Effect of Low Salt and Ckd Progression
Condition: CKD Progression; Blood Pressure; Proteinuria
MeSH terms: Proteinuria; Disease Progression
Study type: Interventional

Summary: 
      Whether an intensive short-term dietary sodium restricted intervention will have beneficial
      effects on the glomerular filtration rate (GFR) and on the susceptibility to develop
      proteinuria, both measures of kidney function will be the objective of this study
    

Detailed description: 
      The prevalence of non-communicable disease (NCD including cardiovascular disease (CVD),
      diabetes mellitus (DM),hypertension(HT) and chronic kidney disease(CKD) continues to rise all
      over the world and lead to global crisis.The world Health Organization (WHO) shows that more
      than 50% of the burden of diseases arise from NCD and 30% is attributed to CVD[1] .In
      Thailand,the prevalence of high blood pressure in population age > 15 is increasing in the
      past 10 years .In 2022 the HT prevalence was 21.4 and the admission rate of CVD increased
      from 109.4 to 793.3 per 100,000 population [2]. Cumulating evidence highlights that higher
      sodium consumption contributes to higher BP [3], thus increasing the risk of cardiovascular
      disease (CVD) [4,5]. According to the World Health Organization, the restriction of sodium
      intake to less than 2.3 g/day of sodium corresponding to 5.8 g of salt (or 100 mmol) is one
      of the most cost-effective measures to improve public health [6]. In particular, in a large
      cohort study in over 100,000 patients from 18 countries the role of higher salt consumption
      was associated with increased BP levels [7], and poor CV outcomes [8].In one meta-analysis
      ,reduce salt intake to 1,800 mg per day will help reduce blood pressure by 2/1 mmHg in
      non-hypertensive cohorts and 5/2.7 mmHg in hypertensive patients [4].In fact, even minor
      sodium restriction for only 700-800 mmol/day was associated with reduction of CVD and
      mortality risks for 20 and 5-7% respectively.

      A long-standing line of evidence also shows beneficial effects of salt reduction in patients
      with chronic kidney disease (CKD) as well as in healthy people [9,10]. A recent review of the
      evidence for the relationship between salt intake and CKD progression concluded there is
      consistent evidence to suggest that dietary salt intake is linked with albuminuria and tissue
      injury [9] [11]. High salt intake is closely associated with the progression of CKD. When the
      urine sodium-to-creatinine ratio increases by 100 mmol/L, the risk of CKD developing into
      end-stage renal disease (ESRD) increases by 1.61 times [12,13]. High salt intake leads to
      renal impairment in various ways, including increasing transforming growth factor (TGF)-β1
      production and enhancing oxidative stress and inflammatory response kidney [14-16]. The
      Lowsalt CKD trial trials had shown that in patients with CKD, salt reduction will have
      additional beneficial effects on renal effects, reduction of proteinuria,independent of blood
      pressure lowering effect. reported that salt reduction helped control blood pressure,reduce
      proteinuria [17] .However,the follow up time was too short. Meta-analysis data from Garofalo
      et al [18] indicates that low sodium intake ( 4.4 gm/day) in 738 CKD patients from 9 studies
      significantly reduce systolic blood pressure by 4.9 mmHg (95%CI 6.8/31 mmHg, p <0.001) .The
      diastolic blood pressure also reduce by 2 mmHg (95%CI 6.8/3.1 mmHg, P<0.001) .In CRIC
      study[19] which followed a cohort of 3,757 CKD patients for nearly 7 years,the authors found
      that the high urine sodium group (UNaV > 195 mmoL/day) significantly increased risk for CKD
      progression and CVD risk. These data support the evidence that reducing dietary sodium can
      reduce cardiovascular risk and rate of CKD progression.

      However, restriction in dietary sodium intake also activates the renin-angiotensin
      -aldosterone system (RAAS) and sympathetic nervous system[20,21].Low dietary sodium has been
      reported to be associated with insulin resistance [22]. To date, the connection between
      sodium intake and CKD progression provided inconsistent results [23]. Although several
      studies have shown that high dietary sodium intake increases the risk of CKD development or
      progression [24-26], some results failed to find significant connections to renal outcome
      [27-30]. In addition, there have also been reports that lower 24-hour urine sodium excretion
      is associated with higher risk of death and ESRD in individuals with type 1 and type 2
      diabetes with overt proteinuria [30,31]. Whether an intensive short-term dietary sodium
      restricted intervention will have beneficial effects on the glomerular filtration rate (GFR)
      and on the susceptibility to develop proteinuria, both measures of kidney function will be
      the objective of this study
    

Intervention name(s): Low salt diet
Intervention type(s): Dietary Supplement
Intervention description(s): Low salt diet less than 2 gram per day
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Prospective open labelled randomized controlled trial study
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: CKD progression; Low salt; Randomized controlled trial