The timing of natural menopause is a clinically important indicator of longevity and risk of morbidity and mortality. Demographic, menstrual, reproductive, familial, genetic, and lifestyle factors ...seem to be important in this timing. Smoking, lower parity and poor socioeconomic status are associated with earlier menopause. However, a number of relationships have been inconsistent; others remain largely unexplored. Much remains to be learned about factors that affect follicular atresia and the onset and duration of perimenopause and the timing of the natural menopause. Knowledge about these relationships offers women and their health care providers enhanced understanding and choices to deal with menopause.
The expected duration of menopausal vasomotor symptoms (VMS) is important to women making decisions about possible treatments.
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.
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.
Total VMS duration (in years) (hot flashes or night sweats) and post-FMP persistence (in years) into postmenopause.
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.
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.
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 multi variable 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.
The time span and patterns of change in serum FSH and E2 across the menopausal transition do not vary by age at the final menstrual period.
Background and Objective:
To determine whether patterns of ...change in serum estradiol (E2) and FSH across the menopausal transition were associated with age at the final menstrual period (FMP).
Design and Setting:
The Study of Women's Health Across the Nation (SWAN) is a seven-site, multiethnic, longitudinal study of the menopausal transition being conducted in 3302 menstruating women who were aged 42–52 yr at the 1996 study baseline.
Measurements:
Annually collected serum was assayed for E2 and FSH levels. Patterns of hormone change were evaluated in the 1215 women with a documented natural FMP by follow-up visit 9 (2006) using semiparametric stochastic and piecewise linear mixed modeling.
Results:
The FSH pattern across the menopausal transition began with an increase 6.10 yr before the FMP, an acceleration 2.05 yr before the FMP, deceleration beginning 0.20 yr before the FMP, and attainment of stable levels 2.00 yr after the FMP, independent of age at the FMP, race/ethnicity, or smoking status. Obesity attenuated the FSH rise and delayed the initial increase to 5.45 yr before the FMP. The mean E2 concentration did not change until 2.03 yr before the FMP when it began decreasing, achieving maximal rate of change at the FMP, then decelerating to achieve stability 2.17 yr after the FMP. Obesity, smoking behavior, and being Chinese or Japanese were associated with some variation in E2 levels but not the pattern of E2 change.
Conclusions:
Time spans and overall patterns of change in serum FSH and E2 across the menopausal transition were not related to age at FMP or smoking, whereas time spans but not overall patterns were related to obesity and race/ethnicity.
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.
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.
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.
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.
We investigated whether vasomotor symptom reporting or patterns of change in symptom reporting over the perimenopausal transition among women enrolled in a national study differed according to ...race/ethnicity. We also sought to determine whether racial/ethnic differences were explained by sociodemographic, health, or lifestyle factors.
We followed 3198 women enrolled in the Study of Women's Health Across the Nation during 1996 through 2002. We analyzed frequency of vasomotor symptom reporting using longitudinal multiple logistic regressions.
Rates of vasomotor symptom reporting were highest among African Americans (adjusted odds ratio OR=1.63; 95% confidence interval CI=1.21, 2.20). The transition to late perimenopause exhibited the strongest association with vasomotor symptoms (adjusted OR = 6.64; 95% CI = 4.80, 9.20). Other risk factors were age (adjusted OR=1.17; 95% CI=1.13, 1.21), having less than a college education (adjusted OR = 1.91; 95% CI = 1.40, 2.61), increasing body mass index (adjusted OR=1.03 per unit of increase; 95% CI=1.01, 1.04), smoking (adjusted OR=1.63; 95% CI=1.25, 2.12), and anxiety symptoms at baseline (adjusted OR=3.10; 95% CI=2.33, 4.12).
Among the risk factors assessed, vasomotor symptoms were most strongly associated with menopausal status. After adjustment for covariates, symptoms were reported most often in all racial/ethnic groups in late perimenopause and nearly as often in postmenopause.
Bayesian Nonparametric Longitudinal Data Analysis Quintana, Fernando A.; Johnson, Wesley O.; Waetjen, L. Elaine ...
Journal of the American Statistical Association,
09/2016, Letnik:
111, Številka:
515
Journal Article
Recenzirano
Odprti dostop
Practical Bayesian nonparametric methods have been developed across a wide variety of contexts. Here, we develop a novel statistical model that generalizes standard mixed models for longitudinal data ...that include flexible mean functions as well as combined compound symmetry (CS) and autoregressive (AR) covariance structures. AR structure is often specified through the use of a Gaussian process (GP) with covariance functions that allow longitudinal data to be more correlated if they are observed closer in time than if they are observed farther apart. We allow for AR structure by considering a broader class of models that incorporates a Dirichlet process mixture (DPM) over the covariance parameters of the GP. We are able to take advantage of modern Bayesian statistical methods in making full predictive inferences and about characteristics of longitudinal profiles and their differences across covariate combinations. We also take advantage of the generality of our model, which provides for estimation of a variety of covariance structures. We observe that models that fail to incorporate CS or AR structure can result in very poor estimation of a covariance or correlation matrix. In our illustration using hormone data observed on women through the menopausal transition, biology dictates the use of a generalized family of sigmoid functions as a model for time trends across subpopulation categories.
•Urinary arsenic was associated with earlier age at natural menopause.•Urinary lead was associated with earlier age at natural menopause.•Metal mixtures may play a role in accelerated ovarian aging.
...Exposure to metals and metal mixtures may influence ovarian aging. However, epidemiologic evidence of their potential impact is lacking.
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.
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.
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.
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.
Early age at the natural final menstrual period (FMP) or menopause has been associated with numerous health outcomes and might be a marker of future ill health. However, potentially modifiable ...factors affecting age at menopause have not been examined longitudinally in large, diverse populations. The Study of Women's Health Across the Nation (SWAN) followed 3,302 initially premenopausal and early perimenopausal women from 7 US sites and 5 racial/ethnic groups, using annual data (1996-2007) and Cox proportional hazards models to assess the relation of time-invariant and time-varying sociodemographic, lifestyle, and health factors to age at natural FMP. Median age at the FMP was 52.54 years (n = 1,483 observed natural FMPs). Controlling for sociodemographic, lifestyle, and health factors, we found that racial/ethnic groups did not differ in age at the FMP. Higher educational level, prior oral contraceptive use, and higher weight at baseline, as well as being employed, not smoking, consuming alcohol, having less physical activity, and having better self-rated health over follow-up, were significantly associated with later age at the FMP. These results suggest that age at the natural FMP reflects a complex interrelation of health and socioeconomic factors, which could partially explain the relation of late age at FMP to reduced morbidity and mortality.
Context:
Emerging research suggests links between menopausal hot flashes and cardiovascular disease risk. The mechanisms underlying these associations are unclear, due to the incomplete understanding ...of the physiology of hot flashes.
Objective and Main Outcome Measures:
We examined the associations between hot flashes/night sweats and glucose and insulin resistance over 8 yr, controlling for cardiovascular risk factors and reproductive hormones.
Design, Setting, and Participants:
Participants in the Study of Women's Health Across the Nation (SWAN) (n = 3075), a longitudinal cohort study, were ages 42–52 yr at entry. Women completed questionnaires (hot flashes, night sweats: none, 1–5 d, ≥6 d, past 2 wk), physical measures (blood pressure, height, weight), and a fasting blood draw serum glucose, insulin, estradiol (E2), FSH annually for 8 yr. Hot flashes/night sweats were examined in relation to glucose and the homeostasis model assessment (HOMA) in mixed models, adjusting for demographics, cardiovascular risk factors, medications, and E2/FSH.
Results:
Compared to no flashes, hot flashes were associated with a higher HOMAlog index vs. none; hot flashes, 1–5 d: % difference (95% confidence interval), 2.37 (0.36–4.43), P = 0.02; and ≥6 d: 5.91 (3.17–8.72), P < 0.0001 in multivariable models that included body mass index. Findings persisted adjusting for E2 or FSH, and were similar for night sweats. Findings were statistically significant, yet modest in magnitude, for the outcome glucose.
Conclusions:
Hot flashes were associated with a higher HOMA index, an estimate of insulin resistance, and to a lesser extent higher glucose. Metabolic factors may be relevant to understanding the link between hot flashes and cardiovascular disease risk.
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