Aim: Menopause is considered a cardiovascular risk factor (CRF), but age at menopause (AAM) varies considerably and could affect the risk among post-menopausal women. The aim of the study was to clarify whether AAM is associated with hypertension, diabetes mellitus (DM) and hypercholesterolemia, independent of chronological age, lifestyle and hormone replacement therapy (HRT), in a sizeable number of Japanese women.
Methods: A retrospective study was conducted using the baseline survey of the ongoing large prospective Japan Nurses' Health Study. The prevalence of hypertension, DM, and hypercholesterolemia of pre-menopausal and three post-menopausal AAM groups (early: <45 years, intermediate: 45-53 years, late: >53 years) was compared among 22,426 women aged 40-59 years. Daily lifestyle such as smoking, alcohol consumption, and physical activity were included.
Results: The estimated risk (odds ratio: OR) was significantly higher in post-menopausal women and linearly elevated according to the AAM groups, and the late AAM group was more likely to have hypertension, DM, or hypercholesterolemia; however, after adjustment for age, BMI (kg/m(2)), HRT and lifestyle, menopause and AAM showed a significant association with only hypercholesterolemia and the early AAM group had the highest OR (2.72 (1.93-3.82)). Menopause and AAM did not show any independent association with the risk of hypertension and DM in the fully adjusted model.
Conclusions: Among the post-menopausal women, early menopause increased the risk for hypercholesterolemia independently. AAM can be a useful screening tool to identify women at high risk for adverse post-menopausal lipid profiles in the Japanese.