ECE2023 Poster Presentations Calcium and Bone (83 abstracts)
1Azienda Ospedaliero-Universitaria of Modena, Italy, Department of Medical Specialties, Unit of Endocrinology, Italy; 2University of Modena and Reggio Emilia, Modena, Italy, Department Biomedical, Metabolic and Neuronal Sciences, Unit of Endocrinology, Italy; 3University of Modena and Reggio Emilia, Modena, Italy, Department of Biomedical, Metabolic and Neural Sciences, Unit of Internal and Metabolic Medicine, Italy; 4Division of General, Emergency Surgery and New Technologies, Ospedale Civile di Baggiovara, Modena, Italy, Italy; 5Department of Metabolic Diseases and Clinical Nutrition, Azienda Ospedaliero-Universitaria of Modena, Modena, Italy, Italy
Background and Aim: Potential adverse effects of metabolic surgery on skeletal integrity remains an important concern. Bone loss is common after surgery due to multiple factors including vitamin D deficiency, altered calcium metabolism, mechanical load reduction and hormonal pattern changes. It is still not clear if the effects on bone health and calcium homeostasis vary according to each surgical technique. Further, long-term data of different surgical approaches are poor. Thus, this study aimed to describe changes in bone metabolism in subjects with severe obesity undergoing both Roux-en-Y gastric by-pass (RYGB) and sleeve gastrectomy (SG).
Methodology: A single center, retrospective, observational clinical study on real-world data was performed enrolling subjects undergoing metabolic surgery.
Results: One hundred twenty-three subjects were overall enrolled, including 31 men (25.2%) and 92 women (74.8%). RYGB procedure was performed in 67 (62.6%) and SG in 46 (37.4%) patients. The mean age at baseline was 48.2 + 7.9 years, ranging from 28.9 to 63.4 years. The entire cohort was evaluated until 16.9±8.1 months after surgery, while a small group was evaluated up to 4.5 years. All individuals were treated after surgery with calcium and vitamin D integration. Both calcium and phosphorous serum levels significantly increased after metabolic surgery and remained stable during follow up. These trends did not differ between RYGB and SG (P=0.245). Ca/P ratio decreased after surgery compared to baseline (P<0.001) and this decrease remained among follow up visits. While 24-h urinary calcium remained stable across all visits, 24-h urinary phosphorous showed lower levels after surgery (P=0.014), also according to surgery technique. Parathyroid hormone decreased (P<0.001) and both vitamin D (P<0.001) and C-terminal telopeptide of type I collagen (P=0.001) increased after surgery. Moreover, no significant change in osteoporosis/osteopenia rate by DXA evaluation was detected one and two years after surgery (P=0.109). Despite this, significant bone mineral density (BMD) reduction was detected at femoral site after surgery (P=0.032 and P<0.001, respectively), also after adjustment for gender.
Conclusion: We demonstrated that calcium and phosphorous metabolism remains slightly rearranged even after several years since metabolic surgery, irrespective of calcium and vitamin D supplementation. This rearrangement is characterized by a phosphorous serum levels increase, together with a persistent bone loss, suggesting that supplementation alone may not ensure the maintenance of bone health in these patients and further therapeutic strategies are needed for longtime including lifestyle, physical exercise and bone active therapy in patients at high risk of fractures.