Relationships between electrochemical skin conductance and kidney disease in Type 2 diabetes.

BACKGROUND SUDOSCAN® non-invasively measures peripheral small fiber and autonomic nerve activity using electrochemical skin conductance. Since neuropathy and nephropathy are microvascular Type 2 diabetes (T2D) complications, relationships between skin conductance, estimated glomerular filtration rate (eGFR), and urine albumin:creatinine ratio (UACR) were assessed. METHODS Two hundred five African Americans (AA) with T2D, 93 AA non-diabetic controls, 185 European Americans (EA) with T2D, and 73 EA non-diabetic controls were evaluated. Linear models were fitted stratified by population ancestry and T2D, adjusted for covariates. RESULTS Relative to EA, AA had lower skin conductance (T2D cases p<0.0001; controls p<0.0001). Skin conductance was also lower in T2D cases vs. controls in each population (p<0.0001, AA and EA). Global skin conductance was significantly associated with eGFR in AA and EA with T2D; adjusting for age, gender, BMI, and HbA1c, positive association was detected between skin conductance and eGFR in AA T2D cases (parameter estimate 3.38, standard error 1.2; p=5.2E(-3)), without association in EA T2D cases (p=0.22). CONCLUSIONS Noninvasive measurement of skin conductance strongly associated with eGFR in AA with T2D, replicating results in Hong Kong Chinese. SUDOSCAN® may prove useful as a low cost, non-invasive screening tool to detect undiagnosed diabetic kidney disease in populations of African ancestry.