A randomised, factorial trial to reduce arterial stiffness independently of blood pressure: Proof of concept? The 'VaSera' trial testing dietary nitrate and spironolactone

TY - JOUR

T1 - A randomised, factorial trial to reduce arterial stiffness independently of blood pressure

T2 - Proof of concept? The 'VaSera' trial testing dietary nitrate and spironolactone

AU - Mills, Charlotte E.

AU - Govoni, Virginia

AU - Faconti, Luca

AU - Casagrande, Maria-Linda

AU - Morant, Steven V.

AU - Crickmore, Hannah

AU - Iqbal, Fahad

AU - Maskell, Perry

AU - Masani, Alisha

AU - Nanino, Elisa

AU - Webb, Andrew J.

AU - Cruickshank, J. Kennedy

N1 - This article is protected by copyright. All rights reserved.

PY - 2020/5

Y1 - 2020/5

N2 - Aims: To test if spironolactone or dietary nitrate from beetroot juice could reduce arterial stiffness as aortic pulse wave velocity (PWVart), a potential treatment target, independently of blood pressure. Methods: Daily spironolactone (≤50 mg) vs doxazosin (control ≤16 mg) and 70 mL beetroot juice (Beet-It ≤11 mmol nitrate) vs nitrate-depleted juice (placebo; 0 mmol nitrate) were tested in people at risk or with type-2 diabetes using a double-blind, 6-month factorial trial. Vascular indices (baseline, 12, 24 weeks) were cardiac–ankle vascular index (CAVI), a nominally pressure-independent stiffness measure (primary outcome), PWVart secondary, central systolic pressure and augmentation. Analysis was intention-to-treat, adjusted for systolic pressure differences between trial arms. Results: Spironolactone did not reduce stiffness, with evidence for reduced CAVI on doxazosin rather than spironolactone (mean difference [95% confidence interval]; 0.25 [−0.3, 0.5] units, P =.080), firmer for PWVart (0.37 [0.01, 0.7] m/s, P =.045). There was no difference in systolic pressure reduction between spironolactone and doxazosin (0.7 [−4.8, 3.3] mmHg, P =.7). Circulating nitrate and nitrite increased on active vs placebo juice, with central systolic pressure lowered −2.6 [−4.5, − 0.8] mmHg, P =.007 more on the active juice, but did not reduce CAVI, PWVart or peripheral pressure. Change in nitrate and nitrite concentrations were 1.5-fold [1.1–2.2] and 2.2-fold [1.3, 3.6] higher on spironolactone than on doxazosin respectively; both P <.05. Conclusion: Contrary to our hypothesis, in at-risk/type 2 diabetes patients, spironolactone did not reduce arterial stiffness, rather PWVart was lower on doxazosin. Dietary nitrate elevated plasma nitrite, selectively lowering central systolic pressure, observed previously for nitrite.

AB - Aims: To test if spironolactone or dietary nitrate from beetroot juice could reduce arterial stiffness as aortic pulse wave velocity (PWVart), a potential treatment target, independently of blood pressure. Methods: Daily spironolactone (≤50 mg) vs doxazosin (control ≤16 mg) and 70 mL beetroot juice (Beet-It ≤11 mmol nitrate) vs nitrate-depleted juice (placebo; 0 mmol nitrate) were tested in people at risk or with type-2 diabetes using a double-blind, 6-month factorial trial. Vascular indices (baseline, 12, 24 weeks) were cardiac–ankle vascular index (CAVI), a nominally pressure-independent stiffness measure (primary outcome), PWVart secondary, central systolic pressure and augmentation. Analysis was intention-to-treat, adjusted for systolic pressure differences between trial arms. Results: Spironolactone did not reduce stiffness, with evidence for reduced CAVI on doxazosin rather than spironolactone (mean difference [95% confidence interval]; 0.25 [−0.3, 0.5] units, P =.080), firmer for PWVart (0.37 [0.01, 0.7] m/s, P =.045). There was no difference in systolic pressure reduction between spironolactone and doxazosin (0.7 [−4.8, 3.3] mmHg, P =.7). Circulating nitrate and nitrite increased on active vs placebo juice, with central systolic pressure lowered −2.6 [−4.5, − 0.8] mmHg, P =.007 more on the active juice, but did not reduce CAVI, PWVart or peripheral pressure. Change in nitrate and nitrite concentrations were 1.5-fold [1.1–2.2] and 2.2-fold [1.3, 3.6] higher on spironolactone than on doxazosin respectively; both P <.05. Conclusion: Contrary to our hypothesis, in at-risk/type 2 diabetes patients, spironolactone did not reduce arterial stiffness, rather PWVart was lower on doxazosin. Dietary nitrate elevated plasma nitrite, selectively lowering central systolic pressure, observed previously for nitrite.

KW - arterial stiffness

KW - beetroot juice

KW - blood pressure

KW - dietary nitrate

KW - nitrate–nitrite–NO

KW - pathway

KW - type 2 diabetes

UR - http://www.scopus.com/inward/record.url?scp=85083620153&partnerID=8YFLogxK

U2 - 10.1111/bcp.14194

DO - 10.1111/bcp.14194

M3 - Article

C2 - 31833569

SN - 0306-5251

VL - 86

SP - 891

EP - 902

JO - British Journal of Clinical Pharmacology

JF - British Journal of Clinical Pharmacology

IS - 5

ER -