title: Albuminuria, renal dysfunction and circadian blood pressure rhythm in older men: a population-based longitudinal cohort study.
abstract: BACKGROUND
  Both albuminuria and kidney dysfunction may affect circadian blood pressure (BP) rhythm, while exacerbating each other's effects. We investigated associations and interactions of these two risk factors with circadian BP rhythm variation and non-dipper pattern progression in community-dwelling older men.
  
  
  METHODS
  This was a cross-sectional and longitudinal analyses in the third and fourth cycles of the Uppsala Longitudinal Study of Adult Men, including 1051 men (age 71 years) with assessments on urinary albumin excretion rate (UAER), 24-h ambulatory BP monitoring (ABPM) and cystatin-C-estimated glomerular filtration rate (eGFR). Of these, 574 men attended re-examination after 6 years. Study outcomes were ABMP changes and non-dipping BP pattern (prevalence and progression).
  
  
  RESULTS
  UAER associated with circadian BP rhythm both cross-sectionally and longitudinally. Longitudinally, significant interactions were observed between UAER and kidney dysfunction (eGFR < 60 mL/min/1.73 m(2)) in its association with the changes of both night-time systolic BP (SBP) and night-day SBP ratio. After stratification, UAER strongly predicted night-day SBP ratio change only in those with concurrent kidney dysfunction. At re-examination, 221 new cases of non-dipper were identified. In multivariable logistic models, high UAER associated with increased likelihood of non-dipper progression, but more strongly so among individuals with concurrent kidney dysfunction. These associations were evident also in the subpopulation of non-diabetics and in participants with normal range UAER.
  
  
  CONCLUSIONS
  UAER associates with circadian BP rhythm variation and non-dipper progression in elderly men. Concurrent renal dysfunction modifies and exacerbates these associations.
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology , Karolinska Institutet , Stockholm , Sweden.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology , Karolinska Institutet , Stockholm , Sweden ; Division of Nephrology , Peking University Shenzhen Hospital , Shenzhen , China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism , Uppsala University , Uppsala , Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Risérus
authors.affiliation: Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism , Uppsala University , Uppsala , Sweden.
authors.forename: Tommy
authors.initials: T
authors.lastname: Cederholm
authors.affiliation: Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism , Uppsala University , Uppsala , Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Sjögren
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology , Karolinska Institutet , Stockholm , Sweden.
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
authors.affiliation: Department of Medical Sciences, Molecular Epidemiology , Uppsala University , Uppsala , Sweden ; School of Health and Social Studies , Dalarna University , Falun , Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Ärnlöv
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention and Technology , Karolinska Institutet , Stockholm , Sweden ; Center for Molecular Medicine , Karolinska Institutet , Stockholm , Sweden.
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Carrero
keywords: albuminuria; ambulatory blood pressure monitoring; circadian BP rhythm; kidney dysfunction; non-dipper pattern