Mediation effect of BMI on the relationship between age at menarche and hypertension: The Henan Rural Cohort Study

Long-term exposure to PM2.5 and its components is associated with elevated blood pressure and hypertension prevalence: Evidence from rural adults

INTRODUCTION

The toxicity of fine particulate matter (PM2.5) is determined by its components, while the evidence regarding associations of PM2.5 components with blood pressure (BP) is limited, especially in rural areas.

OBJECTIVES

This study aimed to explore the associations of PM2.5 and its chemical components with systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), mean artery pressure (MAP) levels and hypertension prevalence, and to identify key components in Chinese rural areas.

METHODS

39,211 adults from the Henan Rural Cohort were included during 2015-2017. Different periods of PM2.5 and chemical components were estimated by hybrid satellite model. The single-pollutant, component-PM2.5 model, component-residual model and component-proportion model were applied to explore the associations of pollutants with BP levels and hypertension prevalence. Exposure-response (E-R) relationships, stratified analyses and sensitivity analyses were used to explore these associations further.

RESULTS

12,826 (32.71%) were identified with hypertension. For each 1 μg/m3 increase of pollutants, the adjusted odds ratio (OR) for hypertension prevalence was 1.03 for PM2.5 mass, 1.40 for BC, 1.16 for NH4+, 1.08 for NO3-, 1.17 for OM, 1.12 for SO42- and 1.25 for SOIL in the single-pollutant model. BC and SOIL were statistically significant in the component-PM2.5 model, component-residual model and component-proportion model. Similarly, associations of these pollutants with elevated BP levels were also found in aforementioned four models. These pollutants produced a stronger association with SBP than DBP, PP and MAP. Most of associations were non-linear in E-R relationships. The groups of older, the men, with lower per capita monthly income, lower educational level and higher BMI were more vulnerable to these pollutants in stratified analyses. The results remained stable in sensitivity analyses.

CONCLUSION

Long-term exposure to PM2.5 and its components, especially BC and SOIL, was associated with elevated BP and hypertension prevalence in rural adults, and decreasing pollutants may provide additional benefits.

Adiposity indices and their higher predictive value for new-onset hypertension in metabolically healthy young women: findings from a population-based prospective cohort study

BACKGROUND AND AIMS

The present study aimed to investigate the predictive ability of selected adiposity indices, such as body mass index (BMI), waist-to-hip ratio (WHR), waist circumference (WC), and waist-to-height ratio (WHtR), for new-onset hypertension in metabolically healthy Taiwanese adults. The study also sought to establish sex-specific cutoff points for these indices and to analyze the risk of new-onset hypertension, taking into account sex and age.

METHODS

This prospective cohort study utilized the Taiwan Biobank database to examine metabolically healthy participants aged between 20 and 65 at baseline. Four adiposity indices, namely BMI, WHR, WC, and WHtR, were calculated and used to predict new-onset hypertension over 4 years. Receiver operating characteristics (ROCs) and areas under the curve (AUCs) were used to evaluate the effectiveness of the parameters in predicting new-onset hypertension over 4 years. Sex-specific cutoff points were identified and used to assess the risk of new-onset hypertension.

RESULTS

This study analyzed 13,375 participants over 4.28 years. The incidence of new-onset hypertension was 17.65%. The new-onset rate of hypertension was 34.39% in men and 65.61% in women. Adiposity indices effectively predict new-onset hypertension, with WHtR having the highest predictive value (i.e., AUC) for both sexes. The classification of participants into low and high categories for each adiposity index was based on sex-specific cutoff points, and the risk of new-onset hypertension was assessed according to sex and age. This study found that high adiposity indices predicted a significantly higher risk of new-onset hypertension in metabolically healthy adults. The risk was equal for both sexes. Young women had a higher risk of new-onset hypertension than middle-aged women when they were further categorized. All risk ratios of the indices in young women were over two-fold and significant.

CONCLUSION

According to the sex-specific cutoff point, high adiposity indices had a higher predictive value for new-onset hypertension in metabolically healthy Taiwanese young women.

Age at menarche and metabolic dysfunction-associated fatty liver disease: Evidence from a large population-based epidemiological study in Southwest China

BACKGROUND

The relationship between age at menarche and metabolic dysfunction-associated fatty liver disease remains largely not clear. The objective of this study was to examine the association between age at menarche (AAM) and metabolic dysfunction-associated fatty liver disease (MAFLD) in Chinese women and whether any observed associations were mediated by early adulthood adiposity.

METHODS

The cross-sectional study included 46,873 Chinese women, aged 30-79 from baseline data of the China Multi-Ethnic Cohort study. Logistic regression models were used to evaluate the association between AAM and MAFLD. Mediation analysis was adopted to examine whether early adulthood adiposity (around 25 years) mediated the association between AAM and MAFLD.

RESULTS

AAM was linearly and inversely associated with the risk of MAFLD (P for nonlinearity =0.743). In a multivariable-adjusted model, the odds ratios and 95% confidence interval (ORs (95% CI)) for MAFLD comparing menarche at <12, 12, 13, 15, 16, 17, ≥18 years to menarche at 14 years were 1.290 (1.082-1.537), 1.172 (1.068-1.285), 1.042 (0.960-1.131), 0.937 (0.861-1.020), 0.911(0.835-0.994), 0.868 (0.786-0.959), and 0.738 (0.670-0.814), respectively (P for trend <0.001). The 6.4% increased MAFLD risk was associated with each preceding year in AAM. The association between AAM and MAFLD was modified by age, ethnicity, and menopause. Early adulthood adiposity partially mediated this association.

CONCLUSION

The findings of this study suggest that obesity prevention strategies are needed from young adulthood in women who undergo early menarche to reduce the risk of MAFLD.

Association of age at menarche with gestational hypertension and preeclampsia: A large prospective cohort in China

This study explored the potential association between age at menarche and the risks of gestational hypertension and preeclampsia in Chinese women. Data were sourced from the China-US Collaborative Project for Neural Tube Defects Prevention, a large population-based cohort study. Our study consisted of 209 411 women pre-registered for pregnancy in two provinces in South China. Trained healthcare workers measured blood pressure at registration and recorded other pertinent health information. Using logistic regression, we assessed the correlations between age at menarche and the likelihood of developing gestational hypertension and preeclampsia, considering confounders such as maternal age, body mass index, ethnicity, parity, folic acid supplementation, education level, and occupation. The observed incidences for gestational hypertension and preeclampsia were 9.65% and 2.54%, respectively. The adjusted odds ratios (ORs) for gestational hypertension, based on age at menarche, were as follows: ≤13 years, 1.18 (95% confidence interval: 1.11-1.26); 14 years, 1.09 (1.04-1.15); 15 years, 1.11 (1.06-1.16); 16 years, 1.06 (1.01-1.12); and ≥17 years, 1.00 (reference; P for trend < .001). The correlation between age at menarche and preeclampsia varied across age groups, with the following respective ORs: 1.35 (1.20-1.52), 1.21 (1.09-1.34), 1.27 (1.15-1.39), 1.14 (1.03-1.26), and 1.00 (reference; P for trend < .001). This association appeared to be more pronounced in women with no folic acid supplementation and those with a lower education level. In conclusion, an earlier age at menarche seems to be linked to increased risks of gestational hypertension and preeclampsia.

Mendelian randomization study and meta-analysis exploring the causality of age at menarche and the risk of intracerebral hemorrhage and ischemic stroke

BACKGROUND

The relationship between the age at menarche (AAM) and the risk of intracerebral hemorrhage (ICH) and ischemic stroke (IS) is still up for debate. The purpose of this study was to investigate potential causal connections between them.

METHODS

Genome-wide association analysis (GWAS) of AAM conducted by the MRC-IEU consortium was utilized for association analyses of ICH and IS by two-sample Mendelian randomization (MR) study. AAM data of the within-family GWAS consortium were used as replication phase data to verify the causal relationship between each other. Inverse variance weighting (IVW) method was the primary method used in this MR study. For additional proof, the weighted median estimation, MR-Egger regression, MR-PRESSO test, and MR-Robust Adjusted Profile Score evaluation were performed. The Cochran's Q test and the MR-PRESSO global test were used, respectively, to examine the sensitivity and pleiotropy. Random effects meta-analysis was utilized to analyze the causal data from the two consortiums to further explore the causality between AAM and ICH, IS.

RESULTS

We found that the AAM was causally linked with the risk of ICH (OR = 0.48, 95% CI: 0.28-0.80, p = 0.006). On the contrary, the causal effect from AAM to IS (OR = 0.98, 95% CI: 0.91-1.06, p = 0.64) has not been confirmed. For all subtypes of ICH, we found that nonlobar intracerebral hemorrhage (NLICH, OR = 0.41, 95% CI: 0.23-0.75, p = 0.004) but not lobar intracerebral hemorrhage (LICH, OR = 0.65, 95% CI: 0.34-1.24, p = 0.19) was associated with AAM without surprise. Similarly, we used the within-family GWAS consortium data to explore causality and found that AAM may reduce the risk of ICH (OR = 0.78, 95% CI: 0.72-0.86, p = 9.5 × 10-8 ) and NLICH (OR = 0.68, 95% CI: 0.61-0.75, p = 3.4 × 10-13 ) by IVW methods, but is not related to IS (OR = 0.97, 95% CI: 0.93-1.02, p = 0.26). These findings are further supported by the meta-analysis. Both Cochran's Q test and the MR-PRESSO global test failed to detect the presence of sensitivity.

CONCLUSION

AAM and ICH, particularly NLICH, are causally related, but not LICH, IS, or its subtypes in European population.

Age at Menarche, Menopause Status and Metabolic Syndrome and its Components: Findings from the Henan Rural Cohort Study

INTRODUCTION

To evaluate the effect of age at menarche on metabolic syndrome (Mets) and its components and explore the impact of menopause status on the association between age at menarche and Mets in rural Chinese women.

METHODS

This cross-sectional study enrolled 23382 women from the Henan Rural Cohort study. The relationship between age at menarche and Mets was assessed using logistic regression and restricted cubic spline. Interaction plots were used to describe interactive effects of age at menarche and menopause status on Mets.

RESULTS

Age at menarche was inversely associated with the risk of Mets with the adjusted OR of 1.16, 0.98, 1.00, 0.82, and 0.77, respectively, for those with age at menarche≤13, 14, 15-16 (reference), 17, and≥18 years. Each year of delay in menarche age correlated with a 6.2% (P<0.001) lower risk of Mets. Among the components of Mets, an inverse association was observed between age at menarche and central obesity (OR (95% CI): 0.92 (0.90, 0.94)), abnormal FPG (OR (95% CI): 0.96 (0.94, 0.97)), abnormal BP (OR (95% CI): 0.967 (0.95, 0.98)), abnormal TG (OR (95% CI): 0.96 (0.94, 0.97)), and abnormal HDL-C (OR (95% CI): 0.96 (0.95, 0.98)). Significant interactions were discovered between age at menarche, menopause status, and the risk of Mets, central obesity, abnormal FPG, abnormal BP, and abnormal TG (all P interaction<0.001). The adverse effect of menopausal status on Mets, central obesity, abnormal FPG, abnormal BP, and abnormal TG decreased with delayed age at menarche.

CONCLUSIONS

Later menarche was associated with a lower risk of Mets. More importantly, the deleterious effect of menopause status on Mets decreased with the increase in age at menarche.

Mediation Effect of Obesity on the Association of Age at Menarche With Blood Pressure Among Women in Southwest China

Background Previous studies have been inconsistent about the association between age at menarche and high blood pressure. Little is known about such association across a wide range of menarcheal ages in less developed ethnic minority regions in China. We aimed to explore the association between age at menarche and high blood pressure (BP; ≥140/90 mm Hg) and to examine the mediating effect of obesity and the moderating effect of menopausal status on this association. Methods and Results A total of 45 868 women from the baseline data of the CMEC (China Multi-Ethnic Cohort) were included in this study. Binary logistic regression was used to analyze the relationship between age at menarche and high BP, and the mediation model was used to evaluate the mediating effects of body mass index and waist circumference on the association of age at menarche with high BP. The mean age at enrollment and age at menarche of participants in our study were 49.3 (SD=10.7) and 14.7 (SD=2.1) years, respectively. Late menarche was associated with a lower risk of high BP (odds ratio, 0.831 [95% CI, 0.728-0.950]). The risk of high BP decreased by 3.1% with each year's delay in the onset of menarche (P for trend <0.001). Body mass index and waist circumference could partially mediate the association of age at menarche and high BP with the indirect effect of body mass index (odds ratio, 0.998 [95% CI, 0.997-0.998]) and waist circumference (odds ratio, 0.999 [95% CI, 0.998-0.999]). In addition, the mediation effects were modified by the status of menopause. Conclusions Women with late menarche have a lower risk of high BP, and obesity could be one of the important mediators. Obesity prevention is an efficient strategy to reduce the association between age at menarche and high BP, especially in premenopausal women.

Age at menarche and its association with blood pressure in adult women of developing countries: a systematic review and meta-analysis

CONTEXT

Evidence about the effect of age at menarche (AAM) on blood pressure (BP) has largely been drawn from studies in developed countries. Studies in developing countries are expanding recently but have not been summarised.

OBJECTIVE

To systematically explore the association between AAM and BP and the potential modifiers in developing countries.

METHODS

We searched PubMed, Embase, and Web of Science for publications until March 2022. A random-effects model was used to calculate the pooled relative risk (RR) with 95% confidence interval (CI).

RESULTS

Twenty studies were eligible. In studies with participants' mean age at BP assessment <55 years, women in the oldest group as compared with the middle or the youngest group of AAM had a higher risk of hypertension in those studies without adjustment for confounders (RR 1.79, 95% CI 1.41-2.28, I²=97.0%), those with adjustment for confounders excluding adiposity (1.25,1.04-1.51, I²=84.8%), and those with adjustment for confounders including adiposity (1.38,1.03-1.86, I²=91.8%). In studies with participants' mean age at BP assessment ≥55 years, no significant differences were found for studies without adjustment for confounders (RR 1.07, 95% CI 0.78-1.47, I²=90.3%), studies with adjustment for confounders excluding adiposity (0.85, 0.78-0.92, I²=12.3%), or studies with adjustment for confounders including adiposity (0.95, 0.80-1.11, I²=45.5%). A similar association was observed between AAM and baseline systolic BP and diabolic BP.

CONCLUSION

Late menarche was associated with a higher risk of BP and this association was modified by age and adiposity in developing countries.

Obesity indicators as mediators of the association between age at menopause and blood pressure values

Having a later age at menopause is associated with having a higher blood pressure (BP) value, but the mediation pathways remain unclear. We quantitatively examined the mediation effects of various obesity indicators using baseline data from phase 4 of the Guangzhou Biobank Cohort Study. The product of coefficients approach and bootstrapping procedures were used to assess the mediation effects of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) on the association between age at menopause and BP values. Age, education, occupation, family income, smoking, drinking, diet, physical activity, age at menarche, number of births, fasting glucose, triglycerides, and high-density lipoprotein cholesterol were adjusted as covariates. Of 5429 women with natural menopause, the mean age and menopausal age were 60.0 (standard deviation = 5.8) and 50.3 (3.1) years, respectively. The prevalence of hypertension was 29.6%. In women with a menopausal age of ≥50 years, BMI, WC, WHR and WHtR showed significant mediation effects on the positive association between menopausal age and BP. The adjusted proportion (95% confidence interval) of the mediation effects for those variables were 26.04% (10.40-116.82%), 25.92% (10.19-108.57%), 14.11% (3.59-62.78%), and 23.17% (8.70-95.81%), respectively, for systolic BP values and 22.59% (10.72-53.60%), 20.67% (9.83-49.31%), 9.21% (2.73-23.92%), and 17.19% (7.56-41.31%) for diastolic BP values. In women with a menopausal age of <50 years, no significant association between age at menopause and systolic/diastolic BP values was found. In conclusion, obesity indicators showed significant mediating effects on the association between having a later age at menopause and having a higher BP value. Further longitudinal studies with detailed and accurate measurements of metabolic changes after menopause and sufficient follow-up are warranted to confirm these results. We demonstrated obesity indicators showed significant mediating effects on the association between later age at menopause (≥50 years) and higher BP.

Contribution of environmental factors and female reproductive history to hypertension and obesity incidence in later life

BACKGROUND

Hypertension (HT) and obesity, which are important risk factors for cardiovascular diseases, are complex traits determined by multiple biological and behavioural factors. However, the role of female reproductive history in evaluating HT and obesity is still unclear.

AIM

To investigate the long-term effects of reproductive factors on the probability of obesity and HT in later life after adjusting for socio-demographic and lifestyle behaviour factors.

SUBJECTS AND METHODS

A total of 503 women (39 - 65 years) were recruited from different localities in Slovakia. Multivariable logistic regression analyses were performed to test the associations.

RESULTS

Early menarche age of 11 years and under was associated with twice higher probability of obesity at midlife, independent of environmental confounders (OR = 2.27, CI = 1.35 - 3.81, p = 0.002). Breastfeeding (Bf) women had a lower likelihood of obesity in later life than non-Bf parous women, independent of environmental confounders (OR = 0.35, CI = 0.17 - 0.72, p = 0.004). Finally, age at menarche was associated with obesity-associated HT.

CONCLUSION

Reproductive factors are significantly associated with obesity and obesity-associated HT in later life. The age at menarche and Bf can be risk factors for early identification of women with increased likelihood of adult cardiovascular risk.

Ideal Cardiovascular Health Metrics Attenuated Association of Age at Menarche With Type 2 Diabetes in Rural China

Objective: It is not clear whether ideal cardiovascular health (ICH) metrics have an impact on the association between age at menarche and type 2 diabetes (T2DM) in rural postmenopausal Chinese women.

Methods: In all, 15,450 postmenopausal women were enrolled from the Henan Rural Cohort study. Logistic regression models and interaction plots were used to analyze associations between age at menarche, ICH metrics and T2DM and interactive effects.

Results: Age at menarche was inversely associated with risk of T2DM, with adjusted OR of 1.224, 1.116, 1.00 and 0.971, 0.850 for those with age at menarche ≤13, 14, 15–16 (reference), 17, and ≥18 years, respectively, and each year of delay in menarche age correlated with a 5.1% lower risk of T2DM. Negative interaction effects of age at menarche and number of ICH metrics on the risk of T2DM was observed.

Conclusion: Meeting more ICH metrics might attenuate the association between early menstrual age and increased risk of T2DM, implying that meeting a higher number of ICH metrics may be an effective way to prevent T2DM for women of early menarche age.

Reproductive lifespan in association with risk of hypertension among Chinese postmenopausal women: Results from a large representative nationwide population

Background

The association between reproductive lifespan and risk of hypertension among postmenopausal women is unclear.

Methods

A total of 94,141 postmenopausal women with a mean age of 64.8 years from the China Hypertension Survey were enrolled at baseline from 2012 to 2015. A standardized questionnaire was used to collect relevant information by well-trained interviewers. Blood pressure and physical examination of the participants were performed by trained medical staff. Logistic regression was used to estimate the odds ratios for hypertension by years of reproductive lifespan.

Results

The average years of reproductive lifespan in Chinese women was 34.0 years. Women who were longer in reproductive lifespan were more likely to have older age at recruitment, higher body mass index, larger waist circumference, lower mean systolic blood pressure, and higher mean diastolic blood pressure (p &lt; 0.05). After adjustments, odds ratios (95% confidence interval) for hypertension were 1.035 (0.988–1.085), 1.007 (0.966–1.048), 1.000 (reference), 0.932 (0.899–0.967), and 0.953 (0.909–0.997) for those with reproductive lifespan at ≤ 28, 29–31, 32–34 (reference), 35–37, and ≥ 38 years, respectively, with a significantly inverse association was seen in those with reproductive lifespan at 35–37 and ≥ 38 years. The overall risk of hypertension declined with the increase in reproductive lifespan, and the risk of hypertension was reduced by 1.1% for every 1-year increase in the reproductive lifespan (odds ratio, 0.989; 95% confidence interval, 0985–0.994) per year. The negative association between reproductive lifespan and hypertension was evident among age at recruitment groups, body mass index categories, and education levels, with the strongest association among women aged ≥ 70 years. Positive associations between reproductive lifespan and risk of hypertension were evident among women aged &lt; 60 years, and this association was stronger among current alcohol drinkers.

Conclusion

Based on the large nationally representative sample, Chinese postmenopausal women with a shorter reproductive lifespan have a higher risk of hypertension.

Mediator or moderator? The role of obesity in the association between age at menarche and blood pressure in middle-aged and elderly Chinese: a population-based cross-sectional study

OBJECTIVE

We investigated the moderation/mediation between the age of menarche and obesity parameters in predicting blood pressure (BP) in middle-aged and elderly Chinese.

DESIGN

Our study is a population-based cross-sectional study.

SETTING

Participants in this study came from the China Health and Retirement Longitudinal Study (CHARLS).

PARTICIPANTS

The analytical sample included 4513 participants aged 45-96 years.

MAIN OUTCOME MEASUREMENTS

Data were selected from the CHARLS, a cross-sectional study. Between-group differences were evaluated using χ², t-test and one-way analysis of variance. The trend of related variables by characteristics was also tested using contrast analysis, as appropriate. Then, correlations between characteristics, moderator, mediator, and independent and dependent variables were used by Spearman's correlation test and Pearson's correlation test. Finally, the mediation analysis was performed by model 4 in PROCESS V3.3 macro for SSPSS, and moderation analysis was used by model 1 for assessment. All covariates were adjusted in the moderation or mediation models.

RESULTS

In the correlation analysis, body mass index (BMI) and waist circle (WC) level were positively correlated with both systolic blood pressure (SBP) and diastolic blood pressure (DBP) in women (BMI and DBP: r=0.221, p<0.001; WC and DBP: r=0.183, p<0.001; BMI and SBP: r=0.129, p<0.001; WC and SBP: r=0.177, p<0.001). Age of menarche was negatively correlated with DBP (r=-0.060, p<0.001). However, the age of menarche was not significantly correlated with SBP (r=-0.014, p=0.335). In the moderator analysis, after controlling for the potential confounders, the interaction term of obesity parameters×age of menarche was not significant for predicting either DBP (BMI: B=0.0260, SE=0.0229, p=0.2556, 95% CI -0.0189 to 0.071; WC: B=0.0099, SE=0.0074, p=0.1833, 95% CI -0.0047 to 0.0244) or SBP (BMI: B=0.0091, SE=0.0504, p=0.8561, 95% CI -0.0897 to 0.108; WC: B=-0.0032, SE=0.0159, p=0.8427, 95% CI -0.0343 to 0.028). All correlations were significant correlation between age of menarche, obesity parameters and BP except the path of the menarche age→SBP (with the addition of the BMI indicator: β=-0.0004, B=-0.0046, p=0.9797, 95% CI -0.3619 to 0.3526; with the addition of the WC indicator: β=0.0004, B=0.0044, p=0.9804, 95% CI -0.3439 to 0.3526) in crude model. In general, after controlling for potential confounders, BMI (DBP: β=-0.0471, B= -0.2682, p=0.0021, 95% CI -0.4388 to -0.0976; SBP: β=-0.0515, B=-0.6314, p<0.001, 95% CI -0.9889 to -0.2739) and WC (DBP: β=-0.0474, B= -0.2689, p<0.001, 95% CI -0.4395 to -0.0984; SBP: β=-0.0524, B=-0.6320, p<0.001, 95% CI -0.9832 to -0.2807) partly mediated the relationship between age of menarche and BP.

CONCLUSIONS

The interaction term of obesity parameters×age of menarche was not significant for predicting either DBP or SBP in women. Moreover, obesity parameters partly mediated the relationship between the age of menarche and BP.

Associations between Age at Menarche and Dietary Patterns with Blood Pressure in Southwestern Chinese Adults

The aim of our study was to examine the relationship between age at menarche (AM) and hypertension and to evaluate whether different dietary patterns have an effect on associations between AM and hypertension in a large-scale Han Chinese population in southwest China. A cross-sectional study was performed that included 44,900 participants from 17 districts in southwest China from September 2018 to January 2019. The study comprised 23,805 individuals in the final analysis. Logistic regression and multivariable linear regression were applied to estimate the dietary pattern-specific associations between AM and hypertension or systolic/diastolic blood pressure (SBP/DBP). Restricted cubic spline regression was utilized to calculate the shape of the relationship between AM and the odds ratio of hypertension. After adjusting for multiple variables, women who had a history of AM > 14 years were associated with an increased risk of hypertension (OR 1.12, 95%CI 1.04−1.19) and elevated levels of SBP (β 0.90, 95%CI 0.41−1.38) compared with those with AM ≤ 14 years among the total population, and this association was still statistically significant when we further adjusted for body mass index (BMI). In participants with AM > 14 years, the odds ratio values of hypertension increased with increasing menarche age. After stratification by age at recruitment, the positive association between menarche age and hypertension only remained in the middle-aged group, and this association was not found in the young and old groups. After stratification by the Dietary Approaches to Stop Hypertension (DASH) score among the total population, the positive association between AM and hypertension was presented only in the low DASH score group; however, this association was not found in the high DASH score group. Women who have a history of AM > 14 years should pay close attention to blood pressure levels and incorporate the DASH diet more in order to achieve the early prevention of hypertension, especially middle-aged women.

Systolic blood pressure as the mediator of the effect of early menarche on the risk of coronary artery disease: A Mendelian randomization study

Background

Menarche timing may not be directly associated with the risk of coronary artery disease (CAD). Therefore, we investigated the roles of metabolic factors in explaining the effect of age at menarche on CAD risk.

Methods

We identified women with age at menarche and CAD by using three analytical methods: Mendelian randomization (MR), logistic regression analysis, and Cox proportional hazard regression. The first two analyses were performed in the Taiwan Biobank (N = 71,923) study, and the last analysis was performed in the Chin-Shan Community Cardiovascular Cohort study (N = 1,598). We further investigated the role of metabolic factors in mediating the effect of age at menarche on CAD risk by using three complementary methods with mediation analyses.

Results

One standard deviation of earlier age at menarche was associated with a 2% higher CAD risk [odds ratio = 1.02, 95% confidence interval (CI) = 1.001-1.03] in the MR analysis, an 11% higher risk (odds ratio = 1.11, 95% CI = 1.02-1.21) in the logistic regression analysis, and a 57% higher risk (hazard ratio = 1.57, 95% CI = 1.12-2.19) in the Cox proportional hazard regression. All the analyses consistently supported the role of systolic blood pressure in mediating this effect. The MR results indicated that 29% (95% CI = 26%-32%) of the effect of genetically predicted earlier age at menarche on CAD risk was mediated by genetically predicted systolic blood pressure.

Conclusion

The results obtained using different analytical methods suggest that interventions aimed at lowering systolic blood pressure can reduce the cases of CAD attributable to earlier age at menarche.

Epidemiological studies of the association between reproductive lifespan characteristics and risk of Type 2 diabetes and hypertension: A systematic review

Some reproductive factors are found to be associated with metabolic outcomes in women; however, little is known about reproductive lifespan characteristics and the mutual effect of age at menarche and age at menopause on cardiovascular risk. This systematic review evaluated reproductive lifespan characteristics and describes the mutual effect of age at menarche and age at menopause on the risk of type 2 diabetes (T2DM) and hypertension at midlife. PubMed, EMBASE, and Web of Science were screened for studies published up to September 1, 2020. The individual effect estimates were reviewed and synthesized without meta-analysis due to methodological and clinical or conceptual diversity in reported studies. Of the 3033 identified studies, 20 were included in the final synthesis: 6 reported reproductive life span; 12 reported age at menarche, and 7 reported age at menopause. Synthesis of two cohorts, with a median follow-up of 9-11 years, showed that a shorter reproductive lifespan was positively associated with T2DM, yielding 6-15% higher risk of T2DM for a one-year decrease in reproductive lifespan. A few studies also demonstrated that women who experienced early menarche (four of six studies) and early menopause (two of five studies) were positively associated with risk of T2DM. The association between reproductive lifespan and hypertension was unclear due to the limited availability of studies. Our findings suggest that a shorter reproductive lifespan is associated with T2DM risk in postmenopausal women, especially those with early menarche and early menopause. Large cohort studies are needed to assess the association between reproductive lifespan and incident hypertension in midlife.

A secular trend in age at menarche in Yunnan Province, China: a multiethnic population study of 1,275,000 women

Background

Age at menarche (AAM) has shown different trends in women from different ethnic and economic regions in recent decades. Data on AAM among multiethnic women living in developing areas are scarce.

Methods

Data on AAM from 1,275,000 women among 26 ethnicities in Yunnan Province, China, who were born from 1965 to 2001 were obtained from the National Free Preconception Health Examination Project from 2010 to 2018. The patterns of AAM trends were analysed according to ethnic group, area of residence, and socioeconomic status.

Results

The mean AAM was 13.7 ± 1.21 years (95% CI 13.697–13.701), with a decrease from 14.12 (±1.41) among women born before 1970 to 13.3 (±1.04) among those born after 2000. The decline was 0.36 years per 10-year birth cohort, and the plateau has not yet been reached in Yunnan. A secular trend of earlier AAM was observed in all 26 ethnic groups. The fastest rate of decline was observed for the Bai ethnicity (0.36 years per decade). Consistent declining trends in AAM appeared among extreme-, middling-, and nonpoverty economic patterns from 1965 to 2001, with reductions of 1.19, 1.44, and 1.5 years, respectively (P < 0.001). The peak reduction among middling poverty and extreme poverty occurred in the early 2000s (0.4 and 0.32 years). Multivariate analysis showed a significant difference in the declining trends in AAM along rural/urban lines (P < 0.001).

Conclusion

There was a secular trend towards a younger AAM during the twentieth century and early twenty-first century birth cohorts in the Yunnan population. Considering the difference in AAM trends due to ethnic and socioeconomic status in Yunnan, the health authority should utilize flexible adjusted health care strategies in different regions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11951-x.

Age at menarche and risk of hypertension in Chinese adult women: Results from a large representative nationwide population

This study explored the association between age at menarche and the risk of hypertension in Chinese women. A total of 234 867 women aged ≥18 years from the China Hypertension Survey were included in this study. Participants were required to complete a standard questionnaire. Blood pressure and physical examination of the participants were performed by trained medical staff. Spearman correlation analysis was used to explore the correlation between age at menarche and other individual characteristics. Logistic regression was used to estimate the odds ratios for hypertension by age in years at menarche. The average age at menarche in Chinese women was 14.8 years. Women who were older at menarche were more likely to have a higher body mass index, larger waist circumference, smoke, and have a primary education (p < .05). After adjustments, odds ratios (95% confidence interval) for hypertension across age at menarche groups were 0.912 (0.877-0.948), 0.927 (0.893-0.963), 1.00 (reference), 1.061 (1.020-1.102), and 1.129 (1.090-1.169) for those aged ≤13, 14, 15 (reference), 16, and ≥17 years at menarche, respectively. Each 1-year delay in menarche was associated with a 6.2% increase in the prevalence of hypertension (odds ratio, 1.062; 95% confidence interval, 1.053-1.071). The positive association between age at menarche and hypertension was evident among age at recruitment groups, BMI categories, and education levels. This association was stronger in urban women and postmenopausal women. Our findings suggest that late menarche is related to a higher risk of hypertension among Chinese adult women, and this association appeared similar among different subgroups.

Association of age at menarche with hypertension in rural Chinese women

OBJECTIVE

The study aimed to explore the association of age at menarche with hypertension and whether adiposity and insulin resistance mediated the association in rural Chinese women.

METHODS

We conducted a cross-sectional study enrolling 7518 women (median age 56 years) from a rural Chinese area from 2013 to 2014. Adiposity was measured by BMI and waist circumference, and insulin resistance was measured by the homeostasis model assessment of insulin resistance (HOMA-IR) index. Odds ratios (ORs) and 95% confidence limits (Cls) for the association of age at menarche with hypertension were estimated by using multivariate logistic regression models. The contribution of adiposity and insulin resistance to the association was estimated by mediation analysis.

RESULTS

Among 7518 women, 3187 (42.39%) had hypertension. Age at menarche was inversely associated with hypertension (per additional year of menarche, OR = 0.965, 95% Cl: 0.935-0.995). BMI or waist circumference and HOMA-IR completely mediated the association of age at menarche with hypertension (for BMI and HOMA-IR: total indirect effect: OR = 0.970, 95% Cl: 0.962-0.978 and direct effect: OR = 0.994, 95% Cl: 0.963-1.026; for waist circumference and HOMA-IR: total indirect effect: OR = 0.981, 95% Cl: 0.973-0.988 and direct effect: OR = 0.983, 95% Cl: 0.952-1.014).

CONCLUSION

Early age at menarche was positively associated with hypertension. Adiposity and insulin resistance seemed to be two vital mediators of the association between age at menarche and hypertension in rural Chinese women.