Impact of the age at menarche on body composition in adulthood: results from two birth cohort studies

Abstract

BackgroundEvidence 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.MethodsIn 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).ResultsAt 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/m2, 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/m2 (95 % Confidence interval: 1.7; 2.6) to 0.26 (95 % Confidence interval: −0.08; 0.60).ConclusionsThe association between age at menarche and body composition in adulthood is strongly explained by pre-pubertal adiposity.

Age at Menarche and Cardiometabolic Health: A Sibling Analysis in the Scottish Family Health Study

“…The reference group in all analyses comprised those with an age at menarche of 12 to 13 years. There is some variation across studies in the definition of early menarche (≤10, ≤11, or ≤12 years) and late menarche (≥14, ≥15, or ≥16 years), likely influenced by the size and information available in the specific study, but our categorization is in line with commonly used cutoff values 4, 5, 6, 7, 8, 10, 11, 14, 16…”

“…Early menarche is associated with reduced insulin sensitivity and higher glucose,1, 2, 3, 4, 5, 6, 7, 8, 9 higher triglycerides and cholesterol levels,2, 6, 10 higher blood pressure,4, 5, 11, 12 and greater waist circumference and body mass index (BMI) 4, 5, 13, 14, 15. In line with these findings, there is some but less consistent evidence of an association between age at menarche and cardiovascular disease (CVD) events 12, 16, 17, 18.…”

“…Mendelian randomization studies suggest causal effects of greater childhood BMI on early timing of menarche and of earlier menarche on higher adult BMI and CVD risk,19, 20 although genetic pleiotropy may at least partially explain these findings 12. The few observational analyses that were able to adjust for childhood adiposity found that the associations of age at menarche with adult cardiometabolic health were virtually completely attenuated, suggesting that childhood adiposity is a key confounder 4, 14. However, studies from populations in which childhood obesity is less prevalent, such as Korea,5, 7, 8 Bangladesh,6 China,9 and Brazil,10 also indicate an association between early menarche and worse cardiometabolic health.…”

Birth weight and prepubertal body size predict menarcheal age in India, Peru, and Vietnam

“…We leave the investigation on the relationship between month and season at birth and age at menarche, which was also studied in the context of the Northern hemisphere, to future research. On the other hand, compared with other studies that asked adult women to retrospectively recall their age at menarche, often many years later, we anticipate that recall bias for menarcheal age in our data should be relatively lower, given the relatively short time span between the occurrence of menarche and the interview date. Hence, we conclude that the age in years reported should be relatively reliable …”

“…2,5 Consistent with this literature, we found an association between prepubertal adiposity, for which BMI is a surrogate marker, and earlier menarche. 2,5,15,40,41 The literature has also highlighted the role of prepubertal skeletal maturity, in addition to adiposity, for menarcheal timing. 5,29,42 We proxied skeletal maturity with HAZ and found that HAZ at ß8 years had strong and independent predictive power, pointing to the importance of both HAZ and BMIZ for menarcheal timing.…”