Genetic and environmental correlations between obesity phenotypes and age at menarche

Abstract

Objective: To assess the extent that the genetic and environmental factors contribute to the phenotypic correlations between obesity traits and age at menarche (AAM), and also to examine the influence of AAM on obesity in both pre-and postmenopausal women. Methods: Five hundred and twelve pedigrees with 2667 Caucasian female subjects from two to four generations were recruited. Fat mass and lean mass (both in kg) were measured by dual-energy X-ray absorptiometry scanner. Body mass index (BMI) (kg/m 2 ) was calculated. We performed bivariate quantitative genetic analyses in the total sample containing 2667 Caucasian women. We also selected 206 unrelated premenopausal women and 140 unrelated postmenopausal women from the total sample, and computed the respective phenotypic correlation between obesity and AAM in these two subgroups. Results: For fat mass, lean mass and BMI, we detected their significant negative genetic correlations with AAM after adjustment for significant covariates, which were À0.3170 (Po0.001), À0.1721 (Po0.05) and À0.3665 (Po0.001), respectively. However, their environmental correlations with AAM were all nonsignificant (P40.05), ranging from À0.0016 to 0.0192. In the premenopausal subgroup, significant associations were observed between fat mass and AAM (r ¼ À0.231, Po0.01) as well as between BMI and AAM (r ¼ À0.257, Po0.01). In the postmenopausal subgroup, no such associations were observed. Conclusion: Our results for the first time suggested that significant phenotypic association between obesity phenotypes and AAM is mainly attributable to shared genetic rather than environmental factors, and AAM may have stronger effects on obesity phenotypes in pre-than in postmenopausal women.

Body Mass Index Influences the Age at Menarche and Duration of Menstrual Cycle

“…These mean values were similar to those observed in other studies conducted in the same geographical location as ours [6], and even other countries [4,20], but dissimilar to that observed among school girls in the Northern region of the same country as ours [5]. These disparities could be attributed to several factors such as genetic [30], environmental, socioeconomic, nutritional and hormonal factors [31][32][33]. "Children and adolescents differ in their rate of development, and adolescents of the same chronological age may differ greatly in their stage of maturity" [34].…”

Update on Age at Menarche in Italy: Toward the Leveling Off of the Secular Trend

“…Covariates were fixed effects and cities were random effects. [1,10,15,27,36,37], and it confirms the role of genetic components, even after the geographical migration of parents.…”

“…including socioeconomic status [5][6][7][8][9][10] and family size [4,11,12], are also thought to influence the onset of puberty. Nevertheless, the causative model has not yet been fully elucidated.…”

Is Obesity at Individual and National Level Associated With Lower Age at Menarche? Evidence From 34 Countries in the Health Behaviour in School-aged Children Study

“…Although our article presents good evidence for the pathway described, other research indicates that early puberty is a cause of later obesity rather than an outcome of early childhood obesity [32]. It has also been argued that common genes explain the association between overweight and early menarche [33]. Our research cannot rule out this latter explanation, and further research is required among the adolescent population to ascertain the relative contribution of genetic and environmental factors.…”