Table 3 Microvascular measurements
Controls (n = 12)AS pre (n = 15)AS post (n = 15)p Value (1)p Value (2)p Value (3)
ACh-mediated vasodilatation:
Skin temperature, °C30.6 (1.3)30.6 (1.0)31.0 (1.4)0.80.40.4
Baseline skin perfusion, PU21.9 (10.8)21.9 (7.5)24.3 (11.5)1.00.41.0
ACh-mediated vasodilatation, %469 (174–692)118 (43–288)318 (37–591)0.020.030.5
SNP-mediated vasodilatation:
Skin temperature, °C30.2 (1.1)30.4 (1.0)31.5 (2.6)0.70.20.2
Baseline skin perfusion, PU17.8 (10.5)18.7 (7.8)23.1 (9.2)0.70.070.2
SNP-mediated vasodilatation, %391 (152–1116)348 (81–649)200 (73–401)0.10.30.05
Capillary recruitment
Skin temperature, °C30.3 (0.9)30.4 (1.4)30.7 (1.5)1.00.20.4
Baseline capillary density, n/mm249.0 (6.9)50.6 (13.4)53.3 (11.0)0.70.10.3
Peak capillary density, n/mm268.5 (12.7)65.4 (16.8)73.9 (15.9)0.60.0030.4
Absolute increase, n/mm219.5 (6.5)14.8 (5.2)20.7 (6.7)0.040.0010.7
Capillary recruitment, %39.2 (9.0)29.6 (9.3)38.9 (10.9)0.010.0061.0
  • Data are mean (SD) or median (Interquartile range); p values were calculated: (1) AS pre vs controls; (2) AS pre vs AS post; (3) AS post vs controls. Bold type indicates signficance.

  • ACh, acetylcholine; AS, ankylosing spondylitis; SNP, sodium nitroprusside; PU, perfusion units.