SUN-052 Effects of Cross-Sex Hormone Therapy on Lipid Metabolism in Transgender Women and Men

Sex hormone therapy in cisgender persons (i.e. postmenopausal women and hypogonadal men and women) leads to changes in lipid metabolism and weight, but it is unclear to what extent this occurs in transgender persons receiving higher doses of cross-sex hormone therapy (CSHT) for the purpose of gender transition.Objective: To determine changes in lipid metabolism among transgender women (TW) and transgender men (TM) on CSHT.Methods: We conducted a retrospective chart review of patients identified at a transgender-specific clinic within an academic medical center. Data were collected on age, ethnicity, hormone therapies, lipid lowering therapy (LLT), surgical status, lipid panel, A1C, LFTs, BMI, and weight before and after initiation of HT. Patients on stable LLT were included but those with LLT initiated after baseline observation were excluded. Changes from baseline to post CSHT in TW and TM groups were evaluated with paired t-tests.Results: We identified 18 TW and 22 TM for whom laboratory data were available. Mean±SD age of TW was 33±13 years and for TM was 28±12 years; the majority (78%) were Caucasian. Mean±SD duration of HT in TW was 10.1±4.5 months and in TM 6.7±4.4 months. No patients had undergone gonadectomy at any time prior to or during the data collection period. One TW and one TM were on stable LLT during the observation period. All TW were treated with estradiol (78% oral, 11% patch) and spironolactone. In TW, there was a significant 10% increase in HDL from 48±17 mg/dl to 53±15 mg/dl (p=0.02) but there were no significant changes in other lipid fractions, A1c, or weight/BMI. The majority of TM (82%) were treated with weekly intramuscular testosterone-esters injections and the remainder with daily testosterone gel. More substantial and unfavorable metabolic changes occurred in the TM with a 15% decrease in HDL from 55±15 mg/dl to 47±10 mg/dl (p=0.004), increase in A1c from 5.07±0.45% to 5.22 ± 0.39%(p=0.04), increase in BMI from 29±10 kg/m2 to 31±10 kg/m2 (p=0.002), and a trend toward increased triglycerides (96±64 mg/dl to 110±80 mg/dl, p=0.07). Hemoglobin and hematocrit significantly increased in TM but there was no significant change in LFT in either group. Limitations include lack of data on body composition to determine relative changes in adipose tissue or muscle mass in relation to weight changes and small sample size.Conclusion: Our study suggests that CSHT has a neutral to slightly favorable impact on lipid metabolism in TW and a negative impact on lipids and glucose in TM. Larger, prospective studies are needed to determine whether these changes persist over the longer duration of CSHT and whether this translates to an increased risk of cardiovascular disease and mortality. Clinicians should inform TM patients about these potential negative effects of CSHT on lipid metabolism so that their patients can adopt healthy lifestyle interventions early on to optimize their cardiovascular risk.