Systematic review and meta-analyses of randomized controlled trials of the effects on blood pressure and lipids
American Journal of Clinical Nutrition, 05/16/2014 > Evidence Based Medicine Review Article
Te Morenga LA, et al. – In this study, authors 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. 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.
- 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.
- Authors pooled data by using inverse–variance methods with random–effects models.
Results
- 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 (I2 = 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].