The relationship between blood glucose excursions and painful diabetic peripheral neuropathy: a pilot study.
Peripheral neuropathy affects 30% of Type 1 diabetic patients. Unfortunately, 10-20% of affected patients have disabling symptoms. The aim of this study was to examine the relationship between blood glucose excursions and pain in patients with symptomatic diabetic neuropathy. Twenty Type 1 diabetic patients with peripheral neuropathy (10 painful and 10 painless) wore a continuous glucose monitoring system for 3 days. Symptomatic patients kept a daily pain score diary. The mean amplitude of glycaemic excursions (MAGE) and the M-values (measure of glucose deviations from an arbitrarily selected point) were calculated. Groups were matched for (mean +/- sd) age: 52.0 +/- 11.1 years; duration of diabetes: 24.8 +/- 10.7 years; HbA1c: 9.7 +/- 2.3%; duration of neuropathy: 5.6 +/- 2.6 years; and CGMS performance. The painful group had a greater mean glucose (12.1 +/- 2.9 mmol/l vs. 9.3 +/- 1.9 mmol/l, P = 0.02), a greater M-value (68.4 vs. 31.1, P = 0.02) and more glycaemic excursions (13 vs. 10, P < 0.01), compared with the painless group. However, there was no difference in the MAGE between both groups, and no correlation between the number of glycaemic excursions and the number of painful episodes in the painful group. Patients with painful neuropathy have greater glucose flux and possibly poorer diabetes control, compared with patients with painless neuropathy.