What We Are Missing: Using Machine Learning Models to Predict Vitamin C Deficiency in Patients with Metabolic and Bariatric Surgery.

PURPOSE: Vitamin C (VC) is implicated in many physiological pathways. Vitamin C deficiency (VCD) can compromise the health of patients with metabolic and bariatric surgery (patients). As symptoms of VCD are elusive and data on VCD in patients is scarce, we aim to characterize patients with measured VC levels, investigate the association of VCD with other lab abnormalities, and create predictive models of VCD using machine learning (ML). METHODS: A retrospective chart review of patients seen from 2017 to 2021 at a tertiary care center in Northeastern USA was conducted. A 1:4 case mix of patients with VC measured to a random sample of patients without VC measured was created for comparative purposes. ML models (BayesNet and random forest) were used to create predictive models and estimate the prevalence of VCD patients. RESULTS: Of 5946 patients reviewed, 187 (3.1%) had VC measures, and 73 (39%) of these patients had VC<23 µmol/L(VCD. When comparing patients with VCD to patients without VCD, the ML algorithms identified a higher risk of VCD in patients deficient in vitamin B1, D, calcium, potassium, iron, and blood indices. ML models reached 70% accuracy. Applied to the testing sample, a "true" VCD prevalence of ~20% was predicted, among whom ~33% had scurvy levels (VC<11 µmol/L). CONCLUSION: Our models suggest a much higher level of patients have VCD than is reflected in the literature. This indicates a high proportion of patients remain potentially undiagnosed for VCD and are thus at risk for postoperative morbidity and mortality.

The Optimal Nutritional Programme for Bariatric and Metabolic Surgery.

PURPOSE OF REVIEW: Bariatric surgery is the most effective treatment for severe and complex obesity; however, the risk of developing nutrient deficiencies varies based upon the type of surgery, degree of malabsorption, and level of nutrition intervention. There are numerous factors that can impact the nutrition status of a patient during their pre- and postoperative journey. We review the critical components and considerations needed in order to provide optimal nutrition care for patients with bariatric surgery. RECENT FINDINGS: A dietitian, specializing in bariatric surgery, is the best equipped healthcare provider to prepare and support patients in achieving and maintaining optimal nutrition status. We present best practices for both the pre- and postoperative nutrition-related phases of a patient's journey. The dietitian specialist is integral in the assessment and ongoing nutrition care of patients with bariatric surgery. Further consideration should be given to enable access for lifelong follow-up and monitoring.

Weight Loss Prior to Bariatric Surgery and 30-Day Mortality, Readmission, Reoperation, and Intervention: an MBSAQIP Analysis of 349,016 Cases.

INTRODUCTION: Despite preoperative weight loss being a common prerequisite to metabolic and bariatric surgery, its relationship to 30-day postoperative outcomes is unclear. The aim of this study was to assess whether preoperative weight loss is associated with 30-day postoperative quality outcomes in adults undergoing metabolic and bariatric surgery. METHODS: Retrospective cohort study assessing adults who underwent Roux-en-Y gastric bypass or sleeve gastrectomy in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Participant Use File, years 2015-2017. The relationship between preoperative weight loss and 30-day readmission, reoperation, mortality, intervention, and morbidity was assessed using multivariable logistic regression. RESULTS: Preoperative weight loss, body mass index loss, and percent weight loss were not associated with 30-day postoperative overall readmission, reoperation, mortality, or intervention (p > 0.01). Preoperative percent weight loss was associated with increased incidence of superficial surgical site infections (OR = 1.023, 95% CI 1.009-1.036; p = 0.001) and urinary tract infections (OR = 1.044, 95% CI 1.030-1.059; p < 0.001). CONCLUSION: Weight loss prior to metabolic and bariatric surgery may not be necessary or safe for all patients. Unsafe weight loss prior to surgery may compromise nutrition status and lead to increased infection rates.