The influence of lifestyle, diet, and reproductive history on age at natural menopause in Spain: Analysis from the EPIC-Spain sub-cohort.

OBJECTIVE: To determinate the role of lifestyle factors, recent diet, menstrual factors, and reproductive history in age at natural menopause in adult Spanish women.

METHODS: In total, 12 562 pre-menopausal women were available for analysis from the EPIC-Spain sub-cohort. Women were recruited between 1992 and 1996 in five regions of Spain (Asturias, Granada, Murcia, Navarra, and San Sebastian) and, for these analyses, were followed for 3 years. Questionnaires on diet, lifestyle, anthropometric measurements, and reproductive and exogenous hormones history were collected at baseline. Menopause status was updated at a median of 3 years of follow-up.

RESULTS: After a median of 3 years of follow-up 1166 women became postmenopausal. An earlier age at menopause was observed in current smokers (HR: 1.29; 95%CI 1.08-1.55) and in non-users of oral contraceptives (HR: 1.32; 95%CI 1.01-1.57). A later age at menopause was observed in women with irregular menses (HR: 0.71; 95%CI 0.56-0.91) and in women with a higher number of pregnancies (HR: 0.74; 95%CI 0.56-0.94).

CONCLUSIONS: Our results confirm that women who smoked had an earlier age at natural menopause, while use of oral contraceptives, higher number of pregnancies, and irregularity of menses were associated with a prolonged reproductive lifespan. No associations were observed for dietary habits assessed after the age of 40 years.