title: What is more damaging to vascular endothelial function: Diabetes, age, high BMI, or all of the above?
abstract: BACKGROUND
  It is well established that there is a reduction in the skin blood flow (SBF) in response to heat with age and diabetes. While it is known that high BMI creates a stress on the cardiovascular system and increases the risk of all cause of morbidity and mortality, little is known of the effect of high BMI on SBF response to heat. Since diabetes is associated with age and a higher BMI, the interrelationship between age, BMI and SBF needs to be investigated to better understand the contribution diabetes alone has to endothelial impairment.
  
  
  METHODS
  This study examined the SBF to heat in young and old people with low and high BMI and people with diabetes with high BMI to determine the contribution these variables have on SBF. Subjects were ten young and older people with BMI <20 and ten young and older people with BMI >20 and ten subjects with diabetes with BMI >20. The SBF response, above the quadriceps, was determined during a 6 minutes exposure to heat at 44°C.
  
  
  RESULTS
  Even in young people, SBF after the stress of heat exposure was reduced in subjects with a high BMI. The effect of BMI was greatest in young people and lowest in older people and people with diabetes; in people with diabetes, BMI was a more significant variable than diabetes in causing impairment of blood flow to heat. BMI, for example, was responsible for 49% of the reduction in blood flow after stress heat exposure (R=-0.7) while ageing only accounted for 16% of the blood flow reduction (R=-0.397).
  
  
  CONCLUSIONS
  These results would suggest the importance of keeping BMI low not only in people with diabetes to minimize further circulatory vascular damage, but also in young people to diminish long term circulatory vascular compromise.
authors.affiliation: Department of Physical Therapy, School of Allied Health Professions, Loma Linda University, Loma LInda, CA, USA. jpetrofsky@llu.edu
authors.forename: Jerrold Scott
authors.initials: JS
authors.lastname: Petrofsky
authors.forename: Faris
authors.initials: F
authors.lastname: Alshammari
authors.forename: Gurinder Singh
authors.initials: GS
authors.lastname: Bains
authors.forename: Iman Akef
authors.initials: IA
authors.lastname: Khowailed
authors.forename: Haneul
authors.initials: H
authors.lastname: Lee
authors.forename: Yashvanth Nagarajamurthy
authors.initials: YN
authors.lastname: Kuderu
authors.forename: Riya D
authors.initials: RD
authors.lastname: Lodha
authors.forename: Sophia
authors.initials: S
authors.lastname: Rodrigues
authors.forename: Diamond
authors.initials: D
authors.lastname: Nguyen
authors.forename: Pooja Ashok
authors.initials: PA
authors.lastname: Potnis
authors.forename: Pooja P
authors.initials: PP
authors.lastname: Deshpande
authors.forename: Jong Eun
authors.initials: JE
authors.lastname: Yim
authors.forename: Lee
authors.initials: L
authors.lastname: Berk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000473:pathology*; D015992:Body Mass Index; D003920:Diabetes Mellitus / Q000473:pathology* / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009132:Muscles / Q000473:pathology / Q000503:physiopathology; D012867:Skin / Q000098:blood supply / Q000503:physiopathology; D012881:Skin Temperature; D055815:Young Adult