title: Blood pressure is correlated with vitamin d(3) serum levels in dialysis patients.
abstract: OBJECTIVE
  The blood pressure, the most influencing factor in cardiovascular disease in end-stage renal failure patients, follows a seasonal variation during the year. Since vitamin D(3) is known to be related to sun exposure, we wanted to evaluate the putative participation of the vitamin D(3) metabolism in blood pressure modifications.
  
  
  METHODS
  We studied 22 stable hemodialysis patients (11 females and 11 males, mean age +/- SD 56 +/- 1 year) who had been continuously treated in our dialysis unit for more than 1 year between 1994 and 1997 and did not receive pulse vitamin D(3) treatment. Supine systolic and diastolic blood pressures were measured before every dialysis session (>12,000 measurements) and the intact parathormone (iPTH), 25-hydroxyvitamin D(3) [25(OH)D(3)], and 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] levels every 3 months (>300 determinations). The mean values of blood pressure per season and per patient were taken for analysis using a 4-year longitudinal study design.
  
  
  RESULTS
  The blood pressure varied during the years studied following a seasonal trend. It was highest during autumn and tended to decrease during spring and warmer months. Systolic as well as diastolic blood pressures were significantly correlated with the 25(OH)D(3) levels (p = 0.0291 and p = 0.0327, respectively). No correlation was observed between blood pressure and 1,25(OH)(2)D(3) or iPTH levels.
  
  
  CONCLUSIONS
  There is a link between blood pressure and 25(OH)D(3) level. This interrelation is not secondary to a iPTH modulation. Although it cannot be excluded that vitamin D(3) and blood pressure vary following a third factor with seasonal variations, since vitamin D(3) varies during the year, mainly following sun exposure, we suggest that vitamin D(3) is one of the factors participating in the seasonal variation of the blood pressure. Other factors known to control the blood pressure and particularly the extracellular volume overload may also participate.
authors.affiliation: Institut de Génétique Humaine - CNRS UPR 1142, Montpellier, France. Angel.Argiles@igh.cnrs.fr
authors.forename: Angel
authors.initials: A
authors.lastname: Argilés
authors.forename: Ronan
authors.initials: R
authors.lastname: Lorho
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Servel
authors.forename: Isabelle
authors.initials: I
authors.lastname: Couret
authors.forename: Guillaume
authors.initials: G
authors.lastname: Chong
authors.forename: Georges
authors.initials: G
authors.lastname: Mourad
mesh_terms: D001794:Blood Pressure; D002112:Calcifediol / Q000097:blood; D002117:Calcitriol / Q000097:blood; D002762:Cholecalciferol / Q000097:blood* / Q000378:metabolism; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D006435:Renal Dialysis; D012621:Seasons
chemical_list: D010281:Parathyroid Hormone; D002762:Cholecalciferol; D002117:Calcitriol; D002112:Calcifediol