Article

Long-term effects of weight-reducing diets in hypertensive patients

Institute for General Practice, Goethe University, Theodor-Stern-Kai 7, Frankfurt am Main, Germany, 60590.
Cochrane database of systematic reviews (Online) (Impact Factor: 5.94). 01/2011; DOI: 10.1002/14651858.CD008274.pub2
Source: PubMed

ABSTRACT All major guidelines for antihypertensive therapy recommend weight loss. Thus dietary interventions that aim to reduce body weight might be a useful intervention to reduce blood pressure and adverse cardiovascular events associated with hypertension.
Primary objectivesTo assess the long-term effects of weight-reducing diets in hypertensive patients on- all cause mortality - cardiovascular morbidity - adverse events (including total serious adverse events, withdrawal due to adverse events and total non-serious adverse events)Secondary objectivesTo assess the long-term effects of weight-reducing diets in hypertensive patients on- change from baseline in systolic blood pressure - change from baseline in diastolic blood pressure - body weight reduction
Studies were obtained from computerised searches of Ovid MEDLINE, EMBASE, CENTRAL and from searches in reference lists and systematic reviews.
Randomised controlled trials (RCT) in adult hypertensive patients were included if they had a study duration of at least 24 weeks and compared weight reducing dietary interventions to no dietary intervention in adult patients with primary hypertension.
Two authors independently assessed risk of bias and extracted data. Studies were pooled using fixed-effect meta-analysis. In case of moderate or larger heterogeneity as measured by Higgins I(2), a random effects model was used.
Eight studies involving a total of 2100 participants with high blood pressure and a mean age of 45 to 66 years met our inclusion criteria. Mean treatment duration was 6 to 36 months. No study included mortality as a pre-defined outcome. One RCT evaluated the effects of dietary weight loss on a combined endpoint, consisting of the necessity of reinstating antihypertensive therapy and severe cardiovascular complications. In this RCT weight reducing diet lowered the endpoint, hazard ratio 0.70 (95% confidence interval [CI], 0.57 to 0.87) compared to no diet. None of the studies evaluated adverse events as designated in our protocol. Blood pressure was reduced in patients assigned to weight loss diets as compared to controls: systolic blood pressure (SBP): weighted mean difference (WMD): -4.5 mm Hg; 95% CI, -7.2 to -1.8 mm Hg (3 of 8 studies included in analysis), and diastolic blood pressure (DBP): WMD -3.2 mm Hg; 95% CI, -4.8 to -1.5 mm Hg (3 of 8 studies included in analysis). Patients' body weight was also reduced in dietary weight loss groups as compared to controls, WMD of -4.0 kg (95% CI: -4.8 to -3.2) (5 of 8 studies included in analysis). Two studies used withdrawal of antihypertensive medication as their primary outcome. Even though this was not considered a relevant outcome for this review, the results of these studies strengthen the finding of reduction of blood pressure by dietary weight loss interventions.
In patients with primary hypertension, weight loss diets reduced body weight and blood pressure, however the magnitude of the effects are uncertain as a result of the small number of patients and studies that could be included in the analyses. It is not known whether weight loss reduces mortality and morbidity. No useful information on adverse effects was reported in the relevant trials.

Full-text

Available from: Andreas Waltering, Apr 24, 2014
0 Followers
 · 
113 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: A systematic review and meta-analysis focusing on patient-relevant outcomes and blood pressure was conducted to assess the clinical effectiveness of stress-reduction techniques in adults with essential hypertension. Methods: Systematic reviews and randomized controlled trials (RCTs) were identified as part of a systematic search in six electronic databases ending September 2012. RCTs comparing stress-reduction techniques versus no such techniques with a follow-up of at least 24 weeks and published in English or German were included. Outcomes of interest were death, cardiovascular morbidity/mortality, end-stage renal disease, health-related quality of life, adverse events, changes in blood pressure, and changes in antihypertensive medication. When appropriate, meta-analyses were used to combine data. Results: Seventeen RCTs analyzing different stress-reduction techniques such as biofeedback, relaxation or combined interventions were identified. Data were not reported for most of the patient-relevant outcomes, and meta-analyses could only be used to evaluate effects on blood pressure. The data indicated a blood pressure-lowering effect, but the studies had methodological shortcomings and heterogeneity between them was high. Mean group differences for DBP ranged from -10 to 1mmHg and for SBP from -12 to 10 mmHg. In terms of antihypertensive medication, no favorable effects of stress-reduction techniques could be identified. Conclusions: The available RCTs on stress-reduction techniques used for at least 24 weeks appeared to indicate a blood pressure-lowering effect in patients with essential hypertension, but this should be interpreted with caution because of major methodological limitations. A benefit of specific stress-reduction techniques in hypertensive patients remains unproven.
    Journal of Hypertension 07/2014; 32(10). DOI:10.1097/HJH.0000000000000298 · 4.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The metabolic syndrome (MetS) is a cluster of metabolic conditions associated to abdominal obesity, such as elevated blood pressure, impaired glucose tolerance, insulin resistance, elevated triglycerides, and low high-density lipoprotein cholesterol concentrations. Each of the associated conditions has an independent effect, but clustering together they become synergistic, making the risk of developing cardiovascular disease (CVD) greater. There is large debate as to whether the MetS alone or its associated health conditions are more important for CVD incidence and mortality or whether prevention and/or treatment of the MetS will reduce CVD incidence and mortality. This article reviews the evidence that demonstrates that individuals with the MetS are at increased risk for CVD incidence and mortality and discusses these debated issues.
    Current Vascular Pharmacology 10/2013; 11(6). DOI:10.2174/15701611113116660176 · 2.91 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dietary sugars have been suggested as a cause of obesity, several chronic diseases, and a range of cardiometabolic risk factors, but there is no convincing evidence of a causal relation between sugars and risk factors other than body weight. We conducted a systematic review and meta-analysis of randomized controlled trials that examined effects of the modification of dietary free sugars on blood pressure and lipids. Systematic searches were conducted in OVID Medline, Embase, Scopus, Cumulative Index to Nursing and Allied Health Literature, and Web of Science databases (to August 2013) to identify studies that reported intakes of free sugars and at least one lipid or blood pressure outcome. The minimum trial duration was 2 wk. We pooled data by using inverse-variance methods with random-effects models. A total of 39 of 11,517 trials identified were included; 37 trials reported lipid outcomes, and 12 trials reported blood pressure outcomes. Higher compared with lower sugar intakes significantly raised triglyceride concentrations [mean difference (MD): 0.11 mmol/L; 95% CI: 0.07, 0.15 mmol/L; P < 0.0001], total cholesterol (MD: 0.16 mmol/L; 95% CI: 0.10, 0.24 mmol/L; P < 0.0001), low-density lipoprotein cholesterol (0.12 mmol/L; 95% CI: 0.05, 0.19 mmol/L; P = 0.0001), and high-density lipoprotein cholesterol (MD: 0.02 mmol/L; 95% CI: 0.00, 0.03 mmol/L; P = 0.03). Subgroup analyses showed the most marked relation between sugar intakes and lipids in studies in which efforts were made to ensure an energy balance and when no difference in weight change was reported. Potential explanatory factors, including a weight change, in most instances explained <15% of the heterogeneity between studies (I(2) = 36-75%). The effect of sugar intake on blood pressure was greatest in trials ≥8 wk in duration [MD: 6.9 mm Hg (95% CI: 3.4, 10.3 mm Hg; P < 0.001) for systolic blood pressure and 5.6 mm Hg (95% CI: 2.5, 8.8 mm Hg; P = 0.0005) for diastolic blood pressure]. Dietary sugars influence blood pressure and serum lipids. The relation is independent of effects of sugars on body weight. Protocols for this review were registered separately for effects of sugars on blood pressure and lipids in the PROSPERO International prospective register of systematic reviews as PROSPERO 2012: CRD42012002379 and 2012: CRD42012002437, respectively.
    American Journal of Clinical Nutrition 05/2014; 100(1). DOI:10.3945/ajcn.113.081521 · 6.92 Impact Factor