Post-bariatric surgery lab tests: are they excessive and redundant?

Abstract

Introduction Following bariatric surgery, ongoing postoperative testing is required to measure nutritional deficiencies; the purpose of this study was to quantify the prevalence of these nutritional deficiencies based on two-year follow-up tests at recommended time points. Methods and procedures A retrospective data analysis was conducted of all laboratory tests for bariatric patients who underwent surgery between May 2016 and January 2018 with available lab data (n = 397). Results for nine different nutritional labs were categorized into six recommended postoperative time periods based on time elapsed since the procedure date. Binary variables were created for each laboratory result to calculate descriptive statistics of abnormalities for each lab test over time and used in the individual GEE logistic regression models. Grouped logistic regression examined the total nutritional deficiencies of the nine combined nutrients considering total available labs. Results Multiple lab tests indicated a very low frequency of abnormalities (e.g., Vitamin A, Vitamin B12, Copper, and Folate). Many of the nine included nutritional labs had an average deficiency of less than 10% across all time points. The grouped logistic model found preoperative nutritional deficiency to be predictive of postoperative nutritional deficiency (OR 3.70, p < 0.001). Conclusions We found the vast majority of routine lab test results to be normal at multiple time points. Current practice can add up to significant lab expenses over time. The frequency of postoperative testing in this population may be redundant and of very little value. Unnecessary follow-up laboratory testing costs the patients and the health care system in both time and resources. Patients with preoperative deficiencies appear to be at higher risk for nutritional deficiencies when compared to bariatric surgery patients that did not have preoperative nutritional deficiencies. Future research should focus on defining cost effective postoperative lab testing guidelines for at risk bariatric patients.

Four-Year Nutritional Outcomes in Single-Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy Patients: an Australian Experience

“…The altered version of the original supplement was prescribed for only 5 months. The ASMBS guidelines recommend postoperative blood testing every 3 months for the first year, every 6 months for the second year, and annually thereafter, regardless of the type of bariatric procedure performed [ 21 ]. One hundred and eighteen patients received the altered version of the supplement for a duration of 5 months.…”

Comorbidities of obesity and preconception counselling: Consideration of bariatric surgery

“…30 Deficiencies of zinc, thiamine, folate, copper, vitamin A, vitamin B1 and vitamin B12 were found in in less than 10% of non-pregnant individuals in the USA at multiple time points within two years following bariatric surgery. 31 Serum vitamin D was <75 nmol/L in 37%, and serum ferritin <30 ng/mL in 25% of individuals. 31 A French study testing for nutrition in each trimester of 57 singleton pregnancies in women with previous bariatric surgery found deficiencies of vitamin A in 21-40%, vitamin D in 8-33%, vitamin C in 41-83%, thiamine in 15-45%, folic acid in 0-14% and selenium in 22-78%.…”

“…31 Serum vitamin D was <75 nmol/L in 37%, and serum ferritin <30 ng/mL in 25% of individuals. 31 A French study testing for nutrition in each trimester of 57 singleton pregnancies in women with previous bariatric surgery found deficiencies of vitamin A in 21-40%, vitamin D in 8-33%, vitamin C in 41-83%, thiamine in 15-45%, folic acid in 0-14% and selenium in 22-78%. 32 It is recommended that ferritin, 25OH-vitamin D, calcium, phosphate, folate, active vitamin B12, prothrombin time, magnesium and zinc be checked preconception and in each trimester, and additionally that vitamin A, thiamine and selenium be measured in the first trimester.…”

Pediatric obesity and anesthetic challenges of metabolic surgery

“…It has been reported in various research studies that bariatric surgery in adolescents makes them highly vulnerable to nutritional deficiencies in the future as compared to adults. [ 104 105 ] Bariatric surgeries accelerate gastric pouch emptying and reduce gastric secretions and intestinal absorption, thus interrupting the nutritional status. [ 106 ] Olber et al .…”

“…Other nutritional deficiencies include 16-22% for vitamin B12 and around 3-78% for vitamin D. Thus, it is crucially important for the multidisciplinary team to monitor nutritional profiles annually and prescribe suitable supplements to cater to any nutritional deficiencies in the future. [ 104 ]…”