Vascular dysfunction persists following nonpharmacological BP reduction

Individuals with hypertension experience persistent vascular dysfunction at both the conduit and microvascular levels even when their blood pressure (BP) is acutely reduced by a nonpharmacological approach, reports a study.

A team of investigators examined the effect of reducing BP by a nonpharmacological approach (5 days of sodium restriction) on vascular function in 22 hypertensive patients (mean age 50 years, 14 men). The participants completed two 5-day dietary phases, liberal sodium (200 mmol/day) followed by restricted sodium (10 mmol/day), after a 2-week withdrawal of antihypertensive medications.

The investigators assessed resting BP and vascular function at the conduit and microvascular levels by brachial artery flow-mediated dilation (FMD), reactive hyperaemia, progressive handgrip exercises, and passive leg movement (PLM).

Despite a sodium restriction-induced decrease in BP (liberal sodium: 141/85 mm Hg; restricted sodium: 124/79 mm Hg; p<0.01 for both systolic and diastolic BP), no changes happened in FMD (liberal sodium: 4.6 percent; restricted sodium: 5.1 percent; p=0.27) and in reactive hyperaemia (liberal sodium: 548 ml; restricted sodium 615 ml; p=0.08).

Brachial artery vasodilation during handgrip exercise also did not differ between liberal and restricted sodium groups (Δ0.36 and Δ0.42 m, respectively; p=0.16). Likewise, PLM-induced changes in peak blood flow (liberal sodium: 5.3 mL/min per mm Hg; restricted sodium: 5.8 mL/min per mm Hg; p=0.5) did not differ between the two conditions.

“Vascular dysfunction, an independent risk factor for cardiovascular disease, often persists in patients with hypertension, despite improvements in BP control induced by antihypertensive medications,” the investigators noted.