Author/Editor		Maver, Jerica; Štrucl, Martin
Title		Central and local microvascular reactivity in normotensive subjects with a family history of hypertension
Translated title		Centralni in lokalni vplivi na odzivnost drobnega žilja pri normotonikih, družinsko obremenjenih s hipertenzijo
Type		članek
Source		Zdrav Vestn
Vol. and No.		Letnik 70, št. 11
Publication year		2001
Volume		str. 613-7
Language		eng
Abstract		Background. Using the laser-Doppler method we measured blood flow on the nailfold skin to compare the reactivity of cutaneous microcirculation between normotensive subjects with a familial predisposition to hypertension and normotensive subjects without a familial predisposition to hypertension. Methods. Three groups of normotensive subjects were included in the study: 11 subjects with a familial predisposition to hypertension without a previous record of high blood pressure, six predisposed subjects with a previous record of high blood pressure and 13 subjects with no predisposition to hypertension. The flow was measured after direct and indirect skin cooling and heating and during postocclusive reactive hyperemia (PRH) after a ten-minute occlusion of digital arteries. The frequency of jlow oscillations in the second pari of the PRH was established. Heart rate spectral analysis was performed based on the monitoring of theperdpheralpudsefrequency by means of the finapres device.. Results. In comparison to the other two groups of subjects, the group with a predisposition and a previous record of high blood pressure displayed a larger surface area in-the low frequency band (0.05 to O.IS Hz) of the heart rate variability power spectrum (the Bonferroni test, p < 0.05). As compared to subjects without predisposition, bath groups ofpredispased subjects exhibit higher frequency of flow oscillations in the second part of the PRH (the Bonferroni test, p < p.05). Conclusions. We conclude that there is a change in cutaneous microvascular reactivity of local (most probably myogenic) origin in normotensivesubjects with apred*sposition to hypertension, whereas normotensives with a predisposition and a previous record of high blood pressure exhibit also different cutaneous microvascular reactivity of central (non-vascular) origin.
Summary		Izhodišča. Z lasersko-doplersko metodo merjenja pretoka smo primerjali odzivnost drobnega žilja kože med normotoniki; ki so družinsko obremenjeni s hipertenzijo, in normotenzivnimi preiskovanci brez take obremenitve. Metode. V študijo smo vklučili tri skupine normotenzivnih preiskovancev: v prvi skupini je bilo 11 normotonikov, družinsko obremenjenih s hipertenzijo, ki jim doslej še niso namerili povišane vrednosti krvnega tlaka, v drugi skupini je bilo 6 družinsko obremenjenih normotonikov, ki so jim v preteklosti že izmerili povišano vrednost krvnega tlaka, v tretji skupini pa je bilo 13 normotonikov brez družinske obremenitve s hipertenzijo. Morebitno prisotnost strukturnih sprememb drobnega žilja smo ocenili z merjenjem: pretoka po dokalnem gretju kože do 40 stopinj C, in največjega pretoka v prvem delu pookluziune reaktivne hiperemije (PRH) po deset minut trajajočem arterijskem zažemu. Za proučitev centralnih vplivov na odzivnost drobnega žilja smo merili kožni pretok po sistemskem ohlajanju in gretju ter opravili spektralno analizo variabidnosti srčne frekvence, določene s spremljanjem frekvence perifernega pulza s finapres aparatom. S Fourierjevo frekvenčno analizo 50 sekund dolgih zapisav pretoka smo določili prevladujočo frekvenco nihanj pretoka v drugem delu PRH, ki nam je služila kat indikator lakalnih (miogenih) vplivov na odzivnost drobnega žilja. Rezultati. Pretok po lokalnem gretju kože in največji pretok v prvem delu PRH se med skupinami nista statistično pomembno razlikovala. Obremenjeni preiskovanci z že izmerjeno povišano vrednostjo tlaka so kazali značilno večjo vrednost površine v nizko frekventnem delu močnostnega spektra variabidnosti frekvence srca (Bonferrond test, p <0,05) inpomembno večjo frekvenca nihanj pretoka v drugem delis PRH (Bonferroni test, p < 0=OS) v primerjavi z ostalimi preiskovanci. (Izvleček skrajšan pri 2000 znakih).
Descriptors		HYPERTENSION MICROCIRCULATION SKIN HEART RATE BLOOD PRESSURE ADULT LASER-DOPPLER FLOWMETRY