title: The effect of hypohydration on endothelial function in young healthy adults.
abstract: OBJECTIVE
  Hypohydration has been suggested as a predisposing factor for several pathologies including cardiovascular diseases (CVD). While CVD are the leading cause of death worldwide, no study has investigated whether acute hypohydration affects endothelial function and cardiovascular function.
  
  
  METHODS
  Ten young, healthy males participated in this crossover study (age: 24.3 ± 2.3 year; weight: 80.8 ± 5.3 kg; BMI: 24.3 ± 0.4 kg m-2). Each subject completed two measurements of endothelial function by flow-mediated dilation (FMD) in euhydrated and hypohydrated state separated by 24 h. Following baseline assessment of hydration status and FMD, the subjects completed 100 min of low-intensity intermittent walking exercise to achieve hypohydration of -2 % of individual body mass. For the rest of the day, a standardized, low water content diet was provided. The following morning, hydration markers and endothelial function were recorded.
  
  
  RESULTS
  Hypohydration by -1.9 ± 0.1 % of body mass resulted in decreased plasma volume by -3.5 ± 1.8 % and increased plasma osmolality by 9 ± 2 mmol kg-1(P < 0.001). FMD as a response to hypohydration decreased by -26.8 ± 3.9 % (P < 0.05).
  
  
  CONCLUSIONS
  The data suggested that a small degree of hypohydration induced by moderate exercise and fluid restriction significantly impaired endothelial function.
authors: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
authors: Giannis
authors: G
authors: Arnaoutis
authors: Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR, 72701, USA. kavouras@uark.edu.
authors: Stavros A
authors: http://orcid.org/0000-0001-7485-8112
authors: SA
authors: Kavouras
authors: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
authors: Nikolaos
authors: N
authors: Stratakis
authors: Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece.
authors: Marita
authors: M
authors: Likka
authors: Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece.
authors: Asimina
authors: A
authors: Mitrakou
authors: Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece.
authors: Christos
authors: C
authors: Papamichael
authors: Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.|Department of Exercise Science and Sports Studies, Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Jersey, USA.
authors: Labros S
authors: LS
authors: Sidossis
authors: Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece.
authors: Kimon
authors: K
authors: Stamatelopoulos
mesh_terms: D015502:Absorptiometry, Photon; D000208:Acute Disease; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D003681:Dehydration / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D015444:Exercise; D005260:Female; D006801:Humans; D008297:Male; D009994:Osmolar Concentration; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D014280:Triglycerides
keywords: Cardiovascular disease; Dehydration; Endothelial; Flow-mediated dilation; Fluid balance