Lower extremity nerve function in patients with lower extremity ischemia.
BACKGROUND
We determined whether lower extremity ischemia, as measured by the ankle brachial index (ABI), is associated with impaired lower extremity nerve function.


METHODS
Participants included 478 persons with peripheral arterial disease (PAD) identified from noninvasive vascular laboratories and 292 persons without PAD identified from a general medicine practice and noninvasive vascular laboratories. Peripheral arterial disease was defined as an ABI lower than 0.90 (mild PAD: ABI, 0.70 to <0.90; moderate PAD: ABI, 0.50 to <0.70; and severe PAD: ABI, <0.50). The ABI and electrophysiologic measures of the peroneal, sural, and ulnar nerves were obtained.


RESULTS
Among 546 participants without diabetes, PAD participants had significantly impaired peripheral nerve function in the upper and lower extremities compared with non-PAD participants. After adjusting for age, sex, race, smoking, height, body mass index, recruitment source, alcohol use, disk disease, spinal stenosis, cardiac disease, and cerebrovascular disease, these associations were not statistically significant. After adjusting for confounders among nondiabetic participants, those with severe PAD (ABI, <0.50) had poorer peroneal nerve conduction velocity (NCV) compared with participants without PAD (42.6 vs 44.8 m/s; P = .003) and poorer peroneal NCV compared with participants with mild PAD (42.6 vs 45.0 m/s; P = .001) or moderate PAD (42.6 vs 44.1 m/s; P = .03). Among 224 participants with diabetes, after adjusting for confounders, PAD was associated with poorer peroneal NCV (40.8 vs 43.5 m/s; P = .01), sural nerve amplitude (3.1 vs 4.8 muV; P = .045), and ulnar NCV (47.6 vs 50.2 m/s; P = .03) compared with those without PAD.


CONCLUSIONS
Our findings suggest that leg ischemia impairs peroneal nerve function. This association is less strong in patients with diabetes, perhaps because of the overriding influence of diabetes on peripheral nerve function. Clinicians should consider screening for PAD in patients with idiopathic peroneal nerve dysfunction. Peripheral arterial disease-associated nerve dysfunction may contribute to PAD-associated functional impairment.
McDermott
Mary M
MM
Department of Medicine, Northwestern University Feinberg School of Medicine, 676 N St Clair, Suite 200, Chicago, IL 60611, USA. mdm608@northwestern.edu
Sufit
Robert
R
Nishida
Takashi
T
Guralnik
Jack M
JM
Ferrucci
Luigi
L
Tian
Lu
L
Liu
Kiang
K
Tan
Jin
J
Pearce
William H
WH
Schneider
Joseph R
JR
Sharma
Leena
L
Criqui
Michael H
MH
D000368:Aged; D001132:Arm / Q000294:innervation; D001794:Blood Pressure / Q000502:physiology; D001916:Brachial Artery / Q000502:physiology; D003928:Diabetic Nephropathies / Q000503:physiopathology; D005260:Female; D006801:Humans; D007511:Ischemia / Q000503:physiopathology*; D007866:Leg / Q000098:blood supply* / Q000294:innervation*; D008297:Male; D009431:Neural Conduction / Q000502:physiology; D010525:Peripheral Nerves / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000503:physiopathology*; D016491:Peripheral Vascular Diseases / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000502:physiology