Circulating Lp-PLA2 activity correlates with oxidative stress and cytokines in overweight/obese postmenopausal women not using hormone-replacement therapy

다국어 초록 (Multilingual Abstract)

Controversy remains regarding whether there is an association between circulating lipoprotein-associated phospholipase A2 (Lp-PLA2), cytokines, and oxidative stress in healthy postmenopausal women. We investigated the influence of age on Lp-PLA2 activity in postmenopausal women not using hormone therapy, and the relationship of Lp-PLA2 enzyme activity to serum cytokine levels and oxidative stress indices. Normal weight (n=1284) and overweight/obese (n=707) postmenopausal women not using hormone therapy were categorized into five age groups: 50？54, 55？59, 60？64, 65？69, and 70？89 years. Overweight-obese women showed higher plasma Lp-PLA2 activity, urinary 8-epi-prostaglandin F2α (8-epi-PGF2α), serum interleukin (IL)-6, and smaller LDL particles than normal-weight women after adjusting for age, years post-menopause, smoking, drinking, blood pressure, glucose, insulin, lipid profiles, BMI, and waist circumference. Overweight/obese women 70？89 years old showed higher Lp-PLA2 activity than those aged 50？54 years, whereas no significant difference in Lp-PLA2 activity existed across normal-weight female age-groups Overweight/obese women aged ≥65 years showed higher Lp-PLA2, oxidized LDL (ox-LDL), IL-6, and 8-epi-PGF2α than age-matched normal-weight controls. Overweight/obese women aged ≥70 years had higher ox-LDL levels than those aged 50？59, and overweight/obese women aged 65-89 showed higher IL-6 and 8-epi-PGF2α. There were strong positive correlations between Lp-PLA2 and ox-LDL (r=0.385, P<0.001), Lp-PLA2 and IL-6 (r=0.293, P<0.001), and ox-LDL and IL-6 (r=0.303, P<0.001) in overweight/obese women; however, these relationships were weak in normal-weight women. These results demonstrate enhanced oxidative- and inflammatory mediator-associated Lp-PLA2 activity in overweight/obese postmenopausal women not using hormone therapy.