Sodium Restriction vs Diuretics: Which Option Is Best For Advanced CKD?
Both dietary sodium restriction and distal diuretic use effectively reduce indices of fluid overload, including body weight, N-terminal pro-brain natriuretic peptide (NT-pro-BNP), and over-hydration, in patients with stage 3 or 4 chronic kidney disease (CKD), according to a recent study. Distal diuretic use alone had effectively reduced blood pressure in these patients.
Findings were presented at the American Society of Nephrology’s Kidney Week 2017, which is taking place from October 31 to November 5, 2017, in New Orleans, Louisiana.
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Fluid overload and salt-sensitive hypertension are common with advanced CKD and are associated with worse outcomes. Although dietary sodium restriction is an acceptable form of intervention, long-term adherence can be challenging. Distal diuretics may serve as an alternative, but they are less effective in patients with advanced CKD due to decreased tubular secretion.
For their study, the researchers assessed 22 patients with CKD stages 3 or 4 with hypertension at a single center. Mean baseline eGFR was 38 ml/min/1.73 m2. Patients had discontinued renin-angiotensin inhibitors and diuretics 2 weeks prior to interventions and throughout the study period.
Dietary sodium restriction, defined as 60 mmol/day, was compared with once-daily 5/50 mg amiloride/hydrochlorothiazide. Each intervention lasted 2 weeks and was separated by a 2-week wash-out period. The primary outcome was systolic blood pressure (SBP) at 24 hours.
Results indicated that urinary sodium excretion had been successfully reduced with dietary sodium restriction, and was similar with diuretic use. Additionally, while dietary sodium restriction had moderately lowered 24-hour SBP, diuretics had a stronger effect.
The researchers found that both interventions had significantly decreased indices of fluid overload, such as body weight, NT-pro-BNP, and over-hydration as assessed by bioimpedance. Both interventions had also decreased eGFR and had demonstrated a trend toward albuminuria reduction, with a median -25 mg/day decrease for both interventions.
“Distal diuretics but not dietary [sodium] restriction effectively lowers blood pressure in CKD 3 or 4 in the absence of renin-angiotensin inhibitors,” the researchers concluded. “Both interventions are equally effective in lowering indices of fluid overload, including body weight, NT- pro-BNP, and over-hydration. These beneficial effects may outweigh the (hemodynamic) reduction in eGFR.”
—Christina Vogt
Reference:
Bovee DM, Danser AH, Zietse R, Hoorn EJ. Dietary sodium restriction versus diuretics for salt-sensitive hypertension in CKD. Paper presented at: American Society of Nephrology Kidney Week 2017; October 31-November 5, 2017; New Orleans, LA. https://www.asn-online.org/education/kidneyweek/2017/program-abstract.aspx?controlId=2785462.