High and low sodium intakes are associated with incident chronic kidney disease in patients with normal renal function and hypertension

Abstract

The association between salt intake and renal outcome in subjects with preserved kidney function remains unclear. Here we evaluated the effect of sodium intake on the development of chronic kidney disease (CKD) in a prospective cohort of people with normal renal function. Data were obtained from the Korean Genome and Epidemiology Study, a prospective community-based cohort study while sodium intake was estimated by a 24-hour dietary recall Food Frequency Questionnaire. A total of 3,106 individuals with and 4,871 patients without hypertension were analyzed with a primary end point of CKD development [a composite of estimated glomerular filtration rate (eGFR) under 60 mL/min/1.73 m and/or development of proteinuria during follow-up]. The median ages were 55 and 47 years, the proportions of males 50.9% and 46.3%, and the median eGFR 92 and 96 mL/min/1.73 m in individuals with and without hypertension, respectively. During a median follow-up of 123 months in individuals with hypertension and 140 months in those without hypertension, CKD developed in 27.8% and 16.5%, respectively. After adjusting for confounders, multiple Cox models indicated that the risk of CKD development was significantly higher in people with hypertension who consumed less than 2.08 g/day or over 4.03 g/day sodium than in those who consumed between 2.93-4.03 g/day sodium. However, there was no significant difference in the incident CKD risk among each quartile of people without hypertension. Thus, both high and low sodium intakes were associated with increased risk for CKD, but this relationship was only observed in people with hypertension.

Science of Salt: A regularly updated systematic review of salt and health outcomes studies (April to October 2018)

“…The weekly search identified 4141 citations over the period from April 3 to October 30, 2018, of which 19 studies including dietary sodium and health outcomes met the criteria for full review (Table ). These included systematic review and meta‐analyses (n = 2), randomized controlled trials (n = 3, including one post hoc analysis of a randomized controlled trial), a non‐randomized controlled trial (n = 1), prospective cohort studies (n = 4), a retrospective cohort study using population data (n = 1), and cross‐sectional studies (n = 8) . Two studies assessed mortality outcomes, four studies assessed morbidity outcomes, and one study assessed symptoms/quality of life/functional status outcomes .…”

“…Of greater concern is the proportional bias that exists whereby the level of over‐ or under‐estimation is proportional to mean sodium excretion. Two cohort studies included in this review used FFQ to assess the association between sodium intake at baseline and incidence of chronic kidney disease among people with normal kidney function in Korea and Iran . A recent review found that FFQs are not adequate for quantifying sodium intake in individuals .…”

“…These included systematic review and meta-analyses (n = 2), 22,23 randomized controlled trials (n = 3, including one post hoc analysis of a randomized controlled trial), [24][25][26] a non-randomized controlled trial (n = 1), 27 prospective cohort studies (n = 4), [28][29][30][31] a retrospective cohort study using population data (n = 1), 32 and cross-sectional studies (n = 8). [33][34][35][36][37][38][39][40] Two studies assessed mortality outcomes, 28,29 four studies assessed morbidity outcomes, [30][31][32][33] and one study assessed symptoms/quality of life/functional status outcomes. 22 Eight studies assessed clinical surrogate outcomes, [23][24][25][26][27][34][35][36] one study assessed physiologic surrogate outcomes, 37 and three studies assessed other outcomes [38][39][40] according to our pre-specified categories.…”

The Visceral Adiposity Index Is a Predictor of Incident Chronic Kidney Disease: A Population-Based Longitudinal Study

“…Second, the follow-up was for a medium-term, and therefore, the statistical power might be limited. Third, sodium and protein intake are associated with pathogenesis of CKD [27,28]. However, we did not have the data of them.…”

Impacting incidence of disease through population‐based interventions: Appraisal of the ARIC study findings

“…However, it is worth noting that reduction of sodium as a population‐based approach for CKD prevention has had mixed results despite being advocated in many guidelines . In addition, both high and low sodium intakes were recently associated with incident chronic kidney disease in patients with normal renal function and hypertension in a Korean community‐based cohort . Conversely, in 13 917 participants from the National Health and Nutrition Examination Survey (NHANES) where sodium and potassium intake were calculated from 24‐hour recall and evaluated in quartiles, higher intake of sodium and potassium were associated with lower odds of CKD among US adults .…”