title: Dietary fiber, kidney function, inflammation, and mortality risk.
abstract: OBJECTIVE
  In the United States population, high dietary fiber intake has been associated with a lower risk of inflammation and mortality in individuals with kidney dysfunction. This study aimed to expand such findings to a Northern European population.
  
  
  METHODS
  Dietary fiber intake was calculated from 7-day dietary records in 1110 participants aged 70-71 years from the Uppsala Longitudinal Study of Adult Men (examinations performed during 1991-1995). Dietary fiber was adjusted for total energy intake by the residual method. Renal function was estimated from the concentration of serum cystatin C, and deaths were registered prospectively during a median follow-up of 10.0 years.
  
  
  RESULTS
  Dietary fiber independently and directly associated with eGFR (adjusted difference, 2.6 ml/min per 1.73 m(2) per 10 g/d higher; 95% confidence interval [95% CI], 0.3 to 4.9). The odds of C-reactive protein >3 mg/L were lower (linear trend, P=0.002) with higher fiber quartiles. During follow-up, 300 participants died (incidence rate of 2.87 per 100 person-years at risk). Multiplicative interactions were observed between dietary fiber intake and kidney dysfunction in the prediction of mortality. Higher dietary fiber was associated with lower mortality in unadjusted analysis. These associations were stronger in participants with kidney dysfunction (eGFR<60 ml/min per 1.73 m(2)) (hazard ratio [HR], 0.58; 95% CI, 0.35 to 0.98) than in those without (HR, 1.30; 95% CI, 0.76 to 2.22; P value for interaction, P=0.04), and were mainly explained by a lower incidence of cancer-related deaths (0.25; 95% CI, 0.10 to 0.65) in individuals with kidney dysfunction versus individuals with an eGFR≥60 ml/min per 1.73 m(2) (1.61; 95% CI, 0.69 to 3.74; P value for interaction, P=0.01).
  
  
  CONCLUSIONS
  High dietary fiber was associated with better kidney function and lower inflammation in community-dwelling elderly men from Sweden. High dietary fiber was also associated with lower (cancer) mortality risk, especially in individuals with kidney dysfunction.
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention, and Technology, and Department of Nephrology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China;
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, and Division of Nephrology, Peking University Shenzhen Hospital, Peking University, Shenzhen, China;
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Huang
authors.affiliation: Sections of Clinical Nutrition and Metabolism and.
authors.forename: Ulf
authors.initials: U
authors.lastname: Risérus
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention, and Technology, and.
authors.forename: Vidya M
authors.initials: VM
authors.lastname: Krishnamurthy
authors.affiliation: Sections of Clinical Nutrition and Metabolism and.
authors.forename: Tommy
authors.initials: T
authors.lastname: Cederholm
authors.affiliation: Geriatrics, Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden; and School of Health and Social Studies, Dalarna University, Falun, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Arnlöv
authors.affiliation: Divisions of Renal Medicine and Baxter Novum, Department of Clinical Science, Intervention, and Technology, and.
authors.forename: Bengt
authors.initials: B
authors.lastname: Lindholm
authors.affiliation: Sections of Clinical Nutrition and Metabolism and.
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, and Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden; juan.jesus.carrero@ki.se.
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Carrero
mesh_terms: D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D002423:Cause of Death; D003430:Cross-Sectional Studies; D055316:Cystatin C / Q000097:blood; D004043:Dietary Fiber; D005919:Glomerular Filtration Rate; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000453:epidemiology*; D007668:Kidney / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D009369:Neoplasms / Q000401:mortality*; D011446:Prospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D055316:Cystatin C; D004043:Dietary Fiber; D002097:C-Reactive Protein
keywords: CKD; GFR; chronic inflammation; mortality risk; nutrition