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Updated: May 18, 2026

A Protocol for Roux-en-Y Gastric Bypass in Rats using Linear Staplers
Published on: August 21, 2021
[Changes in bone metabolism markers in women after Roux-en-Y gastric bypass]
Maria Tereza Amaral dos Santos1, Fabíola Isabel Suano de Souza, Fernando Luiz Affonso Fonseca
1Faculdade de Medicina do ABC, (FMABC). Serviço de Nutrição e Dietética, Centro Hospitalar do Município de Santo André e Curso de Pós-Graduação em Nutrição Clínica e Metabolismo, Faculdade de Pós-Graduação, Escola Técnica (CBES), Brasil.
Objective:
To evaluate bone turnover markers and bone mineral density (BMD) in women after Roux-en-Y (RYGB) gastric bypass.
Subjects And Methods:
In a cross-sectional study, 48 women post-RYGB after three years, and 41 healthy women were evaluated.
Evaluations:
body mass index (BMI); physical activity; food intake; serum levels of calcium, phosphorus, magnesium, alkaline phosphatase, C-terminal telopeptide (CTX), intact parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHD), osteocalcin, urinary calcium and BMD.
Results:
Significantly higher levels were observed for osteocalcin (p < 0.001), CTX (p < 0.001), and PTH (p < 0.001) in the RYGB group when compared with the control group; 25OHD deficiency/insufficiency was more frequent in the RYGB group (p = 0.010), even after adjusted for nutritional status, and it was associated with secondary hyperparathyroidism (p = 0.025); there was no difference in BMD between the groups. Energy (p = 0.036) and protein intake (p = 0.004) were lower in the RYGB group.
Conclusion:
Patients submitted to RYGB showed a significantly higher frequency of vitamin D deficiency, secondary hyperparathyroidism, and increase in bone remodeling markers, with no difference in BMD status.
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