Inorganic nitrate supplementation enhances functional capacity and lower-limb microvascular reactivity in patients with peripheral artery disease.

Twenty-one PAD patients (72±10 years; 12 male/9 female) with Fontaine Stage 1–2a and Rutherford 0–1 were enrolled in a randomized, double-blind, placebo-controlled trial with block randomization (block sizes of six; 4:2). Eight-week intervention.

Sodium nitrate (NaNO3), 1 g/day, for eight weeks; route not specified.

NaNO3 increased plasma nitrate from 32.3±20.0 to 379.8±204.6 μM and nitrite from 192.2±51.8 to 353.1±134.2 nM. 6MWT distance rose from 387±90 to 425±82 m. Calf BF Peak increased from 11.6±4.9 to 14.1±5.1 mL/dL tissue/min; calf VC Peak rose from 11.1±4.3 to 14.2±4.9 mL/dL tissue/min/mmHg. Forearm measures and inflammatory/adhesion biomarkers showed no significant changes. Improvements in calf BF Peak and VC Peak correlated with 6MWT improvement (r=0.70, p<0.05; r=0.61, p<0.05). Eight weeks of daily NaNO3 improved lower-limb vasodilatory capacity and functional capacity in PAD, with no adverse effects reported; suggests NO-boosting therapy could enhance exercise tolerance in PAD.

Small sample size (n=21) and single-dose, eight-week design limit generalizability. Some calf measurements missing due to thigh cuff discomfort (11 NaNO3, 7 placebo). Imbalanced sex distribution between groups. Inflammatory biomarkers were limited to four markers; broader inflammatory profiling may yield different results.