Abstract: TH-OR052

Dietary Sodium Restriction versus Diuretics for Salt-Sensitive Hypertension in CKD

Session Information

Category: Hypertension

  • 1104 Hypertension: Clinical and Translational - Salt and Hypertension

Authors

  • Bovee, Dominique M., Erasmus Medical Center, Rotterdam, Netherlands
  • Danser, Alexander H., Erasmus Medical Center, Rotterdam, Netherlands
  • Zietse, Robert, Erasmus Medical Center, Rotterdam, Netherlands
  • Hoorn, Ewout J., Erasmus Medical Center, Rotterdam, Netherlands
Background

Fluid overload and salt-sensitive hypertension are hallmarks of advanced chronic kidney disease (CKD) and associated with worse outcomes. Dietary sodium (Na+) restriction is an accepted intervention, but longterm adherence remains a challenge. Distal diuretics could provide an alternative approach but they are considered less effective in advanced CKD because of reduced tubular secretion. Here, we compared both approaches head-to-head.

Methods

Twenty-two patients with CKD stage 3 or 4 and hypertension were included in this single-center, open-label, randomized cross-over trial (baseline eGFR 38 ± 13 ml/min/1.73 m2). Renin-angiotensin inhibitors and diuretics were discontinued (2 weeks prior to interventions and during study period). Subsequently, we compared dietary Na+ restriction (60 mmol/day) versus amiloride/hydrochlorothiazide (5/50 mg once daily). Both interventions lasted for two weeks and were separated by a 2-week wash-out period. The primary endpoint was 24h systolic blood pressure (SBP).

Results

Urinary Na+ excretion was successfully lowered with dietary Na+ restriction (156 ± 66 to 60 ± 26 mmol/day, p<0.001), and remained similar with diuretics (147 ± 46 to 135 ± 39 mmol/day, p=0.3). Dietary Na+ restriction lowered 24-hour SBP moderately (134 ± 13 to 131 ± 14 mmHg, p=0.08), whereas diuretics had a strong effect (137 ± 12 to 124 ± 13 mmHg, p<0.01 both for within intervention and between interventions). Both maneuvers significantly lowered indices of fluid overload, including body weight (-1.4 ± 1.1 kg with dietary Na+ restriction and -1.8 ± 1.5 kg with diuretics), NT-pro-BNP (median -13 and -5 pmol/L), and overhydration as assessed by bioimpedance (-0.5 ± 0.6 and -1.4 ± 0.7 L). Finally, both interventions lowered eGFR (-3 ± 4 and -5 ± 4 ml/min/1.73 m2, p<0.05 for both) and showed a trend towards albuminuria reduction (median -25 mg/day for both interventions).

Conclusion

Distal diuretics but not dietary Na+ restriction effectively lowers blood pressure in CKD 3 or 4 in the absence of renin-angiotensin inhibitors. Both interventions are equally effective in lowering indices of fluid overload, including body weight, NT-pro-BNP, and overhydration. These beneficial effects may outweigh the (hemodynamic) reduction in eGFR.