Evaluation of Micronutrient Status Post Laparoscopic Sleeve Gastrectomy: an Australian Perspective.

Background: Laparoscopic sleeve gastrectomy (LSG) is a type of bariatric technique that has comparable outcomes to Roux-en-Y gastric bypass, the current gold standard. However, it can be associated with nutritional deficiencies postoperatively. The aim of this study was to evaluate micronutrient status post LSG.

Methods: This is a retrospective study of 565 patients who underwent an LSG from January 2015 to September 2018. Patients lost to follow-up at 3, 6 and 12 months were 6.3%, 18.6% and 32.4%, respectively. Follow-up of the patients included regular dietetic input and micronutrient supplementation. Data that was collected included both anthropometry and nutritional markers.

Results: The mean preoperative weight and body mass index (BMI) were 118.13 ± 25.36 kg and 42.40 ± 7.66 kg/m, respectively. Statistically, significant reductions in anthropometric parameters including weight, BMI (30.50 kg/m), total weight loss (28.03%), excess weight loss (72.03%) and BMI loss (12.32 kg/m) were observed at all timepoints up to 12 months follow-up. At 12 months, there were significant increases in 25-OH vitamin D with the incidence of deficiency decreasing from 45.7 to 15.0% compared to baseline. The incidence of hyperparathyroidism also decreased from 32.2 to 18.9% compared to baseline, and incidence of folate deficiency increased from 7.7 to 19.2%. Other nutritional parameters including calcium, iron, ferritin, vitamin B12, holotranscobalamin (active B12) and haemoglobin did not significantly change.

Conclusions: Modest effects on micronutrient status were observed in the 12-month postoperative period. Of clinically significant, de novo folate deficiencies increased, and vitamin D deficiency and hyperparathyroidism decreased. Thus, optimizing postoperative micronutrient status is imperative following LSG.