Poster Presentation Australian and New Zealand Obesity Society Annual Scientific Conference 2026

Impact of hospital-funded Tirzepatide on pathology outcomes in adults with BMI >55 kg/m² (#115)

Marjy Grealish 1 2 , Sarah Hirst 3 , Kathy Grudzinskas 1 , Mohammed Monjur 1 , Kate McBride 3 , Nick Kormas 1 , Milan Piya 1 2 3
  1. South Western Syndey Metabolic Rehabilitation and Bariatric Program , Camden, NSW, Australia
  2. School of Medicine, Western Sydney University , NSW, Australia
  3. Translational Health Research Institute, Western Sydney University, NSW, Australia

Background: Patients with severe obesity and related complications carry the greatest disease burden of obesity yet remain underrepresented in clinical trials of newer incretin-based therapies. This study assessed the impact of hospital funded Tirzepatide, a dual GLP1/GIP receptor agonist, on biomarkers in adults with severe obesity (BMI >55 kg/m2) attending a tertiary multidisciplinary metabolic program over 6-9 months.

Methods: A retrospective study assessed 27 patients (baseline BMI >55kg/m2) attending a tertiary multidisciplinary outpatient metabolic program commenced on hospital funded Tirzepatide for weight management. Demographics, full blood count, electrolytes, liver function, HbA1c, iron studies, serum folate and vitamin B12 were recorded at baseline and repeated after 6-9 months. Change from baseline was analysed using Wilcoxon signed-rank tests.

Results: Of 27 patients, 60.7% were female, with mean age 43.1±11.9 years, and 30% (n=8) had type 2 diabetes. Baseline weight was 184.5±33.1kg with BMI 63.3±6.8kg/m². Mean weight loss was 16.6±11.2kg (-8.9%) at 6 months (n=21), and 18.2±12.7kg (-10.0%) at 9 months (n=16). Reductions were seen in HbA1c (−0.36±0.42%, p=0.0011), alkaline phosphatase (ALP) (−7.2±8.4 U/L, p=0.0006) and gamma-glutamyl transferase (GGT) (−5.5±8.5 U/L, p=0.0077), whilst the transaminases did not change significantly. Triglycerides reduced (−0.26±0.5 mmol/L, p=0.022), whilst average rose modestly from 77.5 to 83.6umol/L (p=0.0007). Iron studies, folate, vitamin B12, electrolytes, full blood count and cholesterol subtypes did not change significantly at 6-9 months.

Conclusion: In a real-world cohort of patients with severe complex obesity and BMI >55kg/m2, hospital funded Tirzepatide use was associated with significant weight loss and an early improvement in glycaemic control, hepatic enzymes and triglycerides by 6-9 months, without adversely affecting nutritional or haematological parameters. These findings provide reassuring, though preliminary evidence that Tirzepatide use is safe and effective in patients with severe and complex obesity, supporting their broader use in this underrepresented population.