Body compositional changes in response to testosterone.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to D L Elliot.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effect of exercise conditioning on elevated intraocular pressure has not been previously described among sedentary individuals. We prospectively observed intraocular pressure for nine sedentary subjects suspected of having glaucoma before and after 3 months of aerobic exercise training. Mean (+/- SEM) aerobic capacity, as assessed by maximal oxygen uptake, increased 6.3 +/- 1.6 mL.kg-1.min-1 (30%) (P less than .02). Mean intraocular pressure decreased 4.6 +/- 0.4 mmHg (20%) (P less than .001) at the end of the conditioning period. With cessation of exercise and subsequent detraining, intraocular pressure returned to elevated preconditioning levels by 3 weeks. Regular aerobic exercise is associated with a reduction in elevated intraocular pressure and may represent an effective nonpharmacologic intervention for patients suspected of having glaucoma.
Explore the source record for details and available documents.
Recruiting clinicians to teach bedside skills is often a challenge for Introduction to Clinical Medicine (ICM) course co-ordinations. Little data is available concerning what motivates a faculty to participate in these programmes. Better understanding of these factors might allow enhanced faculty involvement. We surveyed full-time and volunteer faculty as to what forces promote and hinder participation as preceptors for an ICM course. Results documented that both faculty groups found student interactions and teacher fulfillment their major reward, with little perceived academic or patient recognition. Personal time limitations was the greatest deterrent to participation. Assessing faculty needs has allowed focused course changes and new activities to facilitate involvement.
Iron deficiency is frequent among physically active women. Several diagnostic and therapeutic strategies have been advocated. We determined how women's preferences for care varied with their risk of iron deficiency and/or anemia. The women's strength of feelings (utilities) and management costs were used to assess: 1) no evaluation or therapy; treatment based on a 2) complete blood count (CBC) or 3) ferritin level; and 4) empiric iron therapy. The analysis was applied to groups with differing iron deficiency prevalence. Women (N = 22) were adverse to the risk of both anemia and iron deficiency without anemia, and their preferences did not correlate with age, running mileage, years of running, or vitamin supplement use. Because of women's desire to avoid undiagnosed deficiency, the benefits of no evaluation, complete blood count assessment, and, to a less extent, serum ferritin decreased as the prevalence of iron deficiency increased. Ferritin level was more effective per cost than a CBC. However, empiric therapy had the highest effectiveness per cost. These results suggest a strategy that combines both patient concerns and the clinical suspicion of disease in choosing management for physically active women at risk for iron deficiency.
A 27-year-old recreational jogger developed gross hematuria following a 2-mile run. Evaluation revealed a transitional cell carcinoma of the bladder. Etiologies for pigmenturia and the pathogenesis of exertional hematuria are reviewed. The need to exclude other causes of hematuria before attributing the finding to exercise is emphasized.
The opinions (level of agreement) of high school varsity football players with regard to reported effects of anabolic steroids were assessed before and after two different education interventions. Lectures and handouts of a balanced education program (potential risks and benefits) were compared with a risks-only (negative or "scare tactics") presentation, in a controlled manner. Those receiving the balanced review significantly increased their agreement with 5 of 10 targeted adverse effects, while no change occurred for any risks among those taught by the negative intervention. A teaching model that only emphasizes the untoward consequences of anabolic steroids is ineffective, even in the short-term. A balanced education approach can improve understanding of the potential adverse effects of these drugs. Additional strategies may be required to change young athletes' attitudes toward anabolic androgenic steroid use.
A 28-yr-old, female marathon and "fitness" runner presented with leg swelling, fatigue, and loss of endurance. She was running an hour or more daily in addition to regular biking and swimming. She was an instructor in a fitness center. For 2 months prior to her leg swelling, she had increased fatigue and decreased exercise tolerance. She had been seen previously for a slow healing hamstring strain. She had not had a menstrual period for over 2 yr and had refused evaluation. She admitted to very low dietary intake, which she had always denied. She was worried about her body fat. She denied recent blood loss, diuretic or cathartic use, and induced vomiting. She appeared malnourished, pale, and older than her stated age. Her weight was 41.4 kg. Her blood pressure was 90/60, and her pulse was 100 per minute. She had pitting edema of the lower extremities to the knees. The diagnosis of anorexia nervosa was made and will be discussed.
Explore the source record for details and available documents.
OBJECTIVE: To test the hypotheses that obese adolescents have a lower resting metabolic rate and less aerobic endurance than their nonobese siblings. DESIGN: Case-referent study of obese and nonobese siblings from the same kindred. SETTING: Tertiary referral center. PARTICIPANTS: Telephone screening of community volunteers resulted in a consecutive sample of 16 kindreds. Obese and nonobese siblings were similar in age, height, and pubertal status. Significantly more female subjects were in the obese group (p less than 0.01). MEASUREMENTS AND MAIN RESULTS: Body composition studies revealed that the obese siblings had higher body fat (p less than 0.001) but that fat-free mass was similar to that of the lean siblings. Resting metabolic rates determined by indirect calorimetry for the obese and nonobese pairs did not differ. Although the obese siblings appeared less fit when maximal oxygen consumption was measured in relation to total weight, maximal oxygen consumption did not differ when values were standardized for fat-free mass. CONCLUSIONS: The obese adolescents did not have a reduced resting metabolic rate. As in adults, the relationship between resting metabolic rate and fat-free mass was similar for obese and nonobese children and adolescents. Any decreased sport participation by the obese siblings was not due to inherent reductions in aerobic capacity.
To assess potential long-term effects of weight loss on resting metabolic rate (RMR), the RMRs of seven obese women were measured by indirect calorimetry before weight loss, during a protein-sparing modified fast, and for 2 mo while at a stable reduced weight. Body composition was also determined at each interval. RMR significantly decreased 22% (p less than 0.01) with initiation of the modified fast. RMR values during the modified fast and during the maintenance diet at stable reduced weight were not different and all were significantly lower than the prediet RMR. Loss of lean tissue could not account for the decrease because changes in RMR per fat-free mass paralleled the total RMR reduction. A sustained decrement in RMR accompanied weight loss and persisted for greater than or equal to 8 wk despite increased caloric consumption and body weight stabilization.
Exertional muscle pain and fatigue are common complaints; some patients with these symptoms have a metabolic myopathy. We have performed graded exercise testing with analysis of expired ventilation on 13 individuals with various kinds of metabolic myopathies. Their results differed from normal and reflected the underlying biochemical abnormality. Patients with disorders of the mitochondrial electron transport chain demonstrated marked limitations in aerobic metabolism and a greatly reduced maximum oxygen consumption. During intense exertion, normal individuals increase carbon dioxide generation due to buffering of lactic acid. This did not occur in patients with McArdle disease, in whom the respiratory exchange ratio (carbon dioxide production/oxygen consumption) did not rise above 1.0 at maximum exercise. These results indicated a deficit in anaerobic metabolism. Pyruvate dehydrogenase complex allows pyruvate produced from carbohydrate metabolism to enter the citric acid cycle. Patients with this enzyme deficiency showed an initially normal pattern followed by an abrupt cessation in carbohydrate dependent aerobic metabolism at higher work loads. During high-intensity exercise, progressive anaerobic metabolism was not accompanied by additional oxygen consumption. Finally, results from a patient with carnitine palmitoyl transferase deficiency revealed an early dependence on carbohydrate metabolism. The ventilatory threshold occurred at a low percentage of maximal oxygen consumption, reflecting the limited availability of lipid substrates for aerobic metabolism. Detection of some muscle metabolic abnormalities can be made on small biopsy specimens. However, definitive diagnosis of the defect nearly always requires studies on fresh or frozen muscle tissue obtained by an open biopsy. The decision on how the tissue should be processed and which metabolic studies should be performed frequently needs to be made before the biopsy is obtained. Thus, a noninvasive method to initially characterize patients with potential metabolic disorders is useful. Exercise testing with expired gas analysis can indicate the presence of a metabolic myopathy and results can then be used to direct the appropriate biochemical evaluations.
We measured the metabolic rate by indirect calorimetry for 90 minutes following exercise in six healthy individuals. Ten and 30 minutes of cycling at 80% of maximal intensity produced comparable increases in the resting metabolic rate, (37% and 32%, respectively) immediately after exercise. However, by 30 minutes following exertion, the metabolic rate was not different from control values. The total additional caloric use during the 90 minutes of recovery was similar for the two exercise durations, and the mean increment in recovery energy expenditure was 11.4 +/- 7.1 kcals. The majority of caloric use with exercise is during the activity. Recovery energy expenditure following usual aerobic training results in only a minor contribution to total energy use.
Guidelines for training heart rate (HR) during aerobic exercise are often determined by predictive formulas. Measurement of the heart rate at ventilatory threshold (VT) by expired gas analysis provides a direct index of the upper limits of conditioning intensity. We evaluated 115 nonsmoking, healthy adults with measurement of peak oxygen uptake to classify groups as low- (n = 45), average-(n = 45), and high (n = 25) -fitness. Heart rate at VT was compared with the approximate midpoint (77 percent) of recommended training intensity as estimated by the Karvonen equation, predicted maximal (220-age), and measured maximal HR formulas. No significant difference among the various HR formulas at 77 percent and HR at VT were found for high-fitness individuals. Among the low- and average-fitness groups, the Karvonen formula at 77 percent was significantly higher (p less than 0.001) than HR at ventilatory threshold. Predicted and measured maximal HR at 77 percent were not above the VT among the low- and average-fitness individuals and are appropriate for training intensity. However, the Karvonen formula appears to overestimate heart rate intensity among those of low and average fitness and may be excessive for these groups.
Explore the source record for details and available documents.
Cardiac deaths are more likely to be unanticipated than cancer deaths by patients, their families, and their physicians. We hypothesized that differing physician attitudes toward dying patients may affect the degree of expectation of death. To evaluate differences in attitudes and behaviors among subspecialists, we surveyed a randomly selected population of California subspecialists; 44 of 136 (32%) of cardiologists and 91 of 167 (55%) of oncologists responded. Oncologists experienced three times as many deaths as cardiologists and reported having discussed code status more often with patients who died. Cardiologists' patients' deaths were more often unexpected and occurred more frequently in intensive care units. In addition, their patients were more likely to be given cardiopulmonary resuscitation. Oncologists reported being more comfortable dealing with dying patients and having less desire to avoid them. When presented with patient scenarios, however, cardiologists' and oncologists' responses were similar when discussing and estimating prognosis and likelihood of successful therapy.