Relative Weight and Race Influence Average Age at Menarche: Results From Two Nationally Representative Surveys of US Girls Studied 25 Years Apart (original) (raw)
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Growth differences by age of menarche in African American and White girls
Nursing research
Because of the rapid increases in childhood obesity coupled with decreases in the median age of menarche, there is interest in how growth (body mass index [BMI] and height) in childhood may be associated with timing of menarche. Two research questions were addressed in this article: (a) Within each race, at what ages were BMI and height differences evident among the early-, the mid-, and the late-onset groups? And (b) within each timing group, at what ages were BMI and height differences evident between White and African American girls? The mother/child files of the National Longitudinal Survey of Youth were used for this study. Menarcheal timing groups were identified using the 25th and the 75th percentile of the age distribution for each race. Longitudinal statistical techniques were used to estimate BMI and height as polynomial functions of age and age relative to menarche for African American and White girls. Significant differences in BMI by timing group were found. By 3 years ...
BMC Public Health, 2016
Background: Evidence suggests that early menarche is positively associated with adiposity in adulthood. However, it is important to assess whether this association is due to early menarche or to the association of adiposity in late childhood with age at menarche. We evaluated the association between age at menarche and body composition in adolescence and adulthood, among subjects who have been prospectively followed in two Brazilian birth cohort studies. Methods: In 1982 and 1993, the hospitals births in Pelotas were identified, and these subjects have been followed for several times. Information on age at menarche was obtained from the women (1982 cohort) and their mothers (1993 cohort). At 30 and 18 years, the following body composition measures were evaluated: body mass index, waist circumference, fat-free mass index and fat mass index measured by dual-energy x-ray absorptiometry, and thickness of the abdominal visceral fat layer measured by ultrasound. The analyses were adjusted for: birth weight, maternal pregestational weight, gestational age, family income, household score index, maternal schooling, weight-for-height z-score at 4 years (1982), and body mass index at 11 years (1993). Results: At 30 and 18 years, 2045 and 2092 women were evaluated, respectively. The prevalence of early menarche (≤11 years of age) was 24.7 % in the 1982 and 27.6 % in the 1993 cohort. In the 1982 cohort, early menarche was positively associated with all body composition variables compared to those with late menarche (≥14 years of age) even after adjusting for confounders (fat mass index: 2.33 kg/m 2 , 95 % Confidence interval: 1.64; 3.02). However, in the 1993 cohort, after adjusting for body mass index at 11 years, the regression coefficient for the association with fat mass index decreased from 2.2 kg/m 2 (95 % Confidence interval: 1.7; 2.6) to 0.26 (95 % Confidence interval: −0.08; 0.60). Conclusions: The association between age at menarche and body composition in adulthood is strongly explained by pre-pubertal adiposity.
Association of early menarche age and overweight/obesity
Journal of Pediatric Endocrinology and Metabolism, 2012
Aim: The aim of the study is to assess the association of overweight/obesity and early menarcheal age. Patients and methods: The study comprised 2127 healthy girls aged 9 to 16 years. Menarcheal age was estimated by status quo method. The girls ' body weight and height were measured and their body mass index (BMI) calculated. The diagnostic criteria of the WHO were used to defi ne overweight and obesity. Girls with a BMI in the range of 1-2 for age and sex were considered overweight. Girls with a BMI > 2 standard deviation (SD) for age and sex were considered obese. Girls with a BMI > 1 SD for age and sex were considered overweight/obese. Social and economic status was analyzed according to years of education completed, parents ' occupations, and the number of children in the family. Results: Median menarcheal age was 12.83 years; 25 % girls had menarche before 11.98 years and 75 % by 13.69 years. By 11.21 years, 10 % of girls had had menarche, and 95 % by 14.91 years. Girls who had menarche before 11.98 years had higher body weight values (48.5 vs. 40.2 kg) (p < 0.001), height (159.3 vs. 149.2 cm) (p < 0.001), and BMI (18.9 vs. 17.8 kg/m 2) (p = 0.003) than their peers without menarche. Girls with menarche before 11.98 years had signifi cantly higher BMI values than girls with menarche after 13.69 years (18.94 vs. 17.84 kg/m 2) (p = 0.008). Girls with menarche before 11.98 years and those after 13.69 years differ significantly in distribution of thinness (3.4 % vs. 2.54 %), normal weight (85.3 % vs. 91.8 %), and overweight/obesity (11.2 % vs. 5.7 %) (p = 0.002). Conclusions: Girls who experienced early menarche are signifi cantly more often overweight/obese. Overweight/obesity may be considered as one of the predictors for the early occurrence of menarche.
Age at menarche in schoolgirls with and without excess weight
Jornal de Pediatria (Versão em Português), 2015
Objective: To evaluate the age at menarche of girls, with or without weight excess, attending private and public schools in a city in Southeastern Brazil. Methods: This was a cross-sectional study comparing the age at menarche of 750 girls from private schools with 921 students from public schools, aged between 7 and 18 years. The menarche was reported by the status quo method and age at menarche was estimated by logarithmic transformation. The girls were grouped according to body mass index (BMI) cutoff points: (thin + normal) and (overweight + obesity). In order to ensure that they belonged to different strata, 328 parents of these schools answered a questionnaire to rate the student's socioeconomic level. Results: Menarche was reported by 883 girls. Although they belonged to different classes (p < 0.001), there was no difference in the nutritional diagnosis (p = 0.104) between them. There was also no difference in age at menarche between the girls studying in private (12.1 years, 95% CI: 12.0-12.2) and public schools (12.2 years, 95% CI:12.1-12.3; p = 0.383). When evaluated by nutritional status, there was difference only in the age at menarche between girls from private schools with excess weight and without excess weight (11.6 and 12.3 years; p < 0.001). The girls with excess weight attending private schools also had earlier an menarche than those attending public schools (respectively, 11.6 and 12.1 years; p = 0.016). Conclusions: Although the students from private schools belonged to a higher socioeconomic status, there is currently no longer a large gap between them and girls from public schools regarding nutritional and socioeconomic factors that may influence the age at menarche.
Childhood growth and age at menarche
BJOG: An International Journal of Obstetrics and Gynaecology, 1996
Objective To study the influence of birthweight, and weight and height at age seven years, on menarcheal age in a national sample of 1471 girls in England, Scotland and Wales. Methods We studied 1471 girls included in the MRC National Survey of Health and Development. During medical examinations carried out by school doctors in this cohort, born in the first week of March 1946, the mothers of girls were asked whether their daughters had started to menstruate, and if so, the month and year when this happened. Anthropometric measurements at birth and at age seven years were also obtained. Results Girls who were heavier at age seven years had menarche at an earlier age. The average age at menarche of those in the highest fifth of the distribution of weight at seven years was 7.3 months less than that of those in the lowest fifth of the distribution. In contrast, girls who were heavier at birth had menarche at a later age. The average age at menarche of those in the highest fifth of the birthweight distribution was 2.2 months more than those in the lowest fifth. These opposing trends of birthweight and weight at seven years on age at menarche were observed across the distribution of each variable, and exerted statistically significant (P < 0-001) independent effects in a multivariate model. Conclusions These observations are consistent with the hypothesis that menarcheal age is linked to programmed patterns of gonadotrophin release established in utero, when the fetal hypothalamus is imprinted, and is subsequently modified by weight gain in childhood.
Age at Menarche: Influences of Prenatal and Postnatal Growth
The Journal of Clinical Endocrinology & Metabolism, 2007
The objective of this study was to determine the influence of birth weight and postnatal weight gain on age at menarche. Design, Setting, and Participants: This was a prospective cohort study where girls from the West Australian Pregnancy (Raine) Cohort Study were followed prospectively from fetal life (18 wk of pregnancy) to adolescence (12-14 yr). Main Outcome Measure: Age at menarche was the main outcome measure. Results: Growth status at birth was judged by expected birth weight ratio (EBW; a ratio of observed infant's birth weight over median birth weight appropriate for maternal age, weight, height, parity, infant sex, and gestational age). Postnatal growth status was judged by body mass index (BMI). Both EBW (P ϭ 0.020) and BMI in childhood (8 yr of age) (P Ͻ 0.001) were associated with age at menarche. Menarche occurred earlier in girls with lower EBW and higher BMI. Conclusions: We have demonstrated for the first time that both birth weight and weight gain in childhood are associated with age at menarche. Weight gain before birth and subsequent weight gain up to the age of 8 yr were found to have opposing influences on the timing of menarche. Lower EBW combined with higher BMI during childhood predicted early age at menarche, and this relationship existed across normal birth weight and BMI ranges.
Recent decline in age at menarche: The Fels Longitudinal Study
American Journal of Human Biology, 2004
A number of recent reports suggest that the average age at menarche of US girls has declined over the past 20 years. Because the putative declines in the age at menarche are concurrent with increases in childhood body mass index (BMI), it has been suggested that these two trends may be causally linked. We examined differences in mean age of menarche in Fels Longitudinal Study girls who were born in six 10-year birth cohorts (1930s, 1940s, 1950s, 1960s, 1970s, and 1980s) and simultaneous cohort changes in mean BMI measured cross-sectionally at selected ages from 3-35 years (n ¼ 371). Girls born in the 1980s had a mean age at menarche of 12.34 years, which was $3-6 months earlier than that of girls born previously (P < 0.001). While the mean BMI values at ages 25 and 35 generally increased from the 1930s to the 1970s, the mean BMI during childhood and adolescence remained constant across the six birth cohorts. In summary, we found no evidence that the recent decline in the age at menarche in the Fels Longitudinal Study girls was reflected in concurrent increases in BMI at any point in childhood or adolescence. Conversely, girls born in the 1960s and 1970s have subsequently become heavier in young and mid-adulthood than were girls from earlier birth cohorts, without any concurrent change in the mean age at menarche over that time period. These two findings suggest that population-level shifts in BMI and the timing of menarche are largely independent, although sometimes coincident, processes.