Scott Belsley

Preoperative nutritional status of patients undergoing Roux-en-Y gastric bypass for morbid obesity.

Few data exist concerning preoperative nutritional status in patients undergoing bariatric surgery. We retrospectively analyzed the preoperative values of serum albumin, calcium, 25-OH vitamin D, iron, ferritin, hemoglobin, vitamin B12, and thiamine in 379 consecutive patients (320 women and 59 men; mean body mass index 51.8±10.6 kg/m2; 25.8% white, 28.4% African American, 45.8% Hispanic) undergoing bariatric surgery between 2002 and 2004. Preoperative deficiencies were noted for iron (43.9%), ferritin (8.4%), hemoglobin (22%; women 19.1%, men 40.7%), thiamine (29%), and 25-OH vitamin D (68.1%). Low ferritin levels were more prevalent in females (9.9% vs. 0%; P=0.01); however, anemia was more prevalent in males (19.1% vs. 40.7%; P<0.005). Patients younger than 25 years were more likely to be anemic than patients over 60 years (46% vs. 15%; P<0.005). This correlated with iron deficiency, which was more prevalent in younger patients (79.2% vs. 41.7%; P<0.005). Whites (78.8%) and African Americans (70.4%) had a higher prevalence of vitamin D deficiency than Hispanics (56.4%), P=0.01. Whites were the least likely group to be thiamine deficient (6.8% vs 31.0% African Americans and 47.2% Hispanics; P<0.005). Nutritional deficiencies are common in patients undergoing Roux-en-Y gastric bypass, and these deficiencies should be detected and corrected early to avoid postoperative complications.

Glucose Metabolism After Gastric Banding and Gastric Bypass in Individuals With Type 2 Diabetes: Weight Loss Effect

OBJECTIVE The superior effect of Roux-en-Y gastric bypass (RYGB) on glucose control compared with laparoscopic adjustable gastric banding (LAGB) is confounded by the greater weight loss after RYGB. We therefore examined the effect of these two surgeries on metabolic parameters matched on small and large amounts of weight loss. RESEARCH DESIGN AND METHODS Severely obese individuals with type 2 diabetes were tested for glucose metabolism, β-cell function, and insulin sensitivity after oral and intravenous glucose stimuli, before and 1 year after RYGB and LAGB, and at 10% and 20% weight loss after each surgery. RESULTS RYGB resulted in greater glucagon-like peptide 1 release and incretin effect, compared with LAGB, at any level of weight loss. RYGB decreased glucose levels (120 min and area under the curve for glucose) more than LAGB at 10% weight loss. However, the improvement in glucose metabolism, the rate of diabetes remission and use of diabetes medications, insulin sensitivity, and β-cell function were similar after the two types of surgery after 20% equivalent weight loss. CONCLUSIONS Although RYGB retained its unique effect on incretins, the superiority of the effect of RYGB over that of LAGB on glucose metabolism, which is apparent after 10% weight loss, was attenuated after larger weight loss.