Reproductive Health Disparities in the USA: Self-Reported Race/Ethnicity Predicts Age of Menarche and Live Birth Ratios, but Not Infertility.

Self-identified race/ethnicity and socioeconomic status (SES) contribute to disparities in several health domains, although research on their effects on women's reproductive function has largely focused on links between SES and age of menarche. Here, we assessed whether race/ethnicity, SES, and downstream correlates of SES such as food security and health-insurance security are associated with age of menarche, infertility, and live birth ratios (ratios of recognized pregnancies resulting in live births) in the USA. We used cross-sectional data from 1694 women aged 12-18 years for menarche (2007-2016), 974 women aged 23-45 for infertility (2013-2016), and 1714 women aged 23-45 for live birth ratios (2007-2016) from the National Health and Nutrition Examination Survey. We estimated multiple linear and logistic regressions with survey weights to test these associations. When controlling for lifestyle (activity levels, smoking, alcohol consumption) and physiological factors (diabetes, weight status), non-Hispanic (NH) black and Hispanic girls reported a significantly lower age of menarche by about 4.3 (standard error [SE] = 0.08, p < 0.001), and 3.2 months (SE = 0.09, p < 0.001), respectively, relative to NH white girls. NH black women reported live birth ratios 9% (SE = 0.02, p < 0.001) lower than NH white women. Women with unstable health insurance reported live birth ratios 6% (SE = 0.02, p = 0.02) lower than women with stable health insurance. Race/ethnicity, SES, and its downstream correlates were not associated with infertility. One hypothesized explanation for observed disparities in age of menarche and live birth ratios is the embodiment of discrimination faced by NH black women within the USA. Our findings also underscore the importance of health insurance access for favorable reproductive health outcomes. Future work should elucidate the role of embodied discrimination and other downstream correlates of SES in modulating women's reproductive health outcomes to inform strategies to mitigate health disparities.

Menstrual and reproductive characteristics and breast cancer risk by hormone receptor status and ethnicity: The Breast Cancer Etiology in Minorities study.

We pooled multiethnic data from four population-based studies and examined associations of menstrual and reproductive characteristics with breast cancer (BC) risk by tumor hormone receptor (HR) status [defined by estrogen receptor (ER) and progesterone receptor (PR)]. We estimated odds ratios and 95% confidence intervals using multivariable logistic regression, stratified by age (<50, ≥50 years) and ethnicity, for 5,186 HR+ (ER+ or PR+) cases, 1,365 HR- (ER- and PR-) cases and 7,480 controls. For HR+ BC, later menarche and earlier menopause were associated with lower risk in non-Hispanic whites (NHWs) and Hispanics, and higher parity and longer breast-feeding were associated with lower risk in Hispanics and Asian Americans, and suggestively in NHWs. Positive associations with later first full-term pregnancy (FTP), longer interval between menarche and first FTP and shorter time since last FTP were limited to younger Hispanics and Asian Americans. Except for nulliparity, reproductive characteristics were not associated with risk in African Americans. For HR- BC, lower risk was associated with later menarche, except in African Americans and older Asian Americans and with longer breast-feeding in Hispanics and Asian Americans only. In younger African Americans, HR- BC risk associated with higher parity (≥3 vs. 1 FTP) was increased fourfold in women who never breast-fed, but not in those with a breast-feeding history, suggesting that breast-feeding may mitigate the adverse effect of higher parity in younger African American women. Further work needs to evaluate why menstrual and reproductive risk factors vary in importance according to age and ethnicity.

Is menarche occuring earlier among Lebanese girls?

BACKGROUND: Early menarche is associated with increased risks for several diseases such as cardiovascular diseases and breast cancer. This analysis aimed at generating evidence on a historical trend towards younger age at menarche among Lebanese girls. METHODS: A secondary analysis was conducted on data consolidated from three serial cross-sectional national surveys of women in Lebanon (2007, 2009 and 2012). A total of 6150 women were included in order to study the association between date of birth intervals and age at menarche. RESULTS: The mean age at menarche was 13.06 years, with a peak of the distribution at age 12. Women born before 1950 had a significantly higher mean age at menarche (13.21) compared to those born in 1970 and thereafter (12.95). A stratified analysis showed that women living outside the metropolitan Greater Beirut (GB) area were characterized by an older mean age at menarche (13.11) in all date of birth intervals compared to those in GB (12.89). However, age at menarche declined more significantly over the last two decades among women outside GB, compared to those living in GB. CONCLUSIONS: Epidemiological figures emerging from this study confirm that trends in Lebanon are in line with a global pattern of decreasing age at menarche. Urban-rural differences suggest that higher caloric content of diet and consequent early overweight, more evident in urban areas, are likely determinants of younger menarche. Evidence from this study calls for an urgent implementation of comprehensive multisectoral obesity prevention in children in Lebanon.

A cosmopolítica da gestação, do parto e do pós-parto: autoatenção e medicalização entre os índios Munduruku / The cosmopolitics of pregnancy, childbirth and postpartum: self-attention and medicalization among Munduruku Indians

A pesquisadora Raquel Paiva Dias-Scopel, do Instituto Leônidas e Maria Deane (ILMD/Fiocruz Amazônia), levanta questões sobre a valorização e respeito à diversidade étnica e cultural dos povos indígenas e a difícil interface com o processos de medicalização e do direito ao acesso aos serviços de saúde biomédicos. O livro é parte da Coleção Saúde dos Povos Indígenas, da Editora Fiocruz e partiu da tese de doutorado defendida em 2014 no Programa de Pós-Graduação em Antropologia Social da Universidade Federal de Santa Catarina (UFSC). Foi publicado pela primeira vez em 2015 pela Associação Brasileira de Antropologia com o título A Cosmopolítica da Gestação, Parto e Pós-Parto: práticas de autoatenção e processo de medicalização entre os índios Munduruku. No prefácio da primeira edição, sua orientadora, a doutora em antropologia e professora titular da UFSC, Esther Jean Langdon, ressalta que o conceito fundamental deste livro é da autoatenção, que aponta para o reconhecimento da autonomia e da criatividade da coletividade, principalmente da família, como núcleo que articula os diferentes modelos de atenção ou cuidado da saúde.

Age at menarche and age at natural menopause in East Asian women: a genome-wide association study.

Age at menarche (AM) and age at natural menopause (ANM) are complex traits with a high heritability. Abnormal timing of menarche or menopause is associated with a reduced span of fertility and risk for several age-related diseases including breast, endometrial and ovarian cancer, cardiovascular disease, and osteoporosis. To identify novel genetic loci for AM or ANM in East Asian women and to replicate previously identified loci primarily in women of European ancestry by genome-wide association studies (GWASs), we conducted a two-stage GWAS. Stage I aimed to discover promising novel AM and ANM loci using GWAS data of 8073 women from Shanghai, China. The Stage II replication study used the data from another Chinese GWAS (n = 1230 for AM and n = 1458 for ANM), a Korean GWAS (n = 4215 for AM and n = 1739 for ANM), and de novo genotyping of 2877 additional Chinese women. Previous GWAS-identified loci for AM and ANM were also evaluated. We identified two suggestive menarcheal age loci tagged by rs79195475 at 10q21.3 (beta = -0.118 years, P = 3.4 × 10-6) and rs1023935 at 4p15.1 (beta = -0.145 years, P = 4.9 × 10-6) and one menopausal age locus tagged by rs3818134 at 22q12.2 (beta = -0.276 years, P = 8.8 × 10-6). These suggestive loci warrant a further validation in independent populations. Although limited by low statistical power, we replicated 19 of the 98 menarche loci and 5 of the 20 menopause loci previously identified in women of European ancestry in East Asian women, suggesting a shared genetic architecture for these two traits across populations.

UGT2B4 previously implicated in the risk of breast cancer is associated with menarche timing in Ukrainian females.

Age at menarche (AAM) is a multifactorial trait that is regulated by dozens environmental and genetic factors. Recent meta-analysis of GWAS showed significant association of 106 loci with AAM. These polymorphisms need replicating in different ethnic populations in order to confirm their association with menarche timing. This study was aimed to replicate 53 polymorphisms that were previously associated with AAM. DNA samples were collected from 416 Ukrainian young females for further genotyping. After data quality control 47 polymorphisms remained for the association analysis using the linear regression model. SNP rs13111134 located in UGT2B4 showed the most significant association with AAM (0.431years per allele A, padj=0.044 after the Bonferroni correction). Polymorphisms rs7589318 in POMC, rs11724758 in FABP2, rs7753051 in IGF2R, rs2288696 in FGFR1 and rs12444979 in GPRC5B may also contribute to menarche timing. However, none of these associations remained significant after the Bonferroni correction for multiple testing. The obtained results provide evidence that UGT2B4, which was previously associated with predisposition to breast cancer, may play a role in the onset of menarche.

Gene polymorphisms in RANKL/RANK/OPG pathway are associated with ages at menarche and natural menopause in Chinese women.

BACKGROUND: Age at menarche (AAM) and age at natural menopause (AANM) have been shown intimately associated with woman's health later in life. Previous studies have indicated that AAM and AANM are highly heritable. RANKL/RANK/OPG signaling pathway is essential for mammary gland development, which is also found associated with post-menopausal and hormone-related diseases. The aim of this study was to evaluate associations between the polymorphisms in the TNFSF11, TNFRSF11A and TNFRSF11B genes in the RANKL/RANK/OPG pathway with AAM and AANM in Chinese women. METHODS: Post-menopausal Chinese women (n = 845) aged from 42 to 89 years were recruited in the study. Information about AAM and AANM were obtained through questionnaires and the genomic DNA was isolated from peripheral blood from the participants. Total 21 tagging single nucleotide polymorphisms (SNPs) of TNFSF11, TNFRSF11A and TNFRSF11B were genotyped. RESULTS: Three SNPs of TNFRSF11A (rs4500848, rs6567270 and rs1805034) showed significant association with AAM (P < 0.01, P = 0.02 and P = 0.01, respectively), and one SNP (rs9962159) was significantly associated with AANM (P = 0.03). Haplotypes TC and AT (rs6567270-rs1805034) of TNFRSF11A were found to be significantly associated with AAM (P = 0.01 and P = 0.02, respectively), and haplotypes GC and AC (rs9962159-rs4603673) of TNFRSF11A showed significant association with AANM (P = 0.03 and P < 0.01, respectively). No significant association between TNFSF11 or TNFRSF11B gene with AAM or AANM was found. CONCLUSIONS: The present study suggests that TNFRSF11A but not TNFSF11 and TNFRSF11B genetic polymorphisms are associated with AAM and AANM in Chinese women. The findings provide evidence that genetic variations in RANKL/RANK/OPG pathway may be associated with the onset and cessation of the menstruation cycle.

Association of body size and body fat distribution with uterine fibroids among Chinese women.

BACKGROUND: Uterine fibroids are the most common tumors in reproductive women. The present study aims to identify the relationship between uterine fibroids and body size and body fat distribution among Chinese women. METHODS: Data on the records of 826 participants who attended health examinations, including 316 cases and 510 controls were collected from 2009 to 2012 at a health examination center in Beijing. A multivariate logistic regression analysis was used to estimate the odds ratios of body size, body fat distribution, and body composition after adjusting for age, age at menarche, gravity, parity, and age at last birth. RESULTS: Current body mass index, waist circumference, hip circumference, waist-to-height ratio, body fat mass, body fat percentage, and intracellular water were each positively associated with uterine fibroid. Although the effects in hysterectomy-confirmed cases were frequently greater, we observed no associations with waist circumference, hip circumference, or body fat percentage in this subgroup. Combined with different indicators of fat distribution, women with higher body mass indices and waist-to-hip ratios were at the highest risk, which was significant within the total and separate groups. Women with a body fat percentage greater than 30% were also at a higher risk. CONCLUSION: Our study suggested that uterine fibroids in women might be related to excess weight and central obesity.

Association of age at menarche with increasing number of fibroids in a cohort of women who underwent standardized ultrasound assessment.

Age at menarche has been associated with several reproductive conditions, and frequencies differ by race. Racial disparities also impact fibroid risk. We comprehensively examined the relationship between age at menarche, fibroid characteristics, and race. Women were enrolled in Right From the Start (2001-2010), a multistate study that systematically screened for fibroids during very early pregnancy. Endovaginal ultrasounds were conducted, and fibroid presence, number, type, volume, and diameter were recorded according to standardized definitions. Generalized estimating equations adjusted for correlations within study site were used to estimate associations between age at menarche and fibroid status and to test for interactions with race. Of 5,023 participants, 11% had a fibroid. Seven percent underwent menarche before 11 years of age and 11% at 15 years or later. We did not observe interactions between age at menarche and race. A 1-year increase in age at menarche was inversely associated with fibroids (adjusted risk ratio = 0.87, 95% confidence interval: 0.82, 0.91). Early age at menarche had a similar positive association in individual analyses with fibroid size, type, and location but was stronger for multiple fibroids (adjusted risk ratio = 0.75, 95% confidence interval: 0.68, 0.83). Our findings confirm other reports of an association between age at menarche and fibroid development (regardless of characteristics), demonstrate no effect modification by race, and suggest a stronger association for women with multiple fibroids, possibly reflecting a stronger association for early-onset disease.

Replication of genetic loci for ages at menarche and menopause in the multi-ethnic Population Architecture using Genomics and Epidemiology (PAGE) study.

STUDY QUESTION: Do genetic associations identified in genome-wide association studies (GWAS) of age at menarche (AM) and age at natural menopause (ANM) replicate in women of diverse race/ancestry from the Population Architecture using Genomics and Epidemiology (PAGE) Study? SUMMARY ANSWER: We replicated GWAS reproductive trait single nucleotide polymorphisms (SNPs) in our European descent population and found that many SNPs were also associated with AM and ANM in populations of diverse ancestry. WHAT IS KNOWN ALREADY: Menarche and menopause mark the reproductive lifespan in women and are important risk factors for chronic diseases including obesity, cardiovascular disease and cancer. Both events are believed to be influenced by environmental and genetic factors, and vary in populations differing by genetic ancestry and geography. Most genetic variants associated with these traits have been identified in GWAS of European-descent populations. STUDY DESIGN, SIZE, DURATION: A total of 42 251 women of diverse ancestry from PAGE were included in cross-sectional analyses of AM and ANM. MATERIALS, SETTING, METHODS: SNPs previously associated with ANM (n = 5 SNPs) and AM (n = 3 SNPs) in GWAS were genotyped in American Indians, African Americans, Asians, European Americans, Hispanics and Native Hawaiians. To test SNP associations with ANM or AM, we used linear regression models stratified by race/ethnicity and PAGE sub-study. Results were then combined in race-specific fixed effect meta-analyses for each outcome. For replication and generalization analyses, significance was defined at P < 0.01 for ANM analyses and P < 0.017 for AM analyses. MAIN RESULTS AND THE ROLE OF CHANCE: We replicated findings for AM SNPs in the LIN28B locus and an intergenic region on 9q31 in European Americans. The LIN28B SNPs (rs314277 and rs314280) were also significantly associated with AM in Asians, but not in other race/ethnicity groups. Linkage disequilibrium (LD) patterns at this locus varied widely among the ancestral groups. With the exception of an intergenic SNP at 13q34, all ANM SNPs replicated in European Americans. Three were significantly associated with ANM in other race/ethnicity populations: rs2153157 (6p24.2/SYCP2L), rs365132 (5q35/UIMC1) and rs16991615 (20p12.3/MCM8). While rs1172822 (19q13/BRSK1) was not significant in the populations of non-European descent, effect sizes showed similar trends. LIMITATIONS, REASONS FOR CAUTION: Lack of association for the GWAS SNPs in the non-European American groups may be due to differences in locus LD patterns between these groups and the European-descent populations included in the GWAS discovery studies; and in some cases, lower power may also contribute to non-significant findings. WIDER IMPLICATIONS OF THE FINDINGS: The discovery of genetic variants associated with the reproductive traits provides an important opportunity to elucidate the biological mechanisms involved with normal variation and disorders of menarche and menopause. In this study we replicated most, but not all reported SNPs in European descent populations and examined the epidemiologic architecture of these early reported variants, describing their generalizability and effect size across differing ancestral populations. Such data will be increasingly important for prioritizing GWAS SNPs for follow-up in fine-mapping and resequencing studies, as well as in translational research.

Genetic variation and reproductive timing: African American women from the Population Architecture using Genomics and Epidemiology (PAGE) Study.

Age at menarche (AM) and age at natural menopause (ANM) define the boundaries of the reproductive lifespan in women. Their timing is associated with various diseases, including cancer and cardiovascular disease. Genome-wide association studies have identified several genetic variants associated with either AM or ANM in populations of largely European or Asian descent women. The extent to which these associations generalize to diverse populations remains unknown. Therefore, we sought to replicate previously reported AM and ANM findings and to identify novel AM and ANM variants using the Metabochip (n = 161,098 SNPs) in 4,159 and 1,860 African American women, respectively, in the Women's Health Initiative (WHI) and Atherosclerosis Risk in Communities (ARIC) studies, as part of the Population Architecture using Genomics and Epidemiology (PAGE) Study. We replicated or generalized one previously identified variant for AM, rs1361108/CENPW, and two variants for ANM, rs897798/BRSK1 and rs769450/APOE, to our African American cohort. Overall, generalization of the majority of previously-identified variants for AM and ANM, including LIN28B and MCM8, was not observed in this African American sample. We identified three novel loci associated with ANM that reached significance after multiple testing correction (LDLR rs189596789, p = 5×10⁻°8; KCNQ1 rs79972789, p = 1.9×10⁻°7; COL4A3BP rs181686584, p = 2.9×10⁻°7). Our most significant AM association was upstream of RSF1, a gene implicated in ovarian and breast cancers (rs11604207, p = 1.6×10⁻°6). While most associations were identified in either AM or ANM, we did identify genes suggestively associated with both: PHACTR1 and ARHGAP42. The lack of generalization coupled with the potentially novel associations identified here emphasize the need for additional genetic discovery efforts for AM and ANM in diverse populations.

Factors associated with menopausal age in Iranian women: Tehran Lipid and Glucose Study.

AIM: Menopause, considered a special event in a woman's life, has a wide age range, 40-60 years, and there is no consensus regarding the factors influencing it. We aimed to assess factors affecting the menopausal age in a population of women participants of the Tehran Lipid and Glucose Study. MATERIAL AND METHODS: For the present study, 1114 women were selected from among participants of the Tehran Lipid and Glucose Study. Following implementation of our inclusion criteria, their reproductive histories and demographic background as well as anthropometric parameters were assessed, and ordinal regression analysis was conducted using spss version 15. RESULTS: The mean estimated age at menopause ± standard deviation was 49.6 ± 4.5 years. Menopausal age was considerably lower among women with a history of smoking (P = 0.05), and it increased with increasing age of menarche (P = 0.04) and number of children (P = 0.05). There was no significant correlation between the mean age of menopause and the educational level and anthropometric parameters. CONCLUSION: The smoking status, parity and the age of menarche are the influencing factors of age at menopause among the Iranian population.

Edad de menarquia y ascendencia indígena: Un estudio poblacional en Chile / Age at menarche and indigenous ancestry: A population study in Chile

Background: The age at menarche may influence decisively health and disease in women. It also indicates the beginning of the reproductive period and, as a consequence, the possibility of biological continuity for the human species. Genetic and environmental determinants define the age of menarche and can explain differences found among different populations. Aim: To determine the age at menarche among adolescents with different levels of indigenous descent (parental indigenous surnames), considering the effect of socioeconomic and demographic factors. Material and Methods: An observational study of historic cohorts of8.624 girls from the Arauca-nía Region (central-southern Chile) was carried out. Data were collected by health professionals using a previously validated questionnaire. Occurrence of menarche was estimated through survival analysis and compared between groups (according to indigenous parental surnames) adjusted for parents' income and educational level and provenance (rural/urban). Results: Estimated median age of menarche was 151 months (95% Cl: 150-151). In female with four indigenous surnames, menarche occurred two months later than girls without indigenous surnames and with two indigenous surnames (p < 0,001). In girls whose parents had lowest level of schooling, the difference increased to eight months later (p < 0,005). Conclusions: Age at menarche in the group with higher indigenous descent is later even if socio-economic conditions remain stable. Genetic factors might play an important role, however conditions of vulnerability can influence and further delay the onset of reproductive competency.

African-American/white differences in the age of menarche: accounting for the difference.

Lifetime health disparity between African-American and white females begins with lower birthweight and higher rates of childhood overweight. In adolescence, African-American girls experience earlier menarche. Understanding the origins of these health disparities is a national priority. There is growing literature suggesting that the life course health development model is a useful framework for studying disparities. The purpose of this study was to quantify the influence of explanatory factors from key developmental stages on the age of menarche and to determine how much of the overall race difference in age of menarche they could explain. The factors were maternal age of menarche, birthweight, poverty during early childhood (age 0 through 5 years), and child BMI z-scores at 6 years. The sample, drawn from the US National Longitudinal Surveys of Youth Child-Mother file, consisted of 2337 girls born between 1978 and 1998. Mean age of menarche in months was 144 for African-American girls and 150 for whites. An instrumental variable approach was used to estimate a causal effect of child BMI z-score on age of menarche. The instrumental variables were pre-pregnancy BMI, high gestational weight gain and smoking during pregnancy. We found strong effects of maternal age of menarche, birthweight, and child BMI z-score (-5.23, 95% CI [-7.35,-3.12]) for both African-Americans and whites. Age of menarche declined with increases in exposure to poverty during early childhood for whites. There was no effect of poverty for African-Americans. We used Oaxaca decomposition techniques to determine how much of the overall race difference in age of menarche was attributable to race differences in observable factors and how much was due to race dependent responses. The African-American/white difference in childhood BMI explained about 18% of the overall difference in age of menarche and birthweight differences explained another 11%.

Reproductive cancer risk factors among Alaska Native women: the Alaska Education and Research Towards Health (EARTH) Study.

BACKGROUND: The purpose of this study was to provide estimates for the prevalence of reproductive cancer risk factors among Alaska Native (AN) women who enrolled in the Alaska Education and Research Towards Health (EARTH) Study from 2004 to 2006. METHODS: A total of 2,315 AN women 18 years or older completed reproductive health questions as part of a comprehensive health history questionnaire. The reproductive health section included menstrual status (age at menarche and menopause), pregnancy and live birth history, use of hormonal contraception, hormone replacement therapy, and history of hysterectomy and/or oophorectomy. RESULTS: A total of 463 (20%) of women experienced menarche before age 12 with a decline in mean age at menarche by age cohort. More than 86% had been pregnant (mean number of pregnancies, 3.8; mean number of live births, 2.9). More than one half of women (58%) had their first live birth between the ages of 18 and 24. Almost 28% of participants had completed menopause, of whom 24% completed menopause after age 52. Fewer than half (43%) reported ever using hormone replacement therapy. Almost two thirds (62%) reported ever using oral contraceptives, and fewer reported ever using birth control shots (30%) or implants (10%). CONCLUSIONS: This study is unique in reporting reproductive health factors among a large group of AN women. These data show that AN women have selective protective factors for reproductive cancers, including low nulliparity rates, low use of menopausal estrogens, and common use of contraceptive hormones. However, analysis by age cohorts indicates decreasing age at menarche that might increase the risk for reproductive cancers among AN women in the future.

Socioeconomic status and age at menarche in indigenous and non-indigenous Chilean adolescents / Nivel socioeconómico y edad de la menarquia en adolescentes chilenas indígenas y no indígenas

The objective was to analyze the relationship between socioeconomic status and age at menarche among indigenous and non-indigenous girls in the Araucanía Region of Chile, controlling for nutritional status and mother's age at menarche. A total of 8,624 randomly selected girls from 168 schools were screened, resulting in the selection of 207 indigenous and 200 non-indigenous girls who had recently experienced menarche. Age at menarche was 149.6±10.7 months in the indigenous group and 146.6±10.8 months in the non-indigenous group. Among the non-indigenous, the analysis showed no significant association between age at menarche and socioeconomic status. In the indigenous group, age at menarche among girls with low socioeconomic status was 5.4 months later than among those with higher socioeconomic status. There were no differences in nutritional status according to socioeconomic level. Obesity was associated with earlier menarche. Menarche occurred earlier than in previous generations. An inverse relationship between socioeconomic status and age at menarche was seen in the indigenous group only; low socioeconomic status was associated with delayed menarche, regardless of nutritional status or mother's age at menarche.

El objetivo fue analizar la relación entre nivel socioeconómico y edad de menarquia en adolescentes indígenas y no indígenas de la Región de la Araucanía, Chile, controlando el efecto del estado nutricional, y la edad de menarquia de las madres. Se estudiaron 8.624 niñas de 168 escuelas elegidas aleatoriamente, seleccionando 207 indígenas y 200 no indígenas que habían tenido recientemente la menarquia. La edad de menarquia ocurrió a los 149,6±10,7 meses en indígenas y a los 146,6±10,8 meses en no indígenas. En el grupo no indígena, hubo una relación significativa entre edad de menarquia y nivel socioeconómico. En el grupo indígena, edad de menarquia del nivel socioeconómico bajo fue de 5,4 meses más tarde que el nivel socioeconómico más alto. No se observaron diferencias de estado nutricional por nivel socioeconómico. La obesidad adelantó la menarquia y la edad de menarquia ocurrió antes que la de sus madres. Existe una relación inversa entre nivel socioeconómico y edad de menarquia sólo en el grupo indígena; en los niveles socioeconómicos más bajos la edad de menarquia se retrasa independiente del estado nutricional y de la edad de menarquia de la madre.

Age at menarche and related factors in girlsof urban areas of Markazi (Central) province of Iran / Edad de la menarquia y factores relacionados en las niñas de zonas urbanas de la provincia Markazi (Central) de Irán

The age at menarche is an indicator of racial, geographical and nutritional patterns of different societies. This cross-sectional study conducted on 1223 girls aged 14-20 in the Markazi (Central) Province, Iran in 2010. In this research, the age at menarche, as the main variable, was determined for each city and compared between different cities. The statistical analyses included c2 test for determining statistically significant differences, variance analysis for determining the difference between groups, and Pearson correlation coefficient for determining the relationship between variables. The average age of first menstruation was 13.21+/-1.33 years in the Markazi Province, with no significant difference among the cities of the province. This age is inversely related to body mass index (BMI), nutritional status and weight. The pattern of distribution of BMI is similar for all the cities in the province. Although, the average age at menarche in the Markazi (central) Province, a cold area, is higher compared to warmer regions in Iran, it may be more influenced by race than by the climate. Considering the lower age at menarche in Markazi Province compared to previous similar studies, it may be stated that social well-being and nutritional standards have improved in the province.

La edad de la menarquia es un indicador de patrones raciales, geográficos y nutricionales de distintas sociedades. Este estudio transversal fue realizado el 2010 en 1223 niñas entre 14 y 20 años en la Provincia Markazi (Central), Irán. En esta investigación, la edad de la menarquia, como la variable principal, se determinaron para cada ciudad y en comparación entre las diferentes ciudades. Los análisis estadísticos incluyeron la prueba c2 para determinar diferencias estadísticamente significativas, el análisis de varianza para determinar la diferencia entre los grupos, y el coeficiente de correlación de Pearson para determinar la relación entre las variables. El promedio de edad de la primera menstruación fue 13,21+/-1,33 años en la provincia de Markazi, sin diferencias significativas entre las ciudades de la provincia. Esta edad es inversamente proporcional al índice de masa corporal (IMC), el estado nutricional y el peso. El patrón de distribución del IMC es similar para todas las ciudades de la provincia. Aunque la edad media de la menarquia en la Provincia Markazi (central), una zona de clima frío, es mayor en comparación con las regiones más cálidas en Irán, puede estar más influenciadas por la raza que por el clima. Teniendo en cuenta la baja edad de menarquia en la Provincia Markazi en comparación con estudios similares anteriores, se puede afirmar que el bienestar social y los niveles de nutrición han mejorado en la provincia.

Association analyses suggest the effects of RANK and RANKL on age at menarche in Chinese women.

OBJECTIVES: Age at menarche (AAM), the time of the first menstrual bleeding, is an important developmental milestone in the female life. It marks the beginning of the reproductive period. AAM is implicated in the risk of many health complications in later life. In this study, we conducted an analysis for association of single nucleotide polymorphisms (SNPs) and common haplotypes of two candidate genes, RANK (receptor activator of the NF-κB) and RANKL (receptor activator of the NF-κB ligand), with AAM in 825 unrelated Chinese women. METHODS: In total, 73 SNPs of RANKL and 23 SNPs of RANK were genotyped. The SNPs and common haplotypes were then analyzed for their association with AAM. Age and age( 2 ) were used as covariates. RESULTS: We found five individual SNPs (rs7239261, rs8094884, rs3826620, rs8089829, and rs9956850) of RANK significantly associated with AAM (p < 0.05). Although no significant association was identified for the RANKL gene, three polymorphisms showed nearly significant (0.05 < p < 0.08) association with AAM. Seven haplotypes of RANK were significantly associated with AAM (p < 0.05); the most significant association of the AT haplotype composed by rs1805034 and rs4524034 (p = 9.4 × 10(-4)) remained significant (p = 0.0235) after the Bonferroni correction for multiple testing. Three haplotypes of RANKL were significantly associated with AAM (p < 0.05). Importantly, the association of rs3826620 replicated our previous findings for Caucasian females. CONCLUSIONS: The results of the present study suggest that the RANK and RANKL are two candidate genes for AAM in Chinese women.

Gynecological history in chronic fatigue syndrome: a population-based case-control study.

BACKGROUND: Chronic fatigue syndrome (CFS) affects disproportionately more women than men, and the condition is more common at perimenopause. We examined gynecological history events as risk factors for CFS. METHODS: In a case-control study from a randomly selected population sample from Wichita, Kansas, 36 women with CFS and 48 nonfatigued controls, of similar age, race, and body mass index (BMI), answered a structured gynecological history questionnaire. RESULTS: CFS cases and controls had the same mean age (51 years) and age at menarche (12 years). Overall, a greater proportion of women with CFS than controls reported pelvic pain unrelated to menstruation (22.2% vs. 1.7%, p = 0.004), endometriosis (36.1% vs. 16.7, %, p = 0.046), and periods of amenorrhea (53.9 % vs. 46.2%, p = 0.06). Compared to controls, women in the CFS group had a higher mean number of pregnancies (2.8 vs 2.0, p = 0.05) and gynecological surgeries (1.8 vs. 1.1, p = 0.05). Similar proportions of the CFS (69.4%) and control (72.9%) groups were menopausal. Although menopausal women in the CFS and control groups had similar mean age (55.5 and 55.8, respectively), menopause occurred about 4.4 years earlier in the CFS group (41.7 years vs. 46.1 years, respectively, p = 0.11). Among menopausal women, 76% of the CFS group reported hysterectomy vs. 54.6% of controls (p = 0.09), and 56% of women with CFS reported oophorectomy vs. 34.3% of controls (p = 0.11). CONCLUSIONS: The higher prevalence of gynecological conditions and gynecological surgeries in women with CFS highlights the importance of evaluating gynecological health in these patients and the need for more research to clarify the chronologic and the pathophysiological relationships between these conditions and CFS.

Association of maternal and intrauterine characteristics with age at menarche in a multiethnic population in Hawaii.

This study seeks to further elucidate the mother-daughter hormonal relationship and its effects on daughter's breast cancer risk through the association with early age at menarche. Four hundred and thirty-eight healthy girls, age 9-18 and of White, Asian, and/or Polynesian race/ethnicity, were recruited from an HMO on Oahu, Hawaii. Anthropometric measures were taken at a clinic visit, and family background questionnaires were completed. Cox proportional hazards regression was used to test the association of maternal and intrauterine hormone-related exposures with age at menarche. Weight and gestational age at birth and maternal pregnancy-induced nausea were not associated with age at menarche. Each year older of the mother's age at menarche was associated with a 21% reduced risk of an early age at menarche for the daughter (95% CI: 0.73-0.86). This association between mother's and daughter's menarcheal age was statistically significant for girls of Asian, White, and Mixed, Asian/White race/ethnicity, but not for girls of Mixed, part-Polynesian race/ethnicity (p (interaction) = 0.01). There was a suggestion that maternal history of breast cancer was associated with an increased risk of early age at menarche (HR = 2.18, 95% CI: 0.95-4.98); there was no association with second-degree family history. These findings support the hypothesis that maternal and intrauterine hormone-related exposures are associated with age at menarche.