Determinants of age at menarche and time to menstrual cycle regularity in the French E3N cohort.
OBJECTIVE
Early menarche has been associated with a greater risk of several major chronic diseases. Although largely genetically determined, age at menarche also has been related to environmental and lifestyle factors.


METHODS
Using linear regression models, we explored simultaneously several pre- and postnatal factors as potential determinants of age at menarche and time to menstrual cycle regularity in 96,493 women participating, since 1990, in the French E3N prospective cohort.


RESULTS
Younger age at recruitment, greater father's income index, urban birth place, greater birth length, and larger body silhouette during childhood were associated with an earlier age at menarche (from -1.3 to -4.6 months, P(trend) < .0001) whereas greater family size, food deprivation during childhood, and greater birth weight resulted in a delayed menarche (from +1.5 months to +5.3 months, P(trend) < .0001). Father's income index, urban birth place, and prematurity predicted a shorter time to menstrual cycle regularity (from -1.1 to -1.9 months, P(trend) < .04), whereas birth cohort, larger body silhouette at menarche, and childhood exposure to passive smoking were associated with a longer time to menstrual cycle regularity (from +1.1 months to +8.6 months, P(trend) < .006).


CONCLUSIONS
Age at menarche and menstrual cycle regularity are significantly influenced by several individual, environmental and lifestyle factors.
Inserm U1018, Centre for Research in Epidemiology and Population Health (CESP), Nutrition, Hormones and Women's Health Team, Institut Gustave Roussy, F-94805, Villejuif, France.
Laure
L
Dossus
Marina
M
Kvaskoff
Anne
A
Bijon
Béatrice
B
Fervers
Marie-Christine
MC
Boutron-Ruault
Sylvie
S
Mesrine
Françoise
F
Clavel-Chapelon
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D005602:France; D006801:Humans; D008019:Life Style; D016014:Linear Models; D008572:Menarche; D008597:Menstrual Cycle; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D057566:Self Report; D012931:Social Environment; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D013997:Time Factors; D055815:Young Adult