Factors related to age at natural menopause in China: results from the China Kadoorie Biobank

Risk prediction model of metabolic syndrome in perimenopausal women based on machine learning

INTRODUCTION

Metabolic syndrome (MetS) is considered to be an important parameter of cardio-metabolic health and contributing to the development of atherosclerosis, type 2 diabetes. The incidence of MetS significantly increases in postmenopausal women, therefore, the perimenopausal period is considered a critical phase for prevention. We aimed to use four machine learning methods to predict whether perimenopausal women will develop MetS within 2 years.

METHODS

Women aged 45-55 years who underwent 2 consecutive years of physical examinations in Ninth Clinical College of Peking University between January 2021 and December 2022 were included. We extracted 26 features from physical examinations, and used backward selection method to select top 10 features with the largest area under the receiver operating characteristic curve (AUC). Extreme gradient boosting (XGBoost), Random forest (RF), Multilayer perceptron (MLP) and Logistic regression (LR) were used to establish the model. Those performance were measured by AUC, accuracy, precision, recall and F1 score. SHapley Additive exPlanation (SHAP) value was used to identify risk factors affecting perimenopausal MetS.

RESULTS

A total of 8700 women had physical examination records, and 2,254 women finally met the inclusion criteria. For predicting MetS events, RF and XGBoost had the highest AUC (0.96, 0.95, respectively). XGBoost has the highest F1 value (F1 = 0.77), followed by RF, LR and MLP. SHAP value suggested that the top 5 variables affecting MetS in this study were Waist circumference, Fasting blood glucose, High-density lipoprotein cholesterol, Triglycerides and Diastolic blood pressure, respectively.

CONCLUSION

We've developed a targeted MetS risk prediction model for perimenopausal women, using health examination data. This model enables early identification of high MetS risk in this group, offering significant benefits for individual health management and wider socio-economic health initiatives.

Age at natural menopause and its associated characteristics among Brazilian women: cross-sectional results from ELSI-Brazil

OBJECTIVES

This study aimed to determine the median age at natural menopause and analyze lifestyle, anthropometric, and dietary characteristics associated with the age at natural menopause among Brazilian women.

METHODS

This cross-sectional study involved 2,731 women 50 years and over, drawn from the baseline of the Brazilian Longitudinal Study of Aging (ELSI-Brazil, 2015/16). Nonparametric Kaplan-Meier cumulative survivorship estimates were used to assess the median timing of natural menopause. Cox proportional hazards regression models were employed to estimate the associations between age at natural menopause and exposure variables.

RESULTS

The overall median age at natural menopause was 50 years. In the adjusted Cox model, current smoking (hazard ratio [HR], 1.11; 95% CI, 1.01-1.23) and underweight (HR, 1.34; 95% CI, 1.12-1.61) were associated with earlier natural menopause. Conversely, performing recommended levels of physical activity in the last week (HR, 0.88; 95% CI, 0.80-0.97), being overweight (HR 0.86; 95% CI, 0.74-0.99), and adhering to two or three healthy eating markers (HR, 0.80; 95% CI, 0.66-0.97; HR, 0.76; 95% CI, 0.61-0.94, respectively) were associated with later age at natural menopause. Binge drinking and waist circumference were not associated with age at natural menopause.

CONCLUSIONS

Lifestyle, anthropometric, and dietary characteristics are significant factors that affect the age at natural menopause. Our findings can contribute to public policies targeted at Brazilian women's health.

Causal associations between sleep traits and age at natural menopause: A Mendelian randomization study

Observational studies have revealed that several sleep traits can impact ovarian function in women. However, there is no evidence suggesting associations between sleep traits and age at natural menopause (ANM). The objective of this study was to investigate the causal relationship between sleep traits (insomnia, sleep duration, daytime sleepiness) and ANM from the perspective of genetic variation. We selected the single-nucleotide polymorphisms from large-scale genome-wide association studies as instrumental variables and conducted a two-sample Mendelian randomization (MR) analysis on these single-nucleotide polymorphisms, including inverse variance weighting, MR-Egger, weighted median, simple mode and weighted mode. The Steiger test was employed to verify the correct causal directionality. The robustness of the MR analysis was examined through Cochran's Q test, horizontal pleiotropy test, and leave-one-out analysis. The results indicated that insomnia was causally associated with ANM (inverse variance weighting: β = -0.982; 95% CI: -1.852 to -0.111, P = .027), with other analyses confirming the robustness of this finding. Steiger test and reverse MR Analysis validated the absence of a reverse causal association between the two. However, sleep duration and daytime sleepiness did not exhibit a causal effect on ANM. In summary, this study provides initial evidence that insomnia can contribute to an earlier onset of ANM. Nevertheless, further clinical studies are needed to elucidate these findings.

Age at natural menopause and its determinants in female population of Kharameh cohort study: Comparison of regression, conditional tree and forests

BACKGROUND

Natural menopause is defined as the permanent cessation of menstruation that occurs after 12 consecutive months of amenorrhea without any obvious pathological or physiological cause. The age of this phenomenon has been reported to be associated with several health outcomes.

OBJECTIVES

This study aimed to estimate the Age at Natural Menopause (ANM) and to identify reproductive and demographic factors affecting ANM.

METHODS

This cross-sectional, population-based study was conducted on 2517 post-menopausal women aged 40-70 years participating in the first phase of the PERSIAN cohort study of Kharameh, Iran, during 2014-2017. To more accurately detect the determinants of ANM, we applied multiple linear regression beside some machine learning algorithms including conditional tree, conditional forest, and random forest. Then, the fitness of these methods was compared using Mean Squared Error (MSE) and Pearson correlation coefficient.

RESULTS

The mean±SD of ANM was 48.95±6.13. Both applied forests provided more accurate results and identified more predictors. However, according to the final comparison, the conditional forest was the most accurate method which recognized that more pregnancies, longer breastfeeding, Fars ethnicity, and urbanization have the greatest impact on later ANM.

CONCLUSIONS

This study found a wide range of reproductive and demographic factors affecting ANM. Considering our findings in decision-making can reduce the complications related to this phenomenon and, consequently, improve the quality of life of post-menopausal women.

Optimising health after early menopause

The typical age at menopause is 50-51 years in high-income countries. However, early menopause is common, with around 8% of women in high-income countries and 12% of women globally experiencing menopause between the ages of 40 years and 44 years. Menopause before age 40 years (premature ovarian insufficiency) affects an additional 2-4% of women. Both early menopause and premature ovarian insufficiency can herald an increased risk of chronic disease, including osteoporosis and cardiovascular disease. People who enter menopause at younger ages might also experience distress and feel less supported than those who reach menopause at the average age. Clinical practice guidelines are available for the diagnosis and management of premature ovarian insufficiency, but there is a gap in clinical guidance for early menopause. We argue that instead of distinct age thresholds being applied, early menopause should be seen on a spectrum between premature ovarian insufficiency and menopause at the average age. This Series paper presents evidence for the short-term and long-term consequences of early menopause. We offer a practical framework for clinicians to guide diagnosis and management of early menopause, which considers the nature and severity of symptoms, age and medical history, and the individual's wishes and priorities to optimise their quality of life and short-term and long-term health. We conclude with recommendations for future research to address key gaps in the current evidence.

The Association of Early Menopause with Increased Risk of Acute Myocardial Infarction: The INTERHEART China Study

Background and Aim: Little is known about whether early menopause in Chinese ethnicity is associated with acute myocardial infarction (AMI). We aimed to determine whether self-reported early menopause (either surgical or natural menopause at an age <50 year) was associated with first AMI in Chinese women. Methods: The study population was from the INTERHEART China Study, part of the INTERHEART global study. INTERHEART global study was a standardized case-control study that was designed to evaluate the risk factors for first AMI among 52 countries. Data for demographic factors, education, income, and cardiovascular risk factors were obtained by structured questionnaires. A standard set of questions that inquired about menstrual history was included in the interview. Results: Of the 1,771 Chinese women, 1,563 (88.3%) reported either natural or surgical menopause. In univariate logistic regression model, women with early menopause had higher risk of AMI (odds ratio [OR]: 1.51; 95% confidence interval [CI]: 1.23-1.87). After controlling for age, birth control measures, type of menopause, and other traditional risk factors (including waist/hip ratio, lifestyle factors, history of hypertension and diabetes, psychosocial factors, and apolipoprotein B [ApoB]/A1 [ApoA1]), the risk for AMI remained (OR: 1.36; 95% CI: 1.03-1.79). The population attributable risk for AMI in women with early menopause at <50 years was 10.1% (95% CI: 4.0-20.0) compared with women who had menopause at ≥50 years. Conclusion: Early menopause is associated with increased risk of AMI in Chinese women, independent of other traditional coronary heart disease risk factors.

Clinical decision support tool for breast cancer recurrence prediction using SHAP value in cooperative game theory

Background

Recurrence remains the primary cause of death in patients with breast cancer. Although machine learning can efficiently predict the prognosis of breast cancer patients, the black-box nature of the model may result in a lack of evidence for clinicians when making critical decisions.

Methods

In this study, our main objective was twofold: (1) to develop a clinical decision support tool for predicting the prognosis of breast cancer and (2) to identify and explore the key factors that influence breast cancer recurrence. To achieve this, we employed an explainable ensemble learning method called Shapley additive explanation (SHAP), which leverages cooperative game theory. Using real-world data from 1629 breast cancer patients, we analyzed and uncovered the key factors associated with breast cancer recurrence. Subsequently, we used these identified factors to create a recurrence prediction model and establish a decision mechanism for the tool. The proposed method not only provides accurate recurrence predictions but also offers transparent explanations for these predictions.

Results

By utilizing four key factors, namely, tumor size, clinical stage III, number of lymph node metastases, and age, our decision support tool for predicting breast cancer recurrence achieved significant improvements. The extra-tree model exhibited an increased area under the receiver operating characteristic curve (AUC) of 0.97, while the Random Forest model demonstrated an improved AUC of 0.96. We also offer a decision mechanism for a recurrence prediction model based on the identified key factors. This transparent and interpretable decision-making process facilitated by our explainable ensemble learning model enhances trust and promotes its applicability in clinical settings.

Conclusions

The proposed explainable ensemble learning method shows promising results in predicting breast cancer recurrence, outperforming existing methods with high accuracy and transparency. This advancement has the potential to significantly improve clinical decision-making and patient outcomes in breast cancer treatment.

Age at menopause is inversely related to the prevalence of common gynecologic cancers: a study based on NHANES

Background

The fluctuation or even loss of estrogen level caused by menopause in women, and most gynecological cancers often occur before and after menopause, so the age of menopause may be related to the occurrence of gynecological cancer.

Aim

To investigate whether the age at menopause is independently associated with the incidence of gynecological cancers and to analyze the possible influencing factors.

Methods

We selected the NHANES public database to conduct the study, and by excluding relevant influencing factors, we finally included 5706 NHANES participants who had full data on age at menopause and the occurrence of gynecologic cancers to analyze the relationship between the amount of age at menopause and gynecologic cancers based on univariate or multifactorial logistic regression analysis. Further, the relationship between age at menopause and the prevalence of different gynecologic cancers was investigated, and changes in the prevalence of different gynecologic cancers by age at menopause subgroups were observed. Finally, other relevant factors affecting the prevalence of gynecologic cancers were further investigated by subgroup analysis as well as subcluster analysis.

Results

Univariate logistic regression analysis between age at menopause and gynecologic tumor prevalence revealed a negative association between age at menopause and the prevalence of common gynecologic cancers ovarian and cervical cancer, and after adjusting for the effects of covariates, a higher risk of gynecologic tumors was found with statistically significant differences at earlier age at menopause. The regression results showed a negative association between age at menopause and gynecologic cancer prevalence in cervical and ovarian cancer patients (P<0.01,P<0.01). Cervical cancer (OR: 0.91, 95% CI: 0.87,0.94) and ovarian cancer (OR: 0.90, 95% CI: 0.86, 0.95) were more prevalent among those with younger age at menopause.

Conclusion

Age at menopause is negatively associated with the prevalence of cervical and ovarian cancers, and the earlier the age at menopause, the greater the risk of developing gynecological cancers.

Age at Natural Menopause and Influencing Factors in Women Attending the Gynecological Outpatient Clinic at a Tertiary Care Hospital

Background

Menopause is the irreversible cessation of menstruation that results from the lack of ovarian follicular function and is diagnosed after 12 consecutive months of amenorrhea without reasonable cause. This study aims to determine the average age at natural menopause and identify its associated factors among Somali women.

Methods

This is a cross-sectional study conducted at the Mogadishu Somalia Türkiye Recep Tayyip Erdogan research and training hospital's Obstetrics and Gynecology outpatient clinic between June 1 and July 1, 2023. Data was collected from subjects during the data collection period using face-to-face interviews with structured questionnaires consisting of sociodemographic, lifestyle, dietary, and reproductive characteristics. A multivariate logistic regression analysis was conducted to find the association between menopause age and target variables.

Results

Out of the 188 participants recruited for the study, the median age of menopause was 45.00 (95% CI = 44.50-45.62), and 48.9% had either premature or early menopause. The majority (53.7%) of the participants had a minimum of eight children. In Spearman's rank correlation analysis, we found a significantly positive correlation between menopausal age and age at first (p<0.01), last childbirth (p<0.01), number of parities (p<0.05), and age at marriage (p<0.05). In multivariate logistic regression, we found that the odds of developing premature or early menopause among unemployed women were 59% lower than those of employed women (AOR = 0.41, 95% CI = 0.18-0.93).

Conclusion

In this study, we established that the age of natural menopause was lower than the findings reported by previous authors. We also found that employment status, education, history of contraceptive use, BMI, age at first and last childbirth, and parity were associated with age at natural menopause, suggesting that social, lifestyle, and reproductive factors may have an impact on menopausal age.

Sex- and reproductive status-specific relationships between body composition and non-alcoholic fatty liver disease

BACKGROUND

Sex and reproductive status differences exist in both non-alcoholic fatty liver disease (NAFLD) and body composition. Our purpose was to investigate the relationship between body composition and the severity of liver steatosis and fibrosis in NAFLD in different sex and reproductive status populations.

METHODS

This cross-sectional study included 880 patients (355 men, 417 pre-menopausal women, 108 post-menopausal women). Liver steatosis and fibrosis and body composition data were measured using FibroScan and a bioelectrical impedance body composition analyzer (BIA), respectively, and the following parameters were obtained: liver stiffness measurement (LSM), controlled attenuation parameter (CAP), waist circumference (WC), body mass index (BMI), percent body fat (PBF), visceral fat area (VFA), appendicular skeletal muscle mass (ASM), appendicular skeletal muscle mass index (ASMI), fat mass (FM), fat free mass (FFM), and FFM to FM ratio (FFM/FM). Multiple ordinal logistic regression (MOLR) was used to analyze the independent correlation between body composition indicators and liver steatosis grade and fibrosis stage in different sex and menopausal status populations.

RESULTS

Men had higher WC, ASM, ASMI, FFM, and FFM/FM than pre- or post-menopausal women, while pre-menopausal women had higher PBF, VFA, and FM than the other two groups (p < 0.001). Besides, men had greater CAP and LSM values (p < 0.001). For MOLR, after adjusting for confounding factors, WC (OR, 1.07; 95% CI, 1.02-1.12; P = 0.011) and FFM/FM (OR, 0.52; 95% CI, 0.31-0.89; P = 0.017) in men and visceral obesity (OR, 4.16; 95% CI, 1.09-15.90; P = 0.037) in post-menopausal women were independently associated with liver steatosis grade. WC and visceral obesity were independently associated with liver fibrosis stage in men (OR, 1.05; 95% CI, 1.01-1.09, P = 0.013; OR, 3.92; 95% CI, 1.97-7.81; P < 0.001, respectively).

CONCLUSIONS

Increased WC and low FFM/FM in men and visceral obesity in post-menopausal women were independent correlates of more severe liver steatosis. In addition, increased WC and visceral obesity were independent correlates of worse liver fibrosis in men. These data support the sex- and reproductive status-specific management of NAFLD.

Threshold of 25(OH)D and consequently adjusted parathyroid hormone reference intervals: data mining for relationship between vitamin D and parathyroid hormone

PURPOSE

By recruiting reference population, we aimed to (1): estimate the 25(OH)D threshold that maximally inhibits the PTH, which can be defined as the cutoff value for vitamin D sufficiency; (2) establish the PTH reference interval (RI) in population with sufficient vitamin D.

METHODS

Study data were retrieved from LIS (Laboratory Information Management System) under literature suggested criteria, and outliers were excluded using Tukey fence method. Locally weighted regression (LOESS) and segmented regression (SR) were conducted to estimate the threshold of 25(OH)D. Multivariate linear regression was performed to evaluate the associations between PTH concentration and variables including 25(OH)D, gender, age, estimated glomerular filtration rate (EGFR), body mass index (BMI), albumin-adjusted serum calcium (aCa), serum phosphate(P), serum magnesium(Mg), and blood collection season. Z test was adopted to evaluate whether the reference interval should be stratified by determinants such as age and gender.

RESULTS

A total of 64,979 apparently healthy subjects were recruited in this study, with median (Q1, Q3) 25(OH)D of 45.33 (36.15, 57.50) nmol/L and median (Q1, Q3) PTH of 42.19 (34.24, 52.20) ng/L. The segmented regression determined the 25(OH)D threshold of 55 nmol/L above which PTH would somewhat plateau and of 22 nmol/L below which PTH would rise steeply. Multivariate linear regression suggested that gender, EGFR, and BMI were independently associated with PTH concentrations. The PTH RI was calculated as 22.17-72.72 ng/L for subjects with 25(OH)D ≥ 55 nmol/L with no necessity of stratification according to gender, age, menopausal status nor season.

CONCLUSION

This study reported 25(OH)D thresholds of vitamin D sufficiency at 55 nmol/L and vitamin D deficiency at 22 nmol/L, and consequently established PTH RIs in subjects with sufficient vitamin D for northern China population for the first time.

The Distribution of Cervical Human Papillomavirus Infection Among Chinese Adult Women

Background

The characteristics and genotypic distribution of human papillomavirus (HPV) infection differ in different countries and regions. The purpose of this study was to analyze the distribution of 27 HPV subtypes among adult women receiving health examinations in Jinan, China.

Methods

A retrospective analysis was performed to analyze HPV subtype infection among adult women who underwent cervical cancer screening from January 1, 2020, to December 31, 2020.

Results

Among 4746 women receiving HPV testing, 682 cases were positive, representing 14.4% of patients. In total, 514 cases were infected by a single HPV subtype (75.4%), 115 cases had dual infections (16.9%), and 53 cases had multiple infections (7.7%). Among the 682 cases of HPV infection, 503 cases (73.8%) were high-risk HPV infections. The most common high-risk HPV strains were HPV 52 (23.3%), HPV 16 (13.5%), and HPV 58 (12.7%). Low-risk HPV strains infected 179 cases (26.2%). The most common genotypes were HPV 61 (25.7%), HPV 81 (21.2%), and HPV 55 (15.6%).

Conclusion

The HPV infection rate in healthy women was high, and the mixed infection rate was as high as 24.6%, highlighting the need for increased attention to this virus.

Study on depletion of ovarian function and late-life chronic diseases in India

OBJECTIVE

The current study aims to understand premature and early menopausal age in association with chronic conditions.

METHODS

The present cross-sectional study analyzed nationally representative data from LASI (Longitudinal Aging Study in India) from 2017 to 2018. Bivariate analysis including cross-tabulation and χ2 tests were performed. Further multiple regression analysis was performed, using the generalized linear model of logit link.

RESULTS

Approximately 2533 (8%) older women reported that they had experienced premature menopause (before age 40), while 3889 (12.4%) reported having early menopause (age 40-44). The likelihood of a woman with premature menopause developing cardiovascular diseases (CVDs) is 15% higher (adjusted odds ratio [AOR], 1.15; P < 0.05) than those who do not experience premature menopause, while women with early menopause have a 13% higher risk (AOR, 1.13; P < 0.05). For women who experienced premature menopause and were also smokers, the probability of developing CVDs was higher. Other chronic diseases such as bone or joint problems, diabetes, and eye vision problems were also shown to be significant health problems among women who had premature ovarian failure.

CONCLUSION

Our results show significant association between women with premature or early depletion of ovarian function and chronic health conditions such as cardiovascular diseases, bone or joint problems, vision problems, and neurological or psychiatric disorders at their later life ages. Comprehensive strategies in the form of lifestyle changes may regulate hormonal levels and allow the body to reach menopause at the appropriate age.

Factors predicting age at menopause among Iranian women in the Bandare-Kong cohort study (a cross-sectional survey of PERSIAN cohort study)

BACKGROUND

Menopause is a natural period in women's life and can be affected by several factors. The aim of this study was to identify the associated factors for age of natural menopause and among women with early and premature menopause based on a cohort study in Iran.

METHODS

This population-based study was conducted on 894 post menopause women between 35 and 70 years old who participated in the Bandare-Kong Non-Communicable Diseases (BKNCD) Cohort Study, a part of Prospective Epidemiological Research Studies in Iran (PERSIAN) from March 2016 to February 2019. All women completed a standard self-reported questionnaire. Data were analyzed using chi-square test, independent t test, and ANOVA as well as a multivariable linear regression model.

RESULTS

The mean age at natural menopause was 48.31 ± 6.34 years. After adjusting other variables, gravida, history of cardiac disease, socioeconomic status and residence status were predictive of age at menopause (P < 0.001). Among the premature menopause group, the mean age at menopause was significantly higher among women with diabetes compared to women without diabetes group (35.68 ± 2.92 vs. 33.82 ± 3.06; P = 0.043), while the mean age at menopause was significantly lower in women with infertility compared to women without infertility (29.13 ± 5.22 vs. 34.84 ± 2.826; P = 0.048).

CONCLUSIONS

This study suggests that the predictors of menopausal age differed in women with premature menopause compared to overall menopause age. Prospective studies are needed to evaluation the effects of these factors on menopausal age.

Impact of urinary sodium excretion on the prevalence and incidence of metabolic syndrome: a population-based study

OBJECTIVE

To evaluate the association of metabolic syndrome (MetS) risk with 24-hour urinary sodium excretion (24hUNaE) estimated from spot urine samples.

DESIGN

Serial cross-sectional studies were conducted, and those with multiple repeated examinations were used to assess the MetS incidence risk.

SETTING AND PARTICIPANTS

A health check-up programme was conducted between 2018 and 2021 and enrolled 59 292 participants to evaluate the relationship between MetS risk and 24hUNaE in the Third Xiangya Hospital, Changsha, China. Among these participants, 9550 had at least two physical examinations during this period, which were used to evaluate the association of a new occurrence of MetS with 24hUNaE.

OUTCOMES

Guidelines for the prevention and treatment of dyslipidaemia in Chinese adults (revised in 2016) were used to define prevalent and incident MetS.

RESULTS

The prevalence of MetS was 19.3% at the first check-up; among individuals aged ≤55 years, the risk was higher in men than women, while among older individuals, a similar prevalence was observed in both sexes. A significant increase in MetS prevalence was observed per unit increase in 24hUNaE (adjusted OR (AOR) 1.11; 95% CI 1.09 to 1.13), especially for the prevalence of central obesity and elevated blood pressure. Additionally, 27.4% of the participants among the 7842 participants without MetS at the first check-up (male vs female: 37.3% vs 12.9%) were found to have a new occurrence of MetS at the second, third and/or fourth check-ups. A 25% increase in MetS incidence was observed per unit increase in 24hUNaE (95% CI 1.19 to 1.32), which was more prominent in the participants with a new occurrence of central obesity and elevated fasting blood glucose.

CONCLUSIONS

Although the prevalence of MetS seemed stable, new occurrences of MetS remained high, which might result in MetS recurrence. The influence of sodium intake on MetS development is probably attributed to the increase in blood pressure and central obesity, but a new occurrence of MetS may develop through elevated blood glucose and central obesity.

Urban-rural differences in epidemiology and risk factors of menopause syndrome in middle-aged Chinese women

OBJECTIVE

To compare the prevalence and severity of menopausal symptoms and investigate their associated factors among rural and urban middle-aged Chinese women.

METHODS

A descriptive, cross-sectional study of 4,580 urban and 2,729 rural randomly sampled participants aged 40 to 55 years in Gansu Province, China, was conducted. Questionnaires assessing the sociodemographic information and menstrual and reproductive histories of the participants were administered. The modified Kupperman scale was used to assess the presence and severity of menopausal symptoms. Binary and ordinal logistic regression analyses were performed to identify factors associated with the occurrence and severity of menopausal syndrome, respectively, according to the modified Kupperman Menopausal Index score rank.

RESULTS

The natural menopausal age of the rural women was significantly lower than that of the urban women (rural: 47.22, urban: 47.98; P < 0.05). Furthermore, rural women had a higher prevalence (rural: 56.35%, urban: 43.47%) and severity (rural: 11.40%, urban: 6.61%) of menopausal syndrome than the urban women ( P < 0.05). For both the urban and rural women, the prevalence and severity of most menopausal symptoms increased as menopause progressed. The three most prevalent symptoms in both the urban and rural women were fatigue (rural: 70.43%, urban: 68.19%), muscle/joint pain (rural: 62.84%, urban: 59.32%), and vertigo (rural: 57.42%, urban: 47.44%). Positive associations between menopausal symptoms and age, residence, body mass index, level of education, time of pregnancy, menstrual cycle, and presence of chronic diseases were observed.

CONCLUSIONS

Rural women experience more frequent and severe menopausal syndrome than do urban women.

Implementation of visual inspection with acetic acid and Lugol's iodine for cervical cancer screening in rural China

OBJECTIVE

To address the value of visual inspection where HPV-based screening is not yet available, we evaluated the real-world effectiveness of visual inspection with acetic acid (VIA) and with Lugol's iodine (VILI) as a primary screening method for cervical cancer in rural China.

METHODS

A total of 206 133 women aged 30-59 years received two rounds of VIA/VILI screening for cervical cancer in 2006-2010. Women with positive screening results underwent colposcopy and direct biopsy, and were treated if cervical intraepithelial neoplasia grade 2 or worse (CIN2+) was diagnosed. Clinical effectiveness of VIA/VILI was evaluated by process and outcome measures.

RESULTS

The VIA/VILI positivity rate, biopsy rate and detection rate of CIN2+ in the second round were significantly lower than in the first round. The 2-year cumulative detection rate of CIN2+ varied from 0.53% to 0.90% among the four cohorts initiated in 2006, 2007, 2008, and 2009. The first round of screening detected 60%-83% of CIN2, 70%-86% of CIN3, and 88%-100% of cervical cancer. Over 92% of CIN2+ were found at the early stage.

CONCLUSION

Multiple rounds of visual inspection with continuous training and quality assurance could act as a temporary substitutional screening method for cervical cancer in resource-restricted settings.

Impact of lifetime lactation on the risk and duration of frequent vasomotor symptoms: A longitudinal dose-response analysis

OBJECTIVE

To examine the association between lifetime lactation and risk and duration of frequent vasomotor symptoms (VMS).

DESIGN

Prospective cohort.

SETTING

USA, 1995-2008.

SAMPLE

2356 parous midlife women in the Study of Women's Health Across the Nation.

METHODS

Lifetime lactation was defined as the duration of breastfeeding across all births in months. We used generalised estimating equations to analyse risk of frequent VMS and Cox regression to analyse duration of frequent VMS in years.

MAIN OUTCOME MEASURES

Frequent VMS (hot flashes and night sweats) were measured annually for 10 years, defined as occurring ≥6 days in the past 2 weeks.

RESULTS

Overall, 57.1% of women reported hot flashes and 43.0% reported night sweats during follow-up. Lifetime lactation was inversely associated with hot flashes plateauing at 12 months of breastfeeding (6 months: adjusted odds ratio [AOR] 0.85, 95% confidence interval (CI) 0.75-0.96; 12 months: AOR 0.78, 95% CI 0.65-0.93) and was inversely associated with night sweats in a downward linear fashion (6 months: AOR 0.93, 95% CI 0.81-1.08; 18 months: AOR 0.82, 95% CI 0.67-1.02; 30 months: AOR 0.73, 95% CI 0.56-0.97). Lifetime lactation was associated with shorter duration of hot flashes and night sweats in a quadratic (bell-shaped) fashion. The association was strongest at 12-18 months of breastfeeding and significant for hot flashes (6 months: adjusted hazard ratio [AHR] 1.35, 95% CI 1.11-1.65; 18 months: AHR 1.54, 95% CI 1.16-2.03; 30 months: AHR 1.18, 95% CI 0.83-1.68).

CONCLUSIONS

Longer lifetime lactation is associated with decreased risk and duration of frequent VMS.

The effect and safety of Tai Chi on bone health in postmenopausal women: A meta-analysis and trial sequential analysis

Background

Tai Chi may be a promising exercise to prevent and control bone loss in postmenopausal women. This meta-analysis and trial sequential analysis aimed to evaluate the effect and safety of Tai Chi on bone health in postmenopausal women.

Method

Seven databases were searched from their inceptions to 11 May 2022 to collect randomized controlled trials (RCTs) investigating the effect and safety of Tai Chi on bone health in postmenopausal women. Two independent reviewers identified the eligible studies, extracted data, and assessed the risk of bias of included studies using the revised Cochrane risk-of-bias tool for randomized trials. The primary outcome was the bone mineral density (BMD), and secondary outcomes included bone turnover markers and calcaneus quantitative ultrasound. Subgroup analyses were conducted based on the duration of Tai Chi. Sensitivity analyses and publication bias assessment were performed. RevMan software (version 5.4.1) and R software (version 3.6.1) were used for data synthesis. The certainty of evidence was rated with the Grading of recommendations assessment, development, and evaluation (GRADE) system. We also performed the trial sequential analysis to evaluate the reliability of the evidence.

Results

A total of 25 reports involving 24 studies were included. Four studies were considered as high overall risk of bias, and the rest were some concerns. Among included studies, there were three comparisons including Tai Chi vs. non-intervention, Tai Chi vs. other exercises, and Tai Chi plus nutraceutical vs. nutraceutical. Compared with non-intervention, Tai Chi was more effective to improve BMD of lumbar spine (MD = 0.04, 95% CI 0.02 to 0.07, I2 = 0%, low certainty), femoral neck (MD = 0.04, 95% CI 0.02 to 0.06, I2 = 0%, low certainty), and trochanter (MD = 0.02, 95% CI 0.00 to 0.03, I2 = 0%, very low certainty), but there was no significant difference in increasing the BMD of Ward's triangle (MD = 0.02, 95% CI −0.01 to 0.04, I2 = 0%, very low certainty). Trial sequential analysis showed that the effect of Tai Chi vs. non-intervention on the BMD of lumbar spine and femoral neck was reliable, but the effect on the BMD of trochanter and Ward's triangle needed further verification. The subgroup analyses suggested that Tai Chi training for over 6 months had greater improvement in BMD of the lumbar spine, femoral neck, and trochanter than non-intervention. No significant differences were observed in the above outcomes of Tai Chi vs. other exercises, and Tai Chi plus nutraceutical vs. nutraceutical. There was insufficient evidence to support the effect of Tai Chi on bone turnover markers and calcaneus quantitative ultrasound. Few Tai Chi relevant adverse events occurred.

Conclusion

Tai Chi may be an optional and safe exercise for improving BMD loss in postmenopausal women, and practicing Tai Chi for more than 6 months may yield greater benefits. However, more rigorously designed RCTs are required to verify the benefits and to explore the optimal protocol of Tai Chi exercise for bone health.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=309148, identifier: CRD42022309148.

Association of lifetime lactation and age at natural menopause: a prospective cohort study

OBJECTIVE

The aim of this study was to examine the association between duration of lifetime lactation and age at natural menopause.

METHODS

In this prospective cohort study, we analyzed parous premenopausal women in the multiethnic Study of Women's Health Across the Nation who were followed approximately annually for 10 years (1995-2008). Lifetime lactation was defined as the duration of breastfeeding across all births in months. Age at natural menopause was defined as age in years after 12 consecutive months of amenorrhea after the final menstrual period for no other reported cause. We used Cox proportional hazard models to analyze time to natural menopause with age as the underlying time scale. Multivariable models controlled for education, race/ethnicity, parity, smoking, body mass index, and oral contraceptive use.

RESULTS

Among 2,377 women, 52.6% experienced natural menopause during follow-up and reported a valid final menstrual period date. The small, crude association between lifetime lactation up to 24 months and later age at natural menopause attenuated to nonsignificance in adjusted models (6 months: adjusted hazard ratio [AHR], 0.96; 95% confidence interval (CI), 0.87-1.06; 12 months: AHR, 0.95; 95% CI, 0.82-1.11; 18 months: AHR, 0.96; 95% CI, 0.82-1.13; 24 months: AHR, 0.99; 95% CI, 0.84-1.16).

CONCLUSIONS

Duration of lifetime lactation was not associated with age at natural menopause after controlling for sociodemographic characteristics.

Burch colposuspension for stress urinary incontinence: a 14-year prospective follow-up

We aimed to evaluate the long-term effectiveness and safety of Burch colposuspension (BC) for stress urinary incontinence (SUI). In this prospective cohort study, 84 patients with SUI undergoing BC were enrolled from February 2004 to January 2010. Data on long-term subjective success and postoperative complications were collected at clinic visits and by telephone follow-up. During a mean follow-up period of 14.2 years, 68% (57/84) patients completed the follow-up. A total of 68.4% of patients (39/57) reported absence of SUI symptoms, 73.6% (42/57) were subjectively satisfied according to the Patient Global Impression of Improvement, and 68.4% (39/57) reported subjective success regarding urinary symptoms via the Urinary Distress Inventory Short Form. However, 28.1% (16/57) suffered at least one long-term postoperative complication and incident. Specifically, 1 in 25 (4.0%) sexually active patients reported dyspareunia, 3 patients (5.3%) had de novo overactive bladder, and 6 patients (10.5%) reported voiding dysfunction. Four patients (7.0%) reported new onset prolapse symptoms, and 3 patients (5.3%) underwent secondary urinary incontinence surgery. Our study indicated that Burch colposuspension is an effective procedure for SUI, and the cure effect was largely maintained for the 14-year follow-up period, with relatively low complication rates. BC should be considered a surgical option for SUI.