Analysis of Gene Candidate SNP and Ancestral Origin Associated to Obesity and Postoperative Weight Loss in a Cohort of Obese Patients Undergoing RYGB.

INTRODUCTION: Obesity is the result of a complex interaction between multiple genetic traits and psychological, behavioral, nutritional and environmental factors. OBJECTIVES: The aims of the study were (a) to comparatively evaluate the presence of 20 candidate gene single nucleotide polymorphisms (SNPs) in morbidly obese patients, (2) their association to comorbid conditions and (3) their impact on weight loss after a Roux-en-Y gastric bypass (RYGB). PATIENTS AND METHODS: Two hundred forty-nine patients were eligible for this study. Clinical, anthropometric, biochemical and demographic variables were analyzed. Body mass index (BMI) and composition were assessed by bioelectrical impedance. Twenty SNPs were included for analysis. RESULTS: There were 168 Mexican mestizos (67.5 %) and 81 (32.5 %) patients with other ancestral origin. One hundred fifty-nine (64.1 %) were females. Mean ± SD age of the general cohort was 41.1 ± 11.3 years (17-71). Preoperative mean ± SD BMI was 42.5 ± 6.5 kg/m2. There were no significant differences between mestizo and non-mestizo for most SNPs except for IFI, LIPC, and ST8SIA2. FTO (OR = 1.71; CI95 % = 1.14-2.57; p = 0.008) and APOB (OR = 0.31; CI95 % = 0.14-0.72; p = 0.004) result is statistically associated to high blood pressure and FTO (OR = 2.0; CI95 % = 1.3-3.1; p = 0.001), GNB3 (OR = 2.69; CI95 % = 1.0-7.2; p = 0.04), IFI30 (OR = 2.0; CI95 % = 1.16-3.6; p = 0.01), and MC4R (OR = 1.81; CI95 % = 1.13-2.9; p = 0.01) to type 2 diabetes (T2D). Based on ANOVA analysis, POMC (rs1042571) was the SNP most significantly associated to a higher weight loss after RYGB. CONCLUSIONS: Obese patients have similar SNP frequencies. Several SNP results are statistically associated to high blood pressure and T2D. POMC was significantly associated to a higher surgically induced weight loss.

Evaluation of spirometric testing as a routine preoperative assessment in patients undergoing bariatric surgery.

BACKGROUND: The value of spirometry as a routine preoperative test for bariatric surgery is debatable. The aim of this study was to assess the relationship between spirometry results and the frequency of postoperative pulmonary complications in 602 obese patients. METHODS: Clinical files of patients undergoing bariatric surgery between 2004 and 2013 were reviewed. Demography, risk factors, respiratory symptoms, and spirometry results (forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC) were recorded, and their relationship with postoperative pulmonary complications was evaluated. RESULTS: There were 256 males and 346 females with a mean age of 40.2 ± 11.6 years and a mean BMI of 42.1 ± 6.4 kg/m2. History of smoking was found in 408 patients (68 %). Preoperative respiratory symptoms were present in 328 (54.5 %). Most frequent symptoms were snoring (288), dyspnea (119), bronchospasm [6], and chronic productive cough [6]. In 153 patients, history of respiratory disease was documented. The obstructive sleep apnea syndrome (OSAS) was present in 124, 20 requiring continuous positive airway pressure (CPAP). Asthma was present in 27 and chronic obstructive pulmonary disease (COPD) in 2. Variables associated to a higher risk of pulmonary complications were OSAS (OR 2.3), an abnormal spirometry (OR 2.6), male gender (OR 1.9), and preoperative respiratory symptoms (OR 1.9). Using multivariate logistic regression, an abnormal spirometry was a significant predictor of postoperative pulmonary complications in patients with respiratory symptoms and/or OSAS. However, it lost prognostic significance when both conditions were subtracted. CONCLUSIONS: In obese patients undergoing bariatric surgery, abnormal preoperative spirometry predicts postoperative respiratory complications only in patients with OSAS.

Anemia after Roux-en-Y gastric bypass. How feasible to eliminate the risk by proper supplementation?

BACKGROUND: Anemia after Roux-en-Y gastric bypass (RYGB) has been reported in 5 to 64 % of patients. Since absorption of specific elements is reduced, proper supplementation is mandatory. The aim of this study was to investigate the frequency of anemia, its causes, and the related deficiencies during the 1st postoperative year after RYGB. METHODS: A retrospective review of our prospectively collected database was performed. A total of 486 patients who underwent RYGB in a 5-year period and completed at least 1-year follow-up were included. Daily supplements as suggested by the AACE/TOS/ASMBS guidelines were routinely prescribed. Blood count, iron profile, folic acid, and B12 measurements 1 year after surgery were reviewed. RESULTS: One hundred ninety-five males and 291 females were included, with a mean age of 39.9 ± 11.6 years and a mean body mass index (BMI) of 42.4 ± 6.3 kg/m(2). Anemia 1 year after surgery was found in 19 patients (4 %), 6 males and 13 females. In seven women, it was related to iron deficiency. Two additional women had iron deficiency combined with low vitamin B12. Anemia was secondary to inflammation in two and indeterminate in two. In the six males, the cause of anemia was inflammation in three and indeterminate in three. Abnormal bleeding was found in five of these patients. CONCLUSIONS: Frequency of anemia 1 year after RYGB in our population was low (4 %). Anemia non-attributable to malabsorption was frequently present (n = 9/19). Iron deficiency was found exclusively in women. The most common non-malabsorptive types of anemia were inflammation and dysfunctional uterine bleeding.