Separate and combined effects of famine exposure and menarche age on metabolic syndrome among the elderly: a cross-sectional study in China.

BACKGROUND: Epidemiological studies have revealed multiple risk factors for metabolic syndrome. However, there are no consistent findings on the association between famine exposure, age at menarche, and the prevalence of metabolic syndrome. This cross-sectional study aimed to reveal the individual and combined effects of famine exposure and age at menarche on the prevalence of metabolic syndrome among elderly women. METHODS: Four thousand seven hundred seventy participants between 60 and 93 years of age were selected from the China Health and Retirement Longitudinal Study. Statistical differences between the baseline characteristics of famine exposure, age at menarche, and metabolic syndrome were evaluated using the t-test, F-test, and Chi-square test. Three multivariable-adjusted logistic regression models were used to test the association between famine exposure, age of menarche, and the odds ratio of metabolic syndrome. RESULTS: Two thousand one hundred ninety-eight (46.08%) participants had metabolic syndrome, while 2572 (53.92%) participants did not. Furthermore, 3068 (64.32%) women reported onset of menarche under 15 years of age, while 1702 (35.68%) women reported onset of menarche above 16 years of age. Regarding the separate association of famine exposure and age of menarche with metabolic syndrome, in model three, the adolescence/adulthood famine exposure group vs. no famine exposure group odds ratio was 2.45 (95% CI 2.02, 2.97), and the older than 16 years vs. younger than 15 years group odds ratio was 1.23 (95% CI 1.09, 1.39), which was the highest odds ratio among the three models. Regarding the combined association of famine exposure and age of menarche with metabolic syndrome, in model three, among the age of menarche ≤ 15 years group, the adolescence/adulthood famine exposure vs. no famine exposure group odds ratio was 2.45 (95% CI: 1.91, 3.14); among the menarche age ≥ 16 years group, the adolescence/adulthood famine exposure stages vs. exposed group odds ratio was 3.27 (95% CI: 2.44, 4.38), which was the highest odds ratio among the three models. CONCLUSION: These findings suggested that famine exposure and age at menarche, either separately or in combination, were positively associated with the prevalence of metabolic syndrome among older women.

The genetics of autism and steroid-related traits in prenatal and postnatal life.

Background: Autism likelihood is a largely heritable trait. Autism prevalence has a skewed sex ratio, with males being diagnosed more often than females. Steroid hormones play a mediating role in this, as indicated by studies of both prenatal biology and postnatal medical conditions in autistic men and women. It is currently unclear if the genetics of steroid regulation or production interact with the genetic liability for autism. Methods: To address this, two studies were conducted using publicly available datasets, which focused respectively on rare genetic variants linked to autism and neurodevelopmental conditions (study 1) and common genetic variants (study 2) for autism. In Study 1 an enrichment analysis was conducted, between autism-related genes (SFARI database) and genes that are differentially expressed (FDR<0.1) between male and female placentas, in 1st trimester chorionic villi samples of viable pregnancies (n=39). In Study 2 summary statistics of genome wide association studies (GWAS) were used to investigate the genetic correlation between autism and bioactive testosterone, estradiol and postnatal PlGF levels, as well as steroid-related conditions such as polycystic ovaries syndrome (PCOS), age of menarche, and androgenic alopecia. Genetic correlation was calculated based on LD Score regression and results were corrected for multiple testing with FDR. Results: In Study 1, there was significant enrichment of X-linked autism genes in male-biased placental genes, independently of gene length (n=5 genes, p<0.001). In Study 2, common genetic variance associated with autism did not correlate to the genetics for the postnatal levels of testosterone, estradiol or PlGF, but was associated with the genotypes associated with early age of menarche in females (b=-0.109, FDR-q=0.004) and protection from androgenic alopecia for males (b=-0.135, FDR-q=0.007). Conclusion: The rare genetic variants associated with autism appear to interact with placental sex differences, while the common genetic variants associated with autism appear to be involved in the regulation of steroid-related traits. These lines of evidence indicate that the likelihood for autism is partly linked to factors mediating physiological sex differences throughout development.

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

[This corrects the article DOI: 10.3389/fcvm.2022.1023355.].

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.

Interactions between Polygenic Risk Scores, Dietary Pattern, and Menarche Age with the Obesity Risk in a Large Hospital-Based Cohort.

Obese Asians are more susceptible to metabolic diseases than obese Caucasians of the same body mass index (BMI). We hypothesized that the genetic variants associated with obesity risk interact with the lifestyles of middle-aged and elderly adults, possibly allowing the development of personalized interventions based on genotype. We aimed to examine this hypothesis in a large city hospital-based cohort in Korea. The participants with cancers, thyroid diseases, chronic kidney disease, or brain-related diseases were excluded. The participants were divided into case and control according to their BMI: ≥25 kg/m2 (case; n = 17,545) and <25 kg/m2 (control; n = 36,283). The genetic variants that affected obesity risk were selected using a genome-wide association study, and the genetic variants that interacted with each other were identified by generalized multifactor dimensionality reduction analysis. The selected genetic variants were confirmed in the Ansan/Ansung cohort, and polygenetic risk scores (PRS)-nutrient interactions for obesity risk were determined. A high BMI was associated with a high-fat mass (odds ratio (OR) = 20.71) and a high skeletal muscle-mass index (OR = 3.38). A high BMI was positively related to metabolic syndrome and its components, including lipid profiles, whereas the initial menstruation age was inversely associated with a high BMI (OR = 0.78). The best model with 5-SNPs included SEC16B_rs543874, DNAJC27_rs713586, BDNF_rs6265, MC4R_rs6567160, and GIPR_rs1444988703. The high PRS with the 5-SNP model was positively associated with an obesity risk of 1.629 (1.475-1.798) after adjusting for the covariates. The 5-SNP model interacted with the initial menstruation age, fried foods, and plant-based diet for BMI risk. The participants with a high PRS also had a higher obesity risk when combined with early menarche, low plant-based diet, and a high fried-food intake than in participants with late menarche, high plant-based diet, and low fried-food intake. In conclusion, people with a high PRS and earlier menarche age are recommended to consume fewer fried foods and a more plant-based diet to decrease obesity risk. This result can be applied to personalized nutrition for preventing obesity.

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.

Menarche age exceed 17 years and menopausal age smaller than 48 years may affect prevalence of osteoporosis for Chinese women.

In this work, we used a cross-sectional study to evaluate influence of menarche age, menstrual cycle, menstrual period, menopausal age, and menopause years for osteoporosis in women from China. We found that different menarche age, menstrual cycle, menopausal years, and menopausal age are related with the prevalence of osteoporosis. However, menarche age exceeds 17 years and menopausal age smaller than 48 years are risk factors for osteoporosis in women. STUDY DESIGN: A cross-sectional, population-based study. PURPOSE: The purpose of this study was to explore relationship between prevalence of osteoporosis and menarche age, menstrual cycle, menstrual period, menopausal age, and menopause years for women. METHODS: From March to October 2016, the cluster sampling method was used to conduct an osteoporosis-related questionnaire survey on women aged 40-80 in two communities in Lanzhou City, Gansu, China, and bone mineral density(BMD)was carried out using the DTX-200 dual-energy X-ray absorptiometer produced by the US OSTEOMETER company. The relationship between prevalence of osteoporosis and menarche age, menstrual cycle, menstrual period, menopausal age, and menopause years were analyzed using logistic regression analysis. RESULTS: There were 2224 female participates enrolled in this study and average age was 61.60 ± 8.05 years and total rate of prevalence was 32.73%; among them, different menarche age, menstrual cycle, menopausal years, and menopausal age have statistical differences with the prevalence of osteoporosis, but there is no statistical difference between different menstruation and the prevalence of osteoporosis. Single logistic regression analysis found that older menarche age, earlier menopausal age, and longer menopausal years were related factors for the prevalence of osteoporosis, while menarche age exceed 17 years and menopausal age smaller than 48 years are risk factors for osteoporosis for women in multivariate regression analysis. CONCLUSIONS: In China, ages at menarche and menopause are associated with prevalence of osteoporosis. Later, menarche and earlier menopause are associated with higher osteoporosis risk. Menarche and menopause history may help identify women with increased risk of developing osteoporosis.

Late Menarche, Not Reproductive Period, Is Associated with Poor Cognitive Function in Postmenopausal Women in Taiwan.

Female sex hormones such as estrogen and progesterone play an important role in the regulation of a woman's body, including cognition and neurogenesis. However, the effects of age at menarche and reproductive period on cognitive function are still controversial. The aim of this study was to investigate the relationships between age at menarche and reproductive period with cognitive impairment. Data were obtained from the Taiwan Biobank. Cognitive function was assessed using the Mini Mental State Examination (MMSE) and its five subdomains. Multivariable linear regression analysis revealed that an old age at menarche (per one year; coefficient ß, -0.189; p = 0.020) was significantly associated with a low total MMSE score, whereas reproductive period (p = 0.733) was not significantly associated with total MMSE score. Furthermore, an old age at menarche was significantly associated with low MMSE G2 (registration) (per one year; coefficient ß, -0.022; p = 0.035) and G5 (language, construction and obey) scores (per one year; coefficient ß, -0.054; p = 0.047). However, age at menarche was not significantly associated with MMSE G1 (orientation), G3 (attention and calculation) and G4 (recall) scores. In addition, reproductive period was not significantly associated with any MMSE subscores. Late menarche was associated with poor cognitive function, including low total MMSE score and low MMSE G2 and G5 scores. However, reproductive period was not associated with cognitive function in postmenopausal women.

Is There any Association between Age at Menarche and Risk of Metabolic Syndrome? The Tehran Lipid & Glucose Study.

BACKGROUND: There is controversial data available regarding the impact of age at menarche on cardio-metabolic parameters. This community-based study aimed to assess this association among Iranian women. METHODS: We recruited 5,344 eligible women out of 7718, aged 10-50 years who participated in the Tehran lipid and glucose study (TLGS), conducted in 1999-2000. Based on their age at menarche, these women were subdivided into five groups: <11 years, 11-12 years, 13-14 years, 15-16 years and ≥17 years. The status of metabolic syndrome (MetS) and its components were compared among study subgroups. RESULTS: The crude prevalence of MetS was 11.9, 95% CI: 11.0-13.0. Prevalence values for MetS components were 20.1 for central obesity (95% CI: 19.0-21.3), 15.7 for high fasting blood sugar (FBS), (95% CI: 14.5-17.1), 15.1 for high triglycerides, (95% CI: 14.1-16.3), 53.5 for low high density lipoproteins (HDL) (95% CI: 51.9-55.0) and 9.5 for high blood pressure (BP) (95% CI: 8.5-10.4). After adjustment for covariates, menarche age <11 years, compared to 13-14 years, was significantly associated with higher risk of Mets (odds ratio [OR] = 2.3, 95% CI: 1.1-5.4) and its components; i.e. central obesity (OR = 2.5, 95% CI: 1.5-4.2), BP (OR = 2.9, 95% CI: 1.4-6.0) and FBS (OR = 3.0, 95% CI: 1.4-6.0). To compare our results with other studies, we calculated the standardized prevalence of MetS which was based on the WHO standardized population 11.5, 95%CI: 10.7-12.5 and the standardized prevalence of MetS by the population in Tehran was 11.7, 95% CI: 10.7-12.6. CONCLUSION: Early menarche can be associated with an increase in metabolic disturbances later in life.

[Impact of menarche age on the near-term and long-term obesity of adult females].

Objective: To study the relationship between the age of menarche and the near-term/long-term obesity in adult women. Methods: We analyzed the baseline data of 30 895 women with complete data on menarche and body measurement that was from the China Kadoorie Biobank (CKB) study from 2004 to 2008. The age of menarche was divided into three groups: ≤12, 13-16 and ≥17 years old. Prematurity was set at age ≤12 years. Multivariate logistic regression was used to analyze the effects of menarche age on the near/long-term obesity in female adults. Results: The average menarche age of respondent appeared as (15.64±1.92) years old, with prematurity number as 1 421, accounting for 4.6% of the total numbers. Regarding the postponing of dates of birth, the age of menarche in women showed an advancing tendency. Among all the adult women under study, 803 developed near-term obesity, with the prevalence as 2.6%, while the number of long-term obesity was 3 738, accounting for 12.1%. Refining factors of age, lifestyle, menopausal status, hypertension and diabetes showed that the menarche age was related to the risks of both short-term and long-term obesity in women and the ORs (95%CI) were 2.45 (1.74-3.45) and 1.99 (1.69-2.34), respectively. There was no multiplicative interaction shown between the menarche age and menopausal status on long-term obesity (P=0.324). Conclusion: Premature menarche appeared a risk factor for near-term/long-term obesity in adult females.

Onset of menarche is not delayed in Slovenian patients with celiac disease.

OBJECTIVE: Celiac disease (CD) is an autoimmune disorder associated with numerous health problems, including reproductive disorders. This study was performed to analyze the association between CD and the menstrual cycle in a group of patients with CD and compare these patients' characteristics with those of healthy women. METHODS: The study included 145 patients with CD (age, 15-51 years) and 162 healthy women (age, 18-55 years). Age at menarche and characteristics of the menstrual cycle were obtained by an anonymous questionnaire developed for the study. RESULTS: The age at onset of menarche was 12 to 14 years in 72.9% of the patients with CD and 77.3% of the healthy controls. For most patients (74.2%), the length of the menstrual cycle was around 27 to 28 days with 4 to 5 days of bleeding. Furthermore, 8.4% of patients versus 5.9% of controls experienced bleeding between cycles. CONCLUSIONS: Our results suggest that in Slovenia, the age at menarche in patients with CD is 12.7 years, which is comparable with that in healthy women. We conclude that CD (treated or untreated) may not be associated with late menarche.

Impact of menarche age on the near-term and long-term obesity of adult females / 中华流行病学杂志

Objective To study the relationship between the age of menarche and the nearterm/long-term obesity in adult women.Methods We analyzed the baseline data of 30 895 women with complete data on menarche and body measurement that was from the China Kadoorie Biobank (CKB) study from 2004 to 2008.The age of menarche was divided into three groups:≤12,13-16 and ≥ 17 years old.Prematurity was set at age ≤ 12 years.Multivariate logistic regression was used to analyze the effects of menarche age on the near/long-term obesity in female adults.Results The average menarche age of respondent appeared as (15.64 ± 1.92) years old,with prematurity number as 1 421,accounting for 4.6％ of the total numbers.Regarding the postponing of dates of birth,the age of menarche in women showed an advancing tendency.Among all the adult women under study,803 developed near-term obesity,with the prevalence as 2.6％,while the number of long-term obesity was 3 738,accounting for 12.1％.Refining factors of age,lifestyle,menopausal status,hypertension and diabetes showed that the menarche age was related to the risks of both short-term and long-term obesity in women and the ORs (95％CI) were 2.45 (1.74-3.45) and 1.99 (1.69-2.34),respectively.There was no multiplicative interaction shown between the menarche age and menopausal status on long-term obesity (P=0.324).Conclusion Premature menarche appeared a risk factor for near-term/long-term obesity in adult females.

Impact of menarche age on the near-term and long-term obesity of adult females / 中华流行病学杂志

Objective To study the relationship between the age of menarche and the nearterm/long-term obesity in adult women.Methods We analyzed the baseline data of 30 895 women with complete data on menarche and body measurement that was from the China Kadoorie Biobank (CKB) study from 2004 to 2008.The age of menarche was divided into three groups:≤12,13-16 and ≥ 17 years old.Prematurity was set at age ≤ 12 years.Multivariate logistic regression was used to analyze the effects of menarche age on the near/long-term obesity in female adults.Results The average menarche age of respondent appeared as (15.64 ± 1.92) years old,with prematurity number as 1 421,accounting for 4.6％ of the total numbers.Regarding the postponing of dates of birth,the age of menarche in women showed an advancing tendency.Among all the adult women under study,803 developed near-term obesity,with the prevalence as 2.6％,while the number of long-term obesity was 3 738,accounting for 12.1％.Refining factors of age,lifestyle,menopausal status,hypertension and diabetes showed that the menarche age was related to the risks of both short-term and long-term obesity in women and the ORs (95％CI) were 2.45 (1.74-3.45) and 1.99 (1.69-2.34),respectively.There was no multiplicative interaction shown between the menarche age and menopausal status on long-term obesity (P=0.324).Conclusion Premature menarche appeared a risk factor for near-term/long-term obesity in adult females.

El adelanto en la telarquia y edad de la menarquia se relacióna con la malnutrición por exceso en niñas chilenas pero no en varones: estudio de base poblacional / The advance in thelarche and age of menarche is related to malnutrition by excess in Chilean girls but not in boys: population-based study

Introduction: Puberty normally begins after 8 years in girls and 9 years in boys. Objective: To determine the prevalence of signs of precocious puberty (PP), breast development in girls, premature gonadal development (PGD), premature adrenarche (PA), menarche age (MA) and its association with nutritional status (NS). Material and Methods: From a sample of 3.010 children from 5 to 14 years randomly selected in Santiago of Chile were chosen a subsample of 873 kids according to the cutoff to define PP. Survey was applied to obtain MA. Logistic regression were used to evaluate the relationship between PP and NS. Results: In boys the prevalence of PGD and PP was 8.55% and 3.16% respectively, no relationship was found with nutritional status In girls the prevalence of breast development and PA was 8.13% and 0.9% respectively. Only there be association between PP and NS in women: with a prevalence of 1,2%, 13,9% and 21,1% in well-nourished, Overweight and obesity are at greater risk of showing PP compared with eutrophic girls with an OR of 25,5 (IC 95% 3,2-203,0) and 46.93 (IC 95% 6,1-361,5). MA was 12,01 ± 0,94 years in eutrophic girls and 11,40 ± 0,96years in obese girls (p< 0,05). Conclusion: There was a positive correlation in females between overweight and obesity an PP and MA. There is a secular trend in MA, to compare these findings with other national studies. Obesity could have an important role in explaining the advancement observed in pubertal development.

Introducción: El desarrollo puberal se inicia normalmente después de los 8 años en niñas y de los 9 años en varones. Objetivo: Estimar la prevalencia de signos de pubertad precoz (sPP): crecimiento genital (CG) en varones, telarquia en niñas y vello púbico (VP) en ambos sexos; y determinar edad de la menarquia (EM) en una muestra de escolares de Santiago de Chile), y evaluar la asociación de estas variables con el estado nutricional (EN). Material y Métodos: Se examinaron 3.010 escolares de clase media baja de 6 a 14 años, pertenecientes a 10 colegios de Santiago de Chile y seleccionados aleatoriamente. En todos ellos se consignó peso, talla, IMC y desarrollo puberal según Tanner. Se aplicó una encuesta a los padres para obtener la EM a la población total de mujeres (n= 1.433). Para determinar sPP se analizaron por separado los 867 niños (62% mujeres) menores a la edad establecida como puntos de corte para definir PP. Se utilizó regresión logística para determinar la asociación existente entre sPP y el EN. Resultados: En varones la prevalencia de CG y VP fue de 8,55% y 3,16% y no se asocio al EN. La prevalencia de telarquia y VP en niñas fue de 8,13% y 0,9% respectivamente. Se observó una fuerte asociación entre telarquia y EN con prevalencias de 1.2%, 13.9% y 21.1% en eutróficas, sobrepeso y obesas, respectivamente (p< 0,0001) (Gráfico 1). La presencia de sobrepeso y/o obesidad otorgan un mayor riesgo de presentar telarquia, vs comparación con las niñas eutróficas con un OR de 25,5 (IC 95% 3,2-203,0) y 46.93 (IC 95% 6,1-361,5), respectivamente. La EM fue 12,01 ± 0,94 años en niñas eutróficas siendo de 11,40 ± 0,96 años en niñas obesas (p< 0,05). Conclusión: Se observó una correlación positiva solo en el sexo femenino entre malnutrición por exceso, telarquia precoz y EM. Se observa una tendencia secular en la EM al comparar los hallazgos con otros estudios nacionales.

Adult Premenopausal Bone Health Related to Reproductive Characteristics-Population-Based Data from the Canadian Multicentre Osteoporosis Study (CaMos).

Amenorrhea is important for women's bone health. However, few have reported reproductive, anthropometric (body mass index [BMI], height) and bone health (areal bone mineral density [BMD], prevalent fractures) in a population-based study. The purposes of this cross-sectional study of women in the randomly-selected Canadian Multicentre Osteoporosis Study (CaMos) population were: (1) to describe reproductive, demographic, anthropometric and lifestyle variables; and (2) in menstruating women, to relate reproductive and other variables to BMD at the lumbar spine (L1-4, LS), femoral neck (FN) and total hip (TH) sites and to prevalent fragility fractures. This study describes the reproductive characteristics of 1532 women aged 30⁻60 years. BMD relationships with reproductive and other variables were described in the 499 menstruating women. Mean menarche age was 12.8 years, 96% of women were parous and 95% had used combined hormonal contraceptives (CHC). Infertility was reported by 9%, androgen excess by 13%, amenorrhea by 8% and nulliparity by 4%. LS BMD was negatively associated with amenorrhea and androgen excess and positively related to current BMI and height. A later age at menarche negatively related to FN BMD. BMI and height were strongly related to BMD at all sites. Prevalent fragility fractures were significantly associated with quartiles of both LS and TH BMD.

Interactions of physical activity and body mass index with age at menarche: A school-based sample of Chinese female adolescents.

BACKGROUND: To test the independent and interactive associations of physical activity (PA) and body mass index (BMI) with age at menarche among Chinese adolescence. METHODS: We conducted a cross-sectional survey in two elementary schools in September 2015 in Shaoxing city, Zhejiang province, China. We used self-administered questionnaires to collect the information of the participators. Analyses were performed with logistic regression models, and the relative excess risk due to interaction (RERI), the attributable proportion because of the interaction (AP), and the synergy index (S) were used to evaluate the biological interaction. RESULTS: A total of 1530 middle school students from grade 1-3 were selected for this study, and we collected 1505 (98.366%) valid questionnaires for the last analyses. The mean age of menarche is 11.603 (SD=0.447)years. Students with overweight/obesity and without SMPA had the highest risks of early age of menarche (OR=3.507, 95%CI: 1.929-6.376) compared with women both with a normal BMI and with SMPA, and the RERI was 1.846 (95% CI: 0.415-4.107), meaning that there was positive interaction on the additive scale. CONCLUSION: Insufficient PA can significantly modify the association between obesity and early menarche risk. Therefore, the government and society should pay more attention to the promotion of PA throughout childhood and adolescence.

Studying the relationship between a woman's reproductive lifespan and age at menarche using a Bayesian multivariate structured additive distributional regression model.

Studies addressing breast cancer risk factors have been looking at trends relative to age at menarche and menopause. These studies point to a downward trend of age at menarche and an upward trend for age at menopause, meaning an increase of a woman's reproductive lifespan cycle. In addition to studying the effect of the year of birth on the expectation of age at menarche and a woman's reproductive lifespan, it is important to understand how a woman's cohort affects the correlation between these two variables. Since the behavior of age at menarche and menopause may vary with the geographic location of a woman's residence, the spatial effect of the municipality where a woman resides needs to be considered. Thus, a Bayesian multivariate structured additive distributional regression model is proposed in order to analyze how a woman's municipality and year of birth affects a woman's age of menarche, her lifespan cycle, and the correlation of the two. The data consists of 212,517 postmenopausal women, born between 1920 and 1965, who attended the breast cancer screening program in the central region of Portugal.

Timing of menarche in Norwegian girls: associations with body mass index, waist circumference and skinfold thickness.

BACKGROUND: Research studies show conflicting results regarding the association between menarche and body weight. The purpose of the present study was to investigate if anthropometric indicators of body composition, body mass index (BMI), waist circumference (WC), triceps (TSF) and subscapular skinfold (SSF) thicknesses, were differentially associated with age at menarche in Norwegian girls. METHODS: The association between menarche and BMI, WC, TSF and SSF was investigated in 1481 girls aged 8-15.5 years, and in a subgroup of 181 girls with menarche during the 12 months prior to examination. Anthropometric measures were categorized as low (< -1SDS), average (-1 ≤ SDS ≤ +1) or high (> 1SDS), and menarche according to this classification was analysed with Kaplan-Meier curves and unadjusted and adjusted Cox regression. RESULTS: The median age at menarche in the total sample was 13.1 years. In the unadjusted models, low categories of all traits were associated with later menarche, and high categories with earlier menarche. When adjusted for other covariates, earlier menarche was only related with a high BMI (Hazard Ratio 1.41, 95% confidence interval (CI) 1.07, 1.85), and later menarche with a low BMI (HR 0.53, 95%CI 0.38, 0.75) and low SSF (HR 0.54, 95%CI 0.39, 0.75). In girls with recent menarche, early menarche was significantly associated with a high BMI in the final model (HR 1.79, 95%CI 1.23, 2.62). CONCLUSIONS: The timing of menarche was associated with the BMI, WC, TSF and SSF, but more strongly so with the BMI. These associations may be related to a common tempo of growth, as the mean age at menarche has remained stable during the last decades during a time period while the prevalence of overweight and obesity has increased significantly.

Pattern of menarche age (normal, early and late) and its relationship with some demographic characteristics in girls and their parents.

BACKGROUND: Menarche age is an indicator of a girl's puberty besides the clinical assessment of detecting deviations. This study aimed to search the pattern of menarche age (normal, early and late) and its relationship with some demographic characteristics in girls and their parents. METHODS: This cross-sectional study was done on girls aged between 9 and 18 years old in Shiraz city. About 2000 students were selected through cluster sampling. Data collection was done by applying a demographic information form. Finally, the data were analyzed using SPSS software. RESULTS: About 1386 students (69.3%) had the history of menarche (at least once). The mean age of menarche was 12.26±1.11 years in Shiraz. The menarche age of the girls ranged from 9 years (as the least) to 15 (as the maximum). The prevalence of late menarche was 1.1%. In addition, no early menarche was reported. There was no relationship between menarche age and economic status, birth order and number of children, but a significant relationship was found between the parents' education, house status, and the lifestyle of parents. CONCLUSION: The mean menarche age has been decreasing in cities. Therefore, it seems necessary for the families to be aware about the influence of time, trend and affecting factors on menarche; this helps them to make good decisions when educating their teenagers.

Association Between Age at Onset of Schizophrenia and Age at Menarche.

INTRODUCTION: Increasing evidence from clinical practice, as well as from epidemiological and basic research shows that there are gender differences in clinical features of schizophrenia, and this may be related to estrogens. There may be a relationship between earlier puberty and later onset of the disease, because of the protective effects of estrogens in women with schizophrenia. In this study, our aim was to analyze the correlation between age of menarche and age of onset of schizophrenia and to investigate the protective effects of estrogens in schizophrenia. METHOD: In this study, we included 289 patients who were diagnosed with schizophrenia. Those with mental deficiency or organic brain disorders were excluded from the study. All subjects were given a socio-demographic form to determine their personal information, age at menarche, age at first odd behavior, age at onset of the disease and first hospitalization. Data on factors which may affect the association between age at onset of schizophrenia and age at menarche such as family history, head or birth trauma etc. were recorded on the information form. RESULTS: We found out that age at menarche was negatively associated with age at first odd behavior and age at first psychotic symptoms. CONCLUSION: Our study verifies the protective effects of estrogens and shows that the earlier puberty may be the cause of later onset of schizophrenia. A gender-sensitive approach in psychiatry improves our understanding of mental illness and our therapeutic strategies.