The Relation between Systemic Inflammation and the Menopause Transition: The Study of Women's Health Across the Nation

Abstract

Objective: The menopause transition (MT) may substantially contribute to increased systemic inflammation in later life, regardless of aging. We characterized inflammation trajectories over the MT and determined their associations with premenopausal obesity and race/ethnicity.

Methods: Data comprising 15 follow-up visits from SWAN participants who had a known date of their final menstrual period (FMP) and at least three measures of high-sensitivity C-reactive protein (hs-CRP) (n=1470) or interleukin 6 (IL-6) (n=779) were evaluated using group-based trajectory modeling and piecewise linear mixed-effects models.

Results: Based on 21 years of follow-up spanning the MT, we identified three trajectory groups for each inflammatory biomarker: 1) Low-Rise (hs-CRP=27.2%; IL-6=36.0%); 2) Medium-Stable (hs-CRP=41.9%) or Medium-Rise (IL-6=45.2%); and 3) High-Decline (hs-CRP=30.9%) or High-Stable (IL-6=18.8%). The Low-Rise for both hs-CRP and IL-6 and the Medium-Rise for IL-6 trajectories showed significant increases as early as 1 year before to as late as 3 years after the FMP. The other trajectories showed either no change, or a decline around the FMP. Chinese and/or Japanese women were more likely to follow the Low-Rise hs-CRP and IL-6 trajectories, while Black women were more likely to follow the High-Decline hs-CRP and High-Stable IL-6 trajectories. Being overweight or obese was associated with the High-Decline hs-CRP and High-Stable IL-6 trajectories.

Conclusions: Midlife women experience distinct patterns of change in hs-CRP and IL-6 over the MT. Subgroups entering the MT with low-to-medium inflammation levels, particularly for IL-6, showed rises close to the FMP, supporting a contribution of menopause in progression of systemic inflammation.

Keywords: Inflammation; c-reactive protein; menopause; trajectory; women.