Adiposity in relation to age at menarche and other reproductive factors among 300 000 Chinese women: findings from China Kadoorie Biobank study

Early puberty: a review on its role as a risk factor for metabolic and mental disorders

Accumulating evidence indicates that there is a trend of early puberty onset in humans. The early timing of puberty has raised concerns due to its association with significant negative health outcomes. However, overall impact and potential risk of early puberty remain uncertain. In this study, we conducted a comprehensive review of existing epidemiological studies to gain insights into the long-term adverse health effects associated with early puberty. Our objective was to provide a consolidated summary of these outcomes at a population level by considering studies that encompass various indicators of puberty. In all, early puberty has been identified as a potential risk factor for various metabolic diseases, such as obesity, diabetes, cardiovascular diseases (CVD). Children who experience early puberty are more likely to have a higher body mass index (BMI) during adulthood, increasing their risk of obesity. Early puberty also has been found to be an independent risk factor for diabetes mellitus, including gestational diabetes mellitus (GDM) and type 2 diabetes mellitus (T2DM), as earlier onset of menarche in girls and voice breaking in boys is associated with a higher prevalence of T2DM. Furthermore, evidence suggests that early puberty may contribute to an elevated risk of CVD, including conditions like coronary heart disease (CHD), stroke, angina, and hypertension. In addition, adolescents who experience early puberty, particularly girls, are more likely to suffer from mental problems, such as behavioral dysfunction and depression. Notably, early puberty has a more significant impact on girls than boys. Further research should consider the underlying mechanisms and potential preventive measures.

Prevalence and risk factors of thyroid nodules in breast cancer women with different clinicopathological characteristics: a cross-sectional study

BACKGROUND

Association between breast cancer (BC) and thyroid nodules (TNs) is still unclear. This research was to estimate the prevalence and risk factors of TN in Chinese BC women at initial diagnosis.

METHODS

1731 Chinese early-stage BC women at initial diagnosis underwent thyroid ultrasound and 1:1 age-matched Chinese healthy women underwent health examination in corresponding period were enrolled for analysis.

RESULTS

Prevalence of TN and TI-RADS ≥ 4 TN in BC patients (56.27% and 9.76%) were higher than healthy people (46.04% and 5.49%), respectively, P < 0.001. Among BC patients, prevalence of TN and TI-RADS ≥ 4 TN in hormone receptor (HR)-positive patients (59.57% and 11.81%) were higher than HR-negative patients (48.77% and 5.10%), respectively, P < 0.001, while without difference between HR-negative patients and healthy people. After adjusting for age and BMI, HR-positive patients had higher risk of TN (OR = 1.546, 95%CI 1.251-1.910, P < 0.001) and TI-RADS ≥ 4 TN (OR = 3.024, 95%CI 1.943-4.708, P < 0.001) than HR-negative patients. Furthermore, the risk of TI-RADS ≥ 4 TN was higher in patients with estrogen receptor (ER) positive (OR = 2.933, 95%CI 1.902-4.524), progesterone receptor (PR) positive (OR = 1.973, 95%CI 1.378-2.826), Ki-67 < 20% (OR = 1.797, 95%CI 1.280-2.522), and tumor size < 2 cm (OR = 1.804, 95%CI 1.276-2.552), respectively, P < 0.001.

CONCLUSIONS

Prevalence of TN, especially TI-RADS ≥ 4 TN, in Chinese early-stage BC women was higher than healthy people. HR-positive patients had higher prevalence and risk of TN, while without difference between HR-negative patients and healthy people. The increased risk of TN was correlated with ER-positive, PR-positive, lower Ki-67 expression, and smaller tumor size.

Association between physical fitness and normal weight obesity in children and adolescents from Poland

OBJECTIVES

Normal weight obesity (NWO) is defined as elevated adiposity, despite normal body mass index (BMI). The aim of this study was to compare the results of selected fitness parameters in Polish children and adolescents from Poland with and without normal weight obesity.

METHODS

The study was cross-sectional and school-based. Body height, weight and adiposity, as well as the results of selected fitness tests, were obtained. BMI was calculated, and only normal-weight individuals were included. NWO was defined as normal BMI with adiposity ≥85 percentile for age and sex.

RESULTS

Children with NWO tended to have better results of absolute dynamometric strength and overhead medicine ball throw. On the other hand, when the dynamometric strength was normalized for the body mass nonNWO group achieved better results. Furthermore, NWO group had lower explosive muscle strength of the lower limbs, agility, as well as abdominal muscle strength, and endurance.

CONCLUSIONS

Obtained results suggest that NWO is associated with a decrease in at least some fitness parameters in children and adolescents. Therefore, it can be hypothesized, that normal weight obesity can result in poorer fundamental motor skills. Moreover, as parameters such as muscle strength have been shown to be associated with cardiometabolic risks, described results can also be important in the context of the present and future health of the children. The results also highlight the importance of monitoring physical fitness and body composition in children, as individuals with NWO are almost indistinguishable from normal weight non-obese counterparts based on current standard surveillance protocols.

Associations of age at first birth and lifetime parity with weight and adiposity across midlife in women from Project Viva

OBJECTIVE

This study aimed to evaluate the associations of age at first birth and parity with weight, waist circumference (WC), and body fat across midlife.

METHODS

A secondary data analysis was conducted with 735 participants from Project Viva who reported their age at first birth and lifetime parity at a midlife study visit. Weight, WC, and body fat were measured up to four times after the participants' final birth, and associations were examined using linear mixed-effects regression models.

RESULTS

Participants' mean (SD) age was 32.6 (4.9) years at enrollment and 30.4 (5.5) years at their first birth, and they had 2.4 (0.9) lifetime births. In adjusted models, women who had their first birth at age <23 or ≥40 years, versus age 30 to 34 years, had a higher trajectory of weight, WC, and body fat after their final birth (i.e., mean differences in weight 8.38 kg [95% CI: 4.13-12.63] for age <23 years and 6.54 kg [95% CI: 0.64-12.45] for age ≥40 years). Women with four or more births, versus two, had a higher trajectory of adiposity after accounting for covariates.

CONCLUSIONS

Women who have a first birth before age 23 years or after age 40 years and those with multiple births may benefit from more intensive monitoring for excess adiposity gain.

[Secular trends of age at menarche and age at menopause in women born since 1951 from a county of Shandong Province, China]

OBJECTIVE

To describe the secular trends of age at menarche and age at natural menopause of women from a county of Shandong Province.

METHODS

Based on the data of the Premarital Medical Examination and the Cervical Cancer and Breast Cancer Screening of the county, the secular trends of age at menarche in women born in 1951 to 1998 and age at menopause in women born in 1951 to 1975 were studied. Joinpoint regression was used to identify potential inflection points regarding the trend of age at menarche. Average hazard ratios (AHR) of early menopause among women born in different generations were estimated by performing multivariate weighted Cox regression.

RESULTS

The average age at menarche was (16.43±1.89) years for women born in 1951 and (13.99±1.22) years for women born in 1998. The average age at menarche was lower for urban women than that for rural women, and the higher the education level, the lower the average age at menarche. Joinpoint regression analysis identified three inflection points: 1959, 1973 and 1993. The average age at menarche decreased annually by 0.03 (P < 0.001), 0.08 (P < 0.001), and 0.03 (P < 0.001) years respectively for women born during 1951-1959, 1960-1973, and 1974-1993, while it remained stable for those born during 1994-1998 (P=0.968). As for age at menopause, compared with women born during 1951-1960, those born during 1961-1965, 1966-1970 and 1971-1975 showed a gradual decrease in the risk of early menopause and a tendency to delay the age at menopause. The stratified analysis presented that the risk of early menopause gradually decreased and the age of menopause showed a significant delay among those with education level of junior high school and below, but this trend was not obvious among those with education level of senior high school and above, where the risk of early menopause decreased and then increased among those with education level of college and above, and the corresponding AHRs were 0.90 (0.66-1.22), 1.07 (0.79-1.44) and 1.14 (0.79-1.66).

CONCLUSION

The age at menarche for women born since 1951 gradually declined until 1994 and leveled off, with a decrease of nearly 2.5 years in these years. The age at menopause for women born between 1951 and 1975 was generally delayed over time, but the trend of first increase and then decrease was observed among those with relatively higher education levels. In the context of the increasing delay in age at marriage and childbearing and the decline of fertility, this study highlights the necessity of the assessment and monitoring of women' s basic reproductive health status, especially the risk of early menopause.

The relationship of reproductive factors with adiposity and body shape indices changes overtime: findings from a community-based study

BACKGROUND

Studies focusing on the relationships of adiposity and body shape indices with reproductive factors have reported conflicting results. This study aimed to investigate the influence of reproductive factors on adiposity and body shape indices changes overtime.

MATERIALS AND METHODS

In this community-based prospective study, 1636 postmenopausal women were selected from Tehran Lipid and Glucose Study (TLGS). The unadjusted and adjusted Generalized Estimating Equation models (GEE) were applied to investigate secular longitudinal trends of adiposity and body shape indices.

RESULTS

According to the adjusted GEE models, mean changes in body mass index (BMI) in women with early menarche was 1.18 kg/m² higher than those with normal menarche age (P = 0.030). Moreover, the mean changes in BMI overtime were 0.11 kg/m² higher in women with premature/early menopausal age than those with normal menopausal age (P = 0.012). Mean changes of waist circumference (WC) in women with late menopause were 2.27 cm higher than those with normal menopausal age (P = 0.036). We also observed higher mean changes in a body shape index (ABSI) in women with late menopause (P = 0.037), compared to those with normal menopausal age. We found a marginal effect of parity on BMI and WC as well.

CONCLUSIONS

This study demonstrated higher BMI in females with earlier menarche age. We also showed higher values of BMI overtime in women with premature/ early menopause, whereas women with late menopausal age had higher WC and ABSI values. However, more longitudinal studies investigating body composition indices by adjusting all potential confounders are still required to confirm our study findings.

Association of age at menarche with valvular heart disease: An analysis based on electronic health record (CREAT2109)

Background

The association between age at menarche and coronary heart disease has been reported, but the association between age at menarche and valvular heart disease (VHD) has not been described. We aimed to examine the association between age at menarche and VHD.

Methods

By collecting data from four medical centers of the Affiliated Hospital of Qingdao University (QUAH) from January 1, 2016, to December 31, 2020, we sampled 105,707 inpatients. The main outcome of this study was newly diagnosed VHD, which was diagnosed based on ICD-10 coding, and the exposure factor was age at menarche, which was accessed through the electronic health records. We used logistic regression model to investigate the association between age at menarche and VHD.

Results

In this sample (mean age 55.31 ± 13.63 years), the mean age at menarche was 15. Compared with women with age at menarche 14-15 years, the odds ratio of VHD in women with age at menarche ≤13, 16-17, and ≥18 years was 0.68 (95% CI 0.57-0.81), 1.22 (95% CI 1.08-1.38), and 1.31 (95% CI 1.13-1.52), respectively (P for all < 0.001). By restricting cubic splines, we found that later menarche was associated with increased odds of VHD (P < 0.001). Furthermore, in subgroup analysis of different etiologies, the similar trend persisted for non-rheumatic VHD.

Conclusions

In this large inpatient sample, later menarche was associated with higher risk of VHD.

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.

Prevalence of and risk factors for metabolic associated fatty liver disease in an urban population in China: a cross-sectional comparative study

Background

Metabolic associated fatty liver disease (MAFLD) is a new definition for liver disease associated with known metabolic dysfunction. Based on new diagnostic criteria, we aimed to investigate its prevalence and risk factors in Chinese population.

Methods

We conducted this study in a health examination population who underwent abdominal ultrasonography in China. The diagnosis of MAFLD was based on the new diagnostic criteria. The characteristics of the MAFLD population, as well as the associations between MAFLD and metabolic abnormalities, were explored. Mann–Whitney U test and chi-square test were performed to compare different variables. Binary logistic regression was used to determine the risk factors for MAFLD.

Results

Among 139,170 subjects, the prevalence of MAFLD was 26.1% (males: 35.4%; females: 14.1%). The prevalence based on female menopausal status, that is, premenopausal, perimenopausal, and postmenopausal, was 6.1%, 16.8%, and 30.2%, respectively. In different BMI groups (underweight, normal, overweight and obese), the prevalence was 0.1%, 4.0%, 27.4% and 59.8%, respectively. The proportions of abnormal metabolic features in the MAFLD group were significantly higher than those in the non-MAFLD group, as was the proportion of elevated alanine aminotransferase (ALT) (42.5% vs. 11%, P < 0.001). In nonobese individuals with MAFLD, the proportions of abnormal metabolic features were also all significantly higher than those in nonobese individuals without MAFLD. The prevalence of metabolic syndrome (MS), dyslipidaemia, and hyperuricaemia, respectively, in the MAFLD group (53.2%, 80.0%, and 45.0%) was significantly higher than that in the non-MAFLD group (10.1%, 41.7%, and 16.8%). Logistic regression revealed that age, BMI, waist circumference, ALT, triglycerides, fasting glucose, uric acid and platelet count were associated with MAFLD.

Conclusions

MAFLD is prevalent in China and varies considerably among different age, sex, BMI, and female menopausal status groups. MAFLD is related to metabolic disorders, especially obesity, while metabolic disorders also play important roles in the occurrence of MAFLD in nonobese individuals. MAFLD patients exhibit a high prevalence of MS, dyslipidaemia, hyperuricaemia, and elevated liver enzymes. MAFLD tends to coexist with systemic metabolic disorders, and a deep inner relationship may exist between MAFLD and MS. Metabolic disorders should be considered to improve the management of MAFLD.

Sex differences in cardiometabolic risk factors, pharmacological treatment and risk factor control in type 2 diabetes: findings from the Dutch Diabetes Pearl cohort

INTRODUCTION

Sex differences in cardiometabolic risk factors and their management in type 2 diabetes (T2D) have not been fully identified. Therefore, we aimed to examine differences in cardiometabolic risk factor levels, pharmacological treatment and achievement of risk factor control between women and men with T2D.

RESEARCH DESIGN AND METHODS

Cross-sectional data from the Dutch Diabetes Pearl cohort were used (n=6637, 40% women). Linear and Poisson regression analyses were used to examine sex differences in cardiometabolic risk factor levels, treatment, and control.

RESULTS

Compared with men, women had a significantly higher body mass index (BMI) (mean difference 1.79 kg/m² (95% CI 1.49 to 2.08)), while no differences were found in hemoglobin A_1c (HbA_1c) and systolic blood pressure (SBP). Women had lower diastolic blood pressure (-1.94 mm Hg (95% CI -2.44 to -1.43)), higher total cholesterol (TC) (0.44 mmol/L (95% CI 0.38 to 0.51)), low-density lipoprotein cholesterol (LDL-c) (0.26 mmol/L (95% CI 0.22 to 0.31)), and high-density lipoprotein cholesterol (HDL-c) sex-standardized (0.02 mmol/L (95% CI 0.00 to 0.04)), and lower TC:HDL ratio (-0.29 (95% CI -0.36 to -0.23)) and triglycerides (geometric mean ratio 0.91 (95% CI 0.85 to 0.98)). Women had a 16% higher probability of being treated with antihypertensive medication in the presence of high cardiovascular disease (CVD) risk and elevated SBP than men (relative risk 0.84 (95% CI 0.73 to 0.98)), whereas no sex differences were found for glucose-lowering medication and lipid-modifying medication. Among those treated, women were less likely to achieve treatment targets of HbA_1c (0.92 (95% CI 0.87 to 0.98)) and LDL-c (0.89 (95% CI 0.85 to 0.92)) than men, while no differences for SBP were found.

CONCLUSIONS

In this Dutch T2D population, women had a slightly different cardiometabolic risk profile compared with men and a substantially higher BMI. Women had a higher probability of being treated with antihypertensive medication in the presence of high CVD risk and elevated SBP than men, and were less likely than men to achieve treatment targets for HbA_1c and LDL levels.

Associations of Pregnancy History with BMI and Weight Gain in 45-54-Year-Old Women

BACKGROUND

Midlife women have a higher risk of cardiometabolic disease than younger women, but the lifelong biological/lifestyle factors responsible for this increase are unclear.

OBJECTIVES

We investigated whether pregnancy history is a risk factor for midlife overweight/obesity and evaluated potential hormonal mechanisms.

METHODS

The Baltimore Midlife Women's Health Study, a prospective cohort, recruited 772 women aged 45-54 y. Women reported pregnancy characteristics via questionnaires, trained staff measured weight/height to calculate midlife BMI, and serum hormones were assessed by ELISA. Logistic regression models assessed associations of pregnancy history with risk of midlife overweight/obesity and BMI gain since age 18. We additionally explored whether associations differed by menopausal status, and whether midlife hormones mediated relationships of pregnancy history and midlife BMI.

RESULTS

These premenopausal or perimenopausal women were 66% Caucasian/White and 30% African American/Black, with a median of 2 live births (range: 0-11) and median age at first birth of 27 y (range: 12-46 y). Women with 0 and ≥2 live births had lower odds of overweight/obesity than those with 1 birth (OR = 0.47; 95% CI: 0.23, 0.96; P = 0.04, and OR = 0.58; 95% CI: 0.35, 0.95; P = 0.03, respectively). Women with ≥2 live births also had lower odds of BMI gain than those with 1 birth (OR = 0.66; 95% CI: 0.41, 1.06; P = 0.08). Furthermore, women who were older at their first birth had lower odds of overweight/obesity (OR = 0.96; 95% CI: 0.92, 1.00; P = 0.03) and BMI gain (OR = 0.97; 95% CI: 0.93, 1.00; P = 0.06). Number of pregnancies and age at last pregnancy were not associated with midlife overweight/obesity or BMI gain. Associations did not differ by menopausal status and were not explained by midlife hormones.

CONCLUSIONS

Earlier childbirth and having 1 child increased women's risk of midlife overweight/obesity and BMI gain since age 18. Additional studies should focus on women's childbearing years as a critical determinant of midlife metabolic health.

Combined effects of reproductive and hormone factors and obesity on the prevalence of knee osteoarthritis and knee pain among middle-aged or older Chinese women: a cross-sectional study

Background

Knee osteoarthritis (KOA) is one form of degenerative arthritis that results from the breakdown of cartilage and underlying bone. The prevalence of KOA is considerably higher in women than in men; however, the reason for this difference has not been thoroughly elucidated to date. The aim of the present study was to estimate the effects of reproductive and hormone factors and obesity on KOA prevalence among Chinese women.

Methods

The cross-sectional study included 7510 women with a mean age of 62.6 ± 8.6 years. Knee pain was defined as pain or aching stiffness on most days for at least 1 month during the past 12 months or persistent pain or aching stiffness within the past week. Clinical KOA was diagnosed based on both pain complaints and a Kellgren-Lawrence grade ≥ 2 X-ray radiograph of at least one knee.

Results

Oral contraceptives use (OR 1.18, 1.05–1.34), ≥3 pregnancies (1.38, 1.20–1.60), and postmenopausal hormone replacement therapy (HT) (1.59, 1.23–2.06) were positively associated with knee pain, while oral contraceptives use (1.28, 1.04–1.57), and HT (1.79, 1.21–2.65) were positively associated with clinical KOA. Obesity and oral contraceptives use showed additive and multiplicative effects on knee pain. The OR for knee pain among women with a BMI ≥24 kg/m² and oral contraceptives use was 2.00 (1.68–2.38) compared with women with a BMI &lt; 24 kg/m² and no oral contraceptives use.

Conclusions

A high number of pregnancies, oral contraceptives use, and HT are independent risk factors for KOA, and the effects of reproductive and hormone factors on KOA may be increased by obesity.

The eMERGE genotype set of 83,717 subjects imputed to ~40 million variants genome wide and association with the herpes zoster medical record phenotype

The Electronic Medical Records and Genomics (eMERGE) network is a network of medical centers with electronic medical records linked to existing biorepository samples for genomic discovery and genomic medicine research. The network sought to unify the genetic results from 78 Illumina and Affymetrix genotype array batches from 12 contributing medical centers for joint association analysis of 83,717 human participants. In this report, we describe the imputation of eMERGE results and methods to create the unified imputed merged set of genome‐wide variant genotype data. We imputed the data using the Michigan Imputation Server, which provides a missing single‐nucleotide variant genotype imputation service using the minimac3 imputation algorithm with the Haplotype Reference Consortium genotype reference set. We describe the quality control and filtering steps used in the generation of this data set and suggest generalizable quality thresholds for imputation and phenotype association studies. To test the merged imputed genotype set, we replicated a previously reported chromosome 6 HLA‐B herpes zoster (shingles) association and discovered a novel zoster‐associated loci in an epigenetic binding site near the terminus of chromosome 3 (3p29).

Impact of age at menarche on obesity and glycemic control in Japanese patients with type 2 diabetes: Fukuoka Diabetes Registry

AIMS/INTRODUCTION

A younger age at menarche is associated with obesity and type 2 diabetes in adult life. The impact of early-onset menarche on obesity and glycemic control in type 2 diabetes has not been investigated. The present study examined the relationship between age at menarche and obesity and glycemic control in type 2 diabetes.

MATERIALS AND METHODS

A total of 2,133 patients with type 2 diabetes aged ≥20 years were divided into groups according to age at menarche (≤11, 12, 13, 14 and ≥15 years). A retrospective cohort study examined the association of menarcheal age with adiposity and hemoglobin A1c .

RESULTS

Age at menarche was inversely associated with body mass index (BMI) and abdominal circumference (P < 0.001). Each 1-year decrease in age at menarche was associated with a 0.25-kg/m2 and 0.6-cm increase in BMI and abdominal circumference, respectively, using a multivariate-adjusted model. Odds ratios for obesity and abdominal obesity significantly increased in participants with age at menarche ≤11 years after multivariable adjustments when age at menarche of 13 years was used as the reference (odds ratio 1.95, 95% CI 1.33-2.88, odds ratio 1.95, 95% CI 1.32-2.87, respectively). Younger age at menarche was significantly associated with higher hemoglobin A1c (P < 0.001); however, the association was not statistically significant after adjusting for BMI.

CONCLUSIONS

Age at menarche of ≤11 years was associated with obesity after adjusting for confounding factors, and poor glycemic control associated with high BMI in type 2 diabetes. Age at menarche should be considered during clinical assessments.

Menopause Characteristics, Total Reproductive Years, and Risk of Cardiovascular Disease Among Chinese Women

Supplemental Digital Content is available in the text.

Background—

Previous studies, mostly of Western women, have reported inconsistent findings on the association of menopause characteristics (status, age, and time since menopause) and total reproductive years with risk of cardiovascular disease (CVD).

Methods and Results—

The China Kadoorie Biobank recruited 302 632 women in 2004 to 2008 from 10 regions across China. During 9-year follow-up, 19 393 incident cases of stroke, 18 611 of ischemic heart disease, and 4978 CVD deaths occurred. Cox regression yielded adjusted hazard ratios relating each menopause characteristic and total reproductive years to CVD risk. Among 274 233 women with no prior CVD at baseline, 134 010 were naturally postmenopausal women (mean [SD] age at menopause of 48.6 [4.0] years and total reproductive years 32.7 [4.4]). Compared with premenopausal women, naturally peri- or postmenopausal women were at a higher risk of either fatal or nonfatal CVD. Among women who had had menopause, inverse associations were observed between age at menopause and risks of CVD mortality, incident ischemic heart disease, stroke, and subtypes of stroke, with 1.5% higher risk of CVD death (P<0.001), 0.7% for incident ischemic heart disease (P=0.002), and 0.5% for incident stroke (P=0.02) for every 1 year lower age at menopause. Compared with women who had menopause at age 48 to 50 years, lower age at menopause (ie, <43 years) was associated with 14% higher risk of CVD death and 6% higher risks of both incident ischemic heart disease and stroke. Higher risks of both fatal and nonfatal CVD were also found in women with 5 to 10, 10 to 15, 15 to 20, or >20 years since menopause compared with <5 years since menopause. Total reproductive years were inversely associated with risks of both fatal and nonfatal CVD, with 1.4% lower risk of CVD death per additional reproductive year (P<0.001).

Conclusions—

Women with younger age at menopause, longer time since menopause, or fewer total reproductive years had a higher risk of CVD.

Sex Differences in the Burden and Complications of Diabetes

PURPOSE OF THE REVIEW

To review the latest evidence on sex differences in the burden and complications of diabetes and discuss the potential explanations for the sex differences described.

RECENT FINDINGS

Diabetes is a strong risk factor for vascular disease, with compelling evidence that the relative risks of vascular diseases conferred by diabetes are considerably greater in women than men. The mechanisms underpinning women's excess relative risk of vascular disease from diabetes are unknown. Sex differences in the health care provided for the prevention, management, and treatment of diabetes and its complications could contribute to women's greater excess relative risks of diabetes complications. However, since the excess risk of vascular disease is not seen for other major vascular risk factors, inherent biological factors may be more likely to be involved. In addition to other cardiometabolic pathways, the sex dimorphism in body composition and fat distribution may be particularly important in explaining women's greater excess risk of the vascular complications of diabetes. There is strong evidence to suggest that diabetes is a stronger risk factor for vascular disease in women than men. Although several mechanisms may be involved, further research is needed to provide new and deeper insights into the mechanisms underpinning sex differences in the association between diabetes and vascular diseases. Such research will inform patients, health care professionals, and policy makers to ensure that women are not disproportionately affected by diabetes, and will help to reduce the burden in both sexes.

Age at Menarche and Cardiometabolic Health: A Sibling Analysis in the Scottish Family Health Study

BACKGROUND

Previous studies of age at menarche and cardiometabolic health report conflicting findings, and only a few could account for childhood characteristics. We aimed to estimate the associations of age at menarche with cardiovascular risk factors in unrelated women and within sister groups, under the assumption that within-sibship estimates will be better adjusted for shared genetics and early life environment.

METHODS AND RESULTS

Our study included 7770 women, from 5984 sibships, participating in the GS:SFHS (Generation Scotland: Scottish Family Health Study). We used fixed- and between-effects linear regression to estimate the associations within sister groups and between unrelated individuals, respectively. Within sibships, the mean difference between sisters with early menarche (≤11 years) and sisters with menarche at 12 to 13 years was 1.73 mm Hg (95% confidence interval [CI], -0.41 to 3.86) for systolic blood pressure, 1.26 mm Hg (95% CI, -0.02 to 2.55) for diastolic blood pressure, -0.06 nmol/L (95% CI, -0.11 to -0.02) for high-density lipoprotein, 0.20 nmol/L (95% CI, 0.08-0.32) for non-high-density lipoprotein, -0.34% (95% CI, -1.98 to 1.30) for glucose, 1.60 kg/m² (95% CI, 0.92-2.28) for body mass index, and 2.75 cm (95% CI, 1.06-4.44) for waist circumference. There was weak evidence of associations between later menarche (14-15 or ≥16 years) and lower body mass index, waist circumference, and blood pressure. We found no strong evidence that estimates from within- and between-sibship analyses differed (all P values >0.1). The associations with other cardiovascular risk factors were attenuated after adjustment for adult body mass index.

CONCLUSIONS

Our results suggest that confounding by shared familial characteristics is unlikely to be a major driver of the association between early menarche and adverse cardiometabolic health but do not exclude confounding by individual-level characteristics.

Age at Menarche and Incidence of Diabetes: A Prospective Study of 300,000 Women in China

Previous studies of predominantly Western populations have reported inconsistent associations between age at menarche and risk of diabetes. We examined this relationship among Chinese women, who generally experience menarche at a later age than Western women. In 2004–2008, China Kadoorie Biobank recruited 302,632 women aged 30–79 years from 10 areas across China, and recorded 5,391 incident cases of diabetes during 7 years of follow-up among 270,345 women without baseline diabetes, cardiovascular disease or cancer. Cox regression models yielded adjusted hazard ratios for incident diabetes associated with age at menarche. Overall, the mean age at menarche was 15.4 years, and decreased across successive generations. Age at menarche was linearly and inversely associated with incident diabetes, with adjusted hazard ratio of 0.96 (95% confidence interval (CI): 0.94, 0.97) per year delay. Hazard ratios were greater in younger generations (for women born in the 1960s–1970s, hazard ratio (HR) = 0.93, 95% CI: 0.90, 0.97; for women born in the 1950s, HR = 0.95, 95% CI: 0.93, 0.98; and for women born in the 1920s–1940s, HR = 0.97, 95% CI: 0.95, 0.99). Further adjustment for adulthood body mass index significantly attenuated the association (HR = 0.99, 95% CI: 0.97, 1.00), especially among those born before 1950 (HR = 1.00, 95% CI: 0.97, 1.02). Much of the inverse association between age at menarche and incident diabetes was mediated through increased adiposity associated with early menarche, especially in older generations.

Age at natural menopause and risk of diabetes in adult women: Findings from the China Kadoorie Biobank study in the Zhejiang area

Aims/Introduction

There has been considerable professional debate on the association between age at menopause and diabetes risk, while the findings are controversial. The present study explored the association between late menopause and the prevalence of diabetes in the Chinese population.

Material and Methods

The data were part of the baseline survey of China Kadoorie Biobank from Zhejiang Province. A total of 17,076 postmenopausal women were included in the present study. Logistic regression models were used to calculate the adjusted odds ratios and their 95% confidence intervals.

Results

Of the participating women, 1,288 (7.54%) had type 2 diabetes. In comparison with those with menopause at 46–52 years, women with menopause at a later age (≥53 years) were 1.21‐fold (95% confidence interval 1.03–1.43) more likely to have diabetes.

Conclusions

The present findings suggested that later age at menopause was associated with an increased prevalence of diabetes.

Age at menarche and prevalence of preterm birth: Results from the Healthy Baby Cohort study

Little is known about the impact of age at menarche on preterm birth. The aim of this study was to examine the association between age at menarche and preterm birth. A total of 11,016 Chinese women who gave birth to live singleton infants were recruited from the Healthy Baby Cohort between 2012 and 2014 in the province of Hubei, China. Age at menarche was reported via face-to-face interviews and was categorized into five groups (≤11, 12, 13, 14 and ≥15 years). Gestational age was estimated using maternal last menstrual period. Preterm birth was defined as delivering a live singleton infant at <37 weeks' gestational age. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Earlier menarche (≤11 years) was associated with an increased prevalence of preterm birth (OR: 1.67, 95% CI: 1.18, 2.36) compared with menarche age at 13 years after controlling for the potential confounders. The findings of our study suggested that a history of earlier menarche might be useful for identifying women at higher risk of preterm birth.

Breastfeeding and the Risk of Maternal Cardiovascular Disease: A Prospective Study of 300 000 Chinese Women

BACKGROUND

Breastfeeding confers substantial benefits to child health and has also been associated with lower risk of maternal cardiovascular diseases (CVDs) in later life. However, the evidence on the effects of CVD is still inconsistent, especially in East Asians, in whom the frequency and duration of breastfeeding significantly differ from those in the West.

METHODS AND RESULTS

In 2004-2008, the nationwide China Kadoorie Biobank recruited 0.5 million individuals aged 30 to 79 years from 10 diverse regions across China. During 8 years of follow-up, 16 671 incident cases of coronary heart disease and 23 983 cases of stroke were recorded among 289 573 women without prior CVD at baseline. Cox regression yielded adjusted hazard ratios (HRs) and 95% CIs for incident CVD by breastfeeding. Overall, ≈99% of women had given birth, among whom 97% reported a history of breastfeeding, with a median duration of 12 months per child. Compared with parous women who had never breastfed, ever breastfeeding was associated with a significantly lower risk of CVD, with adjusted HRs of 0.91 (95% CI, 0.84-0.99) for coronary heart disease and 0.92 (95% CI, 0.85-0.99) for stroke. Women who had breastfed for ≥24 months had an 18% (HR, 0.82; 0.77-0.87) lower risk of coronary heart disease and a 17% (HR, 0.83; 0.79-0.87) lower risk of stroke compared with women who had never breastfed. Among women who ever breastfed, each additional 6 months of breastfeeding per child was associated with an adjusted HR of 0.96 (95% CI, 0.94-0.98) for coronary heart disease and 0.97 (95% CI, 0.96-0.98) for stroke.

CONCLUSIONS

Among Chinese women, a history of breastfeeding was associated with an ≈10% lower risk of CVD in later life and the magnitude of the inverse association was stronger among those with a longer duration of breastfeeding.