Body Composition Changes With Standard Versus Low-Dose Tirzepatide Titration in Women With Lipedema: A Retrospective Observational Study

Purpose: This study aimed to compare 12-week changes in body composition and anthropometric parameters between standard-dose and lower-dose tirzepatide escalation regimens in women with lipedema, with particular emphasis on changes in fat mass and skeletal muscle mass.Patients and methods: This retrospective observational study included 100 women with lipedema receiving tirzepatide during routine clinical care.Participants were classified into lower-dose (n = 50) and standarddose (n = 50) groups according to their prescribed dosing regimens, which differed in cumulative drug exposure.Body composition, anthropometric measurements, and skinfold thickness were assessed at baseline and after 12 weeks.An exploratory composite responder criterion was defined as a ≥5% reduction in fat mass combined with a <5% reduction in skeletal muscle mass, as estimated by bioelectrical impedance analysis (BIA).Between-group comparisons were unadjusted.Results: Both regimens were associated with reductions in body weight, fat mass, and body fat percentage (all within-group p < 0.001).No statistically significant between-group differences were detected in these changes.The lower-dose regimen was associated with a smaller reduction in BIA-estimated skeletal muscle mass than the standard-dose regimen (-0.7 vs. -2.0kg; p < 0.001).The exploratory composite responder criterion was met by 68% (34/50) of participants in the lower-dose group and 22% (11/50) in the standarddose group (OR = 7.53; 95% CI: 3.08-18.44;p < 0.001).No statistically significant between-group differences were detected in anthropometric measurements or skinfold thickness changes.Conclusion: Both tirzepatide dosing regimens were associated with reductions in body weight and adiposity in women with lipedema.The lower-dose regimen was associated with a smaller reduction in BIA-estimated skeletal muscle mass and a higher proportion of participants meeting the exploratory composite responder criterion.These findings require confirmation in prospective controlled studies, given the non-randomized design, differences in cumulative drug exposure, and potential residual confounding.