The insulin tolerance test in morbidly obese patients undergoing bariatric surgery.

OBJECTIVE: To assess the effect of massive weight loss in relation to insulin resistance and its correlation to changes in glycemic homeostasis and lipid profile in severely obese patients. RESEARCH METHODS AND PROCEDURES: A prospective clinical intervention study was carried out with 31 morbidly obese women (body mass index: 54.2 +/- 8.8 kg/m(2)) divided into three groups according to their glucose tolerance test: 14 normal, 8 impaired glucose tolerance, and 9 type 2 diabetes. All subjects underwent an insulin tolerance test with intravenous bolus of 0.1 U insulin/kg body weight before silastic ring vertical gastroplasty Roux-en-Y gastric bypass surgery, and again at 2, 4, 6, and 12 months postoperatively. Fasting plasma glucose, hemoglobin A1c, and lipid profile were also evaluated. RESULTS: A reduction of 68 +/- 15% in initial excess body weight was evident within 1 year. Along with weight loss, the following statistically significant changes were found: an increase in the insulin-sensitivity index (Kitt) and a decrease in fasting plasma glucose and hemoglobin A1c, most notably in the type 2 diabetes group. An overall improvement in lipid profile was observed in all three groups. DISCUSSION: Bariatric surgery was an effective therapeutic approach for these obese patients because it reduced both weight and insulin resistance, along with improving metabolic parameters. Significant correlations were found between insulin resistance and metabolic improvements. weight loss after bariatric surgery induced an improvement in metabolic fitness, related to the reduction in insulin resistance over a range of glucose tolerance statuses from normal to diabetic.

Nutritional behavior as a predictor of early success after vertical gastroplasty.

BACKGROUND: Patients' nutritional habits are seldom taken in account in planning surgery for clinically severe obesity. Our proposed hypothesis is that the patient's nutritional behavior may influence the outcome of bariatric surgery. METHODS: The impact of nutritional behavior on the postoperative weight-loss was evaluated before and after bariatric surgery. A 6-month prospective consecutive case study was carried out on patients undergoing a Silastic ring vertical gastroplasty (SRVG). Patients were interviewed and examined before and at 1, 3 and 6 months after surgery. Demographic and clinical data were collected from the patients' medical charts. Nutritional data collected from a self-filled questionnaire included information on hunger and satiety perception, nutritional behavior (intake, eating habits and maximum consistency of consumed food) and concomitant symptoms. RESULTS: The sample included 69 patients: 56 were women (81%); average age was 32 years (range 18 50). Average preoperative BMI was 43.4 +/- 5.3 kg/m2 (range 35-58). 6 months after surgery, BMI was 30.3 +/- 3.8 kg/m2 (range 21-42). weight loss forecast models showed a statistically significant role of factors related to: anthropometrical preoperative data, hunger perception, prevalence of oral mucosal sore, and nutritional behavior. CONCLUSION: The short nutrition outcomes after gastric restrictive surgery were looked at, with their impact on weight-loss success. The Eating Status concept should be part of a systematic profiling of morbidly obese patients for preoperative nutritional behavior and postoperative nutritional education, to achieve the best comprehensive treatment in regard to weight loss and quality of life.

Nutritional risk and status assessment in surgical patients: a challenge amidst plenty.

BACKGROUND AND AIMS: No gold standard exists for nutritional screening/assessment. This cross-sectional study aimed to collect/use a comprehensive set of clinical, anthropometric, functional data, explore interrelations, and derive a feasible/sensitive/specific method to assess nutritional risk and status in hospital practice. PATIENTS AND METHODS: 100 surgical patients were evaluated, 49M:51F, 55 +/- 18.9 (18-88) years. Nutritional risk assessment: Kondrup's Nutritional Risk Assessment, BAPEN's Malnutrition Screening Tool, Nutrition Screening Initiative, Admission Nutritional Screening Tool. Nutritional status: anthropometry categorised by Body Mass Index and McWhirter & Pennington criteria, recent weight loss > 10%, dynamometry, Subjective Global Assessment. RESULTS: There was a strong agreement between all nutritional risk (k = 0.69-0.89, p < 0.05) and between all nutritional assessment methods (k = 0.51-0.88, p < or = 0.05) except for dynamometry. weight loss > 10% was the only method that agreed with all tools (k = 0.86-0.94, p < or = 0.05), and was thereafter used as the standard. Kondrup's Nutritional Risk Assessment and Admission Nutritional Screening Tool were unspecific but highly sensitive (> or = 95%). Subjective Global Assessment was highly sensitive (100%) and specific (69%), and was the only method with a significant Youden value (0.7). CONCLUSIONS: Kondrup's Nutritional Risk Assessment and Admission Nutritional Screening Tool emerged as sensitive screening methods; the former is simpler to use, Kondrup's Nutritional Risk Assessment has been devised to direct nutritional intervention. Recent unintentional weight loss > 10% is a simple method whereas Subjective Global Assessment identified high-risk/undernourished patients.

The mini-gastric bypass: experience with the first 1,274 cases.

BACKGROUND: Results of the laparoscopic Mini-Gastric Bypass (MGB) are reported. METHODS: 1,274 MGB patients are continuously monitored as part of an online computer tracking data-base system. RESULTS: Mean preoperative weight (+/- Standard Deviation) was 132 +/- 21 kg, BMI 47 +/- 7. Mean excess weight loss was 51% at 6 months, 68% at 12 months and 77% at 2 years. The mean operating-time was 36.9 +/- 33.5 minutes. The shortest time was 19 minutes. Hospital stay was 1.5 +/- 1.6 days. The overall complication rate has been 5.2%. The overall rate of deep vein thrombosis and pulmonary embolism was 0.08% and 0.16% respectively. The leak rate was 1.6%. There was one hospital death, 0.08%. Associated medical illnesses were either completely reversed or markedly improved. CONCLUSIONS: The MGB is safe, results in major weight loss, has a short operating-time, and has a short hospital stay. The MGB appears to meet many of the criteria of an "ideal" weight loss operation.

Physical activity in free-living, overweight white and black women: divergent responses by race to diet-induced weight loss.

BACKGROUND: Black women are at greater risk of obesity than are white women, perhaps because of their lower levels of physical activity. OBJECTIVE: We compared free-living activity energy expenditure (AEE) in sedentary white and black women (in overweight and normal-weight states) and in never-overweight control subjects. DESIGN: Subjects included 46 women (23 white, 23 black) studied while overweight and after reaching a normal weight and 38 female control subjects (23 white, 15 black). Diet, without exercise training, resulted in a mean weight loss of 13 kg and a body mass index (in kg/m(2)) < 25. Body composition, sleeping energy expenditure, free-living total energy expenditure, and the energy cost of activity and aerobic capacity were assessed before and after weight loss under 4-wk, diet-controlled, weight-stable conditions and in the control subjects. AEE was defined as above-sleep energy expenditure. RESULTS: No significant racial differences in body composition, before or after weight loss, were found. After weight loss, AEE and aerobic capacity increased in the white women and decreased in the black women (P < 0.05 and P < 0.02, respectively). After weight loss, but not before, the white women had a significantly higher mean AEE than did the black women (2448 +/- 979 and 1728 +/- 1373 kJ/d, respectively; P < 0.05), approximating AEEs in the white (2314 +/- 1105) and black (2310 +/- 1251) control subjects. CONCLUSIONS: Relative to the responses of the white women to diet-induced weight loss, the black women became less fit and less physically active. Induction of a normal body weight in overweight black women appeared to produce a more obesity-prone state, favoring weight relapse.

Macrophage inhibitory factor, plasminogen activator inhibitor-1, other acute phase proteins, and inflammatory mediators normalize as a result of weight loss in morbidly obese subjects treated with gastric restrictive surgery.

Obesity is demonstrated to be associated with an enhanced inflammatory state, which is suggested to be a cause for the development of obesity-related morbidity. It was hypothesized that a decrease in body weight in morbid obese subjects would lead to a reduction of the inflammatory state in these subjects.weight loss was achieved by gastric restrictive surgery in 27 morbidly obese patients. Preoperative as well as 3-, 6-, 12-, and 24-month postoperative plasma concentrations of inflammatory mediators macrophage inhibitory factor, plasminogen activator inhibitor-1, lipopolysaccharide binding protein, alpha-1 acid glycoprotein, C-reactive protein, soluble TNFalpha receptors 55 and 75, and leptin were measured.Macrophage inhibitory factor levels remained low normal for 6 months, during weight loss, after which they significantly increased to normal levels at 24 months postoperatively. The other inflammatory mediators remained elevated up to minimally 3 months postoperatively; thereafter they decreased significantly. Both TNFalpha receptors remained elevated up to at least 12 months postoperatively to decrease significantly at 2 yr postoperatively.This study demonstrates that during weight loss, after gastric restrictive surgery, inflammatory mediators remain elevated for at least 3 months postoperatively, suggesting initially an ongoing inflammatory state. However, 2 yr after surgery, the inflammatory mediators reach near normal values.These findings may be an explanation for the reduced comorbidity seen in morbidly obese patients after gastric restrictive surgery.

Intentional weight loss and death in overweight and obese U.S. adults 35 years of age and older.

BACKGROUND: Although weight loss improves risk factors for cardiovascular and metabolic disease, it is unclear whether intentional weight loss reduces mortality rates. OBJECTIVE: To examine the relationships among intention to lose weight, weight loss, and all-cause mortality. DESIGN: Prospective cohort study using a probability sample of the U.S. population. SETTING: Interviewer-administered survey. PARTICIPANTS: 6391 overweight and obese persons (body mass index > or = 25 kg/m2) who were at least 35 years of age. MEASUREMENTS: Intention to lose weight and weight change during the past year were assessed by self-report in 1989. Vital status was followed for 9 years. Hazard rate ratios (HRRs) were adjusted for age, sex, ethnicity, education, smoking, health status, health care utilization, and initial body mass index. RESULTS: Compared with persons not trying to lose weight and reporting no weight change, those reporting intentional weight loss had a 24% lower mortality rate (HRR, 0.76 [95% CI, 0.60 to 0.97]) and those with unintentional weight loss had a 31% higher mortality rate (HRR, 1.31 [CI, 1.01 to 1.70]). However, mortality rates were lower in persons who reported trying to lose weight than those in not trying to lose weight, independent of actual weight change. Compared with persons not trying to lose weight and reporting no weight change, persons trying to lose weight had the following HRRs: no weight change, 0.80 (CI, 0.65 to 0.99); gained weight, 0.94 (CI, 0.65 to 1.37); and lost weight, 0.76 (CI, 0.60 to 0.97). CONCLUSIONS: Attempted weight loss is associated with lower all-cause mortality, independent of weight change. Self-reported intentional weight loss is associated with lower mortality rates, and weight loss is associated with higher mortality rates only if it is unintentional.

Several recent clinical studies show that a low-carbohydrate diet produces a greater initial weight loss than conventional low-fat diets, and is associated with a greater reduction of elevated serum triglycerides. After one year, however, weight loss is similar with both diets. Since the intake of saturated fat is higher on a low-carbohydrate diet, there may be an increased risk of elevated levels of LDL cholesterol, thus furthering atherosclerosis, over the long term. Before low-carbohydrate diets can be considered an equivalent alternative to low-fat diets for the treatment of obesity, long-term clinical trials are urgently required. The greater weight loss under low-carbohydrate diets would appear to be due to a lower caloric intake. Successful weight loss largely depends on restricting the intake of calories, but the supply of essential nutrients should be guaranteed.