Skin microvascular flow motion (SMF) – blood flow fluctuation attributed to the rhythmic contraction and dilation of arterioles – is thought to be an important component of the microcirculation, by ensuring optimal delivery of nutrients and oxygen to tissue and regulating local hydraulic resistance. There is some evidence that SMF is altered in obesity, type 2 diabetes mellitus, and hypertension. Nevertheless, most studies of SMF have been conducted in highly selected patient groups, and evidence how SMF relates to other cardiovascular risk factors is scarce. Therefore, the aim of the present study was to examine in a population-based setting which cardiovascular risk factors are associated with SMF.
We measured SMF in 506 participants of the Maastricht Study without prior cardiovascular event. SMF was investigated using Fourier transform analysis of skin laser Doppler flowmetry at rest within five frequency intervals in the 0.01–1.6-Hz spectral range. The associations with SMF of the cardiovascular risk factors age, sex, waist circumference, total-to-high-density lipoprotein cholesterol, fasting plasma glucose, 24-h SBP, and cigarette smoking were analysed by use of multiple linear regression analysis.
Per 1 SD higher age, waist circumference and 24-h SBP, SMF was 0.16 SD higher [95% confidence interval (CI) 0.07, 0.25; P < 0.001), −0.14 SD lower (95% CI −0.25, −0.04; P = 0.01), and 0.16 SD higher (95% CI 0.07, 0.26; P < 0.001), respectively, in fully adjusted analyses. We found no significant associations of sex, fasting plasma glucose levels, total-to-high-density lipoprotein cholesterol ratio, or pack years of smoking with SMF.
Age and 24-h SBP are directly, and waist circumference is inversely associated with SMF in the general population. The exact mechanisms underlying these findings remain elusive. We hypothesize that flow motion may be an important component of the microcirculation by ensuring optimal delivery of nutrients and oxygen to tissue and regulating local hydraulic resistance not only under physiological conditions but also under pathophysiological conditions when microcirculatory perfusion is reduced, such as occurs with ageing and higher blood pressure. In addition, obesity may result in an impaired flow motion with negative effects on the delivery of nutrients and oxygen to tissue and local hydraulic resistance.
aDepartment of Internal Medicine, Maastricht University Medical Centre (MUMC+)
bCardiovascular Research Institute Maastricht (CARIM)
cDepartment of Social Medicine
dCAPHRI School for Public Health and Primary Care
eDepartment of Epidemiology, Maastricht University, Maastricht, the Netherlands
Correspondence to Alfons J.H.M. Houben, PhD, Maastricht University Medical Centre, Department of Internal Medicine, P.O. Box 5800, 6202 AZ, Maastricht, the Netherlands. E-mail: firstname.lastname@example.org
Abbreviation: SMF, skin microvascular flow motion
Received 26 June, 2014
Revised 16 July, 2014
Accepted 16 July, 2014