Abstract-Increased body weight is a strong risk factor for hypertension. A meta-analysis of randomized controlled trials was performed to estimate the effect of weight reduction on blood pressure overall and in population subgroups. 2 ) for American adults aged 20 to 74 years increased from 13.4% to 30.9%. In 2000, the prevalence of overweight (BMI Ն25 kg/m 2 ) for American adults was 64.5%. 3 Weight loss has been proposed as an effective, nonpharmacologic means for the primary prevention of hypertension. 4 An early meta-analysis by Staessen et al 5 in 1988 showed a reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP) of Ϫ2.4 and Ϫ1.5 mm Hg per kilogram weight loss, respectively.Targeted weight loss interventions in population subgroups might be more effective for the prevention of hypertension than a general-population approach because of interindividual differences in BP and body weight. In the present meta-analysis of 25 randomized controlled trials (RCTs), both the overall and subgroup effects of body weight reduction on BP were assessed. This stratified meta-analysis could strengthen the scientific basis for weight control as an important ingredient of hypertension control programs in the community and in individual patients. Methods Selection of StudiesSystematic literature searches in electronic databases (Cab Abstract, Current Contents, FSTA, and MEDLINE Advanced) were conducted for RCTs of weight reduction and BP by using the search phrase (overweight OR weight reduction OR obes* OR weight OR diet*) AND (hypertension OR blood pressure) AND (trial OR intervention OR random* OR study) as title words or MeSH terms. Article reference lists were examined for additional articles.Trials that fulfilled the following criteria were eligible for metaanalysis: (1) an RCT design, (2) published after 1966, (3) conducted in humans, (4) written in English, and (5) nonpharmacologic reduction of body weight. A total of 97 articles was identified, of which 72 were excluded on the basis of the predefined criteria (literature list of excluded trials is available from the authors); ie, they did not fulfill the inclusion criteria (nϭ21), the intervention period was Ͻ8 weeks (nϭ2), there were co-interventions from which the effect of weight loss could not be separated (nϭ28), inappropriate or missing BP data (nϭ5), study objective was not weight reduction (nϭ4), or overlapping data with other publication(s) (nϭ12). Figure 1 shows the number of studies that were identified and excluded at different stages of the selection process. A total of 25 trials 6 -30 proved eligible for this meta-analysis.

Animal studies show favorable effects of n-3 fatty acids on inflammation and cancer, but results from epidemiologic studies appear to be inconsistent. The authors conducted meta-analyses of prospective cohort studies that evaluated the association between fish consumption or n-3 fatty acids and colorectal cancer incidence or mortality. Random-effects models were used, and heterogeneity between study results was explored through stratified analyses. The pooled relative risks for the highest compared with the lowest fish consumption category were 0.88 (95% confidence interval: 0.78, 1.00) for colorectal cancer incidence (14 studies) and 1.02 (95% confidence interval: 0.90, 1.16) for colorectal cancer mortality (four studies). The pooled relative risks for colorectal cancer incidence were 0.96 (95% confidence interval: 0.92, 1.00) for each extra occurrence of fish consumption per week (seven studies) and 0.97 (95% confidence interval: 0.92, 1.03) for each extra 100 g of fish consumed per week (four studies). Stratified analysis showed that the pooled relative risk for colorectal cancer incidence was more pronounced for women and in studies with a large exposure contrast. In cohort studies, fish consumption was shown to slightly reduce colorectal cancer risk. Existing evidence that n-3 fatty acids inhibit colorectal carcinogenesis is in line with these results, but few data are available addressing this association.

No abstract

No abstract

No abstract