Metabolic and Bariatric Surgery and Bone Mineral Density: A 9-Year Prospective Study.

BACKGROUND: Metabolic and bariatric surgery is the most effective long-term treatment for obesity; however, it may have adverse effects on skeletal health. This study aimed to evaluate long-term changes in skeletal health following sleeve gastrectomy. METHODS: We included consecutive patients who underwent sleeve gastrectomy between 2010 and 2016. All participants underwent dual-energy X-ray absorptiometry of the lumbar spine (L1-L4) and femoral neck at baseline and follow-up. RESULTS: The study cohort consisted of 72 patients (62 women and 10 men; mean age 43.6 ± 9.2 years). The median follow-up was 9 [9-10] years. Body weight decreased from 112.8 [102.4-124.5] kg to 91.5 [82.1-105.6] kg (p < 0.001), and body mass index from 41.2 [38.5-44.2] to 34.3 [30.4-38.2] kg/m² (p < 0.001). Significant reductions in femoral neck bone mineral density (BMD) (-0.10 [-0.17-(-0.04)] g/cm2; p < 0.001), T-score (-0.90 [-1.60-(-0.50)]; p < 0.001), and Z-score (-0.60 [-1.20- (-0.10)]; p < 0.001) were observed. At the lumbar spine, only the Z-score changed (0.10 [-0.35-0.80]; p = 0.048), whereas changes in BMD (-0.03 [-0.08-0.06] g/cm²; p = 0.180) and T-score (-0.35 [-0.85-0.50]; p = 0.052) were not significant. No correlations between changes in densitometric parameters and baseline values or changes in body weight, BMI, fat mass, or lean mass were significant. CONCLUSIONS: Nearly a decade after metabolic and bariatric surgery, bone mineral density may be significantly decreased at the femoral neck. Further prospective studies are warranted to clarify the mechanical, hormonal, and metabolic mechanisms underlying long-term skeletal health following metabolic and bariatric surgery.