Evaluation of changes in vitamin B12, ferritin, folic acid, and thyroid hormone levels after sleeve gastrectomy

Abstract

Aim: The aim of this study was to evaluate the changes in vitamin B12, ferritin, folic acid, and thyroid hormone levels in patients with morbid obesity after laparoscopic sleeve gastrectomy (LSG). Material and Methods: A total of 85 patients who underwent LSG operation with the diagnosis of morbid obesity were included in the study. Levels of vitamin B12, ferritin, folic acid, and thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) hormone were measured using the chemiluminescence method. Pre-and postoperative levels of thyroid hormones, vitamin B12, ferritin, folic acid, and BMI values were evaluated. Results: The mean BMI decreased from 45.44 ± 3.8 kg/m2 to 39.38 ± 3.69 kg/m2 (p<0.001). The mean TSH, fT3, vitamin B12, folic acid, and ferritin levels were statistically significant lower at six months postoperatively than preoperative levels, while the mean fT4 levels were found to be significantly higher (p<0.001). Preoperative and 6thmonth postoperative ferritin levels were significantly lower in female patients than male patients (p<0.001). There was a negative correlation between age with preoperative TSH and fT3 levels. There was a positive correlation between age and preoperative and 6thmonth postoperative folic acid levels. Conclusion: Remodeling of the gastrointestinal system and endocrine alterations after LSG may result in changes in the levels of nutritional parameters such as thyroid hormone, vitamin B12, folic acid, and ferritin. Therefore, based on our study findings, we consider that the nutritional status of patients after bariatric surgery should be monitored particularly in long-term and nutritionally supported, if necessary.