Introduction: The handheld DPNCheck (DPNC) nerve conduction study (NCS) device has shown high sensitivity (SENS) and specificity (SPEC) against classical NCS for detecting peripheral neuropathy (PN), but studies comparing DPNC to clinical assessments are lacking. We aimed to evaluate DPNC against a validated clinical reference standard in adults with T1D.
Methods: Among 88 adults >50 yrs with T1D, we assessed PN with the modified Toronto Clinical Neuropathy Scale (mTCNS) and bilateral sural nerve conduction velocity (VEL) and action potential amplitude (AMP) with DPNC. Abnormal AMP or VEL <u>></u>1 leg=DPNC+. We used McNemar’s test and calculated SENS and SPEC to compare DPNC to mTCNS (score <u>></u>3=PN+) as the reference.
Results: Mean age was 63+6 yrs, T1D duration 46±10 yrs and A1c 7.1±1%; 52% were male. Mean mTCNS score was 5.2+5, AMP 42+10 m/s and VEL 4.8+3 µV. Correlation between mTCNS and worse leg AMP and VEL was -0.36 and -0.52, respectively (p<0.001). The proportion of subjects PN+ by mTCNS was similar to those DPNC+ using standard manufacturer cutoffs (DPNC-std; p=0.85) but significantly higher in those DPNC+ using age and height adjusted cutoffs (DPNC-adj; p<0.001). DPNC-adj had 94% SENS but 28% SPEC; DPNC-std had 71% SENS and 63% SPEC.
Conclusion: DPNC has high SENS for detecting PN in T1D. Lower SPEC may reflect detection of subclinical PN rather than misclassification of true negatives. DPNC alone or combined with mTCNS may aid in early PN detection.
L.A. Marion: None. C.E. Nevarez: None. A.B. Murthy: None. E.W. Yu: Research Support; Amgen Inc.
National Institutes of Health (T32DK007028)
