Calf and forearm blood flow in hypercholesterolemic patients

Area of Science:

• Cardiovascular Physiology
• Vascular Biology
• Metabolic Disorders

Background:

• Hypercholesterolemia is linked to impaired endothelium-dependent vasodilation.
• The impact of hypercholesterolemia on microcirculation vasomotion during postischemic hyperemia requires further investigation.

Purpose of the Study:

• To investigate the effects of hypercholesterolemia and its treatment on microcirculation vasomotion in the calf and forearm during postischemic hyperemia.
• To determine if hypocholesterolemic therapy normalizes impaired vascular function.

Main Methods:

• Study included 13 male patients with heterozygous familial hypercholesterolemia and 10 male controls.
• Calf and forearm blood flow measured using venous occlusion strain gauge plethysmography at rest, during reactive hyperemia, and after isosorbide dinitrate.
• Evaluated plasma lipids, hematologic parameters, and limb vasoreactivity during diet-only and simvastatin therapy.

Main Results:

• Hypercholesterolemia increased calf resting vascular resistance and reduced peak flow during reactive hyperemia and flow debt repayment compared to controls.
• Forearm blood flow measurements showed no significant differences between hypercholesterolemic patients and controls.
• Hypocholesterolemic therapy with simvastatin normalized calf vascular resistance, peak flow, and flow debt repayment.

Conclusions:

• Hypercholesterolemia negatively impacts calf microcirculation vasomotion, characterized by increased resting vascular resistance and impaired reactive hyperemia.
• These microcirculatory abnormalities in hypercholesterolemia are reversible with cholesterol-lowering treatment.
• Forearm vasodilation is not significantly affected by hypercholesterolemia in this study.