Influence of age and gender on skin vessel reactivity to endothelium-dependent and endothelium-independent vasodilators tested with iontophoresis and a laser Doppler perfusion imager.

BACKGROUND: The aim of this study was to evaluate the influence of age and gender on skin vessel reactivity to one endothelium-dependent vasodilator (acetylcholine, ACh), and two endothelium-independent vasodilators with different modes of action (nitroprusside and isoprenaline).
METHODS: The substances were iontophoresed into the skin and the results were mapped through a newly developed laser Doppler perfusion imager. Thirty-four healthy, nonsmoking individuals without any medication and without atopic constitution participated in the study. The subjects, 13 men and 21 women, 18 to 80 years of age, were divided into subgroups according to age and gender.
RESULTS: A correlation to age for the vascular responses to nitroprusside and, to a lesser extent, ACh was shown for the women (p = .0036 and .0920 respectively). Differences were also observed between the age and gender subgroups with respect to their response to these two substances: young and, to a lesser extent, middle-aged women differed from elderly women and middle-aged and elderly men. The response to isoprenaline was affected neither by age nor gender.
CONCLUSIONS: The results of the study suggest that skin vessel reactivity to nitroprusside and, to a lesser extent, ACh is age dependent. This might reflect both functional and structural changes in skin vasculature with aging. Gender differences for these two substances are also suggested, with women exhibiting a greater increase in perfusion after iontophoresis than men. However, higher vasoconstrictor tone among the women may have influenced the results.