Impact of age and gender on microvascular function.

Abstract

Microcirculatory function can be assessed by postocclusive reactive hyperaemia (PORH) using laser Doppler fluxmetry. Previous studies have shown that PORH reveals microvascular damage at an early stage. In particular, at younger ages, PORH might depend on age and gender. To implement PORH into a larger scale of clinical studies, one has to be aware of the influence of age and gender on microcirculation. The aim of this study was to assess the impact of age and gender on microcirculatory function during adolescence. Within the scope of an epidemiological project, 896 children and adolescents underwent assessment of PORH by laser Doppler fluxmetry. Microcirculatory parameters during PORH (baseline perfusion, biological zero, peak perfusion, time to peak perfusion and recovery time) were analysed in relation to age (by tertiles) and gender. Baseline perfusion, biological zero and peak perfusion were lower in children/adolescents in the upper age tertile (12·3-18·1years) than in the middle (9·8-12·2years) and lower (4·3-9·7years) age tertiles (P<0·0001). In the total of participants, baseline perfusion, biological zero and peak perfusion were higher in males than in females (P<0·0001). Analysing microcirculatory parameters as a function of age and gender, the sex differences were only apparent in the upper and the middle age tertiles, but not in the lower. During adolescence, PORH is a function of age. At higher age, microvascular reactivity considerably depends on gender, whereas no sex differences are present at younger ages.