P6.6 A Double Blind, Randomised Trial Investigating if Arterial Stiffness Can be Reduced Independently of Blood Pressure in Participants with or at Risk of Type 2 Diabetes

Abstract

Background

Arterial stiffness (AS) as pulse wave velocity (PWV), is a powerful independent predictor of cardiovascular events, and commonly complicates Type 2 diabetes (T2D). The VaSera machine measures cardiac (by 2nd sound phonogram)-ankle PWV, expressed as a cardio-ankle vascular index (CAVI), aimed to be independent of blood pressure (BP). Our factorial trial tests whether separately randomised dietary nitrate or placebo, and an aldosterone antagonist reduce CAVI and PWV in those at risk of or diagnosed with T2D.

Method

Double-blind, randomised trial assessing AS at baseline, 3 and 6 months. Target recruitment is 120 patients, 18–90 years, excluding those with serious illness or eGFR <45mL/min. Daily interventions are spironolactone (<50mg) or doxazosin (≤16mg), to control for BP change, with a nitrate donor (<0.4g nitrate) or an identical nitrate-free juice.

Results

74 participants are screened, 54 randomised and 34 completed. Mean±SD baseline age and body mass index were 59.7±12.1 years and 32.8±5.5kg/m², respectively; 40% female.

No differences in CAVI or PWV were observed between screening and randomisation (8.30±1.4 to 7.97±1.3 units and 9.30±2.0 to 9.17±1.8m/s, respectively). Systolic (S) and diastolic (D) BP dropped between these visits (138±17 to 133±17mmHg, p<0.005 and 81 ±12 to 71±12mmHg, p<0.001, respectively). Bland-Altman analysis between screening and randomisation for CAVI, PWV, SBP and DBP shows <6% of mean differences fall outside of the 95% limits; mean difference± limits of agreement; −0.13±2.12, −0.32±1.85, −5±26 and −4±19, respectively.

Conclusion

A trial focused on PWV is practical and effective within our target population, with simple recruitment and a low drop-out rate.