Feasibility of a pilot randomised controlled trial on nutrition repletion before metabolic and bariatric surgery

Background: There is a paucity of strong-rigour evidence on micronutrient repletion before metabolic and bariatric surgery despite high prevalence of deficiencies. In Australia, more than 90% of surgeries were performed in private settings, usually with a short timeframe between micronutrient deficiency identification and surgery.

Aim: To evaluate the feasibility of a pragmatic trial comparing intensive preoperative micronutrient repletion to standard care for private surgery candidates.

Methods: A single-centre, open-label, two-arm, parallel, pilot randomised controlled trial recruited adult sleeve gastrectomy candidates between July 2023 and February 2024 from a private clinic. Participants with any deficiency at baseline were randomised to the intervention: repletion through intravenous and/or intramuscular routes as a mega-dose; or control: oral supplements repletion for 14 days. Additionally, both groups routinely received multivitamin and calcium supplementation.

Results: In total, 31 participants (90% female) out of 42 approached were recruited (74% consented). N = 16/25 (64%) were eligible for randomisation; blood tests remain pending for N = 6. Intervention: N = 4/7 received repletion (attendance rate: 57%, adherence rate: 100% for intramuscular/intravenous repletion, and 73% for oral repletion and routine supplementation). N = 2 participants received oral repletion despite being assigned to receive intravenous/intramuscular repletion due to clinical judgement by the usual care team. Control: N = 7/9 received repletion (attendance rate: 78%, adherence rate: 98%).

Conclusion: High consent rate and patient adherence rates were found to be feasible. However, low recruitment rate and attendance rates to receive the allocated treatment suggested trial feasibility may improve with a larger sampling frame, more recruitment sites and increased flexibility of intervention delivery.