SAT-273 Association of Masculinizing Gender Affirming Hormone Therapy with Atherogenic Lipoprotein(a) Levels and Cardiovascular Events: A Retrospective Analysis

Abstract Disclosure: P. Uppal: None. V. Varadarajan: None. M.B. Karpman: None. P. Uppal: None. A. Aldamouk: None. Background: Gender-affirming hormone therapy (GAHT) is used among transgender individuals to align secondary sexual characteristics with gender identity. Lipoprotein (a) (Lp(a)) is a highly atherogenic lipoprotein, and its levels are largely genetically determined. Lower Lp(a) levels are associated with hormone replacement therapy (HRT) amongst menopausal women. On the other hand, an increase in lp(a) levels was observed after orchiectomy in elderly males with prostate carcinoma, and a decrease in lp(a) in the non-orchiectomy group on estrogen supplementation. However, there is a paucity of research on Lp(a), cardiovascular (CV) risk factors, and CV events in association with GAHT. This study aims to investigate the relationship between masculinizing GAHT and Lp(a) levels, along with CV events. Methodology: The study utilized a nationwide de-identified electronic medical records database. The dataset comprised 932 individuals with a diagnosis of transgender who had lp(a) measured and were identified using ICD and CPT codes. Lp (a) level was defined as high if greater than 50mg/dl per previous literature. Outcomes included lp(a) levels, heart failure, atrial fibrillation, and coronary artery disease (CAD). Univariate and multivariate logistic regression analyses were conducted to evaluate the association of masculinizing GAHT with the outcomes. Results: Out of 932 patients, 68 were on testosterone therapy. The mean age of the population was 57.2 years with the majority being White Americans. 279 patients had high lp(a) levels. Hypertension was present amongst 26 patients and 255 were diabetic. In univariate analysis, patients on testosterone were found to be associated with decreased odds of heart failure (OR: 0.43 (0.19,0.89), p:0.025), atrial fibrillation (OR: 0.26 (0.08,0.84), p:0.025), CAD (OR: 0.40 (0.22,0.71), p:0.02). This association was not significant when adjusted for race, gender, diabetes, hypertension, and smoking status. The logistic regression analysis did not show any association of high lp(a) levels with testosterone therapy (OR: 0.93 (0.53,1.62),p:0.81). Discussion: Our study did not show an association between masculinizing GAHT and lp(a) levels. This population differs from others previously studied because of the indication of GAHT and the biological sex of the individuals receiving the therapy. Major limitations included the completeness of the medical record system as a potential error, the low sensitivity of ICD codes, and the small sample size. Larger, prospective studies to further investigate the relationship between lp(a) levels and GAHT are warranted. Presentation: Saturday, July 12, 2025