Background: Essential hyperhidrosis, a disorder of the eccrine sweat glands, is associated with sympathetic overactivity and the aim of the present study was to determine endothelium-dependent vasodilator function in patients with this condition.
Methods and results: Using high-resolution ultrasound, the diameter of the brachial artery at rest and during reactive hyperemia (flow-mediated dilatation, %FMD endothelial-dependent stimulus to vasodilatation), as well as after sublingual administration of nitroglycerin (%NTG endothelium-independent vasodilatation) was measured in 18 subjects (mean age 27+/-5 years) with essential hyperhidrosis and 24 healthy control subjects (mean age 29+/-5 years). Baseline brachial artery diameter and FMD were comparable in both groups (BAD: 4.1+/-0.7 mm vs 4.3+/-0.5 mm (control), p = 0.8; FMD: 5.6+/-1.9% vs 6.7+/-2.2%, p=0.1). The time-averaged flow velocity during peak reactive hyperemia was similar in the 2 groups (75+/-11 cm/s vs 72+/-10 cm/s, p = 0.5), nor did NTG-induced dilatation in the patients with essential hyperhidrosis differ significantly from that in healthy control subjects (12.8+/-2.7% vs 14.0+/-3.6%, p = 0.3).
Conclusion: These findings suggest that endothelium-dependent dilatation of large conduit arteries is preserved in essential hyperhidrosis and it seems to be a localized disorder of the eccrine sweat glands rather than a generalized disorder involving vascular endothelium.