title: Effects of chronotherapy on blood pressure control in non-dipper patients with refractory hypertension.
abstract: BACKGROUND
  Refractory arterial hypertension (RAH) is frequently associated to a non-dipping blood pressure (BP) pattern; this profile has been shown to have a worse clinical prognosis. It is a common clinical practice that patients receive anti-hypertensive medication preferentially in the morning. Non-dipping could be related to the timing of anti-hypertensive drug administration. We analysed whether switching anti-hypertensive medication to bedtime could improve BP control in non-dipper patients with RAH.
  
  
  METHODS
  Twenty-seven consecutive patients with RAH and non-dipper or riser BP pattern on ambulatory blood pressure (ABP) monitoring were studied before and after 6 weeks of a change in the timing of anti-hypertensive medications. The intervention consisted of shifting all non-diuretic anti-hypertensive drugs from morning to evening, maintaining the same drugs at the same doses. A parallel group of 12 consecutive patients with similar characteristics and no changes in the therapeutic regimen formed the control group.
  
  
  RESULTS
  There were 59% women, mean age 65.7 ± 8.4 years. They were treated with 4 ± 0.7 anti-hypertensive drugs, 90% administered in the morning. At baseline, diurnal and nocturnal ABP averaged 141.6 ± 10.6/81.5 ± 9.3 and 141.7 ± 11/78 ± 8.8, respectively. After the drug shift, mean diurnal and nocturnal ABP was 140.5 ± 10.4/80.5 ± 9.6 and 135.7 ± 12.5/73.8 ± 9.3 (P = 0.005 and 0.04 for systolic and diastolic ABP), 15% of the patients restored a normal ABP circadian rhythm. No changes were observed in the control group.
  
  
  CONCLUSIONS
  In non-dipper or riser patients with RAH, changing the timing of anti-hypertensive medication to the evening could improve BP control.
authors.affiliation: Nephrology Service, Departament de Medicina, Corporació Parc Taulí, Institut Universitari Parc Taulí, UAB, Barcelona, Spain. jalmirall@tauli.cat
authors.forename: Jaume
authors.initials: J
authors.lastname: Almirall
authors.forename: Lurdes
authors.initials: L
authors.lastname: Comas
authors.forename: Juan C
authors.initials: JC
authors.lastname: Martínez-Ocaña
authors.forename: Silvia
authors.initials: S
authors.lastname: Roca
authors.forename: Anna
authors.initials: A
authors.lastname: Arnau
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D055870:Drug Chronotherapy; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents