Timothy R. Koch

Small intestinal bacterial overgrowth and thiamine deficiency after Roux-en-Y gastric bypass surgery in obese patients

It has been proposed that thiamine deficiency after gastric bypass surgery in obese patients results from prolonged nausea and emesis. We hypothesized that thiamine deficiency is induced by altered gut ecology. This report includes 2 retrospective studies of obese patients who underwent Roux-en-Y gastric bypass surgery at our institution from 1999 to 2005. In the first study, 80 patients (52 women and 28 men) had measurement of whole-blood thiamine diphosphate level and serum folate level. In these 80 patients, 39 (49%) had thiamine diphosphate levels less than the lower limit of the reference range, and 28 (72%) of the 39 had folate levels higher than the upper limit of the reference range, an indicator of small intestinal bacterial overgrowth. In 41 patients with normal thiamine levels, only 14 (34%) had folate levels higher than the upper limit of the reference range (chi(2) test, P < .01). In the second study, 21 patients (17 women and 4 men) had thiamine diphosphate levels less than the lower limit of the reference range and abnormal glucose-hydrogen breath tests, consistent with small intestinal bacterial overgrowth. Fifteen patients received oral thiamine supplements, but repeated thiamine levels remained low in all 15. Nine of these patients then received oral antibiotic therapy; repeated thiamine levels were found to be normal in all 9 patients. These results support the hypothesis that small intestinal bacterial overgrowth results from altered gut ecology and induces thiamine deficiency after gastric bypass surgery in obese patients.

Postoperative Metabolic and Nutritional Complications of Bariatric Surgery

Bariatric surgery has become an increasingly important method for management of medically complicated obesity. In patients who have undergone bariatric surgery, up to 87% with type 2 diabetes mellitus develop improvement or resolution of their disease postoperatively. Bariatric surgery can reduce the number of absorbed calories through performance of either a restrictive or a malabsorptive procedure. Patients who have undergone bariatric surgery require indefinite, regular follow-up care by physicians who need to follow laboratory parameters of macronutrient as well as micronutrient malnutrition. Physicians who care for patients after bariatric surgery need to be familiar with common postoperative syndromes that result from specific nutrient deficiencies.

Managing medical and surgical disorders after divided Roux-en-Y gastric bypass surgery.

The National Longitudinal Study of Adolescent Health and the National Health and Nutrition Examination Survey reported that over 40% of the US population is overweight. The average weight loss attained by medical management programs is neither sufficient nor durable enough to treat medically complicated obesity. An estimated 220,000 bariatric procedures are performed yearly in the USA and Canada. The divided Roux-en-Y gastric bypass (RYGB) is performed most commonly in these countries and is considered the gold standard bariatric surgical procedure. The complexity of RYGB means that serious and potentially preventable perioperative complications can occur. RYGB alters the normal anatomy and physiology of the upper gut, which has predictable adverse effects and potential complications. Patients seek advice and care for symptoms that develop or persist after RYGB; although some symptoms are expected and predictable, others are complications that may or may not require active medical or surgical intervention. Physicians should be able to predict and manage most postoperative medical and nutritional disorders related to RYGB and should be prepared to assess patients for potential referral for surgical intervention or revision.

Prevalence of clinical thiamine deficiency in individuals with medically complicated obesity

Thiamine is a vitamin whose deficient can result in multiorgan symptoms. We described an 18% prevalence of clinical thiamine deficiency after gastric bypass surgery. Our hypotheses are that individuals with medically complicated obesity frequently have clinical thiamine deficiency and that diabetes mellitus is a mechanism for development of clinical thiamine deficiency. This is a single institution, retrospective observational study of consecutive patients with a body mass index of at least 35 kg/m2 who were evaluated in preoperative gastrointestinal bariatric clinic from 2013 to 2015. Each patient underwent a symptom survey. Clinical thiamine deficiency is defined by both (1) consistent clinical symptom and (2) either a low whole-blood thiamine concentration or significant improvement of or resolution of consistent clinical symptoms after receiving thiamine supplementation. After excluding 101 individuals with prior bariatric surgery or heavy alcohol consumption, 400 patients were included in the study. Sixty-six patients (16.5% of 400) fulfill a diagnosis of clinical thiamine deficiency, with 9 (14% of 66) having consistent gastrointestinal manifestations, 46 (70% of 66) having cardiac manifestations, 39 (59% of 66) having peripheral neurologic manifestations, and 3 (5% of 66) having neuropsychiatric manifestations. Diabetes mellitus is not a risk factor (P=.59). Higher body mass index is a significant risk for clinical thiamine deficiency (P=.007). Clinical thiamine deficiency is common in these individuals and a higher body mass index is an identified risk factor. Mechanisms explaining development of thiamine deficiency in obese individuals remain unclear.

Development of minimally invasive techniques for management of medically-complicated obesity.

The field of bariatric surgery has been rapidly growing and evolving over the past several decades. During the period that obesity has become a worldwide epidemic, new interventions have been developed to combat this complex disorder. The development of new laparoscopic and minimally invasive treatments for medically-complicated obesity has made it essential that gastrointestinal physicians obtain a thorough understanding of past developments and possible future directions in bariatrics. New laparoscopic advancements provide patients and practitioners with a variety of options that have an improved safety profile and better efficacy without open, invasive surgery. The mechanisms of weight loss after bariatric surgery are complex and may in part be related to altered release of regulatory peptide hormones from the gut. Endoscopic techniques designed to mimic the effects of bariatric surgery and endolumenal interventions performed entirely through the gastrointestinal tract offer potential advantages. Several of these new techniques have demonstrated promising, preliminary results. We outline herein historical and current trends in the development of bariatric surgery and its transition to safer and more minimally invasive procedures designed to induce weight loss.

Chronic Gastrointestinal Symptoms of Thomas “Stonewall” Jackson following Mexican-American War Exposure: A Medical Hypothesis

In a recent study, a large proportion of veterans seen for chronic heartburn or dyspepsia after the Persian Gulf War had evidence for Helicobacter pylori. Thomas Jackson was born and raised in an area of West Virginia that has a high prevalence of H. pylori. He suffered chronic dyspeptic symptoms following his service in the Mexican-American War. Therapies that he tried included treatment with a variant of the Sippy diet. Following a bullet wound to the left arm at the battle of Chancellorsville on Saturday, May 2, 1863, Thomas Jackson underwent amputation of the left arm below the left shoulder. He died 1 week later with a diagnosis of pleuropneumonia. The records of the postsurgical course are incomplete. The available clinical information raises the hypothesis that his chronic dyspepsia and his cause of death could have been related to chronic peptic ulcer disease due to gastric H. pylori infection.

Diet and Activity Programs Are Ineffective in Nonalcoholic Steatohepatitis

To the Editor: With the continued international increase in the prevalence of overweight and obese individuals, the recent review by Spengler and Loomba of nonalcoholic fatty liver disease (NAFLD) and the subset of individuals with nonalcoholic steatohepatitis (NASH), as defined by liver histology, is a very important topic. In the United States, NASH is the second most common indication for liver transplant, and the rate of liver transplant procedures is increasing. Prevention and treatment to reduce the rate of liver transplant is therefore a major issue in this field. We certainly agree with the authors’ statement that weight loss is the cornerstone of NAFLD treatment. We disagree, however, with their approach to weight loss. The authors state that it may be worthwhile to encourage patients to seek training on a structured weight loss regimen. This approach will clearly be too little (ie, weight loss) and not long enough (ie, inadequate maintenance of weight loss). A mean weight loss of only 6.4 kg has been reported from a metaanalysis of 19 studies of individuals with class 1 (body mass index [calculated as the weight in kilograms divided by the height in meters squared], 3034.9 kg/m) or class 2 (body mass index, 35-39.9 kg/m) obesity who participated in weight reduction programs that included dietary changes and physical activity. A recent study of an activity and dietary program for treatment of NAFLD found that only 10% of participants were able to lose the goal of more than 10% of their total body weight. Although this 10% of participants had a 90% rate of resolution of NASH, the study did not

Organization of future training in bariatric gastroenterology

A world-wide rise in the prevalence of obesity continues. This rise increases the occurrence of, risks of, and costs of treating obesity-related medical conditions. Diet and activity programs are largely inadequate for the long-term treatment of medically-complicated obesity. Physicians who deliver gastrointestinal care after completing traditional training programs, including gastroenterologists and general surgeons, are not uniformly trained in or familiar with available bariatric care. It is certain that gastrointestinal physicians will incorporate new endoscopic methods into their practice for the treatment of individuals with medically-complicated obesity, although the long-term impact of these endoscopic techniques remains under investigation. It is presently unclear whether gastrointestinal physicians will be able to provide or coordinate important allied services in bariatric surgery, endocrinology, nutrition, psychological evaluation and support, and social work. Obtaining longitudinal results examining the effectiveness of this ad hoc approach will likely be difficult, based on prior experience with other endoscopic measures, such as the adenoma detection rates from screening colonoscopy. As a long-term approach, development of a specific curriculum incorporating one year of subspecialty training in bariatrics to the present training of gastrointestinal fellows needs to be reconsidered. This approach should be facilitated by gastrointestinal trainees’ prior residency training in subspecialties that provide care for individuals with medical complications of obesity, including endocrinology, cardiology, nephrology, and neurology. Such training could incorporate additional rotations with collaborating providers in bariatric surgery, nutrition, and psychiatry. Since such training would be provided in accredited programs, longitudinal studies could be developed to examine the potential impact on accepted measures of care, such as complication rates, outcomes, and costs, in individuals with medically-complicated obesity.