ASSESSMENT OF NUTRITIONAL STATUS AFTER GASTRIC BYPASS SURGERY IN MORBIDLY OBESE PATIENTS

Abstract

Obesity has increased prevalence to the extent that it has reached epidemic proportions and became a major public health concern. Morbid obesity is considered a disease of excess energy stores in the form of fat. Clinically severe obesity correlates with a Body Mass Index (BMI) of greater than or equal to 40 kg/m2 or a BMI of greater than or equal to 35 kg/m2 accompanied by comorbid conditions. The cause of obesity is complex and multifactorial and includes genetic factors, microbiological factor, environmental factors, behavioral factors, psychological factors, eating disorders, endocrine causes and drug induced obesity. There are several factors that are sharing in pathogenesis of obesity including hormonal and enzymatic cause. Obesity increases the risk of many physical and mental conditions, obesity complications are either directly caused by obesity or indirectly related as diabetes mellitus, hypertension, dyslipidaemia, cardiovascular disease, atherosclerosis, cerebrovascular disease, pulmonary dysfunction, gastroesophageal reflux, cholelithiasis, non-alcoholic fatty liver disease, deep venous thrombosis, pulmonary embolism, degenerative joint disease, genital disorders, gestational diabetes, pre-eclampsia, and delivery complications. Effective weight loss therapy can reverse many of the adverse effects of severe obesity. Available therapies include Summary 2015 128 lifestyle changes (diet and exercise), very-low-calorie diets, pharmacologic therapy, and surgery. Of these, bariatric surgery is documented as the most consistently effective therapeutic intervention for the severely obese. Surgery is usually successful in inducing substantial weight loss in the majority of obese patients with improvement or reversal of obesity-related comorbidities and is achieved primarily by an inevitable reduction in energy intake. Bariatric procedures are based on two primary principles to promote weight loss: gastric restriction and intestinal malabsorption. Roux-en-Y gastric bypass (RYGB) is considered the most common restrictive and mal-absorption procedure that surgically alters the stomach capacity using surgical staples. Weight loss is promoted by the restriction of the amount of food and limitation of the absorption of food. Complications of bariatric surgery could be classified into surgical and nutritional complications; furthermore, the surgical complications could be subdivided into early (<2 months) and late complications and includes: Anastomotic or staple line leaks, postoperative hemorrhage, venous thromboembolism, acute gastric distension, small bowel obstruction, gastro-jejunostomy anastomotic stricture, Marginal ulceration, Internal hernia, gastrogastric fistula, gall stone disease and weight gain plus nutritional complications which includes: vitamin B12 deficiency, Iron deficiency, calcium and vitamin D deficiency, vitamin B9 (folates) deficiency, protein and carbohydrates deficiency. Summary 2015 129 Nutrient deficiencies after bariatric surgery are common and have multiple causes. Preoperative factors include obesity, which appears to be associated with risk for several nutrient deficiencies, and preoperative weight loss. Postoperatively, reduced food intake, suboptimal dietary quality, altered digestion and absorption, and nonadherence with supplementation regimens contribute to risk of deficiency.