Treatment of Disorders of Sodium Balance in Chronic Kidney Disease

Abstract

Extracellular fluid volume expansion is nearly universal in patients with chronic kidney disease. Such volume expansion often overlaps with the syndrome of heart failure with preserved ejection fraction, which can not only lead to symptoms, but can also lead to further organ damage. Unique treatment challenges are present in this patient population, including low glomerular filtration, which limits sodium chloride filtration, intrinsic tubule predisposition to sodium chloride retention, and proteinuria. Additionally, pharmacokinetic considerations alter the disposition of diuretics in patients with chronic kidney disease and nephrotic syndrome. Maintaining extracellular fluid volume near to normal is often necessary for hypertension treatment in this population, but it may also help prevent progressive cardiovascular and renal damage. Although powerful diuretics can often accomplish this goal, this often comes at a cost of competing side effects. An approach to reduce extracellular fluid volume while avoiding side effects, therefore, requires a nuanced yet aggressive therapeutic approach.

Heart failure in chronic kidney disease: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference

“…Comorbid conditions make the diagnosis challenging, such as CKD and end-stage kidney disease (ESKD), as sodium and water retention contribute to HF manifestations. 13 CKD is defined on the basis of persistently reduced estimated glomerular filtration rate (eGFR) of <60 ml/min per 1.73 m 2 or at least 1 marker of kidney damage for >3 months. 14 The latter markers include albuminuria, urine sediment abnormalities, histological, or structural abnormalities.…”

Extracellular fluid volume is associated with incident end-stage kidney disease and mortality in patients with chronic kidney disease

“…Analyses of longitudinal data (median number of visits: 2 [1][2][3][4] per patient, median duration between 2 consecutive visits 1.1 [IQR: 1.0-1.5 years]) showed that the mean mGFR slope was -1.64, 95% CI (-1.82, -1.45) ml/min per year in the total population, and -1.31, 95% CI (-1.60, -1.01) ml/min per year; -1.49, 95% CI (-1.81, -1.17) ml/min per year, and -2.28, 95% CI (-2.63, -1.92) ml/min per year for the first, second, and third tertiles of ECF, respectively. In the fully adjusted linear mixed-effect model, ECF was significantly associated with a faster mGFR decline (mean difference in mGFR slope per 1 L/1.73 m 2 increase in ECF: -0.14, 95% CI [-0.23, -0.05] ml/min per year, P ¼ 0.002) ( Table 3; Figure 3).…”

“…mpaired renal salt and water excretion, in combination with other factors such as hypo-albuminemia, often result in chronic ECF overload with CKD. 1 In hemodialysis patients, several large-scale studies have shown that fluid overload is a strong and independent risk factor for mortality. 2,3 In contrast, studies evaluating the role of fluid overload on renal function and mortality in patients with non-dialysis CKD yielded conflicting results.…”

Effect of cocoa powder on hypertension and antioxidant status in uninephrectomized hypertensive rats

“…It takes longer for the kidneys to adjust to changes in dietary sodium chloride in compromised kidneys, as seen with uninephrectomy, old age than it does in normal kidneys. The extracellular fluid is elevated with an increase in sodium levels; this explains why a reduction in salt brings about a decrease in blood pressure [46]. From our findings, 8% salt aggravated blood pressure, markers of oxidative stress, and depleted the level of both enzymatic and non-enzymatic antioxidants.…”