Insulin resistance in nondiabetic morbidly obese patients: effect of bariatric surgery.

OBJECTIVE: To evaluate insulin action on substrate use and insulinemia in nondiabetic class III obese patients before and after weight loss induced by bariatric surgery. RESEARCH METHODS AND PROCEDURES: Thirteen obese patients (four men/nine women; BMI = 56.3 +/- 2.7 kg/m2) and 13 lean subjects (five men/eight women; BMI = 22.4 +/- 0.5 kg/m2) underwent euglycemic clamp, oral glucose tolerance test, and indirect calorimetry. The study was carried out before (Study I) and after ( approximately 40% relative to initial body weight; Study II) weight loss induced by Roux-en-Y Gastric bypass with silastic ring surgery. RESULTS: The obese patients were insulin resistant (whole-body glucose use = 19.7 +/- 1.5 vs. 51.5 +/- 2.4 micromol/min per kilogram fat-free mass, p < 0.0001) and hyperinsulinemic in the fasting state (332 +/- 86 vs. 85 +/- 5 pM, p < 0.0001) and during the oral glucose tolerance test compared with the lean subjects. Fasting plasma insulin normalized after weight loss, whereas whole-body glucose use increased (35.5 +/- 3.7 micromol/min per kilogram fat-free mass, p < 0.05 vs. Study I). The higher insulin clearance of obese did not change during the follow-up period. Insulin-induced glucose oxidation and nonoxidative glucose disposal were lower in the obese compared with the lean group (all p < 0.05). In Study II, the former increased slightly, whereas nonoxidative glucose disposal reached values similar to those of the control group. Fasting lipid oxidation was higher in the obese than in the control group and did not change significantly in Study II. The insulin effect on lipid oxidation was slightly improved (p = 0.01 vs. Study I). DISCUSSION: The rapid weight loss after surgery in obese class III patients normalized insulinemia and improved insulin sensitivity almost entirely due to glucose storage, whereas fasting lipid oxidation remained high.

Weight change, survival time and cause of death in Dutch elderly.

Weight change, subsequent survival time and cause of death are reported from the Dutch Longitudinal Study among the Elderly. Data consist of a national sample of persons aged 65-99 years. Six hundred and fifty-eight subjects were examined in the baseline years 1955-1957 and were re-examined 5 years later. Vital status and cause of death were ascertained for 604 of these subjects through 1983. Those subjects who experienced a decline in body mass index (BMI, kg/m(2)) during the period of observation, were likely to be in poorer health and have a shorter survival time than those subjects with stable weight, regardless of initial BMI. Weight gain was associated with shorter survival time only in the age group 65-74 and in those with heart disease. weight loss, on the other hand, was most likely to result in decreased survival time among those ultimately dying of stroke, pneumonia/influenza or heart disease. As such, weight loss may be an indicator of the severity of disease. The noted associations remained, even when those surviving less than two years were omitted from the analyses. Thus, in longer survivors, weight loss may be associated with decreased vitality and decreased ability to survive once a disease becomes apparent.

Health risks, past usage, and intention to use weight loss products in normal weight women with high and low body dysphoria.

OBJECTIVE: There are many health risks involved with the use of weight loss products by normal weight women. The mass media may compound this problem through the promotion of weight loss products and a thin body size. This study tested women's perceptions of different weight loss product ads to determine if body dysphoria (i.e., an over concern with body size and shape in normal weight people) was associated with risk beliefs, past behaviors, and intention toward using weight loss products. METHOD: Normal weight women (age range = 18-41 yr), who were classified as either high (n=45) or low (n=43) on a measure of body dysphoria, rated different weight loss products according to their perception of health risks, past behavior, and their intention to consume the products. These products were a dietary fat substitute (olestra), a prescription obesity medication (Sibutramine ( Meridia )), and an over-the-counter appetite suppressant (phenylpropanolamine). RESULTS: High body dysphoric women reported higher intentions to use the products as well as increased prior use of two of the three weight loss products. High body dysphoric women did not believe that these weight loss products were harmless. They recognized potential health risks associated with using such products, but nonetheless, expressed intention to use these weight loss products at a higher frequency. Also, several variables related to body image were found to effectively discriminate normal weight women at risk for abusing weight loss products. DISCUSSION: This study found that women who do not need to lose weight but have significant body image concerns were willing to use potentially harmful weight loss products despite the knowledge that such products might pose significant health risks. Techniques utilized by advertising regulatory agencies such as warning labels did not have a strong deterrent effect for stated intentions to use the products. Implications of these findings for public health policy issues were discussed.

Attaining successful weight loss with an ideal macronutrient balance.

A dramatic increase in the number of people who are overweight or obese in this country presents a growing public health problem. Successful weight loss requires diet, physical activity, and behavior modification interventions. weight loss diets with distinctively different macronutrient profiles have resulted in short-term weight loss. There is great interest in identifying the most effective strategies to achieve long-term weight loss. Individualizing weight loss interventions, including diet, will be important to facilitate significant weight loss on a population basis. Nurses and nurse practitioners can play an integral role in supporting their patient's weight loss efforts.

High-fat hypocaloric diet modifies carbohydrate utilization of obese rats during weight loss.

The effects of fat content in the hypocaloric diet on whole body glucose oxidation and adipocyte glucose transport were investigated in two animal-feeding experiments. Diet-induced obese rats were food restricted to 75% of their previous energy intakes with either a high (45% by calorie) or a low (12% by calorie) corn oil diet for 9 wk (experiment 1) or 10 days (experiment 2). The losses of body weight (P < 0.05) and adipose depot weight (P < 0.05) were less in the 45% compared with the 12% fat group. During the dynamic phase of weight loss (day 10 of food restriction), plasma glucose and insulin concentrations were higher (P < 0.05) in the 45% than those in the 12% fat group. Whole body carbohydrate oxidation rate in response to an oral load of glucose was increased (P < 0.001) by food restriction in both dietary groups; however, carbohydrate oxidation rates were lower (P < 0.01) in the 45% than in the 12% fat-fed rats during the weight loss period. Adipocyte glucose transport was greater (P < 0.02) in the 45% than in the 12% fat group in an intra-abdominal adipose depot but not in subcutaneous fat. These data suggest that dietary fat content modifies whole body glucose oxidation and intra-abdominal adipocyte glucose uptake during weight loss.

Sibutramine ( Meridia ): new preparation. Slight weight loss; but also a slight rise in blood pressure ...

(1) The reference treatment for achieving weight loss by obese patients is a combination of dietary measures, exercise and behavioural interventions. There is currently no drug treatment with demonstrated efficacy on the morbidity or mortality associated with excess body weight. (2) Sibutramine ( Meridia ), a serotonin- and noradrenaline-reuptake inhibitor structurally related to the amphetamines has been granted marketing authorisation in France for the treatment of obesity and excess body weight in patients with associated risk factors. (3) The clinical file on Sibutramine ( Meridia ) contains no trial focusing on morbidity or mortality end points. (4) According to comparative clinical trials, weight loss during a 6-12 month course of Sibutramine ( Meridia ) is, on average, between 3 and 9 kg greater than that on placebo. Patients regain weight after Sibutramine ( Meridia ) cessation. (5) Sibutramine ( Meridia ) has little or no benefit on blood sugar or lipid parameters. (6) The main known adverse effect of Sibutramine ( Meridia ) is increased blood pressure. Sibutramine ( Meridia ) also has amphetamine-like side effects. (7) In practice, Sibutramine ( Meridia ) currently has no place in the management of obesity.

Weight change and the risk of gestational diabetes in obese women.

BACKGROUND: obesity is an established risk factor for gestational diabetes. It is not known whether this risk might be reduced through weight loss between pregnancies. We sought to determine whether weight loss between pregnancies reduced the risk of gestational diabetes among obese women. METHODS: We conducted a population-based cohort study of 4102 women with 2 or more singleton live births in Washington State between 1992 and 1998. All subjects were nondiabetic and obese (at least 200 lbs) at their first birth during these years. Weight change was calculated as the difference between prepregnancy weight for the 2 pregnancies. We estimated relative risks of gestational diabetes at the subsequent delivery through stratified analyses and Mantel-Haenszel estimates. RESULTS: Thirty-two percent of women lost weight between pregnancies, with a mean weight loss of 23 lbs. Women who lost at least 10 lbs between pregnancies had a decreased risk of gestational diabetes relative to women whose weight changed by less than 10 lbs (relative risk = 0.63; 95% confidence interval = 0.38-1.02, adjusted for age and weight gain during each pregnancy). Of the 61% of women who gained weight between pregnancies, the mean weight gain was 22 lbs. Women who gained at least 10 lbs had an increased risk of gestational diabetes (1.47; 1.05-2.04). CONCLUSIONS: Even moderate changes in prepregnancy weight can apparently affect the risk of gestational diabetes among obese women. This may offer further motivation for interventions aimed at reducing obesity among women of reproductive age.

Body composition analysis and changes in airways function in obese adults after hypocaloric diet.

STUDY OBJECTIVES: To determine the relationship between weight-loss and pulmonary function indexes, focusing on forced expiratory flows (ie, FEV(1), forced expiratory flow at 50% of vital capacity [FEF(50)], forced expiratory flow at 75% of vital capacity, and forced expiratory flow at 25 to 75% of vital capacity [FEF(25--75)]). Specifically, to determine the effect of losses in total and segmental fat mass (FM) and of modifications in lean body mass, after restricted hypocaloric diet, on pulmonary function among obese adults. DESIGN: Cross-sectional, observational. SETTINGS: Human Physiology Division, Faculty of Medicine and Surgery, "Tor Vergata" University, Rome, Italy. PATIENTS: Thirty obese adults (mean [+/- SD] baseline body mass index [BMI], 32.25 +/- 3.99 kg/m(2)), without significant obstructive airway disease, were selected from among participants in a weight-loss program. MEASUREMENTS AND RESULTS: Anthropometric, body composition (BC), and respiratory parameters of all participants were measured before and after weight loss. Total and segmental lean body and FM were obtained by dual-energy x-ray absorptiometry. Dynamic spirometric tests and maximum voluntary ventilation (MVV) were performed. The BC parameters (ie, body weight [BW], BMI, the sum skinfold thicknesses, thoracic inhalation circumference, thoracic expiration circumference, total FM, and trunk FM [FMtrunk]) were significantly decreased (p < or = .0001) after a hypocaloric diet. The mean vital capacity, FEV(1), FEF(50), FEF(25-75), expiratory reserve volume, and MVV significantly increased (p < or = 0.05) with weight loss. The correlation coefficient for Delta FEF(25--75) (r = 0.20) was numerically higher than Delta FEF(50) and Delta FEV(1) (r = 0.14 and r = 0.08, respectively) for the BW loss. Moreover, the correlation coefficient for Delta FEF(25--75) (r = 0.45) was significantly higher (p < or = 0.02) than those for Delta FEF(50) and Delta FEV(1) (r = 0.38 and r = 0.15, respectively) for FMtrunk loss. CONCLUSIONS: This study shows that a decrease in total and upper body fat obtained by restricted diet was not accompanied by a decrease in ventilatory muscle mass. FMtrunk loss was found to have improved airflow limitation, which can be correlated to peripheral airways function.