Background: Experimental models and observational studies suggest that vitami n E supplementation may prevent cardiovascular disease and cancer. However, seve ral trials of high dosage vitamin E supplementation show...Background: Experimental models and observational studies suggest that vitami n E supplementation may prevent cardiovascular disease and cancer. However, seve ral trials of high dosage vitamin E supplementation showed non statistically significant increases in total mortality. Purpose: To perform a meta analysis of the dose response relationship between vitamin E supplementation and total mortality by using data from randomized, controlled trials. Patients: 135 967 p articipants in 19 clinical trials. Of these trials, 9 tested vitamin E alone and 10 tested vitamin E combined with other vitamins or minerals. The dosages of vi tamin E ranged from 16.5 to 2000 IU/d (median, 400 IU/d). Data Sources:PubMed se arch from 1966 through August 2004, complemented by a search of the Cochrane Cli nical Trials Data base and review of citations of published reviews and meta analyses. No language restrictions were applied. Data Extraction: 3 investigato rs independently abstracted study reports. The investigators of the original pub lications were contacted if required information was not available. Data Synthes is: 9 of 11 trials testing high dosage vitamin E (≥ 400 IU/d) showed increased risk (risk difference >0) for all cause mortality in comparisons of vitamin E versus control. The pooled all cause mortality risk difference in high dosag e vitamin E trials was 39 per 10 000 persons (95% CI, 3 to 74 per 10 000 perso ns; P = 0.035). For low dosage vitamin E trials, the risk difference was 16 per 10 000 persons (CI, - 41 to 10 per 10 000 persons; P >0.2). A dose respo nse analysis showed a statistically significant relationship between vitamin E d osage and all cause mortality, with increased risk of dosages greater than 150 IU/d. Limitations: High dosage (≥ 400 IU/d) trials were often small and were performed in patients with chronic diseases. The generalizability of the findin gs to healthy adults is uncertain. Precise estimation of the threshold at which risk increases is difficult. Conclusion: High dosage (≥ 400 IU/d) vitamin E s upplements may increase all cause mortality and should be avoided.展开更多
Obesity and metabolic syndrome(MS), which often co-exist, are associated with an increased cardiovascular risk. An increased leukocyte count is also associated with an increased cardiovascular risk. However, the role ...Obesity and metabolic syndrome(MS), which often co-exist, are associated with an increased cardiovascular risk. An increased leukocyte count is also associated with an increased cardiovascular risk. However, the role of obesity, independent of MS, has been debated. We sought to assess the influence of MS on the association of obesity and leukocyte count in asymptomatic patients. The data from 431 asymptomatic Brazilian men(mean age 46± 7 years), who presented for cardiovascular risk assessment, were analyzed. MS was defined as the presence of ≥ 3 of the following risk factors: hypertension(≥ 130/85 mm Hg), truncal obesity(≥ 102 cm or 40 in), hypertriglyceridemia(≥ 150 mg/dl), high-density lipoprotein cholesterol(≤ 40 mg/dl), and hyperglycemia(glucose≥ 110 mg/dl). Obesity was defined as a body mass index of ≥ 30 kg/m2. Confounding variables(age, smoking, lipid-lowering therapy, and physical activity) and leukocyte count(109/L) were recorded. The patients were divided into 4 groups:group 1, no obesity and no MS; group 2, obesity but no MS; group 3, no obesity but MS; and group 4, obesity and MS. The mean leukocyte count increased from groups 1 to 4(6.10± 0.09, 6.42± 0.28, 6.71± 0.21, and 6.96± 0.22× 109/L, p< 0.001 for trend). Multivariate regression analysis demonstrated that the leukocyte count was significantly higher in groups 3(coefficient 0.61, p=0.007)and 4(coefficient 0.86, p< 0.001) compared with group 1. However, no significant difference was found in the leukocyte count between groups 1 and 2(coefficient 0.29, p=0.42) and groups 3 and 4(coefficient 0.25, p=0.41). The association between obesity and leukocyte count was highly dependent on the presence of MS.展开更多
文摘Background: Experimental models and observational studies suggest that vitami n E supplementation may prevent cardiovascular disease and cancer. However, seve ral trials of high dosage vitamin E supplementation showed non statistically significant increases in total mortality. Purpose: To perform a meta analysis of the dose response relationship between vitamin E supplementation and total mortality by using data from randomized, controlled trials. Patients: 135 967 p articipants in 19 clinical trials. Of these trials, 9 tested vitamin E alone and 10 tested vitamin E combined with other vitamins or minerals. The dosages of vi tamin E ranged from 16.5 to 2000 IU/d (median, 400 IU/d). Data Sources:PubMed se arch from 1966 through August 2004, complemented by a search of the Cochrane Cli nical Trials Data base and review of citations of published reviews and meta analyses. No language restrictions were applied. Data Extraction: 3 investigato rs independently abstracted study reports. The investigators of the original pub lications were contacted if required information was not available. Data Synthes is: 9 of 11 trials testing high dosage vitamin E (≥ 400 IU/d) showed increased risk (risk difference >0) for all cause mortality in comparisons of vitamin E versus control. The pooled all cause mortality risk difference in high dosag e vitamin E trials was 39 per 10 000 persons (95% CI, 3 to 74 per 10 000 perso ns; P = 0.035). For low dosage vitamin E trials, the risk difference was 16 per 10 000 persons (CI, - 41 to 10 per 10 000 persons; P >0.2). A dose respo nse analysis showed a statistically significant relationship between vitamin E d osage and all cause mortality, with increased risk of dosages greater than 150 IU/d. Limitations: High dosage (≥ 400 IU/d) trials were often small and were performed in patients with chronic diseases. The generalizability of the findin gs to healthy adults is uncertain. Precise estimation of the threshold at which risk increases is difficult. Conclusion: High dosage (≥ 400 IU/d) vitamin E s upplements may increase all cause mortality and should be avoided.
文摘Obesity and metabolic syndrome(MS), which often co-exist, are associated with an increased cardiovascular risk. An increased leukocyte count is also associated with an increased cardiovascular risk. However, the role of obesity, independent of MS, has been debated. We sought to assess the influence of MS on the association of obesity and leukocyte count in asymptomatic patients. The data from 431 asymptomatic Brazilian men(mean age 46± 7 years), who presented for cardiovascular risk assessment, were analyzed. MS was defined as the presence of ≥ 3 of the following risk factors: hypertension(≥ 130/85 mm Hg), truncal obesity(≥ 102 cm or 40 in), hypertriglyceridemia(≥ 150 mg/dl), high-density lipoprotein cholesterol(≤ 40 mg/dl), and hyperglycemia(glucose≥ 110 mg/dl). Obesity was defined as a body mass index of ≥ 30 kg/m2. Confounding variables(age, smoking, lipid-lowering therapy, and physical activity) and leukocyte count(109/L) were recorded. The patients were divided into 4 groups:group 1, no obesity and no MS; group 2, obesity but no MS; group 3, no obesity but MS; and group 4, obesity and MS. The mean leukocyte count increased from groups 1 to 4(6.10± 0.09, 6.42± 0.28, 6.71± 0.21, and 6.96± 0.22× 109/L, p< 0.001 for trend). Multivariate regression analysis demonstrated that the leukocyte count was significantly higher in groups 3(coefficient 0.61, p=0.007)and 4(coefficient 0.86, p< 0.001) compared with group 1. However, no significant difference was found in the leukocyte count between groups 1 and 2(coefficient 0.29, p=0.42) and groups 3 and 4(coefficient 0.25, p=0.41). The association between obesity and leukocyte count was highly dependent on the presence of MS.
