Gastric Bypass(RYGB).
Aim: To illustrate the effect of bariatric surgery on serum calcium levels and serum vitamin D (vit D) levels, demonstrate
the secondary hyperparathyroidism in patients undergoing bariatric surgeries, and compare between the outcome of
RYGB and LSG regarding secondary hyperparathyroidism.
Patients and Methods: This prospective cross-sectional cohort study was conducted on 100 obese patients divided into
two groups: group I: 50 patients who underwent LSG and group II: 50 patients who underwent RYGB at General Surgery
Department, Faculty of Medicine, Beni-Suef University Hospital during the period between January 2019 and March
2022.
Results: Regarding blood calcium level, LSG group elaborated less proportion of patients with low blood calcium levels,
compared with RYGB group, after 6 months and after 1 year (P<0.05). In the LSG group the mean±SD preoperative
vit. D was 14.01±6.39, after 6 months was 18.05±3.20 and after 1 year was 22.07±2.03. In RYGB group the mean±SD
preoperative vit. D was 14.05±6.13, after 6 months was 17.04±5.1 and after 1 year was 18.02±4.6.
Conclusion: The prevalence of secondary hyperparathyroidism is high in morbidly obese patients before bariatric surgery
which is related to vit D deficiency and calcium deficiency. This prevalence increased continually along with the time
after both LSG and RYGB surgery and more apparent after RYGB.