Surgical treatment of morbid obesity

Intestinal Electrical Stimulation Alters Hypothalamic Expression of Oxytocin and Orexin and Ameliorates Diet-Induced Obesity in Rats

BACKGROUND

Intestinal electrical stimulation (IES) has been proposed as a potential treatment for obesity. The aim of this study was to explore the central mechanism underlying the reduction of food intake and body weight by IES by studying the expression of anorexigenic- and orexigenic-peptide-containing neurons in the hypothalamus.

MATERIALS AND METHODS

Diet-induced obese (DIO) rats were divided into three groups to receive sham, IES, and pair-feeding for 4 weeks. Food intake was measured automatically and presented as daily and body weight measured weekly. The expressions of oxytocin, an anorexigenic neuropeptide, in the paraventricular nucleus of the hypothalamus (PVN) and the supraoptic nuclei of the hypothalamus (SON) and orexin-A, an orexigenic neuropeptide, in the lateral hypothalamic area (LHA) were studied using immunohistochemistry.

RESULTS

Compared with sham, IES reduced daily food intake by 28.3% at week 1, 35.6% at week 2, 15.6% at week 3, and 27.1% at week 4. Consistently, IES reduced body weight by 6.3%, compared with a weight gain of 7.2% in sham, and a slight weight loss of 0.5% in pair-feeding. Compared with sham, IES increased the expression of oxytocin-immunoreactive neurons in PVN and SON. Compared with sham, IES decreased the expression of orexin-immunoreactive neurons in LHA. Rats with pair-feeding also showed a relative decease in weight without any changes in the central hormones.

CONCLUSION

IES reduces food intake and body weight and improves glucose tolerance and insulin sensitivity in DIO rats. Its central mechanisms involve enhancement of anorexigenic peptides and suppression of orexigenic peptides in the hypothalamus.

Intestinal Electrical Stimulation Enhances Release of Postprandial Incretin Hormones Via Cholinergic Mechanisms

INTRODUCTION

Intestinal electrical stimulation (IES) has been reported to reduce body weight and improve glucose tolerance in obese and diabetic rats. Our study aimed to investigate possible IES mechanisms involving incretin hormones using intraduodenal glucose infusion in rats. We hypothesized that the enhanced release of postprandial glucagon-like peptide-1 (GLP-1) at early phase by IES was mediated through neuro/paracrine mechanisms involving the vagal nerve and glucose-dependent insulinotropic peptide (GIP).

METHODS

Fifteen normal male Sprague-Dawley rats chronically implanted with duodenal electrodes for IES, and an intra-duodenum catheter for the infusion of glucose were studied in a series of sessions with IES of different parameters with and without atropine and M3 receptor antagonist. Blood samples were collected via the tail vein for the measurement of blood glucose, and plasma GLP-1, and GIP.

RESULTS

(1) Compared to sham-IES, IES of 0.3 ms reduced blood glucose by 16.5-28.4% between 30 and 120 min (all time points p < 0.05), and IES of 3-ms reduced blood glucose at 60 (12.6%) and 90 min (11.8%). IES of 0.3 ms showed a greater hypoglycemic effect than 3 ms (p = 0.024) at 30 min. (2) IES elevated plasma GLP-1 with 0.3 ms (p = 0.001) and with 3 ms p = 0.03). (3) IES substantially elevated plasma GIP with 0.3 ms (p = 0.002) and with 3 ms (p < 0.001). (4) Pretreatment of atropine and the M3 receptor antagonist 4-DAMP blocked the effects of IES on GLP-1, GIP, and blood glucose.

CONCLUSIONS

IES reduces postprandial blood glucose by enhancing the release of GLP-1 and GIP mediated via the cholinergic mechanism.

Dietary daidzein decreases food intake accompanied with delayed gastric emptying in ovariectomized rats

We previously found that equol, a metabolite of intestinal bacterial conversion from soy isoflavone daidzein, has female-specific anorectic effects. In the present study, we used seven-week-old female ovariectomized (OVX) Sprague Dawley rats to test the hypothesis that the anorectic effect of dietary daidzein may be attributed to delayed gastric emptying. Results suggest that dietary daidzein delays gastric emptying and that it has an anorectic effect with residual gastric contents, but not without gastric contents. Dietary equol significantly decreased daily food intake in the OVX rats without sleeve gastrectomy, but not in those with sleeve gastrectomy, suggesting that the accumulation of food in the stomach is required for the anorectic effect of equol to occur. These results support the hypothesis that the anorectic effect of dietary daidzein is attributed to delayed gastric emptying.

Food intake and body weight responses to intermittent vs. continuous gastric electrical stimulation in diet-induced obese rats

BACKGROUND

Gastric electrical stimulation (GES) has recently been introduced as a potential therapy for the treatment of obesity. The main challenge for the new generation of devices is to achieve desired clinical outcomes at a suitably low level of energy consumption. The aim of this study is to compare the effectiveness of GES with continuous and intermittent duty cycles in reducing food intake and body weight in diet-induced obesity-prone rats.

METHODS

In macro duty cycle experiment, 40 rats were divided into groups to receive a sham GES, continuous GES, or intermittent GES (15 min On-45 min Off or 15 min On-15 min Off) for 28 days. In micro duty cycle experiment, 18 rats received cross-over treatment of continuous stimulation, 60 % time cycle or 40 % time cycle. Food intake, body weight, gastric emptying and ghrelin level were measured to evaluate the effect of different GES.

RESULTS

GES with macro duty cycle intensity-dependently reduced mean daily food intake increase by 18.6, 10.2 and -6.0 % compared to 42.7 % with sham GES and body weight gain by 6.1 %, 3.4 and -0.8 % compared to 5 % with sham GES. Daily food intake decreased with increasing micro duty cycle intensity, averaging 16.5, 15.6 and 13.7 g/day under 40 % cycle, 60 % cycle and continuous stimulation respectively. Gastric emptying was intensity-dependently delayed by GES. GES has no effect in modulating plasma ghrelin level.

CONCLUSIONS

GES energy-dependently reduces food intake, body weight and gastric emptying. Peripheral modulation of plasma ghrelin level is not related to the GES effects.

An unusual case of significant weight loss following malposition of a laparoscopic adjustable gastric band

OBJECTIVE

Malposition or misplacement of gastric bands is a rare but recognised early complication of gastric band surgery. Malposition of the band would not normally result in significant weight loss after surgery.

CASE REPORT

To our knowledge, we report the first case in the English literature of a malpositioned gastric band encircling the pericardial fat pad only, who presented with delayed symptoms of dysphagia and gastro-oesophageal reflux resulting in significant weight loss (>60% of excess body weight) approximately 6 years after primary surgery. The patient underwent a water-soluble contrast study with antero-posterior views which was suggestive of a slipped band. However, on laparoscopy the band was found to be encircling the pericardial fat pad.

CONCLUSION

We suggest that all contrast swallow studies for patients presenting with symptoms of gastric band slippage should include lateral views to exclude gastric band malposition, irrespective of the time of onset of symptoms after primary surgery.

Mechanisms and potential applications of intestinal electrical stimulation

PURPOSE

Electrical stimulation of the gut has recently been under intensive investigation and various studies have revealed therapeutic potentials of gastrointestinal electrical stimulation for gastrointestinal motility disorders and obesity. While there have been a number of reviews on gastric electrical stimulation, there is a lack of systematic reviews on intestinal electrical stimulation. The aim of this review is to provide an overview on the effects, mechanisms, and applications of intestinal electrical stimulation.

RESULTS

We evaluated published data on intestinal electrophysiology, pathophysiology, and different methodologies on intestinal electrical stimulation and its possible mechanisms in both research and clinical settings using the MEDLINE database for English articles from 1963 to 2008. Based on this systematic review, intestinal electrical stimulation has been reported to alter intestinal slow waves, contractions and transit; the effects were mediated via both vagal and adrenergic pathways. Intestinal electrical stimulation has been reported to have potentials for treating various intestinal motility disorders and obesity.

CONCLUSIONS

It is concluded that intestinal electrical stimulation may have promising applications for treating motility disorders associated with altered intestinal contractile activity. The most recent studies have revealed possible applications of intestinal electrical stimulation for the treatment of obesity. Basic research results are promising; however, further clinical studies are needed to bring IES from bench to bedside.

The impact of roux limb length on weight loss after gastric bypass

BACKGROUND

Extending the length of the Roux limb (RL) in gastric bypass (GBP) may improve weight loss in super obese patients (body mass index [BMI] > 50 kg/m(2)), but no consensus exists about the optimal length of the RL. We sought to determine the impact of RL length on weight loss in super obese patients 1 year after GBP.

MATERIALS AND METHODS

One-year weight loss outcomes were analyzed in all super obese patients who underwent consecutive and primary laparoscopic or open GBP between January 2003 and June 2006. Patients were divided into two groups according to RL length (100 vs. 150 cm). The RL length was at the discretion of the attending surgeon. Baseline and follow-up data were collected prospectively. Multiple linear regression was used to adjust for potential confounders in the weight loss outcomes.

RESULTS

Twelve-month follow-up data were available in 137 (85%) of 161 patients with a BMI >or= 50 who underwent GBP during the study period. An RL of 100 or 150 cm was used in 102 (74.5%) and 35 patients (25.5%), respectively. In multivariate analysis, patients with the 150-cm RL lost more weight (68.5 vs. 55.3 kg, p < 0.01), had a greater change in BMI (25 vs. 21 kg/m(2), p = 0.01), and had greater excess weight loss (64 vs. 53%, p < 0.01).

CONCLUSION

A 150-cm RL provides better weight loss outcomes in super obese patients at 1-year follow-up.

Gastrointestinal electrical stimulation for treatment of gastrointestinal disorders: gastroparesis, obesity, fecal incontinence, and constipation

Electrical stimulation of the gastrointestinal (GI) tract is an attractive concept. Since these organs have their own natural pacemakers, the electrical signals they generate can be altered by externally delivering electric currents by intramuscular, serosal, or intraluminal electrodes to specific sites in the GI tract. This article reviews the advances in electrical stimulation of the GI tract by describing various methods of GI electrical stimulation and their peripheral and central effects and mechanisms; updating the status of GI electrical stimulation in the clinical settings of gastroparesis, obesity, fecal incontinence, and constipation; and predicting future directions and developments of GI electrical stimulation technology and their areas of possible clinical applications.

Effects of retrograde gastric electrical stimulation with pulse trains on gastric emptying of solids and plasma hormones in dogs

BACKGROUND

Retrograde gastric electrical stimulation (RGES) is proposed as a novel therapy for obesity. However, mechanisms of RGES are not fully investigated. The aim of this study was to investigate the effects of RGES with trains of pulses on gastric slow waves, gastric emptying of solids, and plasma concentrations of satiety-related peptides and glucose.

METHODS

Seven female beagle dogs implanted with 4 pairs of gastric electrodes on the gastric serosa were studied (control and RGES). Gastric emptying, gastric slow waves, and signs were recorded in each session. Plasma leptin, insulin, glucagons, and glucose were also measured.

RESULTS

RGES with pulse trains (a pulse width of 2 milliseconds) significantly decreased gastric emptying of solids and plasma insulin but has no effect on plasma leptin, glucagons, and glucose.

CONCLUSION

Acute gastric electrical stimulation with pulse trains is able to decrease gastric emptying of solids and plasma insulin but has no effects on plasma leptin, glucagons, and glucose.

Long-pulse gastric electrical stimulation at tachygastrial frequency reduces food intake by inhibiting proximal gastric tone

OBJECTIVE

To investigate the effects of long pulse gastric electrical stimulation (GES) at a tachygastrial frequency on food intake, gastric tone and gastric myoelectrical activity (GMA).

MATERIAL AND METHODS

Of twelve dogs implanted with electrodes and a gastric cannula, 6 underwent truncal vagotomy. Stimulus consisted of long pulses with a frequency of 9 cycles/min. Experiment one was performed in all dogs to test for food intake with or without GES. Experiment two on six normal dogs consisted of baseline, GES and recovery periods. Gastric volume and GMA were recorded.

RESULTS

1) GES reduced food intake in both normal (398.5+/-111.7 g versus 573.0+/-97.9 g; p<0.02) and vagotomized dogs (170.6+/-100.4 g versus 401.0+/-97.3 g; p<0.05). 2) Gastric volume was increased with stimulation from 168.4+/-17.7 ml to 301.1+/-34.1 ml (p<0.02 ANOVA) and maintained at 271.8+/-27.6 ml. 3) The percentages of normal slow waves before, during and after GES were 83.3+/-4.6%, 38.0+/-3.5% and 61.0+/-12.5%, respectively (p=0.02 ANOVA).

CONCLUSION

Long-pulse GES at tachygastrial frequency substantially reduces food intake, and is not mediated by the vagal pathway but attributed to relaxation of the stomach and impairment of intrinsic GMA.

Weight loss as a treatment for obstructive sleep apnoea

Obesity is a major health problem in well-developed societies. It is frequently associated with metabolic, cardiovascular and psychological comorbid conditions. Besides, it is known that obesity constitutes a risk factor for obstructive sleep apnoea (OSA). Weight loss has been evaluated as a treatment for OSA. We reviewed the nature of the link between obesity and OSA as well as the conservative and surgical therapeutic approaches of obesity. We consider the effectiveness of weight loss alone or combined with other modalities of treatment in OSA. We conclude that although weight loss is important and can facilitate the treatment of OSA, it can rarely cure it without being associated to classical techniques, such as nasal continuous positive airway pressure (nCPAP).

Inhibitory effects of intestinal electrical stimulation on food intake, weight loss and gastric emptying in rats

The aim was to investigate the effects of intestinal electrical stimulation (IES) on food intake, body weight, and gastric emptying in rats. An experiment on food intake and weight change was performed in 22 rats on a control diet and 10 diet-induced obese (DIO) rats for 4 wk with IES or sham IES. The effect of IES on gastric emptying was performed in another 20 rats in the control group. We found that 1) in control rats, 4-wk IES resulted in a reduction of 18.2% in the total amount of food intake compared with sham-IES (P = 0.02); the rats treated with IES had a weight change of -1 +/- 7.8g (P = 0.03), which was equivalent to a weight loss of 6.2% due to IES when adjusted for normal growing. 2) Acute IES delayed gastric emptying by 20% in the control rats (P < 0.01). 3) In the DIO rats, 1-wk IES with the same parameters as those used in the control rats resulted in a significant reduction in the total amount of food intake (126.6 +/- 6.3 g vs. 116.9 +/- 3.2 g, P < 0.01). More reduction in food intake was noted, and a significant weight change was also observed when stimulation energy was increased. 4) No adverse events were observed in any of the experiments. In conclusion, IES delays gastric emptying, reduces food intake, and decreases weight gain in control growing rats. These data suggest that it is worthy to explore therapeutic potentials of IES for obesity.

Gastric electrical stimulation using endoscopically placed mucosal electrodes reduces food intake in humans

BACKGROUND

Implantable gastric stimulation (IGS) has been proposed for treating obesity. The aim of this study was to investigate the effects of temporary mucosal electrical stimulation on water and food intake as well as gastric emptying in healthy humans.

METHODS

The study was designed to study the effects of temporary gastric electrical stimulation (GES) on symptoms, gastric accommodation, food intake, and gastric emptying. It was performed in 12 healthy volunteers on 3 consecutive days. GES was performed using mucosal electrodes endoscopically placed in the fundus.

RESULTS

The amount of maximum water intake was reduced with GES (894 +/- 326 mL) compared with sham-GES (1,093 +/- 417 mL, p = 0.01). The food intake was also reduced with GES (p = 0.012). In comparison with sham stimulation, GES delayed gastric emptying during the first 45 min after the meal but not during the remaining time. GES with parameters effective in reducing water and food intake and delaying gastric emptying did not induce significant dyspeptic symptoms, compared with sham stimulation.

CONCLUSIONS

GES using temporary mucosal electrodes decreases food intake as well as maximum intake of water, and has a tendency of delaying gastric emptying. It may have a potential application for the treatment of obesity.

Effect of Roux-en-Y gastric bypass on satiety and food likes: the role of genetics

Among factors influencing the outcome of bariatric surgery may be genetics and familial risk. The purpose of this study was to assess the etiology of obesity and its impact on hunger, satiety, and food likes in obese patients undergoing Roux-en-Y gastric bypass (RYGB). This study was based on 76 patients undergoing RYGB procedures performed by a single surgeon. A previously described 100-point obesity risk index (ORI) was used to assess familial obesity risk. Hunger and satiety were assessed using a standardized Visual Analog Scale "Snickers" test, and food preferences for regular vs. low-fat potato chips were measured preoperatively and postoperatively. Patients were stratified preoperatively into high ORI (n = 34) and low ORI (n = 42) groups. Before operation, high-ORI patients preferred high-fat (regular) potato chips to low-fat (baked) potato chips, whereas the low-ORI patients liked both food types equivalently (P < 0.05). After operation (n = 43), both groups showed lower preferences for high-fat potato chips (P < 0.05 for high-ORI group). As anticipated, hunger was dramatically suppressed after RYGB. However, there was more satiety in the high-ORI group (P < 0.05, ANOVA). Most patients undergoing bariatric surgery had a strong familial or genetic component to their disease. RYGB in high-ORI patients was associated with a significant decline in preference of fatty food and a significantly prolonged drop in hunger ratings after a fast and after a standard 282 kcal meal. The success of bariatric surgery may be influenced by the etiology of obesity.

Retrograde gastric electrical stimulation reduces food intake and weight in obese rats

OBJECTIVE

To investigate the therapeutic potential of retrograde gastric electrical stimulation (RGES) for obesity in a rodent model of obesity.

RESEARCH METHODS AND PROCEDURES

The study was performed in 12 obese Zucker rats implanted with two pairs of gastric serosal electrodes, one pair for stimulation and the other for recording intrinsic gastric myoelectrical activity. It was composed of an acute study in three sessions to study the effect of RGES on intrinsic gastric myoelectrical activity and acute food intake and a chronic phase to study the short-term effect of RGES on weight. RGES was performed through the distal stomach using long pulses at a frequency of tachygastria (known to induce gastric hypomotility).

RESULTS

RGES completely entrained intrinsic gastric myoelectrical activity and turned it into tachygastria at a certain strength. RGES reduced acute food intake compared with the control (p < 0.01). A 2-week treatment of RGES resulted in a significant reduction in food intake (p = 0.002) and a significantly greater weight loss than sham stimulation (p = 0.004).

DISCUSSION

RGES at a tachygastrial frequency reduces food intake and results in weight loss in obese Zucker rats, and its effect is probably attributed to the introduction of tachygastria in the stomach.

Retrograde gastric pacing reduces food intake and delays gastric emptying in humans: a potential therapy for obesity?

Obesity is one of the most prevalent health problems in the world with a lack of satisfactory therapies and gastric electrical stimulation has recently been proposed for the treatment of obesity. The aim of this study was to investigate the effects of retrograde gastric pacing (RGP) on food and water intake, and gastric emptying in humans. RGP with a tachygastrial frequency of 9 cycles/min was performed via a pair of submucosal gastric electrodes implanted 5 cm above the pylorus in 12 subjects. The water load test, food intake test and scintigraphic gastric emptying test were performed to assess the efficacy of RGP. RGP resulted in a 13% reduction in the consumption of water, a 16% reduction in food intake and a 15% increase in gastric retention of a solid meal. No significant symptoms were recorded with RGP using the parameters used for the water-load, food intake and scintigraphic gastric emptying tests. Acute RGP at a tachygastrial frequency results in a significant reduction of water and food intake and a delay in gastric emptying without inducing any unacceptable symptoms. It is worthy to explore its therapeutic potential for obesity.

Visceral response to acute retrograde gastric electrical stimulation in healthy human

AIM: To investigate the visceral response to acute retrograde gastric electrical stimulation (RGES) in healthy humans and to derive optimal parameters for treatment of patients with obesity.

METHODS: RGES with a series of effective parameters were performed via a bipolar mucosal electrode implanted along the great curvature 5 cm above pylorus of stomach in 12 healthy human subjects. Symptoms associated with dyspepsia and other discomfort were observed and graded during RGES at different settings, including long pulse and pulse train. Gastric myoelectrical activity at baseline and during different settings of stimulation was recorded by a multi-channel electrogastrography.

RESULTS: The gastric slow wave was entrained in all the subjects at the pacing parameter of 9 cpm in frequency, 500 ms in pulse width, and 5 mA in amplitude. The frequently appeared symptoms during stimulation were satiety, bloating, discomfort, pain, sting, and nausea. The total symptom score for each subject significantly increased as the amplitude or pulse width was adjusted to a higher scale in both long pulse and pulse train. There was a wide diversity of visceral responses to RGES among individuals.

CONCLUSION: Acute RGES can result in a series of symptoms associated with dyspepsia, which is beneficial to the treatment of obesity. Optimal parameter should be determined according to the individual sensitivity to electrical stimulation.

Therapeutic potential of duodenal electrical stimulation for obesity: acute effects on gastric emptying and water intake

OBJECTIVES

No satisfactory treatment is available for obesity. Previous animal studies suggested the therapeutic potential of intestinal electrical stimulation for obesity. The aim of this study was to investigate the effects of duodenal electrical stimulation (DES) on gastric emptying and water intake in healthy humans.

METHODS

The study was performed in 12 healthy volunteers intubated with a feeding tube in the duodenum under endoscopy. There were three ring electrodes at the end tip of the tube and the two distal electrodes were used for recording and electrical stimulation. On two separate days, each subject underwent a session of DES with various stimulation parameters, a water-intake test with DES or with sham-DES, and a gastric-emptying test with DES or with sham-DES.

RESULTS

DES did not induce any noticeable dyspeptic symptoms. The amount of water drunk by the subjects was significantly reduced from 897 +/- 88 ml with sham-DES to 673 +/- 63 ml with DES (p < 0.002). The mean T(50) of gastric emptying was significantly increased from 113.1 +/- 10.0 min with sham-DES to 176.5 +/- 20.8 min with DES state (p < 0.005). The gastric retention at 2 h was increased with DES (42.8 +/- 4.5% vs 61.4 +/- 4.7%; p < 0.02).

CONCLUSIONS

DES delays gastric emptying and reduces water intake. It may have a potential application for the treatment of obesity.

Biliopancreatic diversion in the surgical treatment of morbid obesity

Biliopancreatic diversion is a malabsorptive technique of bariatric surgery that has gained wide acceptance in the Western world. It is performed in one of two ways: In its classic form it consists of partial gastrectomy with a Roux-en-Y gastroenterostomy; in its duodenal switch form a vertical sleeve gastrectomy is combined with a duodenoenterostomy. Both techniques realize diversion of biliopancreatic juice, thereby creating a mild form of malabsorption. Weight loss has been approximately 70% of initial excess weight, exceeding that obtained with most other bariatric procedures. Iron, calcium, and vitamin deficiencies may occur, especially with classic biliopancreatic diversion, and must be prevented with adequate supplements during vigorous follow-up. Weight loss is followed by a substantial reduction in the co-morbidities that are present in many morbidly obese patients. Biliopancreatic diversion should be included in each obesity clinic program and be proposed for morbidly obese patients who are having difficulty with the prospect of continuous restraint of food intake or problems due to failed gastric restrictive interventions. The postoperative results in such patients have been good and have substantially improved quality of life and self-esteem in this category of morbidly obese patients.

Obesity: an overview on its current perspectives and treatment options

Obesity is a multi-factorial disorder, which is often associated with many other significant diseases such as diabetes, hypertension and other cardiovascular diseases, osteoarthritis and certain cancers. The management of obesity will therefore require a comprehensive range of strategies focussing on those with existing weight problems and also on those at high risk of developing obesity. Hence, prevention of obesity during childhood should be considered a priority, as there is a risk of persistence to adulthood. This article highlights various preventive aspects and treatment procedures of obesity with special emphasis on the latest research manifolds.

Bariatric Implications of Critical Care Nursing

The delivery of optimum nursing care to morbidly obese patients in critical care presents unique challenges in critical thinking, planning, and teamwork. The purpose of this article is to review the special needs of this patient population and to provide a template to guide proactive nursing care planning in critical care settings.

The management of the obese diabetic patient

The prevalence of obesity and diabetes is increasing in the United States and worldwide. These diseases are predicted to explode to epidemic proportions, unless appropriate counteractive measures are taken. Several large studies (DCCT, UKPDS, Kumamoto) clearly showed that intensive glycemic control in the diabetic patient reduced microvascular complications and improved mortality. Despite this, the NHANES III showed that only 50% of diabetics have been able to achieve a HgbAic level that is less than 7%; this suggests the need for a re-evaluation of our approach to these patients. The management of the obese diabetic patient involves glycemic control and weight reduction. These goals are particularly difficult to achieve in the obese diabetic patient because progressive beta-cell dysfunction and increasing insulin resistance necessitates the administration of increasingly higher dosages of insulin, which, in turn, promotes weight gain. A vicious cycle may ensue. Lifestyle modifications with diet and exercise are an essential part of the management of the obese diabetic patient. These measures alone are often insufficient and concomitant pharmacologic therapy is usually required to achieve glycemic and weight control. Oral agents that improve glycemia, decrease insulin resistance, and limit weight gain are desirable. Because of the progressive nature of diabetes, glycemic control with monotherapy often deteriorates over time, which necessitates the addition of other pharmacologic agents, including insulin. When insulin therapy is required in the treatment of the obese diabetic patient, combinations with oral agents that have been shown to minimize the amount of exogenous insulin that is required, may minimize weight gain. In addition, the obese diabetic patient who is poorly controlled with maximum oral hypoglycemic therapy may benefit from weight-reducing agents, such as sibutramine or orlistat. The introduction of these agents at other points in the management of the obese diabetic patients have been successful. Finally, for the severely obese diabetic patient, bariatric surgery may be the only effective treatment. Gastric bypass has been unequivocally shown to produce significant weight loss and improve glycemic control on a long-term basis in the obese diabetic patient. It is recommended that physicians avail themselves of all of these strategies in the management of the obese patient who has type 2 diabetes.

Autopsy findings following gastric bypass surgery for morbid obesity

BACKGROUND

Roux-en-Y gastric bypass, currently the most frequently performed surgical procedure for morbid obesity, has a low but significant mortality rate. There are limited data documenting the findings at necropsy in patients who have died following this procedure.

OBJECTIVE

To determine cause of death and pathologic processes present in obese subjects dying after gastric bypass surgery.

PATIENTS

We studied 10 patients who underwent autopsy following gastric bypass surgery for morbid obesity between the years 1994 and 2000.

RESULTS

There were 6 men and 4 women. The mean age of the patients was 48 years (range, 28-62 years). The mean preoperative weight was 162 kg (range, 112-245 kg), and the mean body mass index was 54 kg/m(2) (range, 39-76 kg/m(2)), similar to all patients undergoing gastric bypass at our institution during the same period. Five deaths were directly attributable to technical complications. Five deaths were attributed to underlying comorbid conditions. One patient died of cirrhosis and one of pulmonary hemorrhage. Three patients died from pulmonary embolism. However, 8 of 10 patients had microscopic evidence of pulmonary emboli, despite prophylaxis for deep vein thrombosis. Most patients had some degree of steatohepatitis and hepatic fibrosis (80% and 70%, respectively). There were no deaths from primary cardiac events.

CONCLUSIONS

In patients who die after Roux-en-Y gastric bypass, half die due to technical complications, whereas the other half die of complications of their obesity. Clinically, only 20% of patients were suspected to have pulmonary emboli, yet at autopsy, 80% of patients had pulmonary emboli. In morbidly obese patients undergoing Roux-en-Y gastric bypass, there is an unexpectedly high rate of clinically silent pulmonary emboli contributing to morbidity and mortality.

Insulin resistance in morbid obesity: reversal with intramyocellular fat depletion

Obesity is a frequent cause of insulin resistance and poses a major risk for diabetes. Abnormal fat deposition within skeletal muscle has been identified as a mechanism of obesity-associated insulin resistance. We tested the hypothesis that dietary lipid deprivation may selectively deplete intramyocellular lipids, thereby reversing insulin resistance. Whole-body insulin sensitivity (by the insulin clamp technique), intramyocellular lipids (by quantitative histochemistry on quadriceps muscle biopsies), muscle insulin action (as the expression of Glut4 glucose transporters), and postprandial lipemia were measured in 20 morbidly obese patients (BMI = 49 +/- 8 [mean +/- SD] kg x m(-2)) and 7 nonobese control subjects. Patients were restudied 6 months later after biliopancreatic diversion (BPD; n = 8), an operation that induces predominant lipid malabsorption, or hypocaloric diet (n = 9). At 6 months, BPD had caused the loss of 33 +/- 10 kg through lipid malabsorption (documented by a flat postprandial triglyceride profile). Despite an attained BMI still in the obese range (39 +/- 8 kg x m(-2)), insulin resistance (23 +/- 3 micromol/min per kg of fat-free mass; P < 0.001 vs. 53 +/- 13 of control subjects) was fully reversed (52 +/- 11 micromol/min per kg of fat-free mass; NS versus control subjects). In parallel with this change, intramyocellular-but not perivascular or interfibrillar-lipid accumulation decreased (1.63 +/- 1.06 to 0.22 +/- 0.44 score units; P < 0.01; NS vs. 0.07 +/- 0.19 of control subjects), Glut4 expression was restored, and circulating leptin concentrations were normalized. In the diet group, a weight loss of 14 +/- 12 kg was accompanied by very modest changes in insulin sensitivity and intramyocellular lipid contents. We conclude that lipid deprivation selectively depletes intramyocellular lipid stores and induces a normal metabolic state (in terms of insulin-mediated whole-body glucose disposal, intracellular insulin signaling, and circulating leptin levels) despite a persistent excess of total body fat mass.

Vertical banded gastroplasty: a treatment for morbid obesity

Stomach stapling to aid the morbidly obese patient with weight loss has been available for years. Unfortunately, some methods of bariatric surgery (e.g., gastric bypass surgery) can lead to serious complications. This article discusses vertical banded gastroplasty (VBG) and presents on overview of morbid obesity and its inherent medical problems, the screening process and the physical and psychological needs of patients undergoing bariatric procedures, the anatomy and physiology of normal digestion, and the perioperative nursing considerations in caring for a patient undergoing VBG.

Managing the obese patient after bariatric surgery: a case report of severe malnutrition and review of the literature

Surgery is now considered to be the most effective treatment for reducing weight and maintaining weight loss in patients with clinically severe obesity. Although the jejuno-ileal bypass has been abandoned, the vertical banded gastroplasty (VBG) and Roux-en-Y gastric bypass (RYGB) operations are now commonly performed. A third operation, the bilio-pancreatic diversion (BPD), is performed less frequently. The RYGB and BPD procedures cause predictable selective micronutrient deficiencies that can be avoided by early supplementation. Surgical complications from all of these procedures may result in more severe forms of malnutrition. This article is intended to familiarize the nutrition support specialist with the anatomic and physiologic changes produced by these procedures, the resulting nutritional deficiencies and recommended supplementation, and the manifestations of severe malnutrition caused by complications. A case of severe malnutrition after RYGB surgery is reported for illustration.

Surgical treatment of morbid obesity with biliopancreatic diversion and gastric banding: report on an 8-year experience involving 235 cases

STUDY AIM

Developments have recently been made in bariatric surgery outside the USA. The aim of this retrospective non-randomized study was to report on our experience regarding biliopancreatic diversion (BPD) and non-adjustable gastric banding (GB) in a population of 235 obese patients.

PATIENTS AND METHODS

From March 1990 to March 1998, 235 obese patients were operated on, 142 by BDP and 93 by GB, via laparotomy after rigourous selection of the patient population.

RESULTS

The mean duration of surgery was 2 h 50 minutes for BPD and 1 h for GB. One postoperative death occurred due to massive pulmonary embolism. Early major complications were frequent in the BPD group (n = 21) but rare in the GB group (n = 1). Mean duration of hospitalization was 16 days in the BPD group versus 9 days in the GB group. Mean percentage excess weight loss was 48% for the GB group and 60% for the BPD group after two years. Late mortality was limited to the BPD group (3.5%). Late complications were evenly distributed between the two groups, with a prevalence of malnutrition in the BPD group and outlet stenosis in the GB group. A high incidence of band removal was recorded related to this complication (17.2%). Incisional hernias were present in both groups.

CONCLUSIONS

GB and BPD are techniques which can induce weight loss and bring about subsequent health benefits. Nevertheless, in a few patients further intervention or adaptation of the approach due to clinical failure or to a high complication rate is required. Additional research is needed regarding determination of the surgical treatment that is best adapted to the case in question, i.e., taking into consideration both the restrictive and malabsorbative aspects.

Relationships between changes in body composition and changes in cardiovascular risk factors: the SOS Intervention Study. Swedish Obese Subjects

Relationships between 2-year changes in body composition (estimated from computed tomography-validated anthropometry based on sagittal trunk diameter, weight, and height), adipose tissue (AT) distribution, and cardiovascular risk factors (blood pressure, lipids, glucose, insulin, uric acid) were examined in 842 treated adults with severe obesity with weight changes from -95.5 to +30.6 kg. Although the change (delta) of visceral AT mass (expressed in % total AT) for a given change in body mass index (delta BMI) was 6-fold larger in men than in women, delta waist and delta waist/hip were similar in both sexes. In men, risk factor changes were similarly related to delta waist, delta bodyweight, and delta BMI, whereas in women, delta bodyweight seemed to be the single independent variable with the highest explanatory power. In multivariate regressions adjusted for delta BMI and baseline conditions, delta visceral AT mass was more strongly associated with risk factor changes than were delta waist and delta waist/hip. When using a three-compartment model (lean body mass, subcutaneous and visceral AT masses) plus neck and thigh girths (indicators of subcutaneous AT distribution), risk factor changes were related both to delta subcutaneous and delta visceral AT masses but not to delta lean body mass. In agreement with cross-sectional findings, delta neck was positively and delta thigh was negatively related to some risk factor changes. Thus, the use of waist as a single risk factor indicator seems less effective for epidemiological studies than the simple anthropometric measures presented here, which are able to separate the effects of visceral AT mass, subcutaneous AT mass, and subcutaneous AT distribution on metabolic parameters under both cross-sectional and longitudinal conditions.