Skin microvascular response to pressure load in obese mice

• The role of obesity in the appearance of skin pressure ulcers remains controversial.
• Obesity duration decreased the ischaemic area related to compression that could reduce skin lesion
• The size of the ischemic area at 24-h post-release did not reflect the size of the skin lesion
• Increased adiposity and changes in pressure transmission could reduce skin lesion to pressure load

PurposeThe role of obesity in the appearance of skin pressure ulcers remains controversial. The aim of the present study was to evaluate blood perfusion and related lesions after skin compression in obese mice.MethodsSixty C57BL6 male mice were randomly assigned to a control or hypercalorific diet (HCD) for 2, 4 and 12 weeks. Skin compression was induced by a magnetic force of 11 kPa overlying a subcutaneous metal plate and applied for 4 h. Skin perfusion was examined using laser Doppler imaging before skin compression, immediately after compression release and 24 h later. 24 h after magnet removal, skin injuries were determined by photography.ResultsA heterogeneous distribution of blood perfusion was observed using the colour-coded map of the skin perfusion on the compressed area. At 24-h post-compression release, 60% to 75% of the compressed area was ischaemic in the 2-week HCD group and in all the control groups compared to 35% in the 4- and 15% in the 12-week HCD groups. The lowest occurrence of skin lesion seen as skin redness or pressure-sores was observed in the 12- week HCD group (4%) compared to about 12% in either the control or the 2- and 4-week HCD groups.ConclusionsThis study suggests that there was no clear relationship between the extent of ischaemia and skin lesion occurrence after skin compression in short-duration obese mice. In contrast, it appears that long-duration obesity could reduce both ischaemia and skin lesions in response to skin compression through changes in skin structure.