title: Weight loss improves fasting flow-mediated vasodilation in adults: a meta-analysis of intervention studies.
abstract: BACKGROUND
  Obesity is associated with vascular endothelial dysfunction. Effects of weight loss on endothelial function are however not clear. Therefore, we performed a meta-analysis to quantify effects of weight loss on flow-mediated vasodilation (FMD) of the brachial artery, a measurement of endothelial function.
  
  
  METHODS
  Studies with experimental (RCTs) and quasi-experimental designs published before June 2014 were identified by a systematic search. Changes in FMD were defined as the difference between measurements before and after the study. For RCTs, changes were corrected for those in the no-weight loss control group. Summary estimates of weighted mean differences (WMDs) in FMD and 95% confidence intervals (CIs) were calculated using random-effect meta-analyses. The impact of subject characteristics, type of weight-loss treatment, and dietary composition on changes in FMD was also investigated.
  
  
  RESULTS
  Four RCTs involving 265 subjects were included. Weight loss increased FMD vs. control by 3.29% (95% CI: 0.98-5.59%; P = 0.005; mean weight loss: 8.6 kg). A total of 1517 subjects participated in 33 studies with 49 relevant study arms. It was estimated that each 10 kg decrease in body weight increased fasting FMD by 1.11% (95% CI: 0.47-1.76%; P = 0.001). Effects were more pronounced when participants had coexisting obesity-related morbidities. Also, effects may be larger when subjects received low-fat diets or weight-reduction regimens including exercise therapy or weight-loss medication.
  
  
  CONCLUSIONS
  Weight loss significantly improves fasting FMD in adults, which is a risk marker for cardiovascular disease. Effects may depend on subject characteristics, type of weight-loss treatment, and dietary composition.
authors.affiliation: Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands; Top Institute of Food and Nutrition (TIFN), Wageningen, The Netherlands. Electronic address: p.joris@maastrichtuniversity.nl.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Joris
authors.affiliation: Department of Complex Genetics, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands. Electronic address: m.zeegers@maastrichtuniversity.nl.
authors.forename: Maurice P
authors.initials: MP
authors.lastname: Zeegers
authors.affiliation: Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands; Top Institute of Food and Nutrition (TIFN), Wageningen, The Netherlands. Electronic address: r.mensink@maastichtuniversity.nl.
authors.forename: Ronald P
authors.initials: RP
authors.lastname: Mensink
mesh_terms: D000328:Adult; D000368:Aged; D001835:Body Weight; D002318:Cardiovascular Diseases / Q000503:physiopathology / Q000517:prevention & control; D002986:Clinical Trials as Topic; D015897:Comorbidity; D004032:Diet; D018752:Diet, Fat-Restricted; D004038:Diet, Reducing; D004730:Endothelium, Vascular / Q000503:physiopathology; D005215:Fasting; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D012307:Risk Factors; D016896:Treatment Outcome; D014664:Vasodilation / Q000502:physiology*; D015431:Weight Loss
keywords: Endothelial function; Flow-mediated vasodilation; Intervention studies; Meta-analysis; Weight loss