STUDY QUESTION Do birthweight (BW) and co-twin sex influence the age at menarche in twins? SUMMARY ANSWER BW, but not co-twin sex, was associated with age at menarche in twins. However, BW was not associated with age at menarche after controlling for genetics and shared rearing environment. WHAT IS KNOWN ALREADY Nutritional deprivation during critical developmental periods can trigger long-...

BACKGROUND Given the downward trend in age at menarche and its implications for the reproductive health and wellbeing of women, little is known about menarcheal age in Canada. Most Canadian studies are only representative of specific populations. The present study, therefore, aims to assess the distribution of age at menarche for Canadian girls and explore its variation across socio-economic an...

BACKGROUND Early menarche has been associated with increased risk of coronary heart disease (CHD), but most studies were relatively small and could not assess risk across a wide range of menarcheal ages; few have examined associations with other vascular diseases. We examined CHD, cerebrovascular disease, and hypertensive disease risks by age at menarche in a large prospective study of UK women...

This article presents an overview of the maturation process in children and discusses data from some Brazilian samples. Data related to secondary sexual characteristics in both sexes are compared to other populations. The national median menarcheal age in Brazilian girls obtained by INAN (1990) was 13.2 years. The menarcheal age of Brazilian athletes is higher than the non-athletic population. ...

BACKGROUND Early pubertal timing in girls is associated with elevated risk for dieting and eating pathology. The relative importance of biological versus socio-environmental mechanisms in explaining this association remains unclear. Moreover, these mechanisms may differ between objective measures of pubertal development and girls' subjective perceptions of their own maturation. METHOD The sam...

OBJECTIVE To evaluate the influence of dietary fibre on menarche in a cohort of pre-menarcheal girls. DESIGN Prospective cohort study. SETTING Ontario, Canada. SUBJECTS Free-living pre-menarcheal girls (n = 637), 6 to 14 years of age. METHODOLOGY Information on dietary intake, physical activity and date of menarche was collected at baseline and was updated annually by self-administered ...

Aim: To investigate the determinants of overweight and obesity among 10to 15-yearold schoolchildren in a population in the transitional phase in the North West Province of South Africa. Methods: A cross-sectional survey was used to investigate weight status (anthropometric indicators) and determinants of overweight/obesity including dietary intake, physical activity and socio-economic status. A...

Adolescence is characterized by an increase in risk-taking and reward-seeking behaviors. In other populations, increased risk taking has been associated with tighter coupling between cortisol production and ventral striatum (VS) activation during reward anticipation; this relation has not yet been examined, however, as a function of adolescent development. This study examined the influence of p...