Key result
High-sodium diet reduces orthostatic tachycardia by ~14 bpm vs. low sodium in POTS.
Why the study?
High sodium intake is recommended to treat postural tachycardia syndrome, but evidence supporting its efficacy was lacking.
Does a high sodium diet reduce orthostatic tachycardia and upright heart rate in patients with postural tachycardia syndrome compared to a low sodium diet?
RCT (n=27)
Single-blind (participants blinded to diet assignment, but difference was apparent)
Randomized crossover design
No
Does a high sodium diet reduce orthostatic tachycardia and upright heart rate in patients with postural tachycardia syndrome compared to a low sodium diet?
Absolute Event Rate: 46% vs 60%
p-value: p=0.001
A very high dietary sodium intake significantly reduces orthostatic tachycardia, increases plasma volume, and lowers standing plasma norepinephrine in patients with POTS, providing clinical evidence for professional society recommendations.
High-sodium diet merits consideration in POTS; confirms guideline recommendations with direct RCT evidence.
Background: High sodium intake is recommended for the treatment of postural tachycardia syndrome (POTS) to counteract the hypovolemia and elevated plasma norepinephrine that contribute to excessive orthostatic tachycardia, but evidence of its efficacy is not available. Objectives: We tested whether a high sodium (HS) diet reduces orthostatic tachycardia (ΔHR) and upright heart rate (HR) compared with low sodium (LS) diet in POTS patients, and secondarily its effect on plasma volume (PV) and plasma norepinephrine. Methods: We enrolled 14 POTS patients and 13 healthy controls (HC), 23–49 years old, in a crossover study with six days of LS (10 mEq sodium/day) or HS (300 mEq sodium/day) diet. We measured supine and standing HR, blood pressure, serum aldosterone, plasma renin activity, blood volume, and plasma norepinephrine and epinephrine. Results: In POTS, HS diet reduced upright HR and ΔHR compared with LS diet. Total blood volume and PV increased, and standing norepinephrine decreased with HS compared with LS diet However, upright HR, ΔHR and upright norepinephrine remained higher in POTS than in HC on HS diet [117 (98–121) beats per minute (bpm), 46 (32–55) bpm, and 753 (498–919) pg/mL in POTS vs. 85 (77–95) bpm, 19 (11–32) bpm, and 387 (312–433) pg/mL in HC], despite no difference in the measured PV. Conclusions: In POTS patients, high dietary sodium intake compared with low dietary sodium intake increases plasma volume, lowers standing plasma norepinephrine, and decreases ΔHR. CONDENSED ABSTRACT Postural Tachycardia Syndrome (POTS) is a chronic form of orthostatic intolerance. Augmented oral sodium intake is a frequently prescribed treatment and recommended in professional society scientific statements on POTS, but evidence supporting the effectiveness was lacking. We evaluated one week of a very high sodium diet compared to a very low sodium diet in POTS patients. The high sodium diet expanded the plasma volume and total blood volume, reduced standing plasma norepinephrine levels (a marker of sympathetic nervous system tone), and reduced the orthostatic tachycardia. These data provide supporting evidence for the use of high sodium diets in POTS patients. ClinicalTrials.gov Identifier: NCT01547117
No takes yet. Share an insight, caveat, or question.
Garland et al. (2021) conducted an RCT in Postural Tachycardia Syndrome (POTS) (n=27). High dietary sodium intake vs. Low dietary sodium intake (10 mEq sodium/day) was evaluated on Orthostatic tachycardia (ΔHR) (p=0.001). High dietary sodium intake reduced median orthostatic tachycardia (ΔHR) to 46 bpm compared with 60 bpm on a low sodium diet in patients with Postural Tachycardia Syndrome.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: