Current Clinical Practice Guidelines for Nutritional Screening Before and After Sleeve Gastrectomy and Roux-En-Y Gastric Bypass: A Scoping Review.

Introduction: Long-term data indicate that patients who underwent metabolic bariatric surgery have a higher risk of developing nutritional complications. Therefore, it is of utmost importance to monitor their nutritional status.

Methods: A scoping literature search was conducted in MEDLINE, EMBASE, CINAHL, and TRIP database to identify clinical practice guidelines for nutritional screening before and after metabolic bariatric surgery from learned societies. For full coverage, all websites of learned societies affiliated with the World Obesity Federation were searched. Clinical practice guidelines were eligible if they contained recommendations for nutritional screening before and after sleeve gastrectomy or Roux-en-Y gastric bypass. Content was screened by two reviewers for timing, biochemical markers and cut-off values, and biochemical assays for nutritional screening.

Results: Nine eligible clinical practice guidelines co-authored by 26 learned societies were identified. All guidelines provided recommendations for both bariatric procedures except for one. Majority of guidelines endorsed nutritional screening before surgery and at 3, 6, 12, and 24 months after surgery, and annually thereafter. Pre- and postoperative screening recommendations were available for iron, vitamin B₁₂, folate, calcium and vitamin D, but in a lesser extent for vitamin A, vitamin E, vitamin K, zinc, vitamin B₁, copper and magnesium. Two clinical practice guidelines provided cut-off values for the diagnosis of nutritional deficiencies.

Discussion: The clinical practice guidelines exhibited a high level of consistency for timing of screening, but not for the applied biochemical markers. Going forward, the primary focus should be on harmonizing recommendations for biochemical markers, and cut-off values.