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 Results 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. 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.