Alex M C Macgregor
University of Florida
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Alex M C Macgregor.
International Journal of Eating Disorders | 1997
Colleen S. W. Rand; Alex M C Macgregor; Albert J. Stunkard
OBJECTIVE To determine the prevalence of night-eating syndrome in the general population and among a new sample of obesity surgery patients. METHODS Night-eating syndrome was defined by presence of morning anorexia, excessive evening eating, evening tension and/or feeling upset, and insomnia. A randomly selected sample of 2,097 adults (survey sample) answered structured interview questions on night-eating syndrome. A self-report form was completed by 111 patients who had received gastric restriction surgery for obesity at a patient reunion (patient sample). RESULTS Prevalence of night-eating syndrome in the survey sample was 1.5% (31 of 2,097). Prevalence in the patient sample was 27% (30 of 111). Weights for subjects in each sample, with and without the syndrome, were comparable. DISCUSSION Prevalence of night-eating syndrome was higher in the patient sample than in the survey sample. Within each sample, presence of the syndrome was not related to weight. Prevalence in the survey sample was within the range reported for binge-eating disorder. Night-eating syndrome may warrant consideration as a distinct eating disorder.
Obesity Surgery | 1996
Georgeann N Mallory; Alex M C Macgregor; Colleen S. W. Rand
Background: The dumping syndrome that follows Roux-en-Y gastric bypass for morbid obesity is considered to be the primary mechanism of improved weight loss as compared with the purely restrictive vertical banded gastroplasty. To evaluate the influence of dumping on post-operative weight loss, severity of dumping was determined using Sigstads clinical diagnostic index. Methods: One hundred and thirty seven gastric bypass and 19 gastroplasty patients were assessed 18-24 months following surgery. Sigstads criteria for the dumping syndrome were met by 75.9% of gastric bypass and no gastroplasty patients. Among gastric bypass patients, no relationships were found between severity of dumping and weight loss, as measured by per cent of excess body weight loss or change in body mass index. Weight loss was significantly greater with gastric bypass than gastroplasty patients (72.5 compared to 47.9% of excess body weight loss). All gastroplasty and 24.1% of gastric bypass patients were classified as nondumpers. The difference in weight loss between surgical procedures was not related to dumping: gastric bypass non-dumpers lost significantly more weight (69.1% excess body weight loss) than gastroplasty patients. Conclusions: This study fails to demonstrate a significant relationship between dumping severity and weight loss. It is inferred that the superior weight loss of gastric bypass compared to gastroplasty has some other etiology.
Obesity Surgery | 1993
Alex M C Macgregor; Robert A Greenberg
Forty morbidly obese asthmatic patients who underwent gastric restrictive surgery more than 2 years earlier were evaluated to determine the influence of weight loss on asthma outcome. Mean percentage excess weight loss in this group was 68% and body mass index (BMI) fell from a mean of 46 to 30. Following surgery, 90% showed improvement in asthma symptoms. Complete remission of asthma occurred in 48% and a further 12.5% became asthma free on reduced medications dosage. Of those taking daily medications for asthma before surgery, 42% were completely off medication following weight loss surgery, and another 18.5% experienced fewer asthma attacks on reduced medication dosage. Of the 22 patients with severe asthma (> 10 attacks per year) on routine daily medications for asthma preoperatively, 8(36%) required no medication after surgery, 7(32%) used medication only on an ‘as-needed’ basis, and 7(32%) controlled their asthma on reduced medication dosage. Five patients gained weight during the follow-up period. All developed an increased incidence of asthma attacks, which again abated after successfully losing weight following revisional surgery. Coexistent factors of smoking and clinically apparent esophageal reflux were evaluated, but no statistically significant correlation was shown with either smoking or reflux and improvement in asthma. Possible etiologies of the improvement in asthma with weight loss are discussed.
Obesity Surgery | 1991
Georgeann N Mallory; Alex M C Macgregor
Several previous investigators have reported an incidence of folic acid deficiency following gastric bypass surgery of up to 38%. Failure to encounter any folic acid deficiencies in our postoperative patients led us to discontinue follow-up folate studies for several years. However, due to repeated references to this deficiency in the literature, we re-instituted folate studies as part of the routine follow-up of our patients. Preoperative serum folate levels were obtained in 1,067 patients and pre-existing deficiencies found in 63, an incidence of 6%. Of the 588 folate levels determined 1 to 10 years following gastric bypass, only six were less than 3.0 ng/dl, an incidence of 1%. All patients were instructed preoperatively and postoperatively to take multivitamin/mineral supplements after gastric restrictive surgery, and were continually educated on their importance. In a bariatric surgery practice in which patients are instructed, reminded, encouraged and even badgered into taking postoperative vitamin/mineral supplements, folate deficiency should be a rarity. In such circumstances, folate deficiency may well act as a sensitive marker of non-compliance.
Obesity Surgery | 1999
Alex M C Macgregor; Eric K. Thoburn
Background: Two papers in the literature have described meralgia paresthetica following bariatric surgery. One author ascribed the cause of the condition to pressure from an abdominal retractor. We encountered 11 similar cases in our bariatric surgery practice, but do not use the retractor previously invoked as the cause of the problem. It seems likely that some other factor is involved. Methods: Retrospective chart review. Results: 11 patients were identified whose symptoms and clinical findings were consistent with meralgia paresthetica. There were 6 men and 5 women. Symptoms developed immediately following surgery in 8 cases, and resolved spontaneously within 3 months in 6 of these. Conclusions: Multiple causes have been described for meralgia paresthetica. It appears to be more common in obese patients. While extrinsic pressure from an abdominal retractor may play a role in some cases, other factors are clearly involved in the cases reported here.
Obesity Surgery | 1992
Alex M C Macgregor
Intestinal obstruction is no more frequent after gastric bypass than after any other similar gastric surgical procedure. However, occurrence of any complication requiring revisional surgery in these hugely obese patients may have serious implications. Bariatric surgeons and physicians who take part in the care of such patients must be aware of the different clinical pictures which accompany the varying levels of obstruction following gastric bypass surgery. Particularly critical is an understanding of closed loop gastroduodenal obstruction, a potentially lethal complication, which can cause rapidly occurring hypovolemic shock and death within a few hours of onset.
Obesity Surgery | 1996
Alex M C Macgregor; Lisa Boggs
Background: The pharmacokinetic variables of drug clearance and volume of distribution are usually corrected for body weight or surface area. Only recently have the relationships which exist between body size, physiologic function and pharmacokinetic variables been evaluated in the obese population. These effects are not widely known, and data on this and the effects of bariatric surgical procedures are scantily documented in the surgical literature. Methods: Literature review. Results: Drugs with a low or moderate affinity for adipose tissue have a moderate increase in the volume of distribution (Vd), and this correlates with the increase in lean body mass (LBM). Highly lipophilic drugs, with some exceptions, show the expected increase in Vd and prolongation of elimination half-life, indicating a marked distribution into adipose tissue. Drug absorption, in general, is slowed by delayed gastric emptying and is normal when gastric emptying is normal or increased. Most drug absorption occurs in the small intestine where duration of drug/mucosal contact is the most important factor. Conclusions: Drugs whose distribution is restricted to LBM should utilize a loading dose based on ideal body weight (IBW). For those drugs which distribute freely into adipose tissue, the loading dose should be based on total body weight (TBW). Adjustment of the maintenance dose depends on clearance rates. In a few cases dosage adjustment depends on pharmacodynamic data, since drug clearance does not conform to these recommendations, for reasons which remain to be defined. Following bariatric surgery, in the absence of delayed gastric emptying or uncontrolled diarrhea, drug absorption rates are usually comparable to the non-operated patient.
Obesity Surgery | 1991
Alex M C Macgregor; Colleen S. W. Rand
Eighty-one patients with primary Roux-en-Y gastric bypass for obesity underwent revisional surgery for staple line failure. All patients (100%) were included in the follow-up. Two years later, patients had an excess weight loss of 77%; 91% of the patients had a final weight loss of 50% or more of their excess weight. Weight loss of revision patients was comparable to that reported for patients with primary operations. It was concluded that revision for staple line failure is clearly justified.
Obesity Surgery | 1991
Alex M C Macgregor
Obesity affects approximately one-third of the population of the United States. Pulmonary complications are common following upper abdominal surgery, and constitute the most frequent postoperative complication in the obese surgical patient. This literature review addresses the pathophysiology of the pulmonary changes associated with simple obesity and examines intraoperative and postoperative changes which occur in this patient group. Measures used in prophylaxis and management of these complications are reviewed.
Obesity Surgery | 1991
Colleen S. W. Rand; Alex M C Macgregor
Some centers consider an age over 50 to be a contraindication for obesity surgery. This study was conducted to examine the relationship between age and one-year postoperative weight of patients receiving gastric restrictive surgery (n = 616) for morbid obesity. Patients were divided into four age groups (18-29, 30-39, 40-49, 50-65 years) matched for preoperative obesity. At one year there were no statistically significant differences in weight loss or postoperative obesity. There were four (0.6%) surgically related deaths. The mortality of patients aged 50 or older (1.1%) was not significantly higher than that of younger patients (0.6%). It was concluded that older age per se need not be a contraindication for surgery.