Sex and age-related day-to-day variability in the skin microcirculation during post-occlusive reactive hyperemia

Freya Richter; Moa Nilsson; Joakim Henricson; Carl Johan Östgren; Marcus Larsson; Tomas Strömberg; Ingemar Fredriksson; Fredrik Iredahl

doi:10.1016/j.mvr.2025.104783

Sex and age-related day-to-day variability in the skin microcirculation during post-occlusive reactive hyperemia

Microvasc Res. 2025 Jan 19:104783. doi: 10.1016/j.mvr.2025.104783. Online ahead of print.

Authors

Freya Richter¹, Moa Nilsson¹, Joakim Henricson², Carl Johan Östgren³, Marcus Larsson⁴, Tomas Strömberg⁴, Ingemar Fredriksson⁵, Fredrik Iredahl⁶

Affiliations

¹ Department of Health, Medicine and Caring Sciences, Division of Community Medicine, Linköping University, Linköping, Sweden.
² Department of Emergency Medicine in Linköping, and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden.
³ Primary Health Care Center, Department of Health, Medicine and Caring Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden; Centre for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.
⁴ Department of Biomedical Engineering, Linköping University, Linköping, Sweden.
⁵ Department of Biomedical Engineering, Linköping University, Linköping, Sweden; Perimed AB, Järfälla, Stockholm, Sweden.
⁶ Primary Health Care Center, Department of Health, Medicine and Caring Sciences, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden; Wallenberg Centre for Molecular Medicine, Linköping University, Linköping, Sweden. Electronic address: fredrik.iredahl@liu.se.

PMID: 39837458
DOI: 10.1016/j.mvr.2025.104783

Abstract

Introduction: Little is known about the day-to-day variability of different skin microcirculation parameters, and how this variability is influenced by age and sex. The aim was to examine the day-to-day variability of microcirculatory parameters in relation to age and sex.

Methods: The cutaneous microcirculation was measured using a fiber optic probe integrating laser Doppler flowmetry (LDF) and diffuse reflectance spectroscopy (DRS) to measure oxygen saturation, red blood cell (RBC) tissue fraction, speed-resolved and conventional perfusion. Measurements at two separate days were compared during baseline, a 5-min occlusion and during the following post-occlusive reactive hyperemia (PORH) period on the volar forearm and dorsal foot in totally 48 men and women aged 20-30 and 50-60 years, respectively. Variability was expressed as the coefficient of variation CV and repeatability as the intraclass correlation coefficient ICC.

Results: Peak oxygen saturation during PORH had the lowest day-to-day variability for the forearm (CV = 2.1 %) and the foot (CV = 3.8 %) as well as an excellent repeatability (ICC = 0.80 and ICC = 0.82, respectively). Older women had a higher day-to-day variability in baseline conventional perfusion compared to younger women on the forearm (p = 0.007). On the foot, older women had a lower day-to-day variability than younger women for baseline oxygen saturation (p = 0.006) and peak RBC tissue concentration (p = 0.008). Older men had a lower day-to-day variability than younger men for baseline oxygen saturation (p = 0.012) but a higher variability for baseline and peak RBC tissue concentration (p = 0.008 and p = 0.002) on the foot.

Conclusion: Peak oxygen saturation had the lowest day-to-day variability of the measured parameters. A lower value of peak oxygen saturation has previously been associated with increasing systematic coronary risk implying that this is a suitable parameter for measuring microcirculatory dysfunction. Sex and age only affected the day-to-day variability of very few parameters.

Keywords: Diffuse reflectance spectroscopy; Laser doppler flowmetry; Microcirculation; Skin; Variability.