Osteoporosis
NOFSA Masterclass 2026 Ep 2: The continuum of male bone health in the GLP-1 era
In men, skeletal health is determined by the interplay of body mass, hormonal health and bone strength. It is well-established that glucagon-like peptide-1 receptor agonists (GLP-1RAs) assist with significant weight loss and improvement of testosterone and metabolic dysfunction, but it remains to be established whether these and other incretin therapies offer long-term benefit or harm to skeletal health. In this second of the 2026 National Osteoporosis Foundation of South Africa Masterclass series, Dr Zane Stevens reviews current understanding and the clinical evidence regarding the impacts of obesity, weight loss and incretin therapies on male bone health.
Learning objectives
Upon completing this NOFSA masterclass, you will have an understanding of:
- The physiology of sex hormones on bone throughout the lifespan
- The impact of obesity on bone health and testosterone and the association between type 2 diabetes (T2D) and fracture
- The impact of glucagon-like peptide-1 receptor agonist (GLP-1RA) weight loss therapies on bone
- Practical clinical recommendations for preserving skeletal health in men using GLP-1RAs.
Key learnings
- Male bone health is dynamic throughout the lifespan
- Both testosterone and oestradiol are critical for preservation of trabecular bone and control of bone resorption
- A normal bone mineral density (BMD) in patients with obesity and/or T2D can mask significant deficits in bone quality that increase fracture risk
- The phenotype of weight loss (fat mass vs lean mass) determines changes in the mechanical environment and skeletal impact
- GLP-1RA weight loss therapies have direct and indirect effects on bone health; current evidence suggests a neutral impact on BMD and increased bone resorption – fracture evidence remains uncertain
- Among clinically actionable targets for the preservation of bone health in men are:
- Preservation of muscle strength and function
- Testosterone replacement therapy is not a substitute for evidence-based osteoporosis treatment and should be reserved for the patient with hypogonadism
- Risk stratify, ensure adequate protein intake and mandate progressive resistance exercise.
Dr Zane Stevens
Specialist Physician and Endocrinologist
Cape Institute of Endocrinology
Christiaan Barnard Memorial Hospital
Cape Town
Dr Zane Stevens is a Specialist Physician and Endocrinologist at the Cape Institute of Endocrinology, with a private practice at Christiaan Barnard Memorial Hospital in Cape Town. His clinical interests include diabetes, thyroid disease and osteoporosis, with a particular focus on Fracture Liaison Services. He has extensive experience in undergraduate and postgraduate training in Internal Medicine and Endocrinology and has contributed to South African clinical guidelines, including the SEMDSA guidelines for type 2 diabetes and South African Hypothyroidism guidelines. Dr Stevens is an executive council member of the National Osteoporosis Foundation of South Africa (NOFSA), an examiner for the Colleges of Medicine of South Africa in Endocrinology & Metabolism, and a founding member of the Cape Thyroid Forum MDT. He regularly lectures at CME events on diabetes, thyroid disease and osteoporosis.
- Tenuta M, Hasenmajer V, Gianfrilli D, et al. Testosterone and male bone health: A puzzle of interactions. J Clin Endocrinol Metab 2025; 110(7): e2121-e2135. https://academic.oup.com/jcem/article/110/7/e2121/8090450?login=false
- Sulimani R. Obesity and bone health: Reconciling the density-fragility paradox. Front Endocrinol (Lausanne) 2026; 17: 1864169. https://pmc.ncbi.nlm.nih.gov/articles/PMC13395687/
- Tebe C, Martinez-Laguna D, Carbonell-Abella C, et al. The association between type 2 diabetes mellitus, hip fracture, and post-hip fracture mortality: A multi-state cohort analysis. Osteoporos Int 2019; 30(12): 2407-2415. https://link.springer.com/article/10.1007/s00198-019-05122-3
- Trandafir AI, Sima OC, Gheorghe AM, et al. Trabecular bone score (TBS) in individuals with type 2 diabetes mellitus: An updated review. J Clin Med 2023; 12(23): 7399. https://pmc.ncbi.nlm.nih.gov/articles/PMC10707110/
- Gatto A, Liu K, Milan N, et al. The effects of GLP-1 agonists on musculoskeletal health and orthopedic care. Curr Rev Musculoskelet Med 2025; 18(10): 469-480. https://pmc.ncbi.nlm.nih.gov/articles/PMC12325148/
- Kim JH, Choi SA, Gu MS, et al. Effects of glucagon-like peptide-1 receptor agonist on bone mineral density and bone turnover markers: A meta-analysis. Diabetes Metab Res Rev 2024; 40(6): e3843. https://onlinelibrary.wiley.com/doi/10.1002/dmrr.3843
- Fuggle NR, Beaudart C, Bruyere O, et al. Evidence-based guideline for the management of osteoporosis in men. Nat Rev Rheumatol 2024; 20(4): 241-251. https://www.nature.com/articles/s41584-024-01094-9
- Snyder PJ, Bauer DC, Ellenberg SS, et al. Testosterone treatment and fractures in men with hypogonadism. N Engl J Med 2024; 390: 203-211. https://www.nejm.org/doi/10.1056/NEJMoa2308836?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
- Paccou J, Compston JE. Bone health in adults with obesity before and after interventions to promote weight loss. Lancet Diabetes Endocrinol 2024; 12(10): 748-760. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(24)00163-3/abstract
