Bedside neuropathy disability score compared to quantitative sensory testing for measurement of diabetic neuropathy in children, adolescents, and young adults with type 1 diabetes

Background: While regular yearly screening for diabetic retinopathy and nephropathy is well established in patients with diabetes mellitus, there are no standardized diagnostic tests for diabetic peripheral neuropathy (DPN). In the present study, we compared the bedside neuropathy disability score (NDS) with quantitative sensory testing (QST) for screening for DPN in youth with type 1 diabetes mellitus. Methods: One hundred sixty-six patients aged 10 to 34 years (median 21 years) were evaluated for DPN by the NDS and QST. Quantitative sensory testing was also done in 43 healthy, age-matched controls. Diabetic peripheral neuropathy grade by both methods was correlated with disease-related variables. Results: On QST, the diabetic group had significantly higher mean scores for vibration (P<.001) and warm sensation (P<.01) than controls, and lower scores for cold sensation (P<.05); however, there was a great degree of overlap. The NDS significantly correlated with the vibration threshold, but not with the warm and cold thresholds. The NDS significantly correlated with age at testing, diabetes duration, and long-term and current HbA_1c levels (P<.001), and with the presence of microalbuminuria and diabetic retinopathy (P<.001). Analysis of the QST variables yielded significant correlations of vibration and warm sensation with age at testing (P<.001, P<.05, respectively) and of vibration with diabetes duration (P<.001) and retinopathy (P=.05); none of the quantitative tests correlated with glycemic control. Conclusions: The stronger association of the NDS with glycemic control and other microvascular complications compared to the perception thresholds, and its shorter time of performance and lack of costly equipment, may make the NDS the preferred method for measuring DPN in this population.