Lowering the age at menarche and risk of early menarche in a population of Spanish postmenopausal women during the past two decades.
OBJECTIVE
The purpose of this study is to confirm in our population the decreasing secular trend in the age of menarche (AAM) observed in other European countries. Another aim is to investigate the association between early menarche and breast cancer, metabolic disorders risk or early menopause.


METHODS
We conducted a nationwide population-based study of 1980 Caucasoid Spanish postmenopausal women from 2003 to 2006 to investigate the AAM, the duration of the fertile period and the relation of early menarche with breast cancer and some metabolic disorders.


RESULTS
Regression analysis of AAM demonstrates a trend towards the younger AAM in our population during the past decades (P > 0.001). Parallel to this decrease we observe a significant increase in the fertility period and the height of our population (P < 0.001). In the women with AAM less than 11 years, there is an increased risk of hypercholesterolaemia, being overweight and obesity. However, early menarche does not raise the risk of adult onset diabetes, hypertension or breast cancer.


CONCLUSIONS
These data indicate a decreasing secular trend of AAM in a Spanish population in the last decades. Furthermore, hypercholesterolaemia and obesity, but not breast cancer, appears to be influenced by younger AAM. Only women who have their menarche at the age of nine years or less are more likely to have an earlier menopause.
Mendoza
Nicolás
N
Department of Obstetrics and Gynaecology, University of Granada, Maestro Montero 21, Granada, Spain. nicomendoza@telefonica.net
Galliano
Daniela
D
Salamanca
Alberto
A
Castro
Juan Eloy Ruiz
JE
Mozas
Juan
J
Sánchez-Borrego
Rafael
R
Quereda
Francisco
F
Vázquez
Francisco
F
Martínez-Astorquiza
Txantón
T
D000328:Adult; D000367:Age Factors; D000368:Aged; D001827:Body Height; D001943:Breast Neoplasms / Q000453:epidemiology*; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D005298:Fertility; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology*; D006973:Hypertension / Q000453:epidemiology*; D008572:Menarche / Q000502:physiology*; D008875:Middle Aged; D050177:Overweight / Q000453:epidemiology; D017698:Postmenopause / Q000523:psychology*; D012189:Retrospective Studies; D012306:Risk; D013030:Spain / Q000453:epidemiology; D044465:White People