Update on Age at Menarche in Italy: Toward the Leveling Off of the Secular Trend
Received 14 May 2009; accepted 31 July 2009. published online 13 October 2009. Corrected Proof
Abstract
Purpose
To update the information on age at menarche in the Italian population and to verify the influence of genetic, nutritional, and socioeconomic factors on menarcheal age. Recent studies suggest that the magnitude of the secular trend toward an earlier age at menarche is slackening in industrialized countries.
Methods
This multicenter study was conducted on a large, population-based sample of Italian high school girls (n = 3,783), using a self-administered questionnaire. The questionnaire was used to gather information on the girls, including demography, anthropometry, menarcheal date, regularity of menses, behavioral habits, and physical activity. The questionnaire was also used to gather information on parents, including demography and mothers' and sisters' menarcheal ages. The median age at menarche and its 95% confidence interval were estimated by means of Kaplan-Meier survival analysis. To identify the independent predictive factors of age at menarche, multivariate mixed-effects models were applied.
Results
The median age at menarche of the subjects was 12.4 years (95% confidence interval: 12.34–12.46). The girls had their first menses approximately one-quarter of a year (median–0.13) earlier than did their mothers (p < .0001). Among all variables, parents' birth area, body mass index, family size, and the mother's menarcheal age were significantly and independently associated with age at menarche.
Conclusions
This study confirmed the reduction in the trend toward earlier menarche in Italy. The results also confirmed that genetic and nutritional factors are strong markers for early menarche. Currently, socioeconomic factors do not seem to play as significant a role as in the past.
kDepartment of Pediatrics, University of Verona, Verona, Italy
lCentre of Pediatric Diabetology, Burlo Garofolo Hospital, Trieste, Italy
mDepartment of Environmental Medicine and Public Health, University of Padova, Padova, Italy
Address correspondence to: Egle Perissinotto, Sc.D., Department of Environmental Medicine and Public Health of University of Padua, Via Loredan, 18, 35128 Padua, Italy.
ABSTRACT