title: High sodium intake is associated with important risk factors in a large cohort of chronic kidney disease patients.
abstract: OBJECTIVE
  An increased risk of mortality and cardiovascular disease (CVD) is observed in people with chronic kidney disease (CKD) even in early stages. Dietary sodium intake has been associated with important CVD and CKD progression risk factors such as hypertension and proteinuria in this population. We aimed to investigate the relationship between sodium intake and CVD or CKD progression risk factors in a large cohort of patients with CKD stage 3 recruited from primary care.
  
  
  METHODS
  A total of 1733 patients with previous estimated glomerular filtration rate (eGFR) of 30-59 ml/min/1.73m(2), with a mean age 72.9±9.0 years, were recruited from 32 general practices in primary care in England. Medical history was obtained and participants underwent clinical assessment, urine and serum biochemistry testing. Sodium intake was estimated from three early-morning urine specimens using an equation validated for this study population.
  
  
  RESULTS
  Sixty percent of participants who had estimated sodium intake above recommendation (>100 mmol/day or 6 g salt/day) also had higher diastolic blood pressure, mean arterial pressure (MAP), urinary albumin-to-creatinine ratio, high-sensitive C-reactive protein and uric acid and used a greater number of anti-hypertensive drugs. In multivariable regression analysis, excessive sodium intake was an independent predictor of MAP (B=1.57, 95% confidence interval (CI) 0.41-2.72; P=0.008) and albuminuria (B=1.35, 95% CI 1.02-1.79; P=0.03).
  
  
  CONCLUSIONS
  High sodium intake was associated with CVD and CKD progression risk factors in patients with predominantly early stages of CKD followed up in primary care. This suggests that dietary sodium intake could afffect CVD risk even in early or mild CKD. Intervention studies are warranted to investigate the potential benefit of dietary advice to reduce sodium intake in this population.
authors.affiliation: 1] School of Medicine, Pontificia Universidade Católica do Paraná, Curitiba, Brazil [2] Nephrology Division, Nutrition Department, Pro-rim Foundation, Joinville, Brazil.
authors.forename: F B
authors.initials: FB
authors.lastname: Nerbass
authors.affiliation: School of Medicine, Pontificia Universidade Católica do Paraná, Curitiba, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Pecoits-Filho
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derbyshire, UK.
authors.forename: N J
authors.initials: NJ
authors.lastname: McIntyre
authors.affiliation: 1] Department of Renal Medicine, Royal Derby Hospital, Derbyshire, UK [2] Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, Nottingham, UK.
authors.forename: C W
authors.initials: CW
authors.lastname: McIntyre
authors.affiliation: Department of Renal Medicine, Royal Derby Hospital, Derbyshire, UK.
authors.forename: M W
authors.initials: MW
authors.lastname: Taal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D018450:Disease Progression; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology; D015994:Incidence; D018836:Inflammation Mediators / Q000097:blood; D007676:Kidney Failure, Chronic / Q000097:blood / Q000209:etiology* / Q000503:physiopathology / Q000652:urine; D008297:Male; D011320:Primary Health Care; D011446:Prospective Studies; D011507:Proteinuria / Q000453:epidemiology / Q000209:etiology; D012307:Risk Factors; D012720:Severity of Illness Index; D012964:Sodium / Q000652:urine; D012982:Sodium, Dietary / Q000506:poisoning*
chemical_list: D000959:Antihypertensive Agents; D018836:Inflammation Mediators; D012982:Sodium, Dietary; D012964:Sodium