title: Does repeated and heavy exercise impair blood rheology in carriers of sickle cell trait?
abstract: OBJECTIVE
  To determine if the time courses of hemorheologic parameters are different between carriers of sickle cell trait (SCT) and subjects with normal hemoglobin in response to exercise.
  
  
  METHODS
  Observational and comparative study.
  
  
  METHODS
  Testing was conducted in a laboratory of exercise physiology.
  
  
  METHODS
  Nine carriers of sickle cell trait (SCT group) and 7 subjects with normal hemoglobin (CONT group) performed an exercise protocol of the repetition of 3 successive maximal ramp exercise tests.
  
  
  METHODS
  Blood was sampled at rest (TR), at the end of each of the 3 tests (T1, T2, T3), and during the immediate (T2h) and late (T24h, T48h) recovery periods.
  
  
  METHODS
  Blood and plasma viscosity (etab and etap, respectively), hematocrit (Hct), and red blood cell (RBC) rigidity (Tk and k indexes) were determined.
  
  
  RESULTS
  In both groups, etab significantly increased in response to exercise but the SCT group had significantly higher etab at T3 and T2h. etab then returned to baseline value at T2h in the CONT group and at T24h in the SCT group. Tk and k were not changed by exercise but significantly increased above baseline value in both groups at T24h and T48h. The increase in Tk and k during late recovery was higher in the SCT group than in the CONT group, indicating that SCT carriers had significantly higher RBC rigidity than the CONT group at that time.
  
  
  CONCLUSIONS
  The hemorheologic changes induced by exercise in the SCT carriers could trigger microcirculatory disorders during the recovery.
authors.affiliation: Université des Antilles et de la Guyane, Laboratoire ACTES (EA 3596), Département de Physiologie, Campus de Fouillole, Guadeloupe, French West Indies.
authors.forename: Julien
authors.initials: J
authors.lastname: Tripette
authors.forename: Marie-Dominique
authors.initials: MD
authors.lastname: Hardy-Dessources
authors.forename: Fagnété
authors.initials: F
authors.lastname: Sara
authors.forename: Mona
authors.initials: M
authors.lastname: Montout-Hedreville
authors.forename: Christian
authors.initials: C
authors.lastname: Saint-Martin
authors.forename: Olivier
authors.initials: O
authors.lastname: Hue
authors.forename: Philippe
authors.initials: P
authors.lastname: Connes
mesh_terms: D000328:Adult; D004912:Erythrocytes / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D019430:Guadeloupe; D006801:Humans; D008991:Monitoring, Physiologic / Q000379:methods; D005082:Physical Exertion / Q000502:physiology*; D012212:Rheology; D012805:Sickle Cell Trait / Q000503:physiopathology*