Polyneuropathy in type 1 and type 2 diabetes: comparison of nerve conduction studies, thermal perception thresholds and intraepidermal nerve fibre densities.
BACKGROUND
To evaluate possible differences in distal polyneuropathy (PN) characteristics and degree of abnormalities for various small and large fibre parameters in diabetes type 1 (DM1) and type 2 (DM2).


METHODS
Sixty-six DM1 and 57 DM2 patients with or without PN symptoms were included. Nerve conduction studies (NCS), quantitative sensory testing (QST) and quantification of intraepidermal nerve fibres (IENFs) were performed. Z-scores were calculated from reference materials.


RESULTS
In both groups, 42% had abnormal NCS classification, 42% (DM1) and 39% (DM2) abnormal QST, as well as 40% (DM1) and 32% (DM2) abnormal IENF density. Seventy percent (DM1) and 65% (DM2) had one of the three tests abnormal (differences not significant). Correlations were found between most Z-score parameters and disease duration and HbA1c in DM1, but fewer in DM2. In multivariate analysis, some NCS and QST Z-scores were more abnormal in DM2. Symptom scoring correlated better with NCS and QST parameters in DM1.


CONCLUSIONS
The differences could be referred to disease duration, glycaemic control and possibly patient age. The various parameters from NCS, QST and IENF analysis contribute differently in the assessment of polyneuropathy.
Løseth
Sissel
S
Department of Clinical Medicine-Neurology, University of Tromsö, Tromsö, Norway. sissel.loseth@unn.no
Mellgren
Svein I
SI
Jorde
Rolf
R
Lindal
Sigurd
S
Stålberg
Erik
E
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003929:Diabetic Neuropathies / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology*; D009460:Neurologic Examination; D011115:Polyneuropathies / Q000175:diagnosis* / Q000503:physiopathology
D006442:Glycated Hemoglobin