Effect of Medroxyprogesterone Acetate on Vascular Inflammatory Markers in Postmenopausal Women Receiving Estrogen

Abstract
Background— Estrogen increases C-reactive protein (CRP) in postmenopausal women. Estrogen also decreases cell adhesion molecules, whereas elevated CRP stimulates the expression of cell adhesion molecules. Because androgens have antiinflammatory effects, androgenic progestins such as medroxyprogesterone acetate (MPA) may inhibit proinflammatory effects of estrogen. We investigated the effects of MPA on estrogen-induced changes in acute inflammatory proteins and cell adhesion molecules in postmenopausal women. Methods and Results— Postmenopausal women were treated daily with conjugated equine estrogen (CEE, 0.625 mg), CEE plus MPA 2.5 mg, or CEE plus MPA 5.0 mg for 3 months. CEE significantly increased CRP concentrations by 320.1±210.2% (PPConclusions— Concurrent MPA administration may attenuate estrogen’s proinflammatory effect. Because MPA in combination with CEE decreased cell adhesion molecule concentrations, the anti-inflammatory effect of MPA may actually be responsible for the favorable effect of estrogen-progestogen combinations on cell adhesion molecules in postmenopausal women.