Invited Commentary: Women's Reproductive Life Spans and Subsequent Inflammatory Profiles-How to Best Measure Reproductive Life Span and the Need for Baseline Assessments.

Inflammatory processes are known to drive the pathogenesis of several chronic diseases, including cardiovascular disease and Alzheimer disease, as well as all-cause mortality. Emerging research indicates that women who have a longer reproductive life span-roughly determined as the period from menarche to menopause or lifetime number of ovulatory cycles after accounting for anovulatory time spans-are at lower risk for these inflammation-related chronic diseases. The paradox is that ovulation is known to induce acute inflammation. Given the limited research assessing the relationship between reproductive life span and later inflammatory profiles, Huang et al. (Am J Epidemiol. 2020;189(7):660-670) set out to investigate this relationship within 2 of the most robust longitudinal cohort studies of women, the Nurses' Health studies. They found that after adjustment for other inflammation-related factors, including adiposity, exercise, and diet, lifetime ovulatory years was associated with lower C-reactive protein levels in both premenopausal and postmenopausal women. Huang et al. call attention to several challenges in research on women's reproductive life spans, including how to appropriately capture lifetime ovulatory cycles and the need for repeated measurements of inflammatory biomarkers across the life course if we wish to understand pathogenic processes linking reproductive factors to subsequent chronic disease.