月经初潮与骨龄及发育指标研究

本文研究了兰州市区6～17周岁女生360人的骨龄、身高、体重、胸围等项发育指标与月经初潮的关系,结果表明:已来潮女生各种发育指标均高于同龄未来潮者(P<0.01)。未来潮比已来潮者骨龄相差1.1岁,身高相差7.21cm,体重相差5.46kg,胸围相差3.65cm。平均初潮骨龄为13.45岁,初潮骨龄标准误差、最大-最小值及变异系数均小于生物年龄,说明初潮与骨龄关系最密切,用骨龄估计月经初潮最为准确可靠。初潮一般在拇籽骨出现15.7月内来潮。     

Follow up of growth and steroids in premature adrenarche

In a follow up study of 34 patients with premature adrenarche we examined serum adrenal androgen levels and growth. The majority (28/34) showed an upward bend in the growth curve which, at the mean age of 2.3 years, preceded other signs of adrenarche on average by 3.8 years. Pubertal growth spurt was missing or reduced in 50% of the patients (8/16), however, final height did not differ from that expected from parental heights. Adrenal androgens did not remain elevated at adolescence. The mean age at menarche for all the girls was 0.5 years younger than in the general population.Conclusion Our findings imply that premature adrenarche may start earlier than previously recognized. Compared to ordinary growth these children seen to use a greater part of their potential for adult height already at that early age.     

月经初潮年龄对壮族女大学生体型分布的影响

目的　探讨月经初潮年龄对女大学生体型分布的影响。方法　对 10 3名 2 0岁壮族女大学生的月经初潮年龄进行调查研究 ,并作Heath Carter体型分析。结果　得出 4个不同月经初潮年龄组的体型均值和 10 3名 2 0名壮族女大学生的体型均值 ,表明均为三胚中间型体型。结论　壮族女大学生的体型不受月经初潮年龄的影响。     

Reproductive windows,genetic loci,and breast cancer risk

PurposeThe reproductive windows between age at menarche and age at first birth (standardized age at first birth) and from menarche to menopause (reproductive lifespan) may interact with genetic variants in association with breast cancer risk.MethodsWe assessed this hypothesis in 6131 breast cancer cases and 7274 controls who participated in the population-based Collaborative Breast Cancer Study. Risk factor information was collected through telephone interviews, and DNA samples were collected on a subsample (N= 1484 cases, 1307 controls) to genotype for 13 genome-wide association study-identified loci. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were calculated, and P values for the interaction between reproductive windows and genotypes were obtained by adding cross-product terms to statistical models.ResultsFor standardized age at first birth, the OR was 1.52 (CI, 1.36–1.71) comparing the highest quintile with the lowest quintile. Carrier status for rs10941679 (5p12) and rs10483813 (RAD51B) appeared to modify this relationship (P = .04 and P = .02, respectively). For reproductive lifespan, the OR comparing the highest quintile with the lowest quintiles was 1.62 (CI, 1.35–1.95). No interactions were detected between genotype and reproductive lifespan (all P > .05). All results were similar regardless of ductal versus lobular breast cancer subtype.ConclusionsOur results suggest that the reproductive windows are associated with breast cancer risk and that associations may vary by genetic variants.     

Evidence for a downward secular trend in age of menarche in a rural Gambian population

Abstract

Menarcheal age is a key indicator of female maturity and development. Studies in many countries have reported a downward secular trend in age of menarche over the past century. This study presents data gained using the ‘status quo’ method and interval regression to estimate median menarcheal age of girls in a rural Gambian community. Cross-sectional studies carried out in 1989, 2000 and 2008 revealed a median menarcheal age of 16.06 (95% CI 15.67–16.45), 15.03 (95% CI 14.76–15.30) and 14.90 (95% CI 14.52–15.28), respectively. The average rate of decline of median age of menarche was amongst the most rapid yet reported, at 0.65 years of age per decade (p < 0.00001). There was no evidence for a change in the rate of decline over the two decades studied. These results probably reflect ongoing socio-economic development within the region.     

Menarcheal age in Turkey: Secular trend and socio-demographic correlates

Background: Menarche is an important indicator for assessing the developmental status of pubertal girls. Despite its importance, there is no nationwide information on menarcheal age in Turkey.

Aim: This paper is the first attempt to examine age at menarche for Turkey as a whole. The aim is to present the secular trend of menarcheal age and variations across different socio-demographic groups.

Methods: Data were employed from the Turkey Demographic and Health Survey, 2008. Mean menarcheal ages were estimated for birth cohorts and socio-demographic sub-groups. The pace of decline in menarcheal age has been estimated using multiple linear regression analysis, controlling for year of birth and other variables.

Results: Mean age at menarche was estimated as 13.30 (95% CI = 13.26–13.35). It was estimated as 13.17 years (95% CI 12.95–13.38) for the youngest birth cohort (1989–1993), as opposed to 13.44 (95% CI 13.37–13.52) years for the cohort born in 1959–1968.

Conclusion: Regression analysis indicated a decrease of 1.44 months per decade, providing evidence of a secular trend in menarcheal age in Turkey. Further results suggested childhood place of residence, education, welfare status and number of siblings to be significantly associated with menarcheal age.     

The relationship between body composition and onset of menarche

Background: A late age of menarche in elite adolescent athletes is frequently attributed to low body fat/weight. If a critical body weight/fat is necessary for menarche, a reduction in the variability of these parameters would be observed at menarche compared to times before and after this event.

Aim: The study determined the variability in body mass (BM), per cent body fat (%BF) and total body fat (TBF) of girls between ?2 and +2 years from menarche.

Methods: Participants were part of the Saskatchewan Pediatric Bone Mineral Accrual Study (1991–1998). Body composition was assessed using dual X-ray absorptiometry (DXA). An individual's data was retained for analysis if they had at least four DXA scans between ?3 and +3 years from menarche. Values were interpolated from the cubic spline at whole years between ?2 and +2 years from menarche. Coefficient of variation (CV) was used to assess variability.

Results/Conclusion: Data on 61 girls were retained for analysis. The range in BM, TBF and %BF at menarche was 50.10 kg, 35050.06 g and 31.61%, respectively. Reductions in variability of body fat and weight were not apparent at menarche, which does not provide support for the hypothesis that a critical body weight/fat is required for menarche.     

The Decreasing Age at Menarche in Mexico

Study ObjectiveTo estimate the current age at menarche in 2 urban areas from Mexico and to analyze secular trends in the age at menarche in Mexico City.DesignCross-sectional survey and secondary data analyses.Setting(1) Samples of female students from Mexico City and from the city of Xalapa; and (2) national health surveys.Participants(1) Pre- and postmenarcheal students, aged 8-17 years; and (2) data for women born between 1904 and 1999 who grew up in Mexico City were obtained from 3 relevant national health surveys.Interventions and Main Outcome Measures(1) Students were asked if they had had their first period and when it occurred; (2) information on year of birth and age at menarche for the remaining women was obtained from the national surveys; data were divided in groups according to the decade in which the women were born.Results(1) The estimated mean age at menarche was 11.40 and 11.34 years in Mexico City and Xalapa respectively. (2) There were significant differences in age at menarche among women who were born in the different decades analyzed. Women who were born in the 1990s or later reported an earlier age at menarche than those who were born from the 1940s to 1980s (P < .0001).ConclusionThese results could be helpful to health and education professionals who should take into account that because there is currently a widening gap between the physical and psychosocial maturity of girls, they might need special support.