Body Weight Changes and Exploratory Metabolic Outcomes During Semaglutide and Tirzepatide Treatment: A Real-World Longitudinal Cohort Study from Türkiye

Background/Objectives: Comparative real-world evidence on early body-weight changes during semaglutide and tirzepatide treatment remains limited, particularly in populations with unequal and irregularly timed follow-up. To compare longitudinal percentage changes in body weight between adults initiating semaglutide and those initiating tirzepatide and to describe changes in anthropometric measures, weight-loss responses, and exploratory metabolic outcomes.

Methods

This retrospective, single-center, real-world longitudinal cohort study included adults aged ≥18 years initiating semaglutide or tirzepatide for weight management, with a body mass index (BMI) ≥30 kg/m2 or ≥27 kg/m2 with a weight-related comorbidity. Patients with type 2 diabetes and concomitant obesity were eligible. Participants were naïve to incretin-based therapy; pregnancy, previous bariatric surgery, and active malignancy were exclusion criteria. Anthropometric and laboratory data were extracted from clinical records. Percentage body-weight change over days 1–230 was analyzed using a linear mixed-effects model incorporating exact follow-up time and adjusting for age, sex, baseline BMI, and diabetes status. Scheduled-visit and sensitivity analyses were also performed.