Biomedical subjects
R L Atkinson
Publications and source records attributed to R L Atkinson.
The control of food intake: effects of dieting and intestinal bypass.
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Metabolic and behavioral differences between dieting and intestinal bypass.
The present studies were designed to compare physiological and behavioral changes produced by weight loss induced with dieting and the weight loss which follows intestinal bypass. A group of 7 grossly obese individuals were hospitalized in a metabolic unit and studied at their initial weight after 4 weeks on a hypocaloric diet and again following a comparable weight loss after intestinal bypass surgery. The score indicating depression increased after dieting, but returned to initial levels after bypass. A number of other behavioral changes were recorded including a reduction in the time spent thinking about food, the time when the individual felt hungry and a greater percentage of time when they felt "full". After bypass, the patients also selected and ate smaller quantities of food. There were no metabolic differences following the period of dieting. Among the metabolic changes after bypass were an increase in glycerol and a decrease in insulin. The possible relationships between the metabolic and behavioral changes have been reviewed.
Effects of fasting on gluconeogenesis from alanine in nondiabetic man.
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Gastrin secretion after weight loss by dieting and intestinal bypasss surgery.
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Secondary amenorrhea in obesity: etiologic role of weight-related androgen excess.
A massively obese, amenorrheic young woman had elevated levels of plasma androgens which could be reduced either acutely by dexamethasone administration or chronically by weight loss. Normalization of plasma androgen levels in both instances led to resumption of ovulation, suggesting that weight-related hyperandrogenism is a cause of amenorrhea in obesity.
Use of anthropometric measures to assess weight loss.
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Treatment of obesity: cost-benefit assessment of behavioral therapy, placebo, and two anorectic drugs.
Mazindol, diethylpropion, and a placebo were compared with behavioral therapy for effectiveness in producing weight reduction in an outpatient obesity clinic. Each method was also compared in cost and harmful side effects. The patients were recruited from the middle and lower socioeconomic groups. Of the 120 patients beginning treatment, only 33 completed the entire 14-week study. There was no statistically significant difference in the weight loss among the treatment groups. The program of behavioral therapy was administered by a dietitian who as experienced in the techniques of behavior modification; the drug treatment groups were seen by physicians. We conclude that behavioral therapy may be the treatment of choice in an outpatient obese population since it requires little physician time, is less expensive, and avoids the side effects of anorectic drugs.
Occult thyroid disease in an elderly hospitalized population.
Measurements of thyroxine (T4), triiodothyronine (T3), thyrotropin (TSH), and T3 talc uptake (T3TU) were performed on 425 hospitalized patients over 60 years of age. Unsuspected thyroid disease was found in 10 patients (2.4%); 9 were hypothyroid and 1 hyperthyroid. Another 11% of the population had abnormal T4 or TSH levels but were not proved to have thyroid disease. Repeat measurements in 10 of 40 patients with low serum T4 concentrations showed a return of the tests to normal. The low T4 levels occurred in patients who were seriously ill and were usually associated with low T3TU values. Low serum T3 concentrations were observed in 32 of the patients. Although we found TSH to be the most useful test in the diagnosis of hypothyroidism, it is a relatively expensive test and is not helpful in screening for hyperthyroidism. The present results suggest that the best single test for screening for occult thyroid disease is a serum T4 measurement. We recommend a T4 test on all hospitalized patients over age 60 years. Serum should be held in the laboratory for measurement of TSH concentration if the T4 result is below 6.5 micrograms/dl. A T3 resin or talc uptake and a serum T3 measurement should be performed to rule out hyperthyroidism if the serum T4 concentration is elevated. This regimen will identify virtually all cases of occult thyroid disease.
Plasma zinc and copper in obesity and after intestinal bypass.
Plasma concentrations of zinc and copper were measured in 15 obese patients before intestinal bypass surgery, in 27 patients after intestinal bypass surgery, and in 52 lean control subjects. Preoperatively, the obese patients had zinc concentrations that were significantly lower than in the lean control subjects (76 +/- 3 versus 89 +/- 2 microgram/dl) (+/- SEM) and copper levels that were significantly higher (147 +/- 10 versus 119 +/- 3 microgram/dl). After intestinal bypass, plasma zinc and copper concentrations were significantly lower (zinc, 62 +/- 2 microgram/dl; copper, 90 +/- 5 microgram/dl; P less than 0.001) than in prebypass patients. One patient developed leukopenia associated with a plasma copper concentration of 36 microgram/dl. Leukocyte count and plasma copper level rose with oral copper sulfate replacement therapy. Intestinal bypass surgery may produce clinically significant decreases in plasma concentrations of zinc and copper. Careful observation and replacement therapy are indicated in all patients who develop deficiences after intestinal bypass surgery.
Eating patterns of massively obese individuals.
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Low serum testosterone and sex-hormone-binding-globulin in massively obese men.
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Surgical treatment of obesity: a review of our experience and an analysis of published reports.
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Treatment of obesity: comparison of physician and nonphysician therapists using placebo and anorectic drugs in a double-blind trial.
In a randomized double-blind trial, 60 obese patients were assigned in groups of 12 to five therapists. The patients for each therapist were then randomly assigned in groups of four to placebo or one of two preparations of mazindol. Ninety-three percent of the patients completed the nine weeks of treatment. Weight loss averaged 1.1 lb per week and there was no advantage to pharmacological agents over placebo. However, there were significant differences between therapists. Weight loss by the patients assigned to physicians was no better than for those assigned to nonphysician personnel, but there were significant differences between individual nonphysician personnel. These findings support the concept that nonphysician personnel may be effective in treating many obese patients. In addition, we could not find a significant effect of either form of mazindol when compared to placebo.
Factors affecting basal metabolic rate.
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Predictors of successful weight loss in an outpatient obesity clinic.
Patients attending weight reduction clinics were tested at the beginning of the program to assess a variety of background variables which might influence successful weight loss. These included measures of self-esteem, social acceptance, locus of control, responsiveness to external stimuli, attitudes toward weight loss, and knowledge about nutrition. Success was related to social conformity and desire for social acceptance but not to self esteem or locus of control. Individuals who believed that poor eating habits caused their obesity and those who were less responsive to environmental cues which may trigger feeding, were also more successful.
Biotin and early poult growth.
Commerical Broad Breasted White male poults were fed either a soybean and milo ration, or similar rations containing 7.5% or 20% animal protein, for a period of 0-8 weeks. Three groups of 48 birds each were fed each of the three rations which were isocaloric (2926 M.E. Cal. /Kg. of ration) but differed slightly in protein content. Other groups were fed identical rations supplemented with biotin at a level of 220 mcg/kg. When the growth data were analyzed by analysis of variance, highly significant differences noted for treatment (P less than or equal to 0.01). Biotin supplementation of the soybean-milo ration gave no response, but supplementation of the rations containing animal protein with biotin gave excellent growth responses. When the data were combined so that the effect of biotin could be evaluated, a highly significant (P less than or equal to 0.005) improvement in growth was obtained by supplementing the rations with biotin. Feed efficiency was found to be closely related to growth rate. Mortality did not appear to be related to diet, with the differences being non-significant statistically.
Amino acid supplementation of low protein turkey starting rations.
Turkey poults fed rations containing 22.1% protein had a much slower rate of growth when compared with poults receiving a ration containing 29.8% protein. Methionine supplementation had no effect on body weight and mortality to 18 days of age. Supplementation of the 22.1% protein diet with lysine (0.2%) significantly improved growth rate over the unsupplemented 22.1% protein diet. The addition of methionine to the 22.1% protein diet supplemented with lysine (0.2%) produced slight additional response in body weight; however the drop in mortality was much more dramatic as increments of methionine were added to the 22.1% protein diet supplemented with lysine (0.2%).