SAT-259 - Lipid Changes During Testosterone Therapy in Transmasculine (TM) Individuals Differ by Care Setting: A Comparison of an Uninsured Safety-Net Cohort and a Tertiary Center Specialty Clinic

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Testosterone therapy (TT) in TM individuals is associated with increases in LDL and triglycerides and decreases in HDL. Most existing studies come from insured specialty clinic populations, which may not reflect the experiences of uninsured/low-income individuals facing barriers to care. These differences may influence cardiometabolic risk and longitudinal responses to TT. Here, we compare lipid profiles between an uninsured, low-income cohort (THRIVE) and a specialty clinic cohort (TISCC) to better understand how structural context may shape cardiometabolic outcomes.

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We analyzed longitudinal data from two TM cohorts receiving TT: the THRIVE cohort, recruited from a safety-net clinic serving uninsured, low-income patients, and the TISCC cohort, derived from the Mayo Clinic Transgender and Intersex Specialty Care Clinic database. Data from retrospective chart review included demographics, BMI, testosterone levels, and lipid parameters at baseline and follow-up through 3 years. Baseline characteristics were compared descriptively, and within-cohort longitudinal changes used linear mixed-effects models with categorical time and random intercepts, adjusted for BMI and separately for testosterone.

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The THRIVE cohort included 124 TM individuals and TISCC included 42 (mean age 29.8 ± 6.2 years, BMI 29.7 ± 10.0 vs. 30.4 ± 7.2 kg/m²). At baseline, TISCC had higher total cholesterol (179.3 ± 36.7 vs. 160.8 ± 29.5 mg/dL) and LDL (107.7 ± 32.4 vs. 88.2 ± 28.4 mg/dL); HDL and triglycerides were similar.

In THRIVE, total cholesterol initially decreased at 3 months (β = -15.25, p < 0.001) and 18 months (β = -11.61, p = 0.003) before rising above baseline by 3 years (β = 16.63, p < 0.001). LDL and triglycerides similarly increased by 3 years (β = 14.47, p = 0.002 and β = 29.90, p = 0.016, respectively). HDL decreased early and remained lower through 2 years. In TISCC, triglycerides increased earlier, at 3 months (β = 44.52, p = 0.036) and 1 year (β = 48.76, p = 0.012), while total cholesterol and LDL increases emerged by 3 years (β = 42.81, p = 0.002 and β = 33.63, p = 0.002, respectively). HDL did not show significant changes in TISCC.

BMI was positively associated with triglycerides in both cohorts and inversely associated with HDL in THRIVE. Adding testosterone did not change these patterns or yield significant lipid associations.

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TM individuals in THRIVE had lower baseline total cholesterol and LDL than those in TISCC, but both cohorts showed unfavorable shifts in LDL and triglycerides over 3 years of TT. TISCC demonstrated earlier triglyceride increases, while THRIVE showed a delayed but significant rise in LDL and triglycerides by 3 years. These patterns held after adjustment for BMI and testosterone, suggesting broader structural factors drove these differences. These findings support proactive lipid monitoring across care settings and inclusion of underserved populations in outcomes research.

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