title: Reduction in sodium intake is independently associated with improved blood pressure control in people with chronic kidney disease in primary care.
abstract: Decreasing sodium intake has been associated with improvements in blood pressure (BP) and proteinuria, two important risk factors for CVD and chronic kidney disease (CKD) progression. We aimed to investigate the role of sodium intake by examining the effect of changes in sodium intake over 1 year on BP and proteinuria in people with early stage CKD. From thirty-two general practices, 1607 patients with previous estimated glomerular filtration rate of 59-30 ml/min per 1.73 m² and mean age of 72.9 (sd 9.0) years were recruited. Clinical assessment, urine and serum biochemistry testing were performed at baseline and after 1 year. Sodium intake was estimated from early morning urine specimens using an equation validated for this study population. We found that compared with people who increased their sodium intake from ≤ 100 to >100 mmol/d over 1 year, people who decreased their intake from >100 to ≤ 100 mmol/d evidenced a greater decrease in all BP variables (Δmean arterial pressure (ΔMAP) = -7.44 (SD 10.1) v. -0.23 (SD 10.4) mmHg; P<0.001) as well as in pulse wave velocity (ΔPWV = -0.47 (SD 1.3) v. 0.08 (SD 1.88) m/s; P<0.05). Albuminuria improved only in albuminuric patients who decreased their sodium intake. BP improved in people who maintained low sodium intake at both times and in those with persistent high intake, but the number of anti-hypertensive increased only in the higher sodium intake group, and PWV improved only in participants with lower sodium intake. Decreasing sodium intake was an independent determinant of ΔMAP. Although more evidence is needed, our results support the benefits of reducing and maintaining sodium intake below 100 mmol/d (2.3-2.4 g/d) in people with early stages of CKD.
authors.affiliation: 1Nutrition Department,Nephrology Division,Pro-rim Foundation,Joinville,Santa Catarina 89227-680,Brazil.
authors.forename: Fabiana B
authors.initials: FB
authors.lastname: Nerbass
authors.affiliation: 2School of Medicine,Pontificia Universidade Católica do Paraná,Curitiba,Paraná 80215-901,Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pecoits-Filho
authors.affiliation: 3School of Medicine,Division of Medical Sciences and Graduate Entry Medicine,University of Nottingham,Nottingham NG7 2RD,UK.
authors.forename: Natasha J
authors.initials: NJ
authors.lastname: McIntyre
authors.affiliation: 3School of Medicine,Division of Medical Sciences and Graduate Entry Medicine,University of Nottingham,Nottingham NG7 2RD,UK.
authors.forename: Adam
authors.initials: A
authors.lastname: Shardlow
authors.affiliation: 3School of Medicine,Division of Medical Sciences and Graduate Entry Medicine,University of Nottingham,Nottingham NG7 2RD,UK.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: McIntyre
authors.affiliation: 3School of Medicine,Division of Medical Sciences and Graduate Entry Medicine,University of Nottingham,Nottingham NG7 2RD,UK.
authors.forename: Maarten W
authors.initials: MW
authors.lastname: Taal
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003131:Combined Modality Therapy; D004039:Diet, Sodium-Restricted; D018450:Disease Progression; D004739:England / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006977:Hypertension, Renal / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control*; D059012:Lost to Follow-Up; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D010352:Patient Dropouts; D011320:Primary Health Care; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000178:diet therapy* / Q000503:physiopathology / Q000628:therapy / Q000652:urine; D012307:Risk Factors; D012720:Severity of Illness Index; D012964:Sodium / Q000652:urine
chemical_list: D012964:Sodium
keywords: Albuminuria; Arterial pressure; BP blood pressure; CKD chronic kidney disease; Chronic kidney disease; MAP mean arterial pressure; PWV pulse wave velocity; Primary care; SBP systolic BP; Sodium intake; UACR urinary albumin:creatinine ratio; eGFR estimated glomerular filtration rate