Tirzepatide versus liraglutide effects on bone and body composition in severe obesity.
Official title: Comparative Investigation of Changes in Body Composition and Bone Turnover Markers in People With Obesity After Treatment With Tirzepatide Versus Liraglutide. A Prospective Cohort Study.
Run by National and Kapodistrian University of Athens · NCT07094568 · Data updated 2026-11-12
This study will test whether tirzepatide or liraglutide lead to different changes in bone health and body composition in adults aged 30–65 with severe obesity (BMI ≥40).
Quick facts
| Study type | Observational |
|---|---|
| Ages | 30 Years to 65 Years |
| Sex | All |
| Enrollment | 72 (estimated) |
| Sponsor | National and Kapodistrian University of Athens Academic / other |
| Drugs / interventions | methotrexate |
| Locations | 1 site (Athens, Attica) |
| Status | Recruiting |
| Started | May 23, 2025 |
| Main results expected | December 30, 2026 |
| Study ends | December 30, 2026 |
| Registry record updated | January 21, 2026 |
| Trial ID | NCT07094568 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates are adults 30–65 years old with class 3 obesity (BMI ≥40 kg/m²) who do not have diabetes, recent fractures, metabolic bone disease, prior bariatric surgery, significant organ failure, or use medications that affect bone metabolism.
✕Probably not a fit
Patients with type 1 or type 2 diabetes, prior intestinal bypass/bariatric surgery, active malignancy, uncontrolled thyroid or parathyroid disease, recent fractures, rare metabolic bone diseases, or on medications that alter bone markers are unlikely to benefit from participation.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This is a prospective cohort of adults aged 30–65 with class 3 obesity (BMI ≥40 kg/m²) followed for six months with assessments at baseline, 3 months, and 6 months. The primary outcome is change in the bone resorption marker CTX at 3 months, and secondary outcomes include body weight, BMI, bone mineral density, and detailed body composition measures. Investigators will compare outcomes between participants receiving tirzepatide versus liraglutide and examine whether any differences in bone markers are independent of the amount of weight loss. Key exclusions remove people with diabetes, prior bariatric surgery, significant organ failure, metabolic bone disease, recent fractures, or use of medications known to alter bone turnover.
Why it matters
Potential benefit: If successful, the results could help select the medication that best preserves bone health during substantial weight loss and thereby reduce future fracture risk.
How similar studies have gone: Prior studies of GLP-1 receptor agonists such as liraglutide have produced mixed findings on bone and body composition, and direct comparative data including tirzepatide are limited.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Adults aged between 30 and 65 years * BMI ≥40 kg/m² Exclusion Criteria: * Type 2 Diabetes Mellitus (T2DM) and type 1 Diabetes Mellitus (T1DM) * Chronic kidney disease * Liver failure * Heart failure * Malignancy coexistence * Previous bariatric or gastrointestinal surgery involving intestinal bypass * Uncontrolled hypo/hyperthyroidism * Uncontrolled hypo/hyperparathyroidism * Pregnancy and lactation * Recent fracture (within 2 years) * Rare Metabolic Bone Diseases (e.g., Paget's disease of bone, fibrous dysplasia, osteopetrosis) * Inflammatory arthritis * Medications which can affect bone markers: bone-anabolic agents, antiresorptive agents, antiandrogenic agents, vitamin K antagonists, antipsychotic agents, contraceptives, glucocorticoids (oral), methotrexate, thiazides, aromatase inhibitors etc) * Hemolytic anemia
Where it's running
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Laiko General Hospital
Athens, Attica, Greece Recruiting
Study contacts
- Study coordinator: Maria Evangelia Koloutsou, Endocrinology Resident
- Email: mkoloutsou@yahoo.com
- Phone: +306986606272
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.