaching the FMP.

Associations between exposure to air pollution and sex hormones during the menopausal transition

Menopause is a significant milestone in a woman's life, characterized by decreasing estradiol (E2) and increasing follicle-stimulating hormone (FSH) levels. Growing evidence suggests that air pollution may affect reproductive health and disrupt hormone profiles, yet the associations in women undergoing menopausal transition (MT) remains underexplored. We examined the associations between annual air pollutant exposures and repeated measures of E2 and FSH in 1365 women with known final menstrual period (FMP) date from the Study of Women's Health Across the Nation. Air pollution was calculated as the annual averages of 24-h average PM2.5 levels, daily one-hour maximum NO2 levels, and daily 8-h maximum O3 levels. Linear mixed models with piece-wise linear splines were used to model non-linear trajectories of E2 and FSH in three distinct time periods: up to 2 years before the FMP (early MT), within 2 years before and 2 years after FMP (transmenopause), and >2 years post-FMP (postmenopause). In the transmenopausal period, an interquartile (5 μg/m3) increase in PM2.5 was associated with a significant decrease in E2 levels (-15.7 %, 95 % CI: -23.7, -6.8), and a 10 ppb increase in NO2 was associated with a significant decrease in E2 levels (-9.2 %, 95 % CI: -16.2, -1.7). A higher PM2.5 was also associated with an accelerated rate of decline in E2. Regarding FSH, a 10 ppb increase in NO2 was associated with decline in FSH levels (-11.7 %, 95 % CI: -21.8, -0.1) in the early MT and accelerated rates of decline in the postmenopause (-1.1 % per year, 95 % CI: -2.1, -0.1). Additionally, inverse associations between O3 and FSH were observed in the transmenopause and postmenopause. Our study suggests that increases in PM2.5, NO2, and O3 exposures are linked to significant declines in E2 and FSH levels across menopausal stages, suggesting the detrimental impact of air pollutants on women's reproductive hormones.

Relationships between the vaginal microbiota and genitourinary syndrome of menopause symptoms in postmenopausal women: the Study of Women's Health Across the Nation

OBJECTIVE

To describe vaginal microbiota classified by community state types (CST) in a diverse cohort of postmenopausal women and evaluate relationships among genitourinary syndrome of menopause (GSM) symptoms (vaginal dryness, vulvovaginal irritation, sexual pain, dysuria, urinary urgency), CSTs, estrogen, vaginal maturation index (VMI), and vaginal pH.

METHODS

In the Study of Women's Health Across the Nation, 1,320 women aged 60.4 to 72.5 years self-collected (2015-2017) vaginal samples analyzed for microbiota composition and structure (CSTs) using 16S rRNA gene amplicon sequencing, VMI, and pH. GSM symptoms were collected with self-administered questionnaires; interviewers elicited estrogen use and measured body mass index. Serum E2 and E1 were measured using high-performance liquid chromatography. We analyzed data using Pearson χ2 tests, analysis of variance, Kruskal-Wallis tests, and binomial logistic regression.

RESULTS

The most frequently occurring CST was low Lactobacillus species IV-C (49.8%); 36.4% of women had CSTs dominated by Lactobacillus species. More than half of the women with vaginal atrophy biomarkers (VMI <50 and pH >5) had CST IV-C0, whereas women using estrogen or with higher E1 and E2 levels had a higher prevalence of Lactobacillus crispatus -dominated CST I ( P values < 0.001). Sexual pain was associated with atrophy biomarkers and independently associated with Streptococcus species-dominated CST IV-C1 (odds ratio, 2.26; 95% confidence intervals, 1.20-4.23). For all other GSM symptoms, we found no consistent associations with E1 or E2 levels, atrophy biomarkers, or any CST.

CONCLUSIONS

Although close relationships exist among estrogen, CSTs, VMI, and pH, sexual pain was the only GSM symptom associated with the structure of vaginal microbiota and atrophy biomarkers.

Sexual functioning among breast cancer survivors and non-cancer controls over 5 years post diagnosis: Pink SWAN

PURPOSE

To compare sexual functioning from diagnosis to 5 years post diagnosis among breast cancer survivors (BCS) and women without cancer (controls).

PATIENTS AND METHODS

Analyses included 118 BCS and 1765 controls from 20 years of the longitudinal Study of Women's Health Across the Nation (SWAN), a multiracial/ethnic cohort of mid-life women assessed approximately annually from 1995 to 2015. Pink SWAN participants reported no cancer at SWAN enrollment and developed (BCS) or did not develop (controls) incident breast cancer after enrollment. Outcomes included: being sexually active or not, intercourse frequency, sexual desire, vaginal dryness, and pain with intercourse. Using longitudinal logistic regression, we compared BCS and controls on prevalence of sexual functioning outcomes with respect to years since diagnosis. In addition, we examined whether menopause transition stage, depressive symptoms, relationship satisfaction, vaginal dryness, or pain with intercourse modified the relation between breast cancer and sexual functioning outcomes.

RESULTS

Adjusting for partner status, both BCS and controls reported similar declines over time in being sexually active, sexual intercourse frequency, and sexual desire. Among sexually active women, more BCS than controls consistently reported vaginal dryness with significant differences between 2 and 4 years post-diagnosis, and pain with intercourse, with statistically significant differences between 0.5 years post-diagnosis to 2 years post-diagnosis. Being post-menopausal and reporting depressive symptoms were significant effect modifiers for pain with intercourse with both variables having positive and stronger associations with pain among the controls than among BCS.

CONCLUSION

Except for more reporting of vaginal dryness and pain with intercourse among BCS, negative changes in sexual function during mid-life were similar in those with and without breast cancer.

Exposure to heavy metals and hormone levels in midlife women: The Study of Women's Health Across the Nation (SWAN)

Exposure to heavy metals may alter the circulating levels of sex hormones. However, epidemiologic studies on heavy metals and sex hormones have been limited, and results have been inconsistent. We assessed the associations of heavy metals assayed in urine, including arsenic, cadmium, lead, and mercury, with repeated measures of serum estradiol (E2), follicle-stimulating hormone (FSH), testosterone, and sex hormone-binding globulin (SHBG) levels in the Study of Women's Health Across the Nation Multi-Pollutant Study. The sample included 1355 White, Black, Chinese, and Japanese women, aged 45-56 years at baseline (1999-2000), whose serum hormone levels were repeatedly measured through 2017. Urinary metal concentrations were measured at baseline. Linear mixed effect models were used to calculate percent changes in serum hormone levels per doubling of urinary metal concentrations, adjusting for demographics, socioeconomic status, lifestyle, health-related factors, and urinary creatinine. After multivariable adjustment, a doubling of urinary metal concentration was associated with lower E2 levels by 2.2% (95% CI: 4.0%, -0.3%) for mercury and 3.6% (95% CI: 5.7%, -1.6%) for lead; higher FSH levels by 3.4% (95% CI: 0.9%, 5.9%) for lead; and higher SHBG levels by 3.6% (95% CI: 1.3%, 5.9%) for cadmium. The overall joint effect using the Bayesian kernel machine regression showed that metal mixtures were inversely associated with E2 and positively associated with FSH levels. No association was found between metals and testosterone levels. Results from this prospective cohort study demonstrate that environmental heavy metal exposures, including cadmium, mercury, and lead, may disturb circulating levels of E2, FSH, and SHBG in midlife women.

Dietary, Psychological and Lifestyle Factors Associated with Premenstrual Symptoms

Purpose

To measure the associations of diet, psycological distress, and lifestyle factors with premenstrual symptoms (PMSx) in women in Riyadh, Saudi Arabia.

Patients and Methods

An interview-based, cross-sectional study was conducted on 1831 women aged 18-50 years seen in primary healthcare centers and teaching institutes in Riyadh from December 2015 to June 2016. Question topics included sociodemographics, physical activity, smoking, and dietary habits information. PMSx were assessed using a symptom checklist with 6 domains: anxiety/mood changes; abdominal/back/joint pain; increased appetite/weight gain, breast pain/tenderness, severe headache, and ≥3 PMS symptoms (any). Multivariable logistic regression analyses were conducted to provide adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for factors associated with each PMSx domain.

Results

Except for breast pain, drinking >5 cups of Arabic coffee was associated with increased odds of anxiety/mood [aOR 2.44 (95% CI 1.44, 4.12)], pain [1.83 (1.13, 2.98)], appetite/weight gain [1.66 (1.10, 2.50)], headache [1.57 (1.00, 2.56)] and ≥3 symptoms [1.50 (1.07, 2.11)]. A significant association was noted between sugar intake and anxiety/mood symptoms [1.53 (1.07, 2.19)] and abdominal/back pain symptoms [1.84 (1.17, 2.88)]. Increased severity of psychological distress was associated with all symptom domains: anxiety/mood [2.75 (1.92, 3.94)]; pain [1.45 (0.92, 2.28)]; appetite/weight gain [2.01 (1.53, 2.65)]; breast pain [2.19 (1.68, 2.88)]; headache [1.86 (1.37, 2.54)] and ≥3 symptoms [3.52 (2.49, 4.95)]. Low physical activity was significantly associated with odds of breast pain symptoms [1.29 (1.04, 1.59)]. Smokers were 3.41 (1.19, 9.77) times as likely to report any ≥3 symptoms compared to nonsmokers.

Conclusion

Several potentially modifiable factors, such as diet and stress, were positively associated with PMSx. Thus, we suggest that increasing women's awareness of healthy lifestyles, particularly diet and stress reduction, may help to reduce the occurrence of premenstrual symptoms.

Longitudinal Associations of Air Pollution With Body Size and Composition in Midlife Women: The Study of Women's Health Across the Nation

OBJECTIVE

We examined longitudinal associations of air pollution exposure, including fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3), with weight, BMI, waist circumference, fat mass, lean mass, and proportion fat mass in midlife women.

RESEARCH DESIGN AND METHODS

The study population included 1,654 White, Black, Chinese, and Japanese women from the Study of Women's Health Across the Nation, with the baseline median age of 49.6 years, followed from 2000 to 2008. Annual air pollution exposures were assigned by linking residential addresses with hybrid estimates of air pollutant concentrations at 1-km2 resolution. Body size was measured, and body composition was measured using DXA at approximately annual visits. Linear mixed effects models were used to examine the associations between air pollution and body size and composition measures and whether these associations differed by physical activity.

RESULTS

After adjusting for potential confounders, an interquartile range increase in PM2.5 concentration (4.5 μg/m3) was associated with 4.53% (95% CI 3.85%, 5.22%) higher fat mass, 1.10% (95% CI 0.95%, 1.25%) higher proportion fat mass, and 0.39% (95% CI -0.77%, -0.01%) lower lean mass. Similar associations were also observed for NO2 and O3. Weaker associations of PM2.5 and NO2 with body composition were observed in participants who engaged in more physical activity.

CONCLUSIONS

Our analyses provide evidence that exposure to PM2.5, NO2, and O3, is adversely associated with body composition, including higher fat mass, higher proportional fat mass, and lower lean mass, highlighting their potential contribution to obesity.

Anti-Müllerian hormone levels and breast cancer risk in the study of women's health across the nation

PURPOSE

The relation of premenopausal anti-Müllerian hormone (AMH) levels with breast cancer risk has been evaluated in a few studies, but primarily in non-Hispanic White women.

METHODS

We evaluated the association of AMH levels with breast cancer risk in Study of Women's Health Across the Nation (SWAN), a multi-ethnic cohort of women. At enrollment, participants had an intact uterus and ≥ 1 ovary, and ≥ 1 menstrual period in the last 3 months. AMH at first measurement was assessed in 1,529 pre- or perimenopausal women using a high-sensitivity ELISA assay; values were natural log transformed. Breast cancer diagnoses were assessed at enrollment and subsequent follow-up visits through 2018 (median 6.1 years).

RESULTS

In total, 84 women reported an incident breast cancer diagnosis. In multivariable Cox regression models adjusting for age, race and ethnicity, body mass index, and other factors, higher AMH levels were associated with a non-significant increased breast cancer risk. Compared to women in the 1st quartile, the hazard ratio (95% confidence interval) for women in the 4th quartile was 1.77 (0.87-3.60).

CONCLUSION

Our results did not suggest a significant association between AMH and breast cancer risk; however, estimates were consistent with prior studies that reported positive associations.

Perfluoroalkyl Substances and Incident Natural Menopause in Midlife Women: The Mediating Role of Sex Hormones

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) have been associated with earlier natural menopause; however, the underlying mechanisms are not well understood, particularly the extent to which this relationship is mediated by sex hormones. We analyzed data (1999-2017) on 1,120 premenopausal women from the Study of Women's Health Across the Nation (SWAN). Causal mediation analysis was applied to quantify the degree to which follicle-stimulating hormone (FSH) and estradiol levels could mediate the associations between PFAS and incident natural menopause. Participants with higher PFAS concentrations had shorter times to natural menopause, with a relative survival of 0.82 (95% confidence interval (CI): 0.69, 0.96) for linear perfluorooctane sulfonate (n-PFOS), 0.84 (95% CI: 0.69, 1.00) for sum of branched-chain perfluorooctane sulfonate (Sm-PFOS), 0.79 (95% CI: 0.66, 0.93) for linear-chain perfluorooctanoate (n-PFOA), and 0.84 (95% CI: 0.71, 0.97) for perfluorononanoate (PFNA), comparing the highest tertile of PFAS concentrations with the lowest. The proportion of the effect mediated through FSH was 8.5% (95% CI: -11.7, 24.0) for n-PFOS, 13.2% (95% CI: 0.0, 24.5) for Sm-PFOS, 26.9% (95% CI: 15.6, 38.4) for n-PFOA, and 21.7% (6.8, 37.0) for PFNA. No significant mediation by estradiol was observed. The effect of PFAS on natural menopause may be partially explained by variations in FSH concentrations.

Patterns of Sexual Activity and the Development of Sexual Pain Across the Menopausal Transition

OBJECTIVE

To examine whether patterns of sexual intercourse frequency and demographic, menopausal status, genitourinary, health, and psychosocial factors are associated with developing sexual pain across the menopausal transition.

METHODS

These were longitudinal analyses of questionnaire data from the multicenter, multiracial and ethnic prospective cohort SWAN (Study of Women's Health Across the Nation) (1995-2008). We used multivariable discrete-time proportional hazards models to examine whether incident sexual pain was associated with preceding long-term (up to 10 visits) or short-term (two and three visits) sexual intercourse frequency patterns or other factors (eg, menopause status, genitourinary symptoms, lifestyle factors, and mental health).

RESULTS

Of the 2,247 women with no sexual pain at baseline, 1,087 (48.4%) developed sexual pain at least "sometimes" up to 10 follow-up visits over 13 years. We found no consistent association between prior patterns of sexual intercourse frequency and development of sexual pain. For example, neither decreases in intercourse frequency from baseline (adjusted hazard ratio [aHR] 0.93, 95% CI 0.73-1.19) nor decreases in frequency over three prior visits (aHR 1.00, 95% CI 0.72-1.41) were associated with incident pain. Reasons for interruptions in intercourse activity at the prior visit, including lack of interest (aHR 1.64, 95% CI 0.74-3.65) and relationship issues (aHR 0.36, 95% CI 0.04-2.88), were not associated with developing pain. Being postmenopausal using hormone therapy (aHR 3.16, 95% CI 1.46-6.85), and reported vaginal dryness (aHR 3.73, 95% CI 2.88-4.83) were most strongly associated with incident sexual pain.

CONCLUSION

Long-term and short-term declines in sexual intercourse frequency across the menopausal transition were not associated with increased hazard of developing pain with intercourse. This empirical evidence does not support the common belief that a reduction in women's sexual frequency is responsible for their symptoms of sexual pain.

Comparing polysomnography, actigraphy, and sleep diary in the home environment: The Study of Women's Health Across the Nation (SWAN) Sleep Study

Study Objectives

Polysomnography (PSG) is considered the "gold standard" for assessing sleep, but cost and burden limit its use. Although wrist actigraphy and self-report diaries are feasible alternatives to PSG, few studies have compared all three modalities concurrently across multiple nights in the home to assess their relative validity across multiple sleep outcomes. This study compared sleep duration and continuity measured by PSG, actigraphy, and sleep diaries and examined moderation by race/ethnicity.

Methods

Participants from the Study of Women's Health Across the Nation (SWAN) Sleep Study included 323 White (n = 147), African American (n = 120), and Chinese (n = 56) middle-aged community-dwelling women (mean age: 51 years, range: 48-57). PSG, wrist actigraphy (AW-64; Philips Respironics, McMurray, PA), and sleep diaries were collected concurrently in participants' homes over three consecutive nights. Multivariable repeated-measures linear models compared time in bed (TIB), total sleep time (TST), sleep efficiency (SE), sleep latency (SL), and wake after sleep onset (WASO) across modalities.

Results

Actigraphy and PSG produced similar estimates of sleep duration and efficiency. Diaries yielded higher estimates of TIB, TST, and SE versus PSG and actigraphy, and lower estimates of SL and WASO versus PSG. Diary SL was shorter than PSG SL only among White women, and diary WASO was lower than PSG and actigraphy WASO among African American versus White women.

Conclusions

Given concordance with PSG, actigraphy may be preferred as an alternative to PSG for measuring sleep in the home. Future research should consider racial/ethnic differences in diary-reported sleep continuity.

Vasomotor symptoms in midlife women with incident breast cancer: pink SWAN

PURPOSE

We compared trajectories of vasomotor symptoms (VMS) and their risk factors in women with breast cancer (BrCa) to those of cancer-free controls.

METHODS

Data were from 15 nearly annual follow-up visits (1996-2017) of the multi-racial/ethnic cohort of midlife women enrolled in the Study of Women's Health Across the Nation (SWAN). We compared women with incident BrCa to controls for patterns of VMS, controlling for risk factors identified in bivariate analyses using multivariable longitudinal analyses.

RESULTS

Characteristics at study entry largely did not differ between cases (n = 151) and controls (n = 2161). Adjusted prevalence of any VMS increased significantly among cases from diagnosis to 2.75 years post diagnosis [per-year adjusted odds ratio (aOR) = 1.76, 95% confidence interval (CI) 1.39-2.24], peaking at 2.75 years post diagnosis, whereas prevalence was stable among controls in this interval [aOR = 1.04, 95% CI 0.99-1.11]. Beyond 2.75 years post diagnosis, prevalence declined significantly in cases [aOR = 0.72, 95% CI 0.61-0.84] and less in controls [aOR = 0.96, 95% CI 0.92-1.00]. Patterns were similar for frequent VMS. Adjustment for tamoxifen use slightly reduced the per-year OR for any prevalent VMS post diagnosis, partially explaining excess VMS in cases. Other treatments were unassociated with VMS.

CONCLUSIONS

Patterns of prevalent VMS reporting differed significantly between cases and controls, particularly post diagnosis, the latter only partially explained by tamoxifen use among cases. Risk factors for VMS largely did not differ between cases and controls.

Meta-analysis for individual participant data with a continuous exposure: A case study

OBJECTIVE

Methods for meta-analysis of studies with individual participant data and continuous exposure variables are well described in the statistical literature but are not widely used in clinical and epidemiological research. The purpose of this case study is to make the methods more accessible.

STUDY DESIGN AND SETTING

A two-stage process is demonstrated. Response curves are estimated separately for each study using fractional polynomials. The study-specific curves are then averaged pointwise over all studies at each value of the exposure. The averaging can be implemented using fixed effects or random effects methods.

RESULTS

The methodology is illustrated using samples of real data with continuous outcome and exposure data and several covariates. The sample data set, segments of Stata and R code, and outputs are provided to enable replication of the results.

CONCLUSION

These methods and tools can be adapted to other situations, including for time-to-event or categorical outcomes, different ways of modelling exposure-outcome curves, and different strategies for covariate adjustment.

Urinary metals and metal mixtures and timing of natural menopause in midlife women: The Study of Women's Health Across the Nation

BACKGROUND

Exposure to metals and metal mixtures may influence ovarian aging. However, epidemiologic evidence of their potential impact is lacking.

OBJECTIVE

We prospectively examined the associations of 15 urinary metal concentrations and their mixtures with natural menopause in the Study of Women's Health Across the Nation Multi-Pollutant Study.

METHODS

The study population consisted of 1082 premenopausal women from multiple racial/ethnic groups, aged 45-56 years at baseline (1999-2000), with the median follow-up of 4.1 years. Urinary concentrations of 15 metals, including arsenic, barium, cadmium, cobalt, cesium, copper, mercury, manganese, molybdenum, nickel, lead, antimony, tin, thallium, and zinc, were measured at baseline. Natural menopause was defined as the final bleeding episode prior to at least 12 months of amenorrhea, not due to surgery or hormone therapy. Cox proportional hazards models were used to examine associations between individual metal concentrations and timing of natural menopause. The associations between metal mixtures and natural menopause were evaluated using elastic net penalized Cox regression, and an environmental risk score (ERS) was computed to represent individual risks of natural menopause related to metal mixtures.

RESULTS

The median age at natural menopause was 53.2 years. Using the Cox proportional hazards models, the adjusted hazard ratio (HR) (and its 95% confidence interval (CI)) for natural menopause was 1.32 (1.03, 1.67) for arsenic and 1.36 (1.05, 1.76) for lead, comparing the highest with the lowest quartiles of metal concentrations. The predicted ages at natural menopause in the highest and lowest quartiles were 52.7 and 53.5 years for arsenic; and 52.9 and 53.8 years for lead. A significant association between ERS and menopause was also observed. Women in the highest vs. the lowest quartiles of ERS had an HR of 1.71 (1.36, 2.15), equivalent to a 1.6 year earlier median time to natural menopause.

CONCLUSION

This study suggests that arsenic, lead, and metal mixtures are associated with earlier natural menopause, a risk factor for adverse health outcomes in later life.

Per- and Polyfluoroalkyl Substances and Hormone Levels During the Menopausal Transition

CONTEXT

Per- and polyfluoroalkyl substances (PFAS) are widespread chemicals that may affect sex hormones and accelerate reproductive aging in midlife women.

OBJECTIVE

To examine associations between serum PFAS concentrations at baseline (1999-2000) and longitudinal serum concentrations of follicle-stimulating hormone (FSH), estradiol, testosterone, and sex hormone-binding globulin (SHBG) at baseline and through 2015-2016.

DESIGN

Prospective cohort.

SETTING

General community.

PARTICIPANTS

1371 midlife women 45 to 56 years of age at baseline in the Study of Women's Health Across the Nation (SWAN).

MAIN OUTCOME MEASURE(S)

FSH, estradiol, testosterone, SHBG.

RESULTS

In linear mixed models fitted with log-transformed hormones and log-transformed PFAS adjusting for age, site, race/ethnicity, smoking status, menopausal status, parity, and body mass index, FSH was positively associated with linear perfluorooctanoate [n-PFOA; 3.12% (95% CI 0.37%, 5.95%) increase for a doubling in serum concentration), linear perfluorooctane sulfonate [PFOS; 2.88% (0.21%, 5.63%)], branched perfluorooctane sulfonate [2.25% (0.02%, 4.54%)], total PFOS (3.03% (0.37%, 5.76%)), and 2-(N-ethyl-perfluorooctane sulfonamido) acetate [EtFOSAA; 1.70% (0.01%, 3.42%)]. Estradiol was inversely associated with perfluorononanoate [PFNA; -2.47% (-4.82%, -0.05%)) and n-PFOA (-2.43% (-4.97%, 0.18%)]. Significant linear trends were observed in the associations between PFOS and EtFOSAA with SHBG across parity (Ps trend ≤ 0.01), with generally inverse associations among nulliparous women but positive associations among women with 3+ births. No significant associations were observed between PFAS and testosterone.

CONCLUSIONS

This study observed positive associations of PFOA and PFOS with FSH and inverse associations of PFNA and PFOA with estradiol in midlife women during the menopausal transition, consistent with findings that PFAS affect reproductive aging.

Lowered progesterone metabolite excretion and a variable LH excretion pattern are associated with vasomotor symptoms but not negative mood in the early perimenopausal transition: Study of Women's Health Across the Nation

OBJECTIVE

The menopausal transition is characterized by progressive changes in ovarian function and increasing circulating levels of gonadotropins, with some women having irregular menstrual cycles well before their final menstrual period. These observations indicate a progressive breakdown of the hypothalamic-pituitary-ovarian axis often associated with an increase in menopausal symptoms. Relationships between vasomotor symptoms (VMS) and depressed mood and sleep as well as a bidirectional association between VMS and depressed mood in mid-life women have been reported, but the endocrine foundations and hormone profiles associated with these symptoms have not been well described. Our objective was to determine the relationship between daily urinary hormone profiles and daily logs of affect and VMS during the early perimenopausal transition.

STUDY DESIGN

SWAN, the Study of Women's Health Across the Nation, is a large, mutli-ethnic, multisite cohort study of 3302 women aged 42-52 at baseline, designed to examine predictors of health and disease in women as they traversed the menopause. Inclusion criteria were: an intact uterus and at least one ovary present, at least one menstrual period in the previous three months, no use of sex steroid hormones in the previous three months, and not pregnant or lactating. A subset (n = 849) of women aged 43-53 years from all study sites in the first Daily Hormone Study collection were evaluated for this substudy.

OUTCOME MEASURES

We measured daily VMS, and urinary hormones: follicle stimulating hormone (FSH), luteinizing hormone (LH), pregnanediol glucuronide (PdG) and estradiol (estrone conjugate, E1C).

RESULTS

A variable pattern of LH and negative LH feedback were the hormone patterns most strongly associated with increased VMS. In contrast, no hormone pattern was significantly related to negative mood.

CONCLUSION

Fluctuations of LH associated with low progesterone production were associated with VMS but not negative mood, suggesting different endocrine patterns may be related to increased negative mood than to the occurrence of VMS.

Age at menarche and risk of vasomotor menopausal symptoms: a pooled analysis of six studies

OBJECTIVE

To examine the association between age at menarche and risk of vasomotor menopausal symptoms (VMS) and whether midlife body mass index (BMI) modified the association.

DESIGN

A pooled analysis of six cohort studies.

SETTING

The International collaboration on the Life course Approach to reproductive health and Chronic disease Events (InterLACE).

POPULATION

18 555 women from the UK, USA and Australia.

METHODS

VMS frequency data (never, rarely, sometimes and often) were harmonised from two studies (n = 13 602); severity data (never, mild, moderate and severe) from the other four studies (n = 4953). Multinominal logistic regression models were used to estimate relative risk ratios (RRRs) and 95% CIs adjusted for confounders and incorporated study as random effects.

MAIN OUTCOME MEASURES

Hot flushes and night sweats.

RESULTS

Frequency data showed that early menarche ≤11 years was associated with an increased risk of 'often' hot flushes (RRR 1.48, 95% CI 1.24-1.76) and night sweats (RRR 1.59, 95% CI 1.49-1.70) compared with menarche at ≥14 years. Severity data showed similar results, but appeared less conclusive, with RRRs of 1.16 (95% CI 0.94-1.42) and 1.27 (95% CI 1.01-1.58) for 'severe' hot flushes and night sweats, respectively. BMI significantly modified the association as the risk associated with early menarche and 'often' VMS was stronger among women who were overweight or obese than those of normal weight, while this gradient across BMI categories was not as strong with the risk of 'severe' VMS.

CONCLUSIONS

Early age at menarche is a risk factor for VMS, particularly for frequent VMS, but midlife BMI may play an important role in modifying this risk.

TWEETABLE ABSTRACT

Overweight and obesity exacerbate the risk of vasomotor symptoms associated with early menarche.

Vasomotor menopausal symptoms and risk of cardiovascular disease: a pooled analysis of six prospective studies

BACKGROUND

Menopausal vasomotor symptoms (ie, hot flashes and night sweats) have been associated with unfavorable risk factors and surrogate markers of cardiovascular disease, but their association with clinical cardiovascular disease events is unclear.

OBJECTIVE

To examine the associations between different components of vasomotor symptoms, timing of vasomotor symptoms, and risk of cardiovascular disease.

STUDY DESIGN

We harmonized and pooled individual-level data from 23,365 women in 6 prospective studies that contributed to the International Collaboration for a Life Course Approach to Women's Reproductive Health and Chronic Disease Events consortium. Women who experienced cardiovascular disease events before baseline were excluded. The associations between frequency (never, rarely, sometimes, and often), severity (never, mild, moderate, and severe), and timing (before or after age of menopause; ie, early or late onset) of vasomotor symptoms and incident cardiovascular disease were analyzed. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals.

RESULTS

In the adjusted model, no evidence of association was found between the frequency of hot flashes and incident cardiovascular disease, whereas women who reported night sweats "sometimes" (hazard ratio, 1.22; 95% confidence interval, 1.02-1.45) or "often" (hazard ratio, 1.29; 95% confidence interval, 1.05-1.58) had higher risk for cardiovascular disease. Increased severity of either hot flashes or night sweats was associated with higher risk of cardiovascular disease. The hazards ratios of cardiovascular disease in women with severe hot flashes, night sweats, and any vasomotor symptoms were 1.83 (95% confidence interval, 1.22-2.73), 1.59 (95% confidence interval, 1.07-2.37), and 2.11 (95% confidence interval, 1.62-2.76), respectively. Women who reported severity of both hot flashes and night sweats had a higher risk for cardiovascular disease (hazard ratio, 1.55; 95% confidence interval, 1.24-1.94) than those with hot flashes alone (hazard ratio, 1.33; 95% confidence interval, 0.94-1.88) and night sweats alone (hazard ratio, 1.32; 95% confidence interval, 0.84-2.07). Women with either early-onset (hazard ratio, 1.38; 95% confidence interval, 1.10-1.75) or late-onset (hazard ratio, 1.69; 95% confidence interval, 1.32-2.16) vasomotor symptoms had an increased risk for incident cardiovascular disease compared with women who did not experience vasomotor symptoms.

CONCLUSION

Severity rather than frequency of vasomotor symptoms (hot flashes and night sweats) was associated with increased risk of cardiovascular disease. Vasomotor symptoms with onset before or after menopause were also associated with increased risk of cardiovascular disease.

Association Between Reproductive Life Span and Incident Nonfatal Cardiovascular Disease: A Pooled Analysis of Individual Patient Data From 12 Studies

Importance

Early menarche and early menopause are associated with increased risk of cardiovascular disease (CVD) in midlife, but little is known about the association between reproductive life span and the risk of CVD.

Objective

To investigate the association between the length of reproductive life span and risk of incident CVD events, while also considering the timing of menarche and menopause.

Design, Setting, and Participants

Individual-level data were pooled from 12 studies participating in the International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events consortium. Women provided complete information on the timing of menarche and menopause, nonfatal CVD events, and covariates. Cox proportional hazards models were used to estimate hazard ratios and 95% CIs, adjusted for covariates. The association between reproductive life span and CVD was adjusted for age at menarche and age at menopause separately. Analysis began March 2018 and ended December 2019.

Exposures

Reproductive life span was calculated by subtracting age at menarche from age at menopause and categorized as younger than 30, 30 to 32, 33 to 35, 36 to 38 (reference group), 39 to 41, 42 to 44, and 45 years or older.

Main Outcomes and Measures

First nonfatal CVD event, including coronary heart disease and stroke events.

Results

A total of 307 855 women were included. Overall, the mean (SD) ages at menarche, menopause, and reproductive life span were 13.0 (1.5) years, 50.2 (4.4) years, and 37.2 (4.6) years, respectively. Pooled analyses showed that women with a very short reproductive life span (<30 years) were at 1.71 (95% CI, 1.58-1.84) times higher risk of incident CVD events than women with a reproductive life span of 36 to 38 years after adjustment for covariates. This association remained unchanged when adjusted for age at menarche but was attenuated to 1.26 (95% CI, 1.09-1.46) when adjusted for age at menopause. There was a significant interaction between reproductive life span and age at menarche associated with CVD risk (P < .001). Women who had both short reproductive life span (<33 years) and early menarche (age ≤11 years) had the highest risk of CVD (hazard ratio, 2.06; 95% CI, 1.76-2.41) compared with those with a reproductive life span of 36 to 38 years and menarche at age 13 years.

Conclusions and Relevance

Short reproductive life span was associated with an increased risk of nonfatal CVD events in midlife, and the risk was significantly higher for women with early age at menarche.

Association between coarse particulate matter and inflammatory and hemostatic markers in a cohort of midlife women

BACKGROUND

Exposure to particulate matter air pollution has been associated with cardiovascular disease (CVD) morbidity and mortality; however, most studies have focused on fine particulate matter (PM_2.5) exposure and CVD. Coarse particulate matter (PM_10-2.5) exposure has not been extensively studied, particularly for long-term exposure, and the biological mechanisms remain uncertain.

METHODS

We examined the association between ambient concentrations of PM_10-2.5 and inflammatory and hemostatic makers that have been linked to CVD. Annual questionnaire and clinical data were obtained from 1694 women (≥ 55 years old in 1999) enrolled in the longitudinal Study of Women's Health Across the Nation (SWAN) at six study sites from 1999 to 2004. Residential locations and the USEPA air monitoring network measurements were used to assign exposure to one-year PM_10-2.5, as well as co-pollutants. Linear mixed-effects regression models were used to describe the association between PM_10-2.5 exposure and markers, including demographic, health and other covariates.

RESULTS

Each interquartile (4 μg/m³) increase in one-year PM_10-2.5 exposure was associated with a 5.5% (95% confidence interval [CI]: 1.8, 9.4%) increase in levels of plasminogen activator inhibitor-1 (PAI-1) and 4.1% (95% CI: - 0.1, 8.6%) increase in high-sensitivity C-creative Protein (hs-CRP). Stratified analyses suggested that the association with PAI-1 was particularly strong in some subgroups, including women who were peri-menopausal, were less educated, had a body mass index lower than 25, and reported low alcohol consumption. The association between PM_10-2.5 and PAI-1 remained unchanged with adjustment for PM_2.5, ozone, nitrogen dioxide, and carbon monoxide.

CONCLUSIONS

Long-term PM_10-2.5 exposure may be associated with changes in coagulation independently from PM_2.5, and thus, contribute to CVD risk in midlife women.

Associations of Perfluoroalkyl Substances with Incident Natural Menopause: The Study of Women's Health Across the Nation

CONTEXT

Previous epidemiologic studies of per- and polyfluoroalkyl substances (PFASs) and menopausal timing conducted in cross-sectional settings were limited by reverse causation because PFAS serum concentrations increase after menopause.

OBJECTIVES

To investigate associations between perfluoroalkyl substances and incident natural menopause.

DESIGN AND SETTING

A prospective cohort of midlife women, the Study of Women's Health Across the Nation, 1999-2017.

PARTICIPANTS

1120 multiracial/ethnic premenopausal women aged 45-56 years.

METHODS

Serum concentrations of perfluoroalkyls were quantified by high-performance liquid chromatography isotope dilution tandem mass spectrometry. Natural menopause was defined as the bleeding episode prior to at least 12 months of amenorrhea not due to surgery or hormone use. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Participants contributed 5466 person-years of follow-up, and 578 had incident natural menopause. Compared with the lowest tertile, women at the highest tertile of baseline serum concentrations had adjusted HR for natural menopause of 1.26 (95% CI: 1.02-1.57) for n-perfluorooctane sulfonic acid (n-PFOS) (Ptrend = .03), 1.27 (95% CI: 1.01-1.59) for branched-PFOS (Ptrend = .03), and 1.31 (95% CI: 1.04-1.65) for n-perfluorooctanoic acid (Ptrend = .01). Women were classified into four clusters based on their overall PFAS concentrations as mixtures: low, low-medium, medium-high, and high. Compared with the low cluster, the high cluster had a HR of 1.63 (95% CI: 1.08-2.45), which is equivalent to 2.0 years earlier median time to natural menopause.

CONCLUSION

This study suggests that select PFAS serum concentrations are associated with earlier natural menopause, a risk factor for adverse health outcomes in later life.

Obesity, smoking, and risk of vasomotor menopausal symptoms: a pooled analysis of eight cohort studies

BACKGROUND

Frequent and severe vasomotor symptoms during menopause are linked with adverse health outcomes. Understanding modifiable lifestyle factors for the risk of vasomotor menopausal symptoms is important to guide preventive strategies.

OBJECTIVE

We investigated the associations between body mass index and smoking, their joint effects with the risk of vasomotor symptoms, and whether the associations differed by menopausal stage.

STUDY DESIGN

The International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events pooled data on 21,460 midlife women from 8 studies (median age, 50 years; interquartile range, 49-51 years) for the cross-sectional analysis. Four studies provided data for the prospective analysis (n=11,986). Multinomial logistic regression models with 4 categories of frequency/severity for the outcome of vasomotor symptoms were used to estimate relative risk ratios and 95% confidence intervals that were adjusted for within-study correlation and covariates.

RESULTS

At baseline, nearly 60% of the women experienced vasomotor symptoms. One-half of them were overweight (30%) or obese (21%), and 17% were current smokers. Cross-sectional analyses showed that a higher body mass index and smoking more cigarettes with longer duration and earlier initiation were all associated with more frequent or severe vasomotor symptoms. Never smokers who were obese had a 1.5-fold (relative risk ratio, 1.52; 95% confidence interval, 1.35-1.73) higher risk of often/severe vasomotor symptoms, compared with never smokers who were of normal-weight. Smoking strengthened the association because the risk of often/severe vasomotor symptoms was much greater among smokers who were obese (relative risk ratio, 3.02; 95% confidence interval, 2.41-3.78). However, smokers who quit at <40 years of age were at similar levels of risk as never smokers. Prospective analyses showed a similar pattern, but the association attenuated markedly after adjustment for baseline vasomotor symptoms. Furthermore, we found that the association between body mass index and vasomotor symptoms differed by menopausal status. Higher body mass index was associated with increased risk of vasomotor symptoms in pre- and perimenopause but with reduced risk in postmenopause.

CONCLUSION

High body mass index (≥25 kg/m2) and cigarette smoking substantially increased women's risk for experiencing frequent or severe vasomotor symptoms in a dose-response manner, and smoking intensified the effect of obesity. However, the effect of body mass index on the risk of vasomotor symptoms was opposite among postmenopausal women. Maintaining a normal weight before the menopausal transition and quitting smoking at <40 years of age may mitigate the excess risk of vasomotor symptoms in midlife.

The impact of breast cancer on physical activity from midlife to early older adulthood and predictors of change post-diagnosis

PURPOSE

To examine physical activity (PA) patterns from pre- to post-diagnosis, and compare these changes to women without breast cancer. To determine pre-diagnosis predictors of PA change, post-diagnosis, in breast cancer survivors (BCS).

METHODS

Data were from 2314 Study of Women's Health Across the Nation (SWAN) participants, average age of 46.4 ± 2.7 years at baseline (1996-1997). In Pink SWAN, 151 women who reported an incident breast cancer diagnosis over 20 years were classified as BCS; the remaining 2163 women were controls. LOESS plots and linear mixed models were used to illustrate and compare PA changes (sports/exercise [primary measure] and total PA) from pre- to post-diagnosis (or corresponding period) in BCS versus controls. Adjusted linear regression models were used to determine pre-diagnosis predictors of at-risk post-diagnosis PA change patterns (consistently low and decreased PA).

RESULTS

No differences in pre- to post-diagnosis PA (or corresponding period) were observed in BCS versus controls. Among BCS, the odds of at-risk post-diagnosis PA change patterns was 2.50 (95% CI 0.96-6.48) times higher for those who reported sleep problems at ≥ 50% (compared to 0%) of pre-diagnosis visits and 3.49 (95% CI 1.26-9.65) times higher for those who were overweight or obese at all (compared to no) pre-diagnosis visits. No other statistically significant predictors were noted.

CONCLUSIONS

Age-related declines in PA were not amplified by a breast cancer diagnosis. Given the beneficial role of PA across the cancer control continuum, efforts to increase or maintain adequate PA, post-diagnosis, should be continued.

IMPLICATIONS FOR CANCER SURVIVORS

While age-related physical activity declines were not amplified breast cancer diagnosis, efforts to identify breast cancer survivors at increased risk for post-diagnosis physical activity declines (or maintenance of low activity) may be a high-yield strategy to improve prognosis and quality of life.

Age at natural menopause and risk of incident cardiovascular disease: a pooled analysis of individual patient data

Background

Early menopause is linked to an increased risk of cardiovascular disease mortality; however, the association between early menopause and incidence and timing of cardiovascular disease is unclear. We aimed to assess the associations between age at natural menopause and incidence and timing of cardiovascular disease.

Methods

We harmonised and pooled individual-level data from 15 observational studies done across five countries and regions (Australia, Scandinavia, the USA, Japan, and the UK) between 1946 and 2013. Women who had reported their menopause status, age at natural menopause (if postmenopausal), and cardiovascular disease status (including coronary heart disease and stroke) were included. We excluded women who had hysterectomy or oophorectomy and women who did not report their age at menopause. The primary endpoint of this study was the occurrence of first non-fatal cardiovascular disease, defined as a composite outcome of incident coronary heart disease (including heart attack and angina) or stroke (including ischaemic stroke or haemorrhagic stroke). We used Cox proportional hazards models to estimate multivariate hazard ratios (HRs) and 95% CIs for the associations between age at menopause and incident cardiovascular disease event. We also adjusted the model to account for smoking status, menopausal hormone therapy status, body-mass index, and education levels. Age at natural menopause was categorised as premenopausal or perimenopausal, younger than 40 years (premature menopause), 40–44 years (early menopause), 45–49 years (relatively early), 50–51 years (reference category), 52–54 years (relatively late), and 55 years or older (late menopause).

Findings

Overall, 301 438 women were included in our analysis. Of these 301 438 women, 12 962 (4·3%) had a first non-fatal cardiovascular disease event after menopause, of whom 9369 (3·1%) had coronary heart disease and 4338 (1·4%) had strokes. Compared with women who had menopause at age 50–51 years, the risk of cardiovascular disease was higher in women who had premature menopause (age <40 years; HR 1·55, 95% CI 1·38–1·73; p<0·0001), early menopause (age 40–44 years; 1·30, 1·22–1·39; p<0·0001), and relatively early menopause (age 45–49 years; 1·12, 1·07–1·18; p<0·0001), with a significantly reduced risk of cardiovascular disease following menopause after age 51 years (p<0·0001 for trend). The associations persisted in never smokers, and were strongest before age 60 years for women with premature menopause (HR 1·88, 1·62–2·20; p<0·0001) and early menopause (1·40, 1·27–1·54; p<0·0001), but were attenuated at age 60–69 years, with no significant association observed at age 70 years and older.

Interpretation

Compared with women who had menopause at age 50–51 years, women with premature and early menopause had a substantially increased risk of a non-fatal cardiovascular disease event before the age of 60 years, but not after age 70 years. Women with earlier menopause need close monitoring in clinical practice, and age at menopause might also be considered as an important factor in risk stratification of cardiovascular disease for women.

Funding

Australian National Health and Medical Research Council.

Patterns of Cardiometabolic Health as Midlife Women Transition to Menopause: A Prospective Multiethnic Study

CONTEXT

Cardiometabolic conditions increase in midlife, but early customized prevention strategies are not established for such women.

OBJECTIVE

To characterize and identify factors longitudinally related to constellations of cardiometabolic risk components in multiracial/ethnic women in midlife.

DESIGN

We conducted a prospective, longitudinal, multiethnic cohort study of 3003 midlife women undergoing menopausal transition (MT). Metabolic syndrome (MetS) was defined as having at least three of five components: high fasting triglyceride (hTG) level, low high-density lipoprotein cholesterol (lHDL-C) level, high fasting plasma glucose (hGluc) level, large waist circumference (abdominal obesity; Ob), and hypertension (HTN). We described the patterns of constellations and estimated hazard ratios (HRs) for constellations at (i) incident MetS and (ii) recovery from MetS, using multivariable-adjusted Cox regression.

SETTING

Seven US sites.

PARTICIPANTS

In all, 1412 non-Hispanic white, 851 black, 272 Japanese, 237 Hispanic, and 231 Chinese women.

EXPOSURES

Race/ethnicity, lifestyle factors, and MT stage.

MAIN OUTCOMES MEASURES

Cardiometabolic constellations, incident MetS, and MetS recovery.

RESULTS

Central obesity was the most frequent component. Having no components was the most frequent (31%) baseline constellation. Physical activity (HR = 1.68; 95% CI: 1.06, 2.68) and lower caloric intake (HR = 0.96; 95% CI: 0.93, 0.99 per 100 cal/d) were associated with recovery from MetS. Ob/hTG/lHDL-C (18%), Ob/HTN/lHDL-C (16%), and Ob/HTN/hGluc (14%) were frequent incident constellations. Physically active women had 26% to 62% lower hazards of incident MetS than inactive women.

CONCLUSIONS

Modifiable lifestyle behaviors were related to recovery from MetS and decreased risk of the most frequent MetS constellations in midlife women.

Associations between fine particulate matter and changes in lipids/lipoproteins among midlife women

Fine particles (PM2.5) are known to increase risks of cardiovascular diseases, but it is unclear how they affect plasma lipid levels. In this study, we examined the associations between PM2.5 exposure and lipid/lipoprotein levels from 2289 midlife women enrolled in the longitudinal Study of Women's Health Across the Nation. The average exposure to PM2.5 and gaseous co-pollutants during the prior one year, six months, 30 days, and one day were estimated for each woman based on U.S. Environmental Protection Agency ambient monitoring data. Blood samples were collected annually from 1999 to 2005 and analyzed for lipids/lipoproteins. Mixed-effect models were used to account for repeated measures for each woman, adjusted for demographic, health and behavior covariates. PM2.5 exposures, especially the long-term exposure, were negatively associated with protective lipoproteins, and positively associated with atherogenic lipoproteins. For example, each 3 μg/m3 increase of one-year PM2.5 exposure was associated with decreases of -0.7% (-1.4%, -0.1%) in high-density lipoprotein cholesterols and -0.6% (-1.1%, -0.1%) in apolipoprotein A1 (ApoA1), as well as increases of 3.8% (1.0%, 6.6%) in lipoprotein(a) and 1.4% (0.5%, 2.3%) in the ratio of apolipoprotein B (ApoB)/ApoA1. In stratified analysis, increased atherogenic lipoproteins were mainly observed in women without dyslipidemia, and both increased atherogenic lipoproteins and reduced protective lipoproteins were observed among women in perimenopause. In summary, PM2.5 exposure was associated with adverse lipid level changes, and thus, may increase cardiovascular risks in midlife women.

Relationships between intensity, duration, cumulative dose, and timing of smoking with age at menopause: A pooled analysis of individual data from 17 observational studies

BACKGROUND

Cigarette smoking is associated with earlier menopause, but the impact of being a former smoker and any dose-response relationships on the degree of smoking and age at menopause have been less clear. If the toxic impact of cigarette smoking on ovarian function is irreversible, we hypothesized that even former smokers might experience earlier menopause, and variations in intensity, duration, cumulative dose, and age at start/quit of smoking might have varying impacts on the risk of experiencing earlier menopause.

METHODS AND FINDINGS

A total of 207,231 and 27,580 postmenopausal women were included in the cross-sectional and prospective analyses, respectively. They were from 17 studies in 7 countries (Australia, Denmark, France, Japan, Sweden, United Kingdom, United States) that contributed data to the International collaboration for a Life course Approach to reproductive health and Chronic disease Events (InterLACE). Information on smoking status, cigarettes smoked per day (intensity), smoking duration, pack-years (cumulative dose), age started, and years since quitting smoking was collected at baseline. We used multinomial logistic regression models to estimate multivariable relative risk ratios (RRRs) and 95% confidence intervals (CIs) for the associations between each smoking measure and categorised age at menopause (<40 (premature), 40-44 (early), 45-49, 50-51 (reference), and ≥52 years). The association with current and former smokers was analysed separately. Sensitivity analyses and two-step meta-analyses were also conducted to test the results. The Bayesian information criterion (BIC) was used to compare the fit of the models of smoking measures. Overall, 1.9% and 7.3% of women experienced premature and early menopause, respectively. Compared with never smokers, current smokers had around twice the risk of experiencing premature (RRR 2.05; 95% CI 1.73-2.44) (p < 0.001) and early menopause (1.80; 1.66-1.95) (p < 0.001). The corresponding RRRs in former smokers were attenuated to 1.13 (1.04-1.23; p = 0.006) and 1.15 (1.05-1.27; p = 0.005). In both current and former smokers, dose-response relationships were observed, i.e., higher intensity, longer duration, higher cumulative dose, earlier age at start smoking, and shorter time since quitting smoking were significantly associated with higher risk of premature and early menopause, as well as earlier menopause at 45-49 years. Duration of smoking was a strong predictor of age at natural menopause. Among current smokers with duration of 15-20 years, the risk was markedly higher for premature (15.58; 11.29-19.86; p < 0.001) and early (6.55; 5.04-8.52; p < 0.001) menopause. Also, current smokers with 11-15 pack-years had over 4-fold (4.35; 2.78-5.92; p < 0.001) and 3-fold (3.01; 2.15-4.21; p < 0.001) risk of premature and early menopause, respectively. Smokers who had quit smoking for more than 10 years had similar risk as never smokers (1.04; 0.98-1.10; p = 0.176). A limitation of the study is the measurement errors that may have arisen due to recall bias.

CONCLUSIONS

The probability of earlier menopause is positively associated with intensity, duration, cumulative dose, and earlier initiation of smoking. Smoking duration is a much stronger predictor of premature and early menopause than others. Our findings highlight the clear benefits for women of early smoking cessation to lower their excess risk of earlier menopause.

The role of sleep difficulties in the vasomotor menopausal symptoms and depressed mood relationships: an international pooled analysis of eight studies in the InterLACE consortium

BACKGROUND

Many women experience both vasomotor menopausal symptoms (VMS) and depressed mood at midlife, but little is known regarding the prospective bi-directional relationships between VMS and depressed mood and the role of sleep difficulties in both directions.

METHODS

A pooled analysis was conducted using data from 21 312 women (median: 50 years, interquartile range 49-51) in eight studies from the InterLACE consortium. The degree of VMS, sleep difficulties, and depressed mood was self-reported and categorised as never, rarely, sometimes, and often (if reporting frequency) or never, mild, moderate, and severe (if reporting severity). Multivariable logistic regression models were used to examine the bi-directional associations adjusted for within-study correlation.

RESULTS

At baseline, the prevalence of VMS (40%, range 13-62%) and depressed mood (26%, 8-41%) varied substantially across studies, and a strong dose-dependent association between VMS and likelihood of depressed mood was found. Over 3 years of follow-up, women with often/severe VMS at baseline were more likely to have subsequent depressed mood compared with those without VMS (odds ratios (OR) 1.56, 1.27-1.92). Women with often/severe depressed mood at baseline were also more likely to have subsequent VMS than those without depressed mood (OR 1.89, 1.47-2.44). With further adjustment for the degree of sleep difficulties at baseline, the OR of having a subsequent depressed mood associated with often/severe VMS was attenuated and no longer significant (OR 1.13, 0.90-1.40). Conversely, often/severe depressed mood remained significantly associated with subsequent VMS (OR 1.80, 1.38-2.34).

CONCLUSIONS

Difficulty in sleeping largely explained the relationship between VMS and subsequent depressed mood, but it had little impact on the relationship between depressed mood and subsequent VMS.

Body mass index and age at natural menopause: an international pooled analysis of 11 prospective studies

Current evidence on the association between body mass index (BMI) and age at menopause remains unclear. We investigated the relationship between BMI and age at menopause using data from 11 prospective studies. A total of 24,196 women who experienced menopause after recruitment was included. Baseline BMI was categorised according to the WHO criteria. Age at menopause, confirmed by natural cessation of menses for ≥ 12 months, was categorised as < 45 years (early menopause), 45-49, 50-51 (reference category), 52-53, 54-55, and ≥ 56 years (late age at menopause). We used multinomial logistic regression models to estimate multivariable relative risk ratios (RRRs) and 95% confidence intervals (CI) for the associations between BMI and age at menopause. The mean (standard deviation) age at menopause was 51.4 (3.3) years, with 2.5% of the women having early and 8.1% late menopause. Compared with those with normal BMI (18.5-24.9 kg/m²), underweight women were at a higher risk of early menopause (RRR 2.15, 95% CI 1.50-3.06), while overweight (1.52, 1.31-1.77) and obese women (1.54, 1.18-2.01) were at increased risk of late menopause. Overweight and obesity were also significantly associated with around 20% increased risk of menopause at ages 52-53 and 54-55 years. We observed no association between underweight and late menopause. The risk of early menopause was higher among obese women albeit not significant (1.23, 0.89-1.71). Underweight women had over twice the risk of experiencing early menopause, while overweight and obese women had over 50% higher risk of experiencing late menopause.

Association between gaseous air pollutants and inflammatory, hemostatic and lipid markers in a cohort of midlife women

BACKGROUND

Exposures to ambient gaseous pollutants have been linked to cardiovascular diseases (CVDs), but the biological mechanisms remain uncertain.

OBJECTIVES

This study examined the changes in CVD marker levels resulting from elevated exposure to ambient gaseous pollutants in midlife women.

METHODS

Annual repeated measurements of several inflammatory, hemostatic and lipid makers were obtained from 2306 midlife women enrolled in the longitudinal Study of Women's Health Across the Nation (SWAN) between 1999 and 2004. Ambient carbon monoxide (CO), nitrogen dioxide (NO₂), and sulfur dioxide (SO₂) data were assigned to each woman based on proximity of the monitoring station to her residential address. Short- and long-term exposures were calculated, and their associations with markers were examined using linear mixed-effects regression models, adjusted for demographic, health and other factors.

RESULTS

Short-term CO exposure was associated with increased fibrinogen, i.e., every interquartile increase of average prior one-week exposure to CO was associated with 1.3% (95% CI: 0.6%, 2.0%) increase in fibrinogen. Long-term exposures to NO₂ and SO₂ were associated with reduced high-density lipoproteins and apolipoprotein A1, e.g., 4.0% (1.7%, 6.3%) and 4.7% (2.8%, 6.6%) decrease per interquartile increment in prior one-year average NO₂ concentration, respectively. Fine particle (PM_2.5) exposure confounded associations between CO/NO₂ and inflammatory/hemostatic markers, while associations with lipoproteins were generally robust to PM_2.5 adjustment.

CONCLUSIONS

Exposures to these gas pollutants at current ambient levels may increase thrombotic potential and disrupt cholesterol metabolism, contributing to greater risk of CVDs in midlife women. Caution should be exercised in evaluating the confounding by PM_2.5 exposure.

Menstrual Cycle Hormone Changes in Women Traversing Menopause: Study of Women's Health Across the Nation

CONTEXT

Menstrual cycle hormone patterns in women approaching menopause are inadequately studied.

OBJECTIVE

To describe day-to-day menstrual cycle hormones in women as they approach menopause from the Study of Women's Health Across the Nation Daily Hormone Study (DHS).

DESIGN

DHS enrollees collected daily urine for one entire menstrual cycle or up to 50 days, whichever came first, annually, up to the final menstrual period (FMP) or for up to 10 years.

SETTING

Seven sites across the United States.

PARTICIPANTS

A total of 511 premenopausal or early perimenopausal women at enrollment, within 10 years before menopause.

INTERVENTION

Time-to-FMP measurement.

MAIN OUTCOME MEASURES

Evidence of luteal activity (ELA), determined using objective algorithms. Menstrual cycle/segment length; whole cycle, and segment integrated urinary luteinizing hormone, follicle-stimulating hormone, estrone conjugates, and pregnanediol glucuronide (Pdg) for each year, organized around the FMP.

RESULTS

Mean menstrual cycle length was remarkably preserved at 26 to 27 days in ELA cycles; non-ELA cycles had greater variability. The percentage of cycles that were ELA remained high until 5 years before the FMP (87.9%); only 22.8% of cycles within 1 year of the FMP were ELA. Whole cycle hormones remained relatively stable up to 3 years before the FMP, when gonadotropins began to increase. Pdg excretion declined slowly with progress to the FMP, but Pdg patterns of ELA cycles remained distinguishable from non-ELA.

CONCLUSIONS

Menstrual cycle hormone patterns in perimenopausal women resemble those of midreproductive-aged women until 5 years before menopause, and presumably ovulatory cycles retain a potentially fertile pattern up to the end of reproductive life.

Duration of the menopausal transition is longer in women with young age at onset: the multiethnic Study of Women's Health Across the Nation

OBJECTIVE

The menopausal transition (MT) is a critical period associated with physiologic changes that influence women's long-term health and longevity. Information is, however, limited regarding factors that influence age at the onset of the MT and its duration (ie, time from MT onset to the final menstrual period).

METHODS

We analyzed data for 1,145 women from four sites of the Study of Women's Health Across the Nation who participated in the menstrual calendar substudy, had the start of the MT identified, and had no missing covariate information. Participants included from four racial/ethnic groups: African American, white, Chinese, and Japanese. Women completed daily menstrual calendars from 1996 to 2006 and questions on hormone therapy use monthly. Baseline measures included education, economic strain, and menstrual cycle characteristics. Annual measures included height, weight, and smoking status. Cox proportional hazards models were used to analyze the data.

RESULTS

The adjusted median duration of the MT ranged from 4.37 years among the oldest age-at-onset quartile to 8.57 years among the youngest age-at-onset quartile (P < 0.001). Cigarette smoking was associated with an earlier onset (P < 0.001) and a shorter duration (P < 0.001). African American women had a longer duration (P = 0.012) than white women. Body mass index was associated with a later onset of the MT (P = 0.001) but not its duration.

CONCLUSIONS

The duration of the MT was largely influenced by the age at which it began: earlier onset was associated with a longer transition. This finding provides a strong rationale for developing improved markers of the onset of the early MT.

Estimating the associations of apparent temperature and inflammatory, hemostatic, and lipid markers in a cohort of midlife women

Associations between temperature and cardiovascular (CVD) mortality have been reported, but the underlying biological mechanisms remain uncertain. We explored the association between apparent temperature and serum biomarkers for CVD. Using linear mixed effects models, we examined the relationships between residence-proximate apparent temperature (same day and 1, 7, and 30 days prior) and several inflammatory, hemostatic, and lipid biomarkers for midlife women from 1999 through 2004. Our study population consisted of 2,306 women with mean age of 51 years (± 3 years) enrolled in Study of Women's Health Across the Nation (SWAN) in Chicago, Illinois; Detroit, Michigan; Los Angeles and Oakland, California; Newark, New Jersey; and Pittsburgh, Pennsylvania. Mean daily apparent temperature was calculated using temperature and relative humidity data provided by the National Climatic Data Center and the US Environmental Protection Agency, while daily data for fine particles, ozone, carbon monoxide, and nitrogen dioxide from the US Environmental Protection Agency Air Quality Data Mart were considered as confounders. All analyses were stratified by warm and cold seasons. More significant (p < 0.10) negative associations were found during the warm season for various lag times, including hs-CRP, fibrinogen, tissue plasminogen activator antigen (tPA-ag), tissue plasminogen activator antigen (PAI-1), Factor VIIc, high-density lipoprotein (HDL), and total cholesterol. During the cold season, significant negative associations for fibrinogen and HDL, but significant positive associations for tPA-ag, PAI-1, and triglycerides were observed for various lag times. With the exception of ozone, pollutants did not confound these associations. Apparent temperature was associated with several serum biomarkers of CVD risk in midlife women, shedding light on potential mechanisms.

Menopausal vasomotor symptoms and incident breast cancer risk in the Study of Women's Health Across the Nation

PURPOSE

Two case-control studies reported a 50 % decreased breast cancer risk among women who experienced menopausal vasomotor symptoms (VMS), but one cohort study found no association. VMS may be triggered by declining estrogen levels during menopause, whereas elevated estrogen levels have been associated with increased breast cancer risk. VMS may thus be indicative of lower susceptibility to breast cancer.

METHODS

We evaluated this relationship in the longitudinal Study of Women's Health Across the Nation (SWAN), using discrete survival analysis of approximately annual data on VMS and self-reported breast cancer occurrences for up to 13 years of follow-up in 3,098 women who were pre- or early perimenopausal at enrollment.

RESULTS

Over an average 11.4 years of follow-up, 129 incident breast cancer cases were self-reported, and approximately 50 % of participants experienced VMS. Symptomatic women had a reduced risk of breast cancer compared to non-symptomatic women (adjusted HR 0.63, 95 % CI 0.39, 1.00). The association was stronger in the subgroup of women who fully transitioned to postmenopause during follow-up (n = 67 cases, adjusted HR 0.45, 95 % CI 0.26, 0.77).

CONCLUSION

VMS appeared to be a marker of reduced breast cancer risk. Future research is needed to understand the biology underlying this relationship.

Triglyceride Levels and Fracture Risk in Midlife Women: Study of Women's Health Across the Nation (SWAN)

CONTEXT

Unfavorable lipid levels contribute to cardiovascular disease and may also harm bone health.

OBJECTIVE

Our objective was to investigate relationships between fasting plasma lipid levels and incident fracture in midlife women undergoing the menopausal transition.

DESIGN AND SETTING

This was a 13-year prospective, longitudinal study of multiethnic women in five US communities, with near-annual assessments.

PARTICIPANTS

At baseline, 2062 premenopausal or early perimenopausal women who had no history of fracture were included.

EXPOSURES

Fasting plasma total cholesterol, triglycerides (TG), low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol at baseline and follow-up visits 1 and 3-7.

MAIN OUTCOME MEASURE(S)

Incident nontraumatic fractures 1) 2 or more years after baseline, in relation to a single baseline level of lipids; and 2) 2-5 years later, in relation to time-varying lipid levels. Cox proportional hazards modelings estimated hazard ratios and 95% confidence interval (CI).

RESULTS

Among the lipids, TG levels changed the most, with median levels increased by 16% during follow-up. An increase of 50 mg/dl in baseline TG level was associated with a 1.1-fold increased hazards of fracture (adjusted hazard ratio, 1.11; 95% CI, 1.04-1.18). Women with baseline TG higher than 300 mg/dl had an adjusted 2.5-fold greater hazards for fractures (95% CI, 1.13-5.44) than women with baseline TG lower than 150 mg/dl. Time-varying analyses showed a comparable TG level-fracture risk relationship. Associations between total cholesterol, low-density lipoprotein cholesterol, or high-density lipoprotein cholesterol levels and fractures were not observed.

CONCLUSIONS

Midlife women with high fasting plasma TG had an increased risk of incident nontraumatic fracture. Secondary Abstract: Midlife women with fasting plasma triglyceride (TG) of at least 300 mg/dl had 2.5-fold greater hazards of fracture in 2 years later and onward, compared to those with TG below 150 mg/dl, in a multiethnic cohort. Time-varying analyses revealed comparable results.

The InterLACE study: Design, data harmonization and characteristics across 20 studies on women's health

OBJECTIVES

The International Collaboration for a Life Course Approach to Reproductive Health and Chronic Disease Events (InterLACE) project is a global research collaboration that aims to advance understanding of women's reproductive health in relation to chronic disease risk by pooling individual participant data from several cohort and cross-sectional studies. The aim of this paper is to describe the characteristics of contributing studies and to present the distribution of demographic and reproductive factors and chronic disease outcomes in InterLACE.

STUDY DESIGN

InterLACE is an individual-level pooled study of 20 observational studies (12 of which are longitudinal) from ten countries. Variables were harmonized across studies to create a new and systematic synthesis of life-course data.

MAIN OUTCOME MEASURES

Harmonized data were derived in three domains: 1) socio-demographic and lifestyle factors, 2) female reproductive characteristics, and 3) chronic disease outcomes (cardiovascular disease (CVD) and diabetes).

RESULTS

InterLACE pooled data from 229,054 mid-aged women. Overall, 76% of the women were Caucasian and 22% Japanese; other ethnicities (of 300 or more participants) included Hispanic/Latin American (0.2%), Chinese (0.2%), Middle Eastern (0.3%), African/black (0.5%), and Other (1.0%). The median age at baseline was 47 years (Inter-quartile range (IQR): 41-53), and that at the last follow-up was 56 years (IQR: 48-64). Regarding reproductive characteristics, half of the women (49.8%) had their first menstruation (menarche) at 12-13 years of age. The distribution of menopausal status and the prevalence of chronic disease varied considerably among studies. At baseline, most women (57%) were pre- or peri-menopausal, 20% reported a natural menopause (range 0.8-55.6%) and the remainder had surgery or were taking hormones. By the end of follow-up, the prevalence rates of CVD and diabetes were 7.2% (range 0.9-24.6%) and 5.1% (range 1.3-13.2%), respectively.

CONCLUSIONS

The scale and heterogeneity of InterLACE data provide an opportunity to strengthen evidence concerning the relationships between reproductive health through life and subsequent risks of chronic disease, including cross-cultural comparisons.

Environmental tobacco smoke and risk of late-diagnosis incident fibroids in the Study of Women's Health across the Nation (SWAN)

OBJECTIVE

To assess the longitudinal relationship of environmental tobacco smoke (ETS) exposure during midlife, and its interaction with active smoking, with the risk of late-diagnosis incident uterine fibroids during the menopausal transition.

DESIGN

Thirteen-year prospective cohort study.

SETTING

Not applicable.

PATIENT(S)

Community-based, multiracial/ethnic cohort of 2,575 women aged 42 to 52 years at baseline, undergoing the menopausal transition.

INTERVENTION(S)

Questionnaire and blood draws.

MAIN OUTCOME MEASURE(S)

Discrete-time proportional odds models were used to estimate the conditional odds ratio (OR) and 95% confidence interval (CI) of incident fibroids, adjusted for menopausal status, race/ethnicity, study site, age, education, estradiol levels, sex hormone use, body mass index, timing of blood draw, age at menarche, alcohol use, and smoking status and pack-years.

RESULT(S)

As part of SWAN, at each near-annual study visit, ETS exposure, smoking, and fibroid occurrence were self-reported via questionnaire, and blood draws were collected. Women who were exposed to ETS (≥1 person-hour/week) had 1.28 (95% CI, 1.03, 1.60) times the adjusted odds of incident fibroids in the ensuing year compared the unexposed. The odds were elevated in never smokers (adjusted OR 1.34; 95% CI, 1.06, 1.70) and former smokers (adjusted OR 2.57; 95% CI, 1.05, 7.23).

CONCLUSION(S)

In midlife, ETS exposure was associated with an increased risk of late-diagnosis incident fibroids in women undergoing the menopausal transition.

The Association of Inflammation with Premenstrual Symptoms

BACKGROUND

About 80% of women experience premenstrual symptoms (PMSx), and about 50% of women seek medical care for them, posing a large medical care burden. However, despite women's use of anti-inflammatory agents for relief from these symptoms, and the fact that anti-inflammatory agents provide relief from some PMSx, the relationship of inflammation to PMSx has not been well investigated.

METHODS

We, therefore, undertook the present cross-sectional analyses using baseline data from the longitudinal Study of Women's Health Across the Nation (SWAN), a racially/ethnically diverse cohort of midlife women (n = 2939), to determine if a biomarker of inflammation, high-sensitivity C-reactive protein (hs-CRP), was associated with PMSx. We performed factor analyses with Varimax rotations to determine five groupings of eight symptoms to develop a parsimonious set of outcome variables. We conducted backward stepwise multiple logistic regression models for each grouping, eliminating non-significant (p > 0.05) covariates.

RESULTS

Having an hs-CRP level >3 mg/L was significantly positively associated with premenstrual mood symptoms (adjusted odds ratio [aOR] = 1.27, 95% confidence interval [95% CI] 1.02-1.58), abdominal cramps/back pain (aOR = 1.40, 95% CI 1.09-1.80), appetite cravings/weight gain/bloating (aOR = 1.41, 95% CI 1.04-1.89), and breast pain (aOR = 1.26, 95% CI 1.02-1.55). Elevated hs-CRP level was not associated with premenstrual headaches or reporting three or more PMSx.

CONCLUSIONS

The significant relationships of specific groups of PMSx with elevated hs-CRP levels have potential clinical implications for treatment and possibly for prevention by advising women about the factors associated with inflammation and the potential for treatment with anti-inflammatory agents.

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.

Circulating Sex Hormones and Risk of Uterine Fibroids: Study of Women's Health Across the Nation (SWAN)

CONTEXT

Estrogen has been implicated in the development of uterine fibroids. However, the contribution of androgen in women is unknown.

OBJECTIVE

Our objective was to assess the longitudinal relations of circulating androgens and estradiol (E2) and their joint effects to the risk of developing fibroids.

DESIGN

This is a 13-year longitudinal study in the Study of Women's Health Across the Nation.

SETTING

This study was conducted in seven sites across the United States (1997-2013).

PARTICIPANTS

At baseline, 3240 pre- or early peri-menopausal women with an intact uterus, ages 45-52 years were included; 43.6% completed the follow-up. There were 512 incident and 478 recurrent fibroid cases.

EXPOSURES

We measured near-annual time-varying serum levels of bioavailable E2 and bioavailable T, dichotomized at the median (high vs low).

MAIN OUTCOMES AND MEASURES

We estimated the conditional odds ratio (OR) of fibroids in the ensuing year using discrete-time proportional odds models adjusted for race/ethnicity/site, age, body mass index, menopausal stage, reproductive factors, smoking, timing of blood draw, and FSH.

RESULTS

Women with high T had a statistically significant increased risk of incident fibroids (OR, 1.33; 95% confidence interval [CI], 1.01-1.76; P = .04), but not recurrent fibroids. This risk was further elevated in those with high T and E2 (OR, 1.52; 95% CI, 1.07-2.17; P = .02). High E2 and T was associated with lower risk of recurrent fibroids (OR, 0.50; 95% CI, 0.26-0.96; P = .04).

CONCLUSIONS

High T with high E2 was associated with an elevated risk of incident fibroids in midlife women who never reported fibroids before baseline. Conversely, the risk of recurrent fibroids was mitigated in women with high E2 and high T.

Duration of menopausal vasomotor symptoms over the menopause transition

IMPORTANCE

The expected duration of menopausal vasomotor symptoms (VMS) is important to women making decisions about possible treatments.

OBJECTIVES

To determine total duration of frequent VMS (≥ 6 days in the previous 2 weeks) (hereafter total VMS duration) during the menopausal transition, to quantify how long frequent VMS persist after the final menstrual period (FMP) (hereafter post-FMP persistence), and to identify risk factors for longer total VMS duration and longer post-FMP persistence.

DESIGN, SETTING, AND PARTICIPANTS

The Study of Women's Health Across the Nation (SWAN) is a multiracial/multiethnic observational study of the menopausal transition among 3302 women enrolled at 7 US sites. From February 1996 through April 2013, women completed a median of 13 visits. Analyses included 1449 women with frequent VMS.

MAIN OUTCOMES AND MEASURES

Total VMS duration (in years) (hot flashes or night sweats) and post-FMP persistence (in years) into postmenopause.

RESULTS

The median total VMS duration was 7.4 years. Among 881 women who experienced an observable FMP, the median post-FMP persistence was 4.5 years. Women who were premenopausal or early perimenopausal when they first reported frequent VMS had the longest total VMS duration (median, >11.8 years) and post-FMP persistence (median, 9.4 years). Women who were postmenopausal at the onset of VMS had the shortest total VMS duration (median, 3.4 years). Compared with women of other racial/ethnic groups, African American women reported the longest total VMS duration (median, 10.1 years). Additional factors related to longer duration of VMS (total VMS duration or post-FMP persistence) were younger age, lower educational level, greater perceived stress and symptom sensitivity, and higher depressive symptoms and anxiety at first report of VMS.

CONCLUSIONS AND RELEVANCE

Frequent VMS lasted more than 7 years during the menopausal transition for more than half of the women and persisted for 4.5 years after the FMP. Individual characteristics (eg, being premenopausal and having greater negative affective factors when first experiencing VMS) were related to longer-lasting VMS. Health care professionals should counsel women to expect that frequent VMS could last more than 7 years, and they may last longer for African American women.

Chronic PM2.5 exposure and inflammation: determining sensitive subgroups in mid-life women

BACKGROUND

Several cohort studies report associations between chronic exposure to ambient fine particles (PM2.5) and cardiovascular mortality. Uncertainty exists about biological mechanisms responsible for this observation, but systemic inflammation has been postulated. In addition, the subgroups susceptible to inflammation have not been fully elucidated.

METHODS

We investigated whether certain subgroups are susceptible to the effects of long-term exposure to PM2.5 on C-reactive protein (CRP), a marker of inflammation directly linked to subsequent cardiovascular disease. We used data from the SWAN cohort of 1923 mid-life women with up to five annual repeated measures of CRP. Linear mixed and GEE models accounting for repeated measurements within an individual were used to estimate the effects of prior-year PM2.5 exposure on CRP. We examined CRP as a continuous and as binary outcome for CRP greater than 3mg/l, a level of clinical significance.

RESULTS

We found strong associations between PM2.5 and CRP among several subgroups. For example a 10 µg/m(3) increase in annual PM2.5 more than doubled the risk of CRP greater than 3mg/l in older diabetics, smokers and the unmarried. Larger effects were also observed among those with low income, high blood pressure, or who were using hormone therapy, with indications of a protective effects for those using statins or consuming moderate amounts of alcohol.

CONCLUSIONS

In this study, we observed significant associations between long-term exposure to PM2.5 and CRP in several susceptible subgroups. This suggests a plausible pathway by which exposure to particulate matter may be associated with increased risk of cardiovascular disease.

The relationship of violence and traumatic stress to changes in weight and waist circumference: longitudinal analyses from the study of women's health across the nation

This article investigates the associations of violence and traumatic stress with changes in weight and waist circumference, hypothesizing that violence in midlife would be associated with increases or decreases in weight and waist circumference. The longitudinal cohort of the Study of Women's Health Across the Nation comprised the study sample, which included an ethnically/racially and socially diverse group of 2,870 women between the ages of 42 and 52 years at baseline. Women were followed annually for 10 years, and assessments included weight and waist circumference measures and data on violence, health outcomes, and confounders. At baseline, 8.6% Caucasian, 10.8% African American, 9.2% Chinese, and 5.0% Japanese women reported violence and traumatic stress. Reporting violence and traumatic stress during follow-up was significantly associated with weight gain (odds ratio [OR] = 2.39, 95% confidence interval [CI] = [1.28-4.47]), weight loss (OR = 3.54, 95% CI = [1.73-7.22]), and gain (OR = 2.44, 95% CI = [1.37-4.37]) or loss (OR = 2.66, 95% CI = [1.23-5.77]) in waist circumference, adjusting for age, race/ethnicity, education, marital status, and smoking. Violence and traumatic stress against midlife women were associated with gains or losses in weight and waist circumference.

Bleeding patterns during the menopausal transition in the multi-ethnic Study of Women's Health Across the Nation (SWAN): a prospective cohort study

OBJECTIVE

Previous studies describing menses duration and heaviness of flow during the menopausal transition (MT) have been short in duration and limited to white women. We estimated the frequency of and risk factors for prolonged bleeding, spotting and heavy bleeding during the MT in an ethnically diverse population.

DESIGN

Prospective community-based cohort study.

SETTING USA

southeastern Michigan, northern California and Los Angeles, California.

POPULATION

A total of 1320 midlife women who participated in the Study of Women's Health Across the Nation (SWAN) Menstrual Calendar Substudy. Participants included African-American, white, Chinese, and Japanese women.

METHODS

Women completed daily menstrual calendars from 1996 to 2006, and provided information on hormone therapy, smoking and physical activity. Annual measures included height and weight. Kaplan-Meier survival analysis and multivariable regression were used to analyse the data.

MAIN OUTCOME MEASURES

Menses of 10+ days, spotting of 6+ days, heavy bleeding of 3+ days.

RESULTS

At least three occurrences of menses 10+ days was reported by 77.7% (95% confidence interval [95% CI] 56.7-93.2), of 6+ days of spotting by 66.8% (95% CI 55.2-78.0) and of 3+ days of heavy bleeding by 34.5% (95% CI 30.2-39.2) of women. Menses of 10+ days, 6+ days of spotting, and 3+ days of heavy bleeding were associated with MT stage, uterine fibroids, hormone use and ethnicity. Body mass index was associated with 3+ days of heavy bleeding.

CONCLUSIONS

These data provide clinicians and women with important information about the expected frequency of prolonged and heavy bleeding and spotting during the menopausal transition that may facilitate clinical decision making.

Is crime associated with over-the-counter pharmacy syringe sales? Findings from Los Angeles, California

BACKGROUND

More than 50,000 new HIV infections occur annually in the United States. Injection drug users represent twelve percent of incident HIV infections each year. Pharmacy sales of over-the-counter (OTC) syringes have helped prevent HIV transmission among injection drug users in many states throughout the United States. However, concerns exist among some law enforcement officials, policymakers, pharmacists, and community members about potential links between OTC syringe sales and crime.

METHODS

We used a geographic information system and novel spatial and longitudinal analyses to determine whether implementation of pharmacy-based OTC syringe sales were associated with reported crime between January 2006 and December 2008 in Los Angeles Police Department Reporting Districts. We assessed reported crime pre- and post-OTC syringe sales initiation as well as longitudinal associations between crime and OTC syringe-selling pharmacies.

RESULTS

By December 2008, 9.3% (94/1010) of Los Angeles Police Department Reporting Districts had at least one OTC syringe-selling pharmacy. Overall reported crime counts and reported crime rates decreased between 2006 and 2008 in all 1010 Reporting Districts. Using generalized estimating equations and adjusting for potential confounders, reported crime rates were negatively associated with OTC syringe sales (adjusted rate ratio: 0.89; 95% confidence interval: 0.81, 0.99).

CONCLUSION

Our findings demonstrate that OTC pharmacy syringe sales were not associated with increases in reported crime in local communities in Los Angeles during 2006-2008.

Factors associated with presence of pharmacies and pharmacies that sell syringes over-the-counter in Los Angeles County

Community pharmacies serve as key locations for public health services including interventions to enhance the availability of syringes sold over-the-counter (OTC), an important strategy to prevent injection-mediated HIV transmission. Little is known about the community characteristics associated with the availability of pharmacies and pharmacies that sell syringes OTC. We conducted multivariable regression analyses to determine whether the sociodemographic characteristics of census tract residents were associated with pharmacy presence in Los Angeles (LA) County during 2008. Using a geographic information system, we conducted hot-spot analyses to identify clusters of pharmacies, OTC syringe-selling pharmacies, sociodemographic variables, and their relationships. For LA County census tracts (N = 2,054), population size (adjusted odds ratio [AOR], 1.22; 95 % confidence interval [CI], 1.16, 1.28), median age of residents (AOR, 1.03; 95 % CI, 1.01, 1.05), and the percent of households receiving public assistance (AOR, 0.97; 95 % CI, 0.94, 0.99) were independently associated with the presence of all pharmacies. Only 12 % of census tracts had at least one OTC syringe-selling pharmacy and sociodemographic variables were not independently associated with the presence of OTC syringe-selling pharmacies. Clusters of pharmacies (p < 0.01) were located proximally to clusters of older populations and were distant from clusters of poorer populations. Our combined statistical and spatial analyses provided an innovative approach to assess the sociodemographic and geographic factors associated with the presence of community pharmacies and pharmacies that participate in OTC syringe sales.

Thyroid hormones and thyroid disease in relation to perchlorate dose and residence near a superfund site

Perchlorate is a widely occurring contaminant, which can competitively inhibit iodide uptake and thus thyroid hormone production. The health effects of chronic low dose perchlorate exposure are largely unknown. In a community-based study, we compared thyroid function and disease in women with differing likelihoods of prior and current perchlorate exposure. Residential blocks were randomly selected from areas: (1) with potential perchlorate exposure via drinking water; (2) with potential exposure to environmental contaminants; and (3) neighboring but without such exposures. Eligibility included having lived in the area for ≥6 months and aged 20-50 years during 1988-1996 (during documented drinking water well contamination). We interviewed 814 women and collected blood samples (assayed for thyroid stimulating hormone and free thyroxine) from 431 interviewed women. Daily urine samples were assayed for perchlorate and iodide for 178 premenopausal women with blood samples. We performed multivariable regression analyses comparing thyroid function and disease by residential area and by urinary perchlorate dose adjusted for urinary iodide levels. Residential location and current perchlorate dose were not associated with thyroid function or disease. No persistent effect of perchlorate on thyroid function or disease was found several years after contaminated wells were capped.