Assessment of Sudomotor Function to Predict Future Abnormalities of Glucose Tolerance in at Risk Population

Abstract

Aims: This study done in subjects with an initial normal glucose tolerance (NGT) was to assess the ability of EZSCAN, a new device developed to evaluate sudomotor function, to predict future abnormalities in glucose tolerance. Methods: South Asian (Indian) subjects (n= 69, 48% male, mean age 42 ± 9 years, mean BMI 28 ± 5 kg/m 2 ) diagnosed as NGT with a previous oral glucose tolerance test (OGTT, T0) underwent a frequently sampled OGTT (FSOGTT), 8 months later (T8). At both times EZSCAN tests were done. Using the AUC glucose and AUC insulin measured by the FSOGTT, subjects were categorised as normal, high AUC insulin or isolated high AUC glucose . Odds ratio (OR) for having high AUC insulin or isolated high AUC glucose vs normal was computed by logistic regression analysis using EZSCAN risk classification at T0 as independent variable ( 65%=high risk). Results: At T8, 11 and 5 subjects developed impaired glucose tolerance and diabetes respectively. OR of having high AUC insulin or isolated high AUC glucose in the different risk groups was 6.19 (CI 95% 1.50 – 25.48, p = 0.0116) for high risk vs no risk and 3.0 (CI 95% 0.98 – 9.19, p = 0.0545) for intermediate risk vs no risk. Sensitivity of EZSCAN for early detection of these abnormalities in glucose tolerance was 77% while it was 14% for fasting plasma glucose and 66% for HbA 1C . Conclusions: Assessment of sudomotor function by EZSCAN, a sensitive method when compared with the con - ventional methods may be very useful to identify and manage subjects at risk for developing glucose intolerance.