Abstract 13735: Circulating Total and Free Testosterone are Associated with Lipoprotein Phospholipase A2 Mass in Postmenopausal Women
Lipoprotein phospholipase A2 (LpPLA2), a marker of inflammation, is a risk factor for cardiovascular disease (CVD). Endogenous sex hormones and hormone therapy (HT) influence circulating lipids and potentially CVD in postmenopausal women. The association between sex hormones and HT with LpPLA2 mass and activity in postmenopausal women is unclear.
Objective: To determine the relations between circulating total (TT) and free (FT) testosterone, estradiol (E2), and estrone (E1) and LpPLA2 mass and activity in postmenopausal women in the context of HT use.
Methods: Postmenopausal women without diabetes from the Framingham Heart Study Offspring Cohort were studied (n=1229). Circulating levels of sex hormones and LpPLA2 mass and activity were compared in HT users (n=467) and non-users (n=762). Multivariable linear regression was used to assess cross-sectional associations between TT, FT, E2, E1 and LpPLA2 mass and activity adjusting for HT use. Regression models also adjusted for age, BMI, smoking, insulin resistance, hypertension, LDL, HDL, statin use, and levels of the primary sex hormone binding protein and globulin (SHBG).
Results: FT (2.1 ± 1.2 vs. 3.3 ± 1.9 pg/ml, p<0.001) and LpPLA2 mass (268 ± 84 vs. 301 ± 90 ng/ml, p<0.001) and activity (119 ± 29 vs. 136 ± 31 nmol/ml/min, p<0.001) were lower in HT users compared to non-users while E2 (29 ± 24 vs. 10 ± 13 pg/ml, p<0.001) and E1 (141 ± 109 vs. 30 ± 16 pg/ml, p<0.001) were higher in HT users. TT did not differ with HT use. In multivariable-adjusted regression models, both TT and FT, but not E2 or E1, were positively associated with LpPLA2 mass (Table 1). Adjustment for SHBG did not alter results.
Conclusion: FT and LpPLA2 mass and activity were lower in women using HT compared to non-users. Testosterone was positively associated with LpPLA2 mass in cross-sectional analysis adjusting for HT use. Further work is needed to determine if testosterone influences CVD risk through inflammatory lipoproteins in postmenopausal women.
- © 2011 by American Heart Association, Inc.