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GS Cowan

Publications and source records attributed to GS Cowan.

16 recordsLinked to original sources
PubMed1996

A Predicted Future for Bariatric Surgery: Using the Surgical Model.

Bariatric surgery is the only currently available, effective, long-term method for controlling morbid obesity. 'Long-term' non-surgical, medical, voluntary weight loss data is rare; where it exists, it averages only 5-10% of patients' total body weight - of minimal long-term value for the morbidly obese - and has a consistently high failure rate, with many patients ultimately progressing to disability, End-Stage Obesity Syndrome or premature death. The author predicts that the time will come when most members of the lay and medical communities accept that bariatric surgery is the conservative approach to treatment for the morbidly obese. The mechanism will be by bariatric surgeons gathering and reporting data on their morbidly obese patients from the options presented. Data collection may take the form of controlled, randomized, descriptive, case or group studies of surgical and nonsurgical therapies upon patients' psycho-socioeconomic-physical-behavioral-medical co-morbidities. Stressed is the concept that all bariatric surgeons have the capability and the implied duty to analyze their patients' data and disseminate the results, in part to achieve the predicted improvement in medical and lay acceptance of bariatric surgery as a conservative concept.

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PubMed1995

Sixth Time Bariatric-Related Surgery for Intractable Nausea, Vomiting, Abdominal Pain, Diarrhea and Weight Loss Failure.

A 42-year-old patient with a sixth bariatric-related surgical procedure is presented. The steps taken for the management of her intractable nausea, vomiting, abdominal pain, unacceptable weight loss and diarrhea are described, together with the rationale therefor. Bariatric reoperative surgical procedure and outcome are discussed, together with some alternative considerations.

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PubMed1995

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 (VO&inf2; max); (3) basal respiratory quotient (RO); (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. VO&inf2; max and RO 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.

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PubMed1994

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 postoperatively. 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.

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PubMed1994

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 nonsignificant 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.

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PubMed1993

Vitamin D Deficiency in the Morbidly Obese.

Although vitamin D deficiency has been well-documented following gastric bypass surgery, there are few studies of vitamin D status in the non-operative morbidly obese patient. We examined 25-hydroxyvitamin D (25-OHD) levels in 60 morbidly obese pre-operative females; 62% of them had 25-OHD levels below normal range (16-74 ng/ml) which were not associated with reductions in serum calcium or phosphorus, liver or kidney dysfunction, and were not significantly correlated to patients' age. However, 25-OHD levels were significantly (p < 0.0001) and negatively correlated to body mass (r = -0.49). These data suggest that low vitamin D may be associated with obesity per se. Hypovitaminosis D, when it is found in post-bariatric surgery patients, may not be caused by the surgery since it may have been present to some degree pre-operatively.

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PubMed1993

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 overtime (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 percentage 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.

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PubMed1992

The Future of Bariatric Surgery.

Scientific evidence is pointing more and more strongly to the fact that serious, or morbid, obesity is not a moral issue. Serious obesity is a consequence of a genetically related, powerful biophysiological drive to consume more calories than are burned. This concept must eventually become incorporated into lay and medical paradigms of obesity. It will result in an increased understanding and sympathy for the suffering of the seriously obese and, as a consequence, stronger support for definitive treatment of serious obesity such as bariatric surgery. Reoperative bariatric surgery principles, currently limited by individual exposure and experience, will develop and evolve. Laparoscopic bariatric surgery may, in time, be developed and prove itself to be of value. Bariatric surgeons should also find it useful to enhance their teams' skills for nutritional, behavioral and psychological management, as well as broaden their operative base into other, related surgical areas such as partial ileal bypass procedures for hyperlipidemia management. As fields mature, organizational maturation is a natural and necessary accompaniment. An International Federation for Bariatric Surgery, or similar entity, will be founded to constructively unite national bariatric surgery and related organizations together. The international bariatric surgery journal, Obesity Surgery, will become more and more accepted as the truly professional and essential vehicle of communication concerning bariatric surgery that it has been since its first issue. Medical management simulating the effects of surgery will be employed successfully; it may arise out of the current genetic work. It may ultimately, in the next 25 years or so, replace the surgical treatment of serious obesity.

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PubMed1991

Aorta and Iliac Arterial Sizes in Pre-operative Morbidly Obese Patients: a preliminary report.

Central blood flow and cardiac output are increased in most morbidly obese patients. This may be reflected in abnormal vessel sizes. Other influences such as smoking, age, weight, vertebral size, hypertension and age at onset of obesity may also be operative. Abnormal aorta and common iliac artery diameters were retrospectively measured on abnormal computer-assisted axial tomography scans of 44 morbidly obese, vascular disease-free females prior to their bariatric surgery. They were compared at standardized aortic and ileac levels with normal weight, similar age, control patients. There was no correlation between patient body weight, body mass index, percent excess body weight or age at onset of obesity versus any of the aortic or iliac diameters. Pearson's correlation analysis of smoking, age and hypertension each showed a significant positive relationship with aorto-iliac diameters (p < 0.05). Vertebral coronal body widths revealed a significant correlation with age (p < 0.05) but not with body weight, aortic or iliac diameters at any level. We conclude that the aortic and iliac arterial diameters of morbidly obese patients are significantly enlarged relative to normal weight controls. Smoking, age and hypertension also appear to have some degree of influence on aorto-iliac diameters in morbidly obese middle-aged women.

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PubMed1991

Obesity Stereotypes Among Physicians, Medical and College Students, Bariatric Surgery Patients and Families.

Cultural indoctrination throughout childhood largely defines adult value systems including stereotypic attitudes towards the obese. It is possible that medical education may alter physicians' earlier stereotypes of obesity. 156 subjects, comprising sex distinct adult groups, morbidly obese persons, their family members and significant others. college undergraduates, medical students, medical and surgical residents, and medical school faculty, were surveyed with a questionnaire. It required that each of 32 bipolar adjectives describing obese persons be answered on a -0 to 9-point scale. The adjectives were selected to provide a sweeping array of attributes used commonly to note differences among people (e.g. intelligent-unintelligent, happy-sad, complex-simple) with low values corresponding to the first, usually more favorable, adjective of each pair. Discriminant analysis identified only 5 of 32 adjective pairs (16%) as useful (p < 0.05) in isolating the respondent groups. Although it reached statistical significance, the magnitudes of these differences were not very substantive with reference to a 9-point scale. We conclude that obesity appears to carry a burdensome degree of societal prejudice, as reflected by negative stereotypes, which is largely unaffected by undergraduate or postgraduate medical education.

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PubMed1991

An Analysis of the Predictability of Hypoxemia Following Vertical Banded Gastroplasty.

Postoperative (post-op) hypoxemia is unpredictable, often undetected by physical examination, sometimes fatal. We studied 45 morbidly obese patients with an average age of 37, including 16 smokers, having vertical banded gastroplasty (VBG) for useful preoperative (preop) predictor(s) of post-op hypoxemia during the first five days following VBG. Patient blood gases (arterial blood oxygen, P&infa;O&inf2; in mmHg), pre-op and five post-op days (POD), after 30 min in room air were: pre-op, 85 +/- 9; POD1, 63 +/- 9*; POD2, 61 +/- 9*; POD3, 63 +/- 10*; POD4, 63 +/- 9* POD5, 64 +/- 1 * (* p < 0.05, Student's t-test compared with pre-op). Linear regression showed no practical, predictive value for P.02 for age, Body Mass Index (BMI), pulmonary function tests (PFTs), smokers or preop P&infa;O&inf2;. Post-op atelectasis occurred in 84% of patients, mostly the posterior basilar regions on chest X-ray. No patient developed clinically diagnostic pneumonia. VBG patients experienced profound hypoxemia post-op, the lowest on POD2. There is no reliable method to predict which patient may develop severe hypoxemia. It is, therefore, extremely helpful to uniformly monitor P&infa;O&inf2; post-op in morbidly obese patients.

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