AUTONOMIC AND PERIPHERAL-NERVE FUNCTION IN ADOLESCENTS WITH AND WITHOUT DIABETES

In this study reference ranges were established for autonomic and peri pheral nerve tests in 122 non-diabetic adolescents. Regression analysi s was used to evaluate the effect of age and gender on neurological fu nction. Increasing age was associated with: less heart rate variabilit y during deep breathing (p = 0.03), higher thermal threshold for cold at the wrist (p = 0.009), and higher vibration threshold at the toe (p = 0.001) and medial malleolus (p = 0.01). Male gender was associated with higher Valsalva ratio (p = 0.0004), higher thermal threshold for hot at the foot (p = 0.002), and higher vibration threshold at the mal leolus (p = 0.03). The REFVAL programme was used to determine parametr ic or non-parametric reference limits: the 5 % limits for autonomic an d 95 % limits for peripheral tests. One hundred and eighty-one adolesc ents with diabetes were studied under identical conditions and similar effects of age and gender were found. Twenty-eight percent of the gro up with diabetes had at least one abnormal autonomic test result out o f four (expected 18.5 %); 24 % had at least one abnormal peripheral te st result out of six (expected 26.5 %). Glycaemic control was associat ed with autonomic (p = 0.04) but not peripheral abnormalities. Using m ultiple regression analysis and adjusting for age and gender, there wa s no effect of diabetes duration or glycaemic control on neurological function.