THE IMPACT OF REVERSAL OF HYPOXIA BY REVASCULARIZATION ON THE PERIPHERAL-NERVE FUNCTION OF DIABETIC-PATIENTS

Hypoxia is considered to be one of the main aetiopathogenic factors of diabetic neuropathy. We have examined the effects of the reversal of hypoxia, achieved by revascularization, on peripheral nerve function i n diabetic patients with or without clinical neuropathy. Fifty-six pat ients [mean age 62 (range 30-74) years, 44 (79%) males, 15 (27%) with insulin-dependent diabetes of 20 years (range 1-57) duration, and crea tinine level 92.8 +/- 30.9 mu mol/l (mean +/- SD)] were tested pre-ope ratively while 30 (54%) were reexamined at least 6 weeks post-operativ ely. At baseline the leg scheduled for operation showed worse measurem ents compared to the control leg when tested for Semmes-Weinstein mono filaments, peroneal motor conduction velocity (PMCV) (33.7 +/- 7.18 vs 35.7 +/- 6.09 m . s(-1), p < 0.05) and transcutaneous oxygen tension (37.4 +/- 24.6 vs 52.0 +/- 21.5 mm Hg, p < 0.0001) while no difference s were found in the vibration perception threshold and leg temperature . When baseline and post-operative measurements were later compared in the operated leg, no differences were noticed in the vibration percep tion threshold, PMCV and Semmes-Weinstein monofilaments but the transc utaneous oxygen tension increased significantly (32.7 +/- 27.1 vs 64.6 +/- 14.5 mm Hg, p < 0.001). No differences were noticed in any of the above parameters in the contralateral leg. No correlations were found between changes in transcutaneous oxygen tension and PMCV values meas ured at baseline and at the follow-up visit in either leg. Similar res ults were found when patients were stratified according to severity of neuropathy, ischaemia and the level of the bypass. We conclude that a lthough there is greater impairment of nerve function in the more isch aemic leg, reversal of hypoxia does not result in any significant impr ovement of the nerve function measurements.