title: Aldosterone-to-renin ratio and nocturnal blood pressure decline in a general population: the Ohasama study.
abstract: BACKGROUND
  Aldosterone-to-renin ratio (ARR) is an index for inappropriate aldosterone activity and salt sensitivity. We previously reported that elevated ARR might be associated with salt-sensitive hypertension. Because salt-sensitive hypertensive patients are reported to show a diminished nocturnal decline in blood pressure, we hypothesized that high ARR may be associated with diminished nocturnal decline in blood pressure (generally referred to as a 'nondipping' pattern), especially in individuals with high sodium intake.
  
  
  METHODS
  This study tested this hypothesis in 184 participants aged at least 55 years not receiving antihypertensive treatment in a general Japanese population (age: 67.6 ± 6.9 years; 71.7% women).
  
  
  RESULTS
  Ambulatory blood pressure monitoring identified 63 (34.2%) participants with a nondipping pattern (nocturnal decline of SBP <10%). The median plasma renin activity (PRA), plasma aldosterone concentration (PAC), and ARR were 0.8 ng/ml per h, 8.3 ng/dl, and 8.7 ng/dl per (ng/ml per h), respectively. After adjustment for possible confounding factors, each 1 SD increase in logARR was associated with the prevalence of nondipping pattern (odds ratio, 1.95; P = 0.002). This association was observed in individuals in the highest tertile of 24-h urinary sodium excretion estimated from spot urine data (e24-hUNa; ≥179.6 mEq/day; P = 0.01) but disappeared in those in the lowest tertile of e24-hUNa (<147.9 mEq/day; P = 0.6). In those in the highest tertile of e24-hUNa, PRA was significantly lower in nondippers than in dippers (0.49 vs. 0.85 ng/ml per h) despite no differences in PAC.
  
  
  CONCLUSIONS
  These results suggest that relative aldosterone excess might be related to a nondipping pattern of blood pressure, especially in individuals with high sodium intake.
authors.affiliation: Tohoku University Graduate School of Medicine and Pharmaceutical Science, Sendai, Japan.
authors.forename: Michihiro
authors.initials: M
authors.lastname: Satoh
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuya
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Takefumi
authors.initials: T
authors.lastname: Mori
authors.forename: Hirohito
authors.initials: H
authors.lastname: Metoki
authors.forename: Takanao
authors.initials: T
authors.lastname: Hashimoto
authors.forename: Azusa
authors.initials: A
authors.lastname: Hara
authors.forename: Megumi T
authors.initials: MT
authors.lastname: Utsugi
authors.forename: Takuo
authors.initials: T
authors.lastname: Hirose
authors.forename: Taku
authors.initials: T
authors.lastname: Obara
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Inoue
authors.forename: Kei
authors.initials: K
authors.lastname: Asayama
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Kanno
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Totsune
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Hoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Satoh
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Imai
mesh_terms: D000368:Aged; D000450:Aldosterone / Q000097:blood*; D001794:Blood Pressure / Q000502:physiology*; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D016017:Odds Ratio; D012083:Renin / Q000097:blood*; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage
chemical_list: D017673:Sodium Chloride, Dietary; D000450:Aldosterone; D012083:Renin