title: Decrease in urinary albumin excretion associated with the normalization of nocturnal blood pressure in hypertensive subjects.
abstract: Previous results have indicated that valsartan administration at bedtime as opposed to on wakening improves the diurnal/nocturnal ratio of blood pressure without loss in efficacy and therapeutic coverage. We hypothesized that increasing this ratio could reduce microalbuminuria. We conducted a prospective, randomized, open-label, blinded endpoint trial on 200 previously untreated nonproteinuric patients with grade 1 to 2 essential hypertension, assigned to receive valsartan (160 mg/d) as a monotherapy either on awakening or at bedtime. Blood pressure was measured by ambulatory monitoring for 48 consecutive hours before and after 3 months of treatment. Physical activity was simultaneously monitored every minute by wrist actigraphy to accurately calculate the diurnal and nocturnal means of blood pressure on a per-subject basis. The significant blood pressure reduction after 3 months of therapy was similar for both treatment times. The diurnal/nocturnal blood pressure ratio was unchanged after valsartan on awakening, but significantly increased from 7.5 to 12.2 (P<0.001) when valsartan was administered at bedtime. Urinary albumin excretion was significantly reduced by 41% after bedtime treatment. This reduction was independent of the 24-hour blood pressure decrease but highly correlated with the decrease in nocturnal blood pressure and mainly with the increase in diurnal/nocturnal ratio (P<0.001). Bedtime valsartan administration improves the diurnal/nocturnal blood pressure ratio to a more dipper profile. This normalization of the circadian blood pressure pattern is associated with a significant decrease in urinary albumin excretion and plasma fibrinogen, and could thus reduce the increased cardiovascular risk in nondipper hypertensive patients.
authors.affiliation: Bioengineering Laboratory, University of Vigo, Campus Universitario, Vigo, Spain. rhermida@tsc.uvigo.es
authors.forename: Ramón C
authors.initials: RC
authors.lastname: Hermida
authors.forename: Carlos
authors.initials: C
authors.lastname: Calvo
authors.forename: Diana E
authors.initials: DE
authors.lastname: Ayala
authors.forename: José E
authors.initials: JE
authors.lastname: López
mesh_terms: D000328:Adult; D000419:Albuminuria / Q000503:physiopathology*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000008:administration & dosage* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology* / Q000652:urine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013777:Tetrazoles / Q000008:administration & dosage* / Q000627:therapeutic use; D014633:Valine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000068756:Valsartan
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D013777:Tetrazoles; D000068756:Valsartan; D005340:Fibrinogen; D014633:Valine