Preoperative and Postoperative Assessments of Biochemical Parameters in Patients with Severe Obesity Undergoing Laparoscopic Sleeve Gastrectomy

Background: The study aim was to determine the prevalence of abnormal serum biochemistries associated with micronutrient deficiencies before and after laparoscopic sleeve gastrectomy (LSG).

Methods: Two hundred and one patients had LSG surgery between May 2011 and May 2014. Using a prospective cohort study design, data were collected on ferritin, hemoglobin (Hgb), mean cell volume (MCV), calcium, albumin, 25-hydroxyvitamin D (25-OH-D), PTH, and vitamin B with follow-up of 75.6% (n = 152), 63.7% (n = 128), 52.7% (n = 106), and 40.3% (n = 81) at 6, 12, 18, and 24 months, respectively.

Results: Patients were female (81.6%) with mean ± SD, BMI (48.8 ± 6.8 kg/m), weight (135.1 ± 23.6 kg), and age (44.0 ± 9.6 years). Mean values for all biochemical parameters pre- and post-LSG were within reference limits. After adjusting for age, weight, and supplement use, trend tests post-LSG were significant for mean differences in ferritin (p = 0.002), calcium (p = 0.017), and vitamin B (p = 0.034). Pre-LSG, the proportion of patients with values below reference limits included 25-OH-D (20.4%), ferritin (12.3%), and Hgb (10.0%), while the proportion above reference limits included PTH (29.1%) and ferritin (17.4%). After adjustment, hypoalbuminemia was more prevalent after 1 year; the proportion of patients with PTH levels in the upper reference limit was higher 6 months post-LSG (p < 0.05). Multivitamin use increased presurgery from 44 to 88% 2 years postsurgery. Vitamin B supplementation increased from 7% before surgery to 32% 2 years postsurgery.

Conclusion: Abnormal serum biochemistries indicative of micronutrient deficiencies were prevalent before surgery; reduced abnormal values were observed after surgery, likely due to an increased use of multivitamins.