Lower adherence to a prudent dietary pattern is associated with earlier age at menarche in adolescents from the Growth and Obesity Chilean Cohort Study.

Introduction: Early menarche is associated with obesity, and metabolic and mental health risks, among other diseases. Thus, it is relevant to identify modifiable risk factors of early menarche. Some nutrients and foods have been linked to pubertal timing, but how menarche relates to overall dietary patterns is unclear. Methods: The aim of this study was to analyze the association between dietary patterns and age at menarche in a prospective cohort of Chilean girls from low and middle-income families. We conducted a survival analysis of 215 girls (median = 12.7 years, IQR = 12.2-13.2) from the Growth and Obesity Cohort Study (GOCS) who had been followed prospectively since 4 years of age (2006). Age at menarche and anthropometric measurements were recorded every 6 months since 7 years of age while diet (24-hour dietary recall) was collected for 11 years. Dietary patterns were obtained from exploratory factor analysis. Accelerated Failure Time models adjusted for potential confounding variables were used to study the association between dietary patterns and age at menarche. Results: Girls' median age at menarche was 12.7 years. Three dietary patterns were identified: "Breakfast/Light Dinner," "Prudent" and "Snacking" which explained 19.5% of the diet variation. Girls in the lowest tertile of the "Prudent" pattern had menarche 3 months earlier than girls in the highest tertile (ß: 0.022; 95% CI: 0.003; 0.041). "Breakfast/Light Dinner" and "Snacking" patterns were not associated with age at menarche. Conclusion: Our results suggest that healthier dietary patterns during puberty might be associated with menarche timing. Nevertheless, further studies are required to confirm this result and to clarify the association between diet and puberty.

Effect of age at menarche on the mother's weight status two and four years after delivery: a cohort study.

We aimed to estimate the effect of age at menarche on the risk of excess body weight in Brazilian women two and four years after delivery. This was a cohort study that used data from adult women of the Predictors of Maternal and Child Excess Body Weight (PREDI) Study obtained at baseline (2012) and at 1st(2014) and 2nd(2016) follow-up. A total of 435 women attending a public maternity hospital in Joinville-Brazil were initially included in the study (baseline) and 215 of them continued to participate in the 2nd follow-up carried out in the homes of the participants. Regression analysis was used to estimate the association between age at menarche (<12; ≥12 years) and excess body weight (≥25 kg/m2) trajectory during the follow-ups. Unadjusted analysis showed that mothers with age at menarche <12 years were 1.29 times (p = .018) more likely to be overweight/obese than those with age at menarche ≥12 years. After adjustment, age at menarche continued to exert an independent effect on the mother's body mass index (RR = 1.23; p = .037) four years after delivery. Strategies designed to attenuate the rising prevalence of maternal overweight and obesity, especially after pregnancy, could help improve the mother's health status in the future.

Early lead exposure and pubertal development in a Mexico City population.

BACKGROUND: Previous studies have examined the association between blood lead levels and pubertal timing in adolescent girls; however, the evidence is lacking on the role of lead exposure during sensitive developmental periods on sexual maturation. OBJECTIVES: To examine the association of prenatal and early childhood lead exposure with pubertal stages among 264 boys and 283 girls aged 9.8-18.0 years in Mexico City. METHODS: We measured maternal bone lead (a proxy for cumulative fetal exposure to lead from maternal bone stores mobilized during pregnancy) at 1 month postpartum. Blood lead was measured annually from 1 to 4 years. Pubertal stage was assessed by a pediatrician. We examined the association between lead and pubertal stages of breast, pubic hair and genitalia using ordinal regression. Age at menarche was evaluated using Cox proportional-hazard models. RESULTS: Multivariate models showed that maternal patella lead and early childhood blood lead were inversely associated with breast growth (patella OR = 0.72, 95% CI: 0.51-1.00; blood OR = 0.70, 95% CI: 0.53-0.93) in girls. Girls with maternal patella lead in the 3rd tertile and child blood lead in the 2nd tertile had a later age at menarche compared with girls in the 1st tertile (patella HR = 0.60, 95% CI: 0.41-0.88; blood HR = 0.65, 95% CI 0.46-0.91). Additionally, early childhood blood lead was negatively associated with pubic hair growth (OR = 0.68, 95% CI: 0.51-0.90) in girls. No associations were found in boys. CONCLUSIONS: These data suggest that higher prenatal and early childhood exposure to lead may be associated with delayed pubertal development in girls but not boys. Our findings are consistent with previous analyses and reinforce the reproductive effects of lead for girls.

Comparison of Measurements of Bone Mineral Density in Young and Middle-Aged Adult Women in Relation to Dietary, Anthropometric and Reproductive Variables.

The objective of this study was to compare current measurements of bone mineral density (BMD) of the lumbar spine (LS), femoral neck (FN), and total femur (TF) regions with initial values recorded 12 years ago in women from Northwest Mexico, and evaluate their correlation with dietary, anthropometric, and reproductive variables. BMD was assessed by Dual-energy X-ray absorptiometry. Participants were grouped as follows: Nulliparous (G1); women who were mothers 12 years ago (G2); and women who were nulliparous 12 years ago, but are now mothers (G3). In all three groups, current LS BMD was higher than initial (p ≤ 0.05) and current TF BMD in G2 was higher than initial values (p ≤ 0.05). When comparing current FN and TF BMD among the three groups, G2 had higher values than G3 (p ≤ 0.05). G2 also showed higher LS BMD than G1 and G3 (p = 0.006). Age at menarche was inversely-correlated with FN and TF BMD in G1 (p < 0.01), while the body mass index (BMI) correlated positively with all three bone regions in G2 (p < 0.05). This study shows that in women without and with children, age at menarche, BMI, and age were factors associated to BMD in healthy subjects in reproductive age.

Applicability of a novel mathematical model for the prediction of adult height and age at menarche in girls with idiopathic central precocious puberty

OBJECTIVES: Unfavorable predicted adult height and psychosocial inadequacy represent parameters used to guide therapeutic intervention in girls with central precocious puberty. Gonadotropin-releasing hormone analog is the first-line treatment. The aim of this study was to compare two methods used to predict adult height and assess a validated tool for predicting the age at menarche in girls with central precocious puberty. METHODS: The predicted adult height of 48 girls with central precocious puberty was calculated at diagnosis using the Bayley-Pinneau method based on average and advanced bone age tables and compared with the predicted adult height calculated using a mathematical model. In addition, the age at spontaneous menarche was predicted using the new formulae. After Gonadotropin-releasing hormone analog treatment, the predicted adult height was calculated using only the Bayley-Pinneau tables. RESULTS: The achieved adult height was within the target height range in all treated girls with central precocious puberty. At diagnosis, the predicted adult height using the Bayley-Pinneau tables was lower than that using the mathematical model. After the Gonadotropin-releasing hormone analog treatment, the predicted adult height using the Bayley-Pinneau method with the average bone age tables was the closest to the achieved adult height. Using the formulae, the predicted age at spontaneous menarche was 10.1±0.5 yr. The Gonadotropin-releasing hormone analog treatment significantly postponed this event until 11.9±0.7 yr in these "idiopathic" central precocious puberty girls, highlighting the beneficial effect of this treatment. CONCLUSION: Both initial adult height prediction methods are limited and must be used with caution. The prediction of the age at spontaneous menarche represents an innovative tool that can help in clinical decisions regarding pubertal suppression.

Dairy intake in relation to breast and pubertal development in Chilean girls.

Background: Frequent dairy consumption in childhood has been related to higher growth-hormone concentrations that may affect mammary gland and pubertal development.Objective: We evaluated the relation of dairy intake to breast composition at Tanner stage 4 and age at menarche.Design: A total of 515 Chilean girls are included in the Growth and Obesity Cohort Study. The subjects have been followed longitudinally since they were 3-4 y old (from 2006 to the present). Starting in 2013, diet was assessed every 6 mo via a 24-h recall. The breast fibroglandular volume (FGV) was measured with the use of dual-energy X-ray absorptiometry at Tanner stage 4. The date of menarche was reported every 6 mo. Our analysis included 290 girls with data on prospective diet and breast composition and 324 girls with data on prospective diet and age at menarche.Results: The mean ± SD breast FGV and percentage of fibroglandular volume (%FGV) (i.e., FGV divided by total breast volume times 100) at Tanner stage 4 was 81.7 ± 32.2 cm3 and 42.0% ± 16.7%, respectively. Only sweetened, artificially flavored milk-based drinks were associated with the %FGV with girls who consumed >125 g/d having a %FGV that was 4.5% (95% CI: 0.9%, 8.1%) higher than that of girls who consumed none (P-trend = 0.007). Yogurt intake was associated with a lower FGV. Specifically, girls who consumed >125 g yogurt/d had -10.2 cm3 (95% CI: -20.2, -0.3 cm3) less FGV than did girls who consumed no yogurt (P-trend = 0.03). The majority (90.7%) of girls in our cohort attained menarche before the data analyses with a mean ± SD age at menarche of 11.9 ± 0.7 y. In multivariable models, low-fat dairy, low-fat milk, and yogurt intakes were associated with a later age at menarche. In particular, girls who consumed >125 g yogurt/d had menarche, on average, 4.6 mo (95% CI: 1.9, 7.4 mo) later than girls who consumed no yogurt (P-trend = 0.01).Conclusion: More-frequent consumption of sweetened, artificially-flavored milk-based drinks is associated with a higher %FGV, whereas higher yogurt intake is associated with a lower FGV and delayed age at menarche in Chilean girls.

Childhood abuse and early menarche among Peruvian women.

PURPOSE: Childhood abuse has been associated with age of menarche in some studies, but not all, and few have assessed the independent associations of sexual and physical abuse with early menarche. We examined the association between childhood abuse and early menarche among pregnant women in Lima, Peru. METHODS: Multinomial logistic regression procedures were used to estimate odds ratios (OR) and 95% confidence intervals (CIs) for early menarche (≤11 years) in relation to any physical or sexual childhood abuse, physical abuse only, sexual abuse only, and both physical and sexual abuse in a cohort of 1,499 pregnant (first trimester) women. RESULTS: Approximately 69% of participants reported experiencing physical or sexual abuse in childhood. The frequencies of physical abuse only, sexual abuse only, and both physical and sexual abuse were 37.4%, 7.7%, and 24.5%, respectively. Compared with women who reported no childhood abuse, those who reported any childhood abuse had a 1.38-fold increased odds of early menarche (95% CI, 1.01-1.87). Compared with no abuse, the odds of early menarche was 1.60-fold among women with childhood sexual abuse only (OR, 1.60; 95% CI, .93-2.74) and 1.56-fold for those with both physical and sexual abuse (OR, 1.56; 95% CI, 1.07-2.25) during childhood. Isolated physical abuse was weakly associated with early menarche (OR, 1.23; 95% CI, .87-1.74). There was no clear evidence of association of childhood abuse with late menarche (≥15 years). CONCLUSIONS: Childhood abuse, particularly joint physical and sexual abuse, is associated with early menarche. Our findings add to an expanding body of studies documenting the enduring adverse health consequences of childhood abuse.

Early age at menarche: a risk factor for overweight or obesity in patients with type 1 diabetes living in urban areas?

AIMS: Determine the relationship between age at menarche, glycemic control and cardiovascular risk factors in patients with type 1 diabetes living in urban areas. METHODS: This was a multicenter cross-sectional study conducted in 20 cities in four Brazilian geographic regions. Data were obtained from 1527 female patients, 59.3% Caucasians, aged 25.1 ± 10.6 years. Diabetes duration was 11.4 ± 8.1 years. Age at menarche was stratified in four groups: 8-11 (group 1, early menarche), 12 (group 2), 13 (group 3) and 14-18 years (group 4, late menarche). RESULTS: The mean age at menarche was 12.7 ± 1.7 years without difference among geographical regions, economic status, level of care and ethnicity. BMI had an inverse correlation with age at menarche (r=-0.14, p<0.001). No significant difference was observed among the four groups for blood pressure, lipid profile and diabetes-related chronic complications. Logistic regression analysis showed that early age at menarche, 8-11 years (odds ratio (ORs) 1.77 [1.30-2.41], p<0.001) and duration of diabetes [ORs 1.01 (1.00-1.03), p=0.02], were related to greater risk of patients' overweight or obesity; adherence to diet [ORs 0.78 (0.60-0.93), p=0.01], physical activity [ORs 0.75 (0.94-0.94), p=0.01], and lower insulin dose (U/kg) [ORs 0.54 (0.59-0.90), p=0.001] were related to lower risk for overweight or obesity. CONCLUSIONS: Early menarche occurred in 23.4% of women with type 1 diabetes living in Brazilian urban areas and was strongly associated with overweight/obesity in pubertal/adult life. Further studies are warranted to establish the relationship between early menarche, glycemic control and cardiovascular risk factors.

The monthly rhythm of incidence and age at menarche: thirty five years of research: The circa-vacation-study expectancy rhythm of incidence and age at menarche

The hypothesis that the vacation-study-expectancy scholar regime produces most of the monthly rhythm of the age at menarche (AaM) was tested. Studies on monthly menarche incidence (MI) refuted climatic factors as a main factor in this rhythm, and indicated that the main factor of this rhythm is the succession of expectancies of study (Stu-months) or vacation (Vac-months) months within a year. Thus the hypothesis of seasonal circa-annual rhythm should be modified to the circa-[vacation (fiesta)]-[study (non-fiesta)]-expectancies rhythm for the MI and age at menarche annual rhythms. In several countries Vac-months had higher MI than Stu-months. The high MI of Vac-months was followed by a large decrease when girls started their studies and a MI increase occurred as vacations approached. The hypothesis proposes that at the end of vacations and at the beginning of the study period the AaM should be lowest, and then the mean of AaM should increase because of the menarche delay of girls whose menarche was arrested by the initiation of school work. This pattern was found in four independent samples, from Chile, Colombia, USA and Brazil. The probability that this result be due to random fluctuation of means is extraordinarily low (P<10-8). I conclude that the influence of the expectancy of vacation and study periods on the monthly rhythm of the age at menarche is a real process that accounts for most of this rhythm.