George S M Cowan

Significant changes in blood pressure, glucose, and lipids with gastric bypass surgery

Abstract. The morbidly obese have a disproportionately greater risk of hypertension, diabetes, and coronary artery disease than their lean or less seriously obese counterparts. Roux-en-Y gastric bypass surgery has been found to be highly effective in inducing, and sustaining, weight loss in individuals with morbid obesity. The purpose of the present study was to examine the effects of weight loss with Roux-en-Y gastric bypass surgery (GBP) on blood pressure, fasting blood glucose, and the lipid/lipoprotein status of 61 morbidly obese women and 21 men. Anthropometric and blood pressure assessments and blood samples for glucose and lipid/lipoprotein analyses were obtained before surgery and at 6 to 12 months postoperatively. By this time, morbidly obese (MO) males and females had lost 33% and 30% of their initial body weight, respectively, along with significant reductions in fasting blood glucose (p < 0.01) and systemic blood pressure (p < 0.05). Weight loss with GBP was also associated with significant reductions in the apoprotein B-containing lipoproteins and the triglyceride and cholesterol composition of these particles. There was a trend (p < 0.10) toward increased serum levels of high density lipoprotein (HDL)-cholesterol following GBP, and significant (p < 0.05) improvement in HDL subfraction distribution and composition. These findings demonstrate the effectiveness of GBP in inducing metabolic changes in the MO population, which may reduce the risk of coronary artery disease, diabetes, and hypertension.

Taste Acuity of the Morbidly Obese before and after Gastric Bypass Surgery.

Obese individuals have an increased preference for high caloric foods, such as sweets and fats. However, following gastric bypass (GBP) surgery, morbidly obese patients tend to avoid these foods. We hypothesize that this aversion may occur, in part, from permutations in taste acuity. To test this hypothesis, taste detection and recognition thresholds for the four basic tastes (salt, sweet, sour, and bitter) were assessed using a modification of the Henkin forced choice three stimulus technique. Taste acuity measurements were obtained at baseline and at 30, 60, and 90 days post-operative for six morbidly obese GBP women and ten non-surgical, lean female controls. We found non-significant differences in taste detection and recognition thresholds between morbidly obese and lean control study subjects at baseline, and no significant correlation between taste acuity and body size. Furthermore, in our study population of lean and obese women, ages 26 to 52, there were no significant interrelationships between baseline taste thresholds and known effectors of taste acuity, i.e., zinc levels, glycemic status, liver and kidney function, or age. Following GBP surgery, a significant up-regulation in taste acuity for bitter and sour was observed along with a trend toward a reduction in salt and sweet detection and recognition thresholds. These findings would suggest the following: (1) taste acuity does not influence taste preferences of the obese individual who has not had bariatric surgery; (2) taste effectors such as zinc, when within the range of normal values, do not alter thresholds of the 4 basic tastes; and (3) weight loss following gastric bypass surgery is associated with an up-regulation in taste acuity in the morbidly obese. Studies are currently under investigation at our center to identify the specific etiology of taste acuity upregulation in the morbidly obese following GBP surgery.

Significant Changes in the Lipid-Lipoprotein Status of Premenopausal Morbidly Obese Females following Gastric Bypass Surgery

The morbidly obese premenopausal female may be more dyslipoproteinemic and at greater risk for developing coronary heart disease than her lean or less seriously obese counterparts. The purpose of the present study was to examine the effects of weight loss with Roux-en-Y gastric bypass surgery on the lipid-lipoprotein status of morbidly obese, premenopausal females. Anthropometrics and blood samples for lipid-lipoprotein analyses were obtained before surgery and 6 - 12 months post-operatively. Following surgery, patients lost 30% of their initial body weight, along with a 40% decline (p < 0.01) in total triglyceride and a 20% decrease (p < 0.01) in total cholesterol. Levels of cholesterol in the high density lipoprotein (HDL) fraction were unaffected by weight loss, but there was a significant (p < 0.05) increase in the proportion of HDL in its more buoyant and anti-atherogenic form, i.e. HDL-L. The apolipoprotein B-containing lipoproteins, very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), and low density lipoprotein (LDL), were reduced up to 70% following surgery. There were no significant changes in VLDL or IDL particle composition, i.e. cholesterol/triglyceride, cholesterol/protein, but there was a significant (p < 0.01) increase in the ratio of cholesterol/apolipoprotein B in LDL, suggesting a shift from the small, dense atherogenic LDL to a larger, less atherogenic particle. We conclude that weight loss following gastric bypass surgery markedly improves the lipid-lipoprotein status of morbidly obese premenopausal females and, thereby, significantly reduces the risk of coronary disease.

Influence of body fat distribution on oxygen uptake and pulmonary performance in morbidly obese females during exercise

Objective: The aim of this study was to determine the effects of fat distribution on aerobic and ventilatory response to exercise testing in morbidly obese (MO) females.

Comparison of Lifestyles Among Obese and Nonobese African American and European American Women in the Community

BACKGROUND Gender and race differences in preventive health behavior have been examined in several studies. A few race- and gender-specific studies of health-promoting activities have been conducted although none of these specifically addresses race, female gender, obesity, and health-promoting activities. Such a study would fill an important gap in the literature. OBJECTIVES To examine the effects of race and obesity on health-promoting behaviors in women. METHOD A comparative descriptive design was used with two levels of body size (obese and nonobese) and two levels of race (African American and European American). RESULTS Obese women scored lower than nonobese women on all Health-Promoting Lifestyle Profile (HPLP) scales. African American women scored lower than European women only on nutrition. CONCLUSIONS Health promotion counseling should be considered for all obese women because obesity may be a mediating variable between race and health-promoting behaviors.

Assessment of the effects of a taped cognitive behavior message on postoperative complications (therapeutic suggestions under anesthesia)

Background: The authors studied whether playing a taped cognitive-behavior message during and immediately following bariatric surgery will improve performance of a postoperative regimen designed to enhance recovery. Methods:The double-blinded placebo-controlled study consisted of 27 morbidly obese bariatric surgical patients randomly assigned to listen to either a blank (Controls) or a positive therapeutic message audiotape (Tape). A Postoperative Regimen Checklist (PRC) quantified different parts of the postoperative recovery regimen. Results:The data showed that patients in the Tape group, compared to the Controls: 1) achieved better scores at most PRC assessment points (p<0.05), 2) required less encouragement to perform tasks (p<0.05), and 3) were discharged from the hospital a mean of 1.6 days earlier. Conclusions: A taped cognitive-behavioral message, played to patients repetitively during and immediately following bariatric surgery, is effective in enhancing postoperative compliance and reducing in-patient length of stay.

What Do Patients, Families and Society Expect From The Bariatric Surgeon?

The expectations of patients, their families and society of the bariatric surgeon are often unrealistic, but for different reasons. The morbidly obese patient often expects ‘everything’ from bariatric surgery. The patients family is frequently ambivalent. Society, on the other hand, tends to unrealistically regard the morbidly obese as billboards advertising them as willful deviants whose problems can all be resolved by ‘just pushing away from the table’. This invalid stereotype has prompted some to incorrectly regard bariatric surgery as an undeserved reward for individuals who will not control their own behavior. The undeserved intentional deviant status of the morbidly obese causes members of society to harass, mock or otherwise mistreat this subpopulation. Societys harmful, destructive and unjust weight harassment ‘fat-ism’ has made the morbidly obese modern day moral equivalents of lepers. We conclude that society must be persuaded to accept weight harassment as ‘politically incorrect’, subject to the same consequences as any other form of bigotry. Once society regards the morbidly obese as victims, not perpetrators, of their nonsurgically curable disease, bariatric surgery results should become held to similar standards as surgery for carcinoma, cardiovascular and other diseases. Until then, the morbidly obese remain the last true bastion of prejudice.

Weight Loss and Caloric Intake after Regular and Extended Gastric Bypass

The morbidly obese and especially the super-morbidly obese (>225% ideal body weight) often require gastric bypass surgery as treatment for long-term remission of their obesity. The extended gastric bypass Roux-en-Y (X-GBP) procedure evolved as a result of a perceived need to increase weight loss in morbidly obese subjects beyond the limitations of the regular gastric bypass Roux-en-Y (R-GBP). We compared weight loss, caloric intake, and percentage of total caloric intake from carbohydrate, protein, and fat in eight R-GBP and eight X-GBP patients at 3, 6, 9, and 12 months following surgery. We found that R-GBP and X-GBP groups were similar in age and height, adjusting for baseline weight differences (p = 0.122). Both groups demonstrated significant weight loss over time (p<0.0001), with similar patterns of weight loss at each interval of nonsignificant interaction (p = 0.585). Weight loss for the two groups did not differ statistically. The X-GBP group lost 5% more weight than the R-GBP group by 12 months following surgery. The adjusted average weight loss over 12 months was 56.82 kg for X-GBP and 46.82 kg for R-GBP patients. Furthermore, the X-GBP group ingested fewer calories than the R-GBP group at 3, 6, 9, and 12 months following surgery. The X-GBP group ingested a lower percentage of calories from fat than the R-GBP group at 3, 9, and 12 months following surgery. This study depicts clinical trends in weight loss following X-GBP and R-GBP surgeries. The greater weight loss of the X-GBP group may be due to differences in total caloric intake or the lower perventage of calories ingested from fat. Other possibilities for the greater weight loss shown by the X-GBP group may include changes in malabsorption or resting energy expenditure over time following surgery.

A Medieval Medical View on Obesity

Medieval medical views on obesity are presented from Avicennas Canon of Medicine. Health risks associated with obesity were appreciated, including respiratory and cardiovascular problems, infertility and even sudden death.

The Effects of Fat Distribution on Resting Energy Expenditure in Premenopausal Morbidly Obese Females.

Background: upper body, or abdominal, distribution of body fat is associated with a number of metabolic and hormonal aberrations that could influence resting energy expenditure REE. The purpose of our study was to examine the effects of fat distribution on REE of 96 morbidly obese premenopausal females. Methods: the study population consisted of three groups of study subjects, 32 with lower body fat distribution (LBD) and waist-to-hip circumference ratios WHR < 0.80, 20 with intermediate (INT) fat distribution and WHR between 0.80 and 0.85 and 34 females with upper body distribution of fat (UBD) and WHR > 0.85. Indices measured included: (1) REE; (2) maximal oxygen consumption during an exercise tolerance test (VO2max); (3) basal respiratory quotient (RQ); (4) fasting blood glucose; and (5) serum cholesterol and triglycerides. Results: we found that morbidly obese women who store fat abdominally (WHR > 0.80) have significantly (p < 0.01) higher REE (kcal per h per BSA) than those with lower body obesity. Levels of triglyceride and glucose of the UBD group were also higher than those of the LBD subjects, i.e. 35% and 23%, respectively. VO2max and RQ were similar between the study groups, suggesting that the elevated REE of the patients with abdominal adiposity were likely not the result of their greater muscle mass or differences in substrate utilization. Conclusion: fat distribution affects REE in morbidly obese premenopausal females, and further research is needed to identify the various entities regulating REE in the morbidly obese.