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Biomedical subjects

Warren G Thompson

Publications and source records attributed to Warren G Thompson.

7 recordsLinked to original sources

Correlations between measures of insulin sensitivity and weight loss.

OBJECTIVE: Many formulas have been proposed to calculate insulin sensitivity and studies have shown their effectiveness. However, few studies have been done to compare formulas. METHODS: Seventy-two obese participants completed a randomized weight loss study. Weight loss, change in body fat and change in waist circumference were used as surrogates for change in insulin sensitivity. Correlation coefficients were calculated for each of these surrogates with proposed formulas for insulin sensitivity found in the literature. RESULTS: The change in insulin sensitivity using the formula proposed by McAuley (exp(2.63-0.28 x ln(fasting insulin)-0.31 x ln(fasting triglyceride in mmol/l)) showed the greatest correlation with weight loss (r=-0.59, p<0.0001) and was statistically superior to change in fasting glucose, fasting insulin and homeostasis model assessment (HOMA). CONCLUSIONS: The insulin sensitivity formula proposed by McAuley provides an accurate means of detecting insulin resistance. As it does not require a glucose tolerance test, it is also easier and less expensive than most other formulas. Use of this formula rather than fasting glucose would detect many more patients with insulin resistance who are at risk for subsequent diabetes and other complications.

Adipose Tissue↗

Impact of self-assessment questions and learning styles in Web-based learning: a randomized, controlled, crossover trial.

PURPOSE: To determine the effect of self-assessment questions on learners' knowledge and format preference in a Web-based course, and investigate associations between learning styles and outcomes. METHOD: The authors conducted a randomized, controlled, crossover trial in the continuity clinics of the Mayo-Rochester internal medicine residency program during the 2003-04 academic year. Case-based self-assessment questions were added to Web-based modules covering topics in ambulatory internal medicine. Participants completed two modules with questions and two modules without questions, with sequence randomly assigned. Outcomes included knowledge assessed after each module, format preference, and learning style assessed using the Index of Learning Styles. RESULTS: A total of 121 of 146 residents (83%) consented. Residents had higher test scores when using the question format (mean +/- standard error, 78.9% +/- 1.0) than when using the standard format (76.2% +/- 1.0, p = .006). Residents preferring the question format scored higher (79.7% +/- 1.1) than those preferring standard (69.5% +/- 2.3, p < .001). Learning styles did not affect scores except that visual-verbal "intermediate" learners (80.6% +/- 1.4) and visual learners (77.5% +/- 1.3) did better than verbal learners (70.9% +/- 3.0, p = .003 and p = .033, respectively). Sixty-five of 78 residents (83.3%, 95% CI 73.2-90.8%) preferred the question format. Learning styles were not associated with preference (p > .384). Although the question format took longer than the standard format (60.4 +/- 3.6 versus 44.3 +/- 3.3 minutes, p < .001), 55 of 77 residents (71.4%, 60.0-81.2%) reported that it was more efficient. CONCLUSIONS: Instructional methods that actively engage learners improve learning outcomes. These findings hold implications for both Web-based learning and "traditional" educational activities. Future research, in both Web-based learning and other teaching modalities, should focus on further defining the effectiveness of selected instructional methods in specific learning contexts.

Cross-Over Studies↗

Effect of energy-reduced diets high in dairy products and fiber on weight loss in obese adults.

OBJECTIVE: Studies suggest that high-dairy and high-fiber/low-glycemic index diets may facilitate weight loss, but data are conflicting. The effects on weight loss and body fat of a high-dairy diet and a diet high in dairy and fiber and low in glycemic index were compared with a standard diet. RESEARCH METHODS AND PROCEDURES: Ninety obese subjects were recruited into a randomized trial of three diets designed to provide a calorie deficit of 500 calories/d over a 48-week period. The study compared a moderate (not low)-calcium diet with a high-calcium diet. RESULTS: Seventy-two subjects completed the study. Significant weight and fat loss occurred with all three diets. A diet with 1400 mg of calcium did not result in greater weight (11.8 +/- 6.1 kg) or fat (9.0 +/- 6.0 kg) loss than a diet with 800 mg of calcium (10.0 +/- 6.8 and 7.5 +/- 6.6 kg, respectively). A diet with 1400 mg of calcium, increased fiber content, and fewer high-glycemic index foods did not result in greater weight (10.6 +/- 6.8 kg) or fat (8.5 +/- 7.8 kg) loss than the standard diet with 800 mg of calcium. Lipid profile, high-sensitivity C-reactive protein, leptin, fasting glucose, and insulin improved significantly, but there were no significant differences between the experimental diets and the control diet. DISCUSSION: We found no evidence that diets higher than 800 mg of calcium in dairy products or higher in fiber and lower in glycemic index enhance weight reduction beyond what is seen with calorie restriction alone.

Adult↗

Web-based learning in residents' continuity clinics: a randomized, controlled trial.

PURPOSE: To determine whether internal medicine residents prefer learning from Web-based (WB) modules or printed material, and to compare the effect of these teaching formats on knowledge. METHOD: The authors conducted a randomized, controlled, crossover study in the internal medicine resident continuity clinics of the Mayo School of Graduate Medical Education during the 2002-03 academic year. Participants studied two topics of ambulatory medicine using WB modules and two topics using paper practice guidelines in randomly assigned sequences. Primary outcomes were format preference (assessed by an end-of-course questionnaire) and score changes from pre- to postintervention tests of knowledge. RESULTS: A total of 109 consented and 75 (69%) completed the postintervention test. Fifty-seven of 73 (78% [95% CI, 67-86%]) preferred the WB format (p < .001). Test scores improved for both formats (67.7% to 75.0% for WB, 66.0% to 73.3% for paper), but score change was not different between formats both before (p = .718) and after (p = .080) adjusting for topic, clinic site, study group, postgraduate year, and gender. Residents spent less time on WB modules (mean = 47 +/- 26 minutes) than paper (mean = 59 +/- 35, p = .024). Difficulties with passwords limited their use of WB modules for 71% (59-80%) of residents. CONCLUSION: No difference was found between WB and paper-based formats in knowledge-test score change, but residents preferred learning with WB modules and spent less time doing so. Passwords appeared to impede use of WB modules. WB learning is effective, well accepted, and efficient. Research should focus on aspects of WB instruction that will enhance its power as a learning tool and better define its role in specific settings.

Attitude of Health Personnel↗

Use of glucose, insulin, and C-reactive protein to determine need for glucose tolerance testing.

OBJECTIVE: Glucose intolerance has been shown to be a better predictor of morbidity and mortality than impaired fasting glucose. However, glucose tolerance tests are inconvenient and expensive. This study evaluated the relative frequencies of glucose intolerance and impaired fasting glucose and sought to determine if 2-hour glucose could be predicted from simple demographic and laboratory data in an obese population. RESEARCH METHODS AND PROCEDURES: Eighty-nine obese subjects (median BMI 35 kg/m(2), range 30 to 40 kg/m(2)) underwent glucose tolerance testing. Using step-wise linear and logistic regression analysis, fasting glucose, high-sensitivity C-reactive protein (hsCRP), fasting insulin, high-density lipoprotein cholesterol, triglycerides, weight, height, BMI, waist circumference, hip circumference, waist-to-hip ratio, sex, and age were assessed as predictors of glucose intolerance. RESULTS: Impaired glucose tolerance was more prevalent (27%) than impaired fasting glucose (5.6%). Only fasting glucose and hsCRP were significant (p < 0.05) independent predictors of impaired 2-hour glucose (>140 mg/dL). A fasting glucose > or =100 mg/dL or an hsCRP > 0.32 mg/dL (upper quartile of the normal range) detected 81% (sensitivity) of obese subjects with impaired glucose tolerance; however, specificity was poor (46%). Fasting insulin > or =6 micro U/mL had better sensitivity (92%) but poorer specificity (30%). DISCUSSION: Impaired glucose tolerance is more common than impaired fasting glucose in an obese population. Possible strategies to avoid doing glucose tolerance tests in all obese patients would be to do glucose tolerance testing only in those whose fasting glucose is > or =100 mg/dL or whose hsCRP exceeds 0.32 mg/dL or those whose fasting insulin is > or =6 micro U/mL.

Adult↗

Effects of resistance versus aerobic training on coronary artery disease risk factors.

Individuals exhibiting "the metabolic syndrome" have multiple coronary artery disease risk factors, including insulin resistance, hyperlipidemia, hypertension, and android obesity. We performed a randomized trial to compare the effects of aerobic and resistance training regimens on coronary risk factors. Twenty-six volunteers who exhibited android obesity and at least one other risk factor for coronary artery disease were randomized to aerobic or resistance training groups. Body mass index, waist-to-hip ratio, glucose, insulin, body composition, 24-hr urinary albumin, fibrinogen, blood pressure, and lipid profile were measured at baseline and after 10 weeks of exercise training. Both groups showed a significant reduction in waist-to-hip ratio and the resistance training group also showed a reduction in total body fat. There was no significant change in mean arterial blood pressure in either group. Fasting plasma glucose, insulin, total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides were unchanged in both groups. High-density lipoprotein (HDL) cholesterol increased (13%) with aerobic training only. Plasma fibrinogen was increased (28% and 34%, P < 0.02) in both groups and both groups showed a significant decrease (34% and 28%, P < 0.03) in microalbuminuria after their respective training regimen. In conclusion, resistance training was effective in improving body composition of middle-aged obese sedentary males. Only aerobic training was effective in raising HDL cholesterol. More studies are warranted to assess the effects of exercise on plasma fibrinogen and microalbuminuria.

Adult↗