Measurements of sweat response and skin vasomotor reflex for assessment of autonomic dysfunction in patients with diabetes.
OBJECTIVE
Some physical or arousal stimuli induce a rise in sweat secretion (sympathetic sweat response or SSwR) and a reduction in skin blood flow (skin vasomotor reflex or SkVR) to the palm. We recorded SSwRs and SkVRs in diabetic patients and assessed the usefulness of these parameters for evaluating autonomic dysfunction in diabetes.


METHODS
We studied 42 diabetic patients (58+/-12 years) and 42 normal control subjects (59+/-11 years). Focal sweat secretion and skin blood flow were measured on the palm by a sudorometer and a Doppler flowmeter, respectively. SSwRs and SkVRs to deep inspiration, mental arithmetic, and isotonic exercise were recorded. SSwR amplitude was measured from baseline to peak, and SkVR amplitude (reduction rate) was calculated as: (blood flow reduction/basal blood flow)x100%. We also conducted head-up tilt tests and R-R interval variation tests (coefficient of variation of R-R intervals or CV(R-R)).


RESULTS
The SSwR or SkVR amplitudes in the diabetic group were significantly lower than those in the control group for any stimulus. CV(R-R) in the diabetic group was significantly less than that in the control group. The diabetic group showed a significantly greater reduction in systolic blood pressure during head-up tilt compared with the control group. In the diabetic group, there were significant correlations in SSwR or SkVR amplitudes versus blood pressure falls during the head-up tilt test, and CV(R-R) values.


CONCLUSIONS
We believe that SSwR and SkVR are useful indexes for the evaluation of autonomic involvement in diabetic patients.
Asahina
Masato
M
Department of Neurology, Chiba University School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan. asahina@faculty.chiba-u.jp
Yamanaka
Yoshitaka
Y
Akaogi
Yuichi
Y
Kuwabara
Satoshi
S
Koyama
Yu
Y
Hattori
Takamichi
T
D000368:Aged; D001794:Blood Pressure; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D003924:Diabetes Mellitus, Type 2 / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012018:Reflex; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology*; D013542:Sweat / Q000378:metabolism*; D013546:Sweating; D014666:Vasomotor System / Q000503:physiopathology*