Impaired microvascular flow motion in subclinical diabetic feet with sudomotor dysfunction

• Published in: Microvascular research Vol. 83; no. 2; pp. 243 - 248
• Main Authors: Sun, Pi-Chang, Chen, Chen-Sheng, Kuo, Cheng-Deng, Lin, Hong-Da, Chan, Rai-Chi, Kao, Mu-Jung, Wei, Shun-Hwa
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.03.2012
• Subjects: Analysis of Variance; Autonomic Nervous System - physiopathology; Blood Flow Velocity; Case-Control Studies; Diabetic Foot - diagnosis; Diabetic Foot - pathology; Diabetic Foot - physiopathology; Diabetic Neuropathies - diagnosis; Diabetic Neuropathies - pathology; Diabetic Neuropathies - physiopathology; Electromyography; Female; Humans; Laser-Doppler Flowmetry; Male; Microcirculation; Middle Aged; Predictive Value of Tests; Regional Blood Flow; Skin - blood supply; Skin - innervation; Skin - pathology; Sweating; Taiwan; Taiwan
• ISSN: 0026-2862; 1095-9319; 1095-9319
• DOI: 10.1016/j.mvr.2011.06.002

Impaired cutaneous blood flow and sweating dysfunction might be among the earliest manifestations of diabetic autonomic neuropathy. This study assessed the pathophysiological basis underlying skin vasomotion changes and their relation with progressive sudomotor dysfunction and other autonomic and somatic measures in subclinical diabetic feet. Laser Doppler skin perfusion was assessed on 68 diabetic and 25 control subjects. The low-frequency vasomotion was transformed into three frequency intervals 0.0095–0.021, 0.021–0.052 and 0.052–0.145Hz, respectively, for the investigation of endothelial, neurogenic and myogenic effects on microcirculatory alterations. The diabetic patients were categorized into three groups by increasing severity of sudomotor dysfunction: SSR+ (sympathetic skin response present; 27 patients), SSR− (SSR absent; 23 patients) and at-risk (SSR absent and of preulcerative cracked skin; 18 patients). All diabetic patients underwent nerve conduction and cardiovascular autonomic studies. The total spectral and endothelial activity was significantly decreased only in the at-risk group. The SSR− group had lower neurogenic vasomotion than the SSR+ group (p<0.05). Although no statistical difference was noted between any group in absolute myogenic spectrum, the SSR− group had higher normalized myogenic activity than the SSR+ group (p<0.01). The larger drop in orthostatic pressure was paralleled by a reduction in the myogenic amplitude (r=−0.33, p<0.01). These results suggested that early impairment of low-frequency flow motion correlated closely with the presence of sudomotor dysfunction of subclinical feet mainly in neurogenic and endothelial components. Impaired systemic vascular tone as manifested by orthostatic hypotension was proportional to the degree of myogenic dysregulation in diabetic patients. ► The pathophysiological basis underlying skin microcirculatory changes in subclinical diabetic feet. ► Impaired low-frequency flow motion correlated with sudomotor dysfunction. ► Vasomotion changes were mainly in neurogenic and endothelial components. ► Impaired systemic vascular tone was proportional to the degree of myogenic dysregulation.