Biomedical subjects
Publications and source records attributed to L Leiter.
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OBJECTIVE: To compare the use of lipid-lowering agents in 42 628 elderly patients (aged > or =65 years) after acute myocardial infarction, before and after the publication of the Scandinavian Simvastatin Survival Study (4S), using the Ontario Myocardial Infarction Database. METHODS: Multivariate regression models were created to estimate changes in the rate of statin use over time in monthly cohorts of elderly patients after acute myocardial infarction in Ontario from April 1, 1992, to March 31, 1997. Changes in the rate of statin use over time were estimated using patient and prescriber characteristics. RESULTS: We found a 3.6-fold significant increase in the monthly rate of statin use after the publication of 4S compared with before the publication of 4S (P<.001); specifically, the rate of increase in simvastatin and pravastatin sodium use was higher after the publication of 4S (P<.001 for each). Before the publication of 4S, the rate of increase in statin use in younger patients (aged 65-74 years) was 2.7 times higher than in older patients (aged > or =75 years) (P =.02), while after the publication of 4S, the rate of increase in statin use was only 1.8-fold higher in the younger group (P<.001). After the publication of 4S, there was a 1.6-fold higher rate of increase in statin use in male compared with female patients (P =.006). Also after the publication of 4S, specialists (cardiologists and internists) had a 2-fold higher rate of increased use of the statins than did generalists (P<.001). CONCLUSION: It is possible to shift practice if the evidence of benefit is strong, the intervention is easy to implement, and the intervention is marketed aggressively.
OBJECTIVE: To compare long-term glycemic control and safety of using insulin aspart (IAsp) with that of regular human insulin (HI). RESEARCH DESIGN AND METHODS: This was a multicenter randomized open-label 6-month study (882 subjects) with a 6-month extension period (714 subjects) that enrolled subjects with type 1 diabetes. Subjects administered IAsp immediately before meals or regular HI 30 min before meals; basal NPH insulin was taken as a single bedtime dose in the majority of subjects. Glycemic control was assessed with HbA1c values and 8-point blood glucose profiles at 3-month intervals. RESULTS: Mean postprandial blood glucose levels (mg/dl +/- SEM) were significantly lower for subjects in the IAsp group compared with subjects in the HI group after breakfast (156 +/- 3.4 vs. 185 +/- 4.7), lunch (137 +/- 3.1 vs. 162 +/- 4.1), and dinner (153 +/- 3.1 vs. 168 +/- 4.1), when assessed after 6 months of treatment. Mean HbA1c values (% +/- SEM) were slightly, but significantly, lower for the IAsp group (7.78% +/- 0.03) than for the regular HI group (7.93% +/- 0.05, P = 0.005) at 6 months. Similar postprandial blood glucose and HbA1c values were observed at 12 months. Adverse events and overall hypoglycemic episodes were similar for both treatment groups. CONCLUSIONS: Postprandial glycemic control was significantly better with IAsp compared with HI after 6 and 12 months of treatment. The improvement was not obtained at an increased risk of hypoglycemia. HbA1c was slightly, but significantly, lower for IAsp compared with HI at 6 and 12 months.
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It is thought that a number of interrelated variables, all involved in insulin resistance, may play a role in the pathophysiology of coronary artery disease. These include dyslipidemia, dysglycemia and hyperinsulinemia. Insulin resistance, the insulin resistance syndrome and atherogenesis are all thought to involve endothelial dysfunction, though in different vascular beds.
OBJECTIVE: To revise and expand the 1992 edition of the clinical practice guidelines for the management of diabetes in Canada incorporating recent advances in diagnosis and outpatient management of diabetes mellitus and to identify and assess the evidence supporting these recommendations. OPTIONS: All aspects of ambulatory diabetes care, including organization, responsibilities, classification, diagnosis, management of metabolic disorders, and methods for screening, prevention and treatment of complications in all forms of diabetes were reviewed, revised as required and expressed as a set of recommendations. OUTCOMES: Reclassification of types of diabetes based on pathogenesis; increased sensitivity of diagnostic criteria; recommendations for screening for diabetes; improved delivery of care; recommendations for tighter metabolic control; and optimal methods for screening, prevention and treatment of complications of diabetes. EVIDENCE: All recommendations were developed using a justifiable and reproducible process involving an explicit method for the citation and evaluation of the supporting evidence. VALUES: All recommendations were reviewed by an expert committee that included people with diabetes, family physicians, dietitians, nurses, diabetologists, as well as other subspecialists and methodologists from across Canada. BENEFITS, HARM AND COSTS: More aggressive screening strategies and more sensitive testing and diagnostic procedures will allow earlier detection and management of diabetes. Cost-effectiveness analyses suggest that this will lead to savings in health care costs relating to diabetes care by reducing the incidence of complications of diabetes. Similarly, tighter metabolic control in most people with diabetes, through intensive diabetes management, seeks to reduce the incidence of complications and, hence, their associated social and economic burdens. RECOMMENDATIONS: This document contains numerous detailed recommendations pertaining to all aspects of ambulatory diabetes care, ranging from service delivery to prevention and treatment of diabetes-related complications. The terms "insulin-dependent diabetes mellitus" and "non-insulin-dependent diabetes mellitus" should be replaced by the terms "type 1" and "type 2" diabetes. Testing for diabetes using fasting plasma glucose (FPG) level should be performed every 3 years in those over 45 years of age. More frequent or earlier testing should be considered for people with additional specific risk factors for diabetes. The FPG level at which diabetes is diagnosed should be reduced from 7.8 to 7.0 mmol/L to improve the sensitivity of the main diagnostic criterion and reduce the number of missed diagnoses. Depending on the type of diabetes and the therapy required to achieve euglycemia, people with diabetes should generally strive for close metabolic control to achieve optimal glucose levels. This entails receiving appropriate diabetes education through a diabetes health care team, diligent self-monitoring of blood glucose, attention to lifestyle and adjustments in diet and physical activity, and the appropriate and stepwise use of oral agents and insulin therapies needed to maintain glycemic control. Also highlighted is the need for appropriate surveillance programs for complications and management options. VALIDATION: All recommendations were graded according to the strength of the evidence and consensus of all relevant stakeholders. Collateral efforts of the American Diabetes Association and the World Health Organization and the input of international experts were also considered throughout the revision process.
OBJECTIVE: To describe the pattern of weight dissatisfaction and weight loss attempts among Canadian adults and the reasons for and methods of weight loss among those trying to lose weight. DESIGN: Population-based, cross-sectional surveys. SETTING: Ten Canadian provinces between 1986 and 1992. PARTICIPANTS: A probability sample of 29,855 men and women aged 18 to 74 years was selected using provincial health insurance registration files; this paper describes the subsample of 19,841 (66%) participants from whom anthropometric data were collected. OUTCOME MEASURES: Discrepancy between actual and desired body mass index (BMI); attempts to lose weight; reasons for losing weight; methods of weight loss used. RESULTS: Whether their weight was in the acceptable range (BMI 20-24 kg/m2) or at a level of increasing risk (BMI > or = 27 kg/m2), women were more likely than men to wish they weighed less and to be trying to lose weight; almost two-thirds of women but less than half the men with BMI > or = 27 kg/m2 were trying to lose weight. Even among those with BMI 20-24 kg/m2, 32% of women (v. 10% of men) were trying to reduce their weight. Weight dissatisfaction and current and past weight loss attempts were all negatively associated with age among women, but were unrelated to age among men. People with higher ratios of waist to hip circumference (WHR), controlling for BMI, were no more likely to be trying to lose weight than those with lower WHR; in fact, for women with BMI 27-29 kg/m2, WHR was negatively associated with prevalence of weight loss attempts. The presence of diabetes, hypertension and hypercholesterolemia was also unrelated to weight loss attempts; regular smokers and sedentary people were less likely to report trying to lose weight, controlling for BMI. Among those currently trying to lose weight, the most commonly mentioned reason was to improve general health, followed by increasing attractiveness. Overall, the most frequently mentioned method of weight loss was dieting, followed by exercise. CONCLUSIONS: Substantial numbers of men whose BMI places them at increased health risk appear to be content with their weight and are not attempting to reduce it. Conversely, women, especially the young and middle-aged, are likely to consider themselves above their desired weight and to be trying to lose weight, even when their weight is within acceptable limits. This reinforces the need to consider differences between men and women in efforts to promote and support healthy weights among Canadians.
OBJECTIVE: To examine the association of obesity, as reflected by body mass index, with other cardiovascular risk factors specifically blood pressure, smoking, physical inactivity, plasma lipid levels and diabetes mellitus. DESIGN: Population-based, cross-sectional surveys. SETTING: Ten Canadian provinces between 1986 and 1992. PARTICIPANTS: A probability sample of 29,855 men and women aged 18 to 74 years was selected from the health insurance registration files of each province and invited to participate. Anthropometry was performed on 19,841 (66%) of these adults. OUTCOME MEASURES: Body mass index (BMI, kg/m2), systolic and diastolic blood pressure, smoking status, level of leisure-time physical activity, self-reported diabetes, levels of plasma total cholesterol, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL) and triglycerides (TRIG). RESULTS: The prevalence of high blood pressure increased with increasing BMI. The gradient of increase was steepest for younger (18-34 years) men and women compared with older (55-74 years) groups. The prevalence of physical inactivity in women tended to increase with increasing BMI except in the lowest BMI category. The J-shaped relationship, although weaker, was also seen in men. The prevalence of self-reported diabetes mellitus was greater with higher BMI categories at all ages and for both sexes except for the youngest group of men. The prevalence of dyslipidemia was related to BMI, as LDL and TRIG levels were higher and HDL levels lower in those with higher BMI. BMI was strongly related to blood pressure, diabetes mellitus and lipid abnormalities. CONCLUSION: These data suggest a central role for obesity in cardiovascular risk and the potential importance of intervention strategies aimed at reducing population obesity in the management of other cardiovascular risk factors.
This 24-week, randomized, open-label multicenter study evaluated the efficacy and safety of atorvastatin compared with fenofibrate in the treatment of patients with combined hyperlipidemia (CHL). Following a 6-week baseline period, 84 patients with CHL were randomly assigned to either atorvastatin treatment, 10 mg QD for 12 weeks increasing to 20 mg QD for 12 weeks, or fenofibrate treatment, 100 mg TID for 24 weeks. Changes from baseline in lipid parameters were evaluated at weeks 12 and 24. At both 10- and 20-mg doses, atorvastatin treatment resulted in significantly greater reductions in LDL cholesterol, apolipoprotein (apo) B, total cholesterol, LDL-apoB, and lipoprotein-B compared to 300-mg fenofibrate treatment (P < .05). While atorvastatin also resulted in clinically significant reductions in triglyceride, VLDL cholesterol, apoB in VLDL, triglyceride in VLDL, and apoC-III and significant increases in HDL cholesterol and apoA-I levels, fenofibrate was more effective than atorvastatin in altering all these parameters. However, by significantly affecting both the cholesterol-rich and triglyceride-rich particles, atorvastatin holds promise as a lipid-regulator able to adequately treat a broad range of patients that includes those with CHL.
The use of amino acid (AA) dialysate in CAPD patients may have theoretical disadvantages, since protein ingestion is known to suppress food intake in humans disproportionately to its energy value. Therefore we measured subjective appetite and food intake of CAPD patients in a cross-over study of 16 subjects (age 22-75 years, BMI 19-31, > 3 months on CAPD, non-diabetic and not protein malnourished). They received, in random order, either 4 weeks of dextrose only (their usual treatment), or one AA (1%) exchange replacing the first dextrose exchange each day. Subjective measurements of food intake (3 day food record) and quantitative measurements of lunch time food intake were obtained during a morning dextrose exchange after 28 days of each regimen. Except for a reduction in feelings of fullness during the AA treatment, there were no effects on feelings of hunger/satiety, food appeal, lunch-time food intake, or on 3-day food intake. We conclude that the use of a daily AA (1%) dialysate for 4 weeks does not affect subjective appetite or food intake of CAPD patients. There may even be a beneficial effect as the feeling of fullness decreased with the AA treatment.
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Two hundred and thirty-six marijuana users who volunteered for a study in which they would use the drug were administered a Drug History and a Marihuana Effects Questionnaires. In addition to obtaining descriptive information of drug experiment volunteers and a factor analysis of the marijuana experience, the relationship between experience and effect variables were studied. The results of the above analysis suggest that the "typical" subject in marijuana experiments is not a "typical" user, that the marijuana experience is verbally definable, and that prior expectancies and histories of effect alter the experience.
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