Do diuretics reduce glomerular hyperfiltration in Chronic Kidney Disease (CKD), and what is the mechanism involved?

From the Guidelines

Diuretics can reduce glomerular hyperfiltration in chronic kidney disease (CKD), primarily through their effects on tubuloglomerular feedback and intravascular volume, as supported by the most recent guideline evidence 1. The mechanism involves reducing sodium reabsorption in the nephron, which increases sodium delivery to the macula densa, triggering afferent arteriolar vasoconstriction via tubuloglomerular feedback, thereby decreasing intraglomerular pressure and filtration. Some key points to consider when using diuretics in CKD include:

• Loop diuretics like furosemide (20-80mg daily) and thiazide diuretics such as hydrochlorothiazide (12.5-50mg daily) are most commonly used for this purpose.
• Diuretics reduce extracellular fluid volume and systemic blood pressure, which decreases renal perfusion pressure and glomerular filtration.
• This effect is particularly beneficial in conditions where hyperfiltration contributes to progressive kidney damage, such as diabetic nephropathy or early CKD.
• However, the use of diuretics must be carefully monitored as excessive volume depletion can paradoxically worsen kidney function.
• Regular assessment of electrolytes, especially potassium, is essential as hypokalemia is a common side effect.
• The reduction in hyperfiltration may help preserve kidney function over time by reducing the mechanical stress on glomeruli that contributes to progressive glomerulosclerosis and nephron loss in CKD, as noted in recent studies 1. It is also important to consider the potential risks and benefits of diuretic use in CKD, including the risk of acute kidney injury (AKI) and the importance of monitoring renal function and adjusting diuretic doses accordingly, as recommended in recent guidelines 1.

From the Research

Diuretics and Glomerular Hyperfiltration in CKD

• Diuretics are used to manage volume overload and hypertension in patients with Chronic Kidney Disease (CKD) 2, 3, 4.
• The mechanism of diuretics in reducing glomerular hyperfiltration is not directly stated in the provided studies, but it is suggested that diuretics can reduce blood pressure and improve renal function by enhancing urinary sodium excretion 2, 3.
• Thiazide and loop diuretics are commonly used in CKD patients, with loop diuretics often needed for volume overload and thiazide diuretics used for hypertension management 2, 3, 5.

Effectiveness of Diuretics in CKD

• Some studies suggest that diuretics can improve blood pressure control and reduce proteinuria in CKD patients, even in advanced stages of the disease 6, 5.
• However, other studies have raised concerns about the effectiveness and safety of diuretics as first-line therapy for hypertension in CKD patients, citing potential worsening of electrolyte imbalance and kidney function 2.
• The use of diuretics in CKD patients requires careful selection of the diuretic agent and dose, as well as monitoring for adverse effects such as dehydration, hypokalemia, and hypercalcemia 4, 5.

Renoprotective Effects of Diuretics

• Some studies suggest that diuretics may have renoprotective effects in CKD patients, potentially by reducing intraglomerular pressure and slowing the progression of kidney disease 2, 6.
• However, the direct benefit of diuretics on renal function remains controversial, and further studies are needed to fully understand their renoprotective effects 2, 5.