Fig. 1Receiver operating characteristic curves of the current perception threshold (CPT) measurements for the diagnosis of diabetic peripheral neuropathy. AUC, area under the curve.
Table 1Patient demographics
Variable |
Total (n=202) |
Non-DPN (n=128) |
DPN (n=74) |
P value |
Female sex |
85 (42.1) |
53 (40.5) |
32 (45.1) |
0.553 |
Age, yr |
62.6±12.3 |
62.3±11.6 |
63.2±13.6 |
0.629 |
BMI, kg/m2
|
23.7±3.3 |
23.7±3.2 |
23.6±3.4 |
0.931 |
Duration of diabetes, yr |
12.7±8.5 |
11.4±7.4 |
15.2±9.8 |
0.007 |
Hypertension |
101 (50.0) |
67 (51.1) |
34 (47.9) |
0.768 |
HbA1c, % |
8.9±2.7 |
8.6±2.3 |
9.6 ±3.0 |
0.017 |
FPG, mg/dL |
202.4±103.3 |
167.6±56.0 |
284.3±141.2 |
0.021 |
PPG, mg/dL |
270.1±117.3 |
263.4±115.9 |
288.0±120.6 |
0.259 |
TC, mg/dL |
167.2±45.0 |
164.9±41.4 |
170.7±50.2 |
0.424 |
TG, mg/dL |
150.3±84.7 |
150.3±92.4 |
150.4±64.3 |
0.994 |
HDL-C, mg/dL |
45.0±12.1 |
44.6±11.5 |
46.0±13.9 |
0.549 |
LDL-C, mg/dL |
110.3±33.0 |
108.4±32.1 |
114.6±35.0 |
0.344 |
MNSI score |
2.8±2.3 |
1.8±1.9 |
4.7±1.7 |
<0.001 |
Abnormal NCS |
133 (65.8) |
62 (47.3) |
71 (100.0) |
<0.001 |
Table 2Univariate correlation coefficients for relationships between diabetic peripheral neuropathy indices and CPT measurements
|
L5 2,000 Hz |
L5 250 Hz |
L5 5 Hz |
CPT grade |
γ |
P value |
γ |
P value |
γ |
P value |
γ |
P value |
MNSI |
0.109 |
0.125 |
0.136 |
0.056 |
0.171 |
0.016 |
0.211 |
0.003 |
PL |
0.165 |
0.025 |
0.266 |
<0.001 |
0.180 |
0.015 |
0.130 |
0.079 |
PV |
−0.197 |
0.008 |
−0.210 |
0.004 |
−0.173 |
0.019 |
−0.203 |
0.006 |
TL |
0.200 |
0.005 |
0.282 |
<0.001 |
0.246 |
0.001 |
0.231 |
0.001 |
TV |
−0.271 |
<0.001 |
−0.297 |
<0.001 |
−0.264 |
<0.001 |
−0.309 |
<0.001 |
Samp |
−0.215 |
0.006 |
−0.157 |
0.044 |
−0.120 |
0.126 |
−0.166 |
0.033 |
SuV |
−0.101 |
0.198 |
−0.155 |
0.047 |
−0.079 |
0.313 |
−0.177 |
0.023 |
Table 3Comparisons of demographics and DPN indices in patients with normoesthesia, hyperesthesia, and hypoesthesia
Variable |
Normoesthesia (n=84) |
Hyperesthesia (n=62) |
Hypoesthesia (n=56) |
P value |
L5 2,000 Hza
|
321.1±75.9 |
268.4±115.5b
|
574.2±228b,c
|
<0.001 |
L5 250 Hza
|
109.9±31.1 |
79.4±51.5b
|
309.3±257.8b,c
|
<0.001 |
L5 5 Hza
|
64.3±27.9 |
42.7±39.0b
|
182.2±205.3b,c
|
<0.001 |
CPT grade |
0.4±0.5 |
4.7±1.0b
|
8.5±1.5b,c |
<0.001 |
Female sex |
36 (42.9) |
28 (45.2) |
21 (37.5) |
0.689 |
Age, yr |
63.0±12.0 |
61.9±11.9 |
62.7±13.3 |
0.865 |
BMI, kg/m2
|
23.6±3.2 |
24.2±3.7 |
23.2±3.0 |
0.291 |
Duration of diabetes, yr |
12.4±7.9 |
11.9±8.2 |
14.3±9.6 |
0.291 |
Hypertension |
42 (50.0) |
35 (56.5) |
24 (42.9) |
0.337 |
HbA1c, % |
9.0±2.8 |
8.7±2.6 |
9.1±2.6 |
0.739 |
FPG, mg/dL |
182.9±80.3 |
232.1±139.9 |
200.7±95.7 |
0.527 |
PPG, mg/dL |
277.3±120.1 |
253.3±111.0 |
276.1±120.1 |
0.551 |
TC, mg/dL |
167.9±40.7 |
164.0±46.6 |
170.0±49.3 |
0.790 |
TG, mg/dL |
145.1±85.5 |
151.0±76.7 |
157.5±93.2 |
0.782 |
HDL-C, mg/dL |
45.3±10.3 |
46.9±13.8 |
42.2±12.3 |
0.222 |
LDL-C, mg/dL |
113.9±34.9 |
103.7±25.9 |
111.2±35.9 |
0.334 |
MNSI score |
2.5±2.3 |
2.7±2.0 |
3.4±2.6 |
0.057 |
Abnormal NCS |
49 (58.3) |
39 (62.9) |
45 (80.4)b
|
0.022 |
DPN |
19 (22.6) |
23 (37.1) |
29 (51.8)b
|
0.002 |
PL, ms |
3.9±0.8 |
4.0±0.8 |
4.2±1.0 |
0.070 |
PV, m/sec |
42.4±5.2 |
42.5±6.7 |
39.3±5.6b,c
|
0.009 |
TL, ms |
4.0±0.6 |
4.0±0.7 |
4.3±0.9b,c
|
0.014 |
TV, m/sec |
41.7±4.9 |
41.4±6.1 |
37.8±6.1b,c
|
<0.001 |
Samp, μV |
14.6±8.5 |
12.8±6.3 |
10.9±6.6b
|
0.043 |
SuV, m/sec |
36.6±4.6 |
36.1±5.0 |
34.1±4.2b
|
0.028 |
Table 4Linear regression evaluating the associations between clinical phenotypes and indices of nerve conduction studies in the whole population
|
Summed velocity |
Summed latency |
Sural amplitude |
Sural velocity |
b |
SE b |
β |
b |
SE b |
β |
b |
SE b |
β |
b |
SE b |
β |
Model 1 |
|
|
|
|
|
|
|
|
|
|
|
|
Constant |
842.48 |
11.52 |
|
78.01 |
1.39 |
|
146.31 |
8.64 |
|
365.68 |
5.37 |
|
Hyperesthesia |
−2.16 |
17.67 |
−0.01 |
1.34 |
2.12 |
0.05 |
−17.81 |
13.50 |
−0.11 |
−4.10 |
8.39 |
−0.04 |
Hypoesthesia |
−61.53 |
19.72 |
−0.24b
|
5.92 |
2.37 |
0.20a
|
−37.10 |
14.90 |
−0.21a
|
−24.55 |
9.26 |
−0.22b
|
Model 2 |
|
|
|
|
|
|
|
|
|
|
|
|
Constant |
916.28 |
41.61 |
|
82.99 |
5.07 |
|
216.89 |
29.76 |
|
378.81 |
18.71 |
|
Hyperesthesia |
−4.50 |
17.45 |
−0.02 |
1.30 |
2.13 |
0.05 |
−19.06 |
13.06 |
−0.12 |
−4.97 |
8.21 |
−0.05 |
Hypoesthesia |
−58.37 |
19.49 |
−0.23b
|
5.66 |
2.37 |
0.19a
|
−32.23 |
14.49 |
−0.18a
|
−22.31 |
9.11 |
−0.20a
|
Age, yr |
−0.87 |
0.64 |
−0.10 |
−0.09 |
0.08 |
−0.09 |
−0.95 |
0.47 |
−0.15a
|
−0.19 |
0.29 |
−0.05 |
Duration of diabetes, yr |
−1.98 |
0.91 |
−0.16a
|
0.13 |
0.11 |
0.09 |
−1.73 |
0.71 |
−0.19a
|
−0.79 |
0.45 |
−0.14 |
Female sex |
13.71 |
15.42 |
0.06 |
−2.05 |
1.88 |
−0.08 |
19.92 |
11.49 |
0.13 |
19.16 |
7.22 |
0.20a
|
Table 5Linear regression evaluating the associations between clinical phenotypes and indices of nerve conduction studies in patients with hyperesthesia according to DPN status
|
Summed velocity |
Summed latency |
Sural amplitude |
Sural velocity |
b |
SE b |
β |
b |
SE b |
β |
b |
SE b |
β |
b |
SE b |
β |
Model 1 |
|
|
|
|
|
|
|
|
|
|
|
|
Constant |
897.50 |
19.16 |
|
78.40 |
2.67 |
|
209.95 |
15.99 |
|
390.40 |
8.24 |
|
Hyperesthesia/DPN (−) |
35.61 |
34.40 |
0.13 |
−1.18 |
4.79 |
−0.04 |
−64.06 |
28.71 |
−0.30a
|
24.04 |
14.78 |
0.18 |
Hyperesthesia/DPN (+) |
−120.27 |
26.48 |
−0.56b
|
7.65 |
3.69 |
0.31a
|
−104.55 |
22.62 |
−0.61b
|
−68.30 |
11.65 |
−0.64b
|
Model 2 |
|
|
|
|
|
|
|
|
|
|
|
|
Constant |
853.02 |
66.03 |
|
90.39 |
9.02 |
|
294.66 |
57.93 |
|
427.04 |
28.39 |
|
Hyperesthesia/DPN (−) |
32.48 |
34.76 |
0.12 |
−2.95 |
4.75 |
−0.09 |
−74.33 |
29.25 |
−0.34a
|
20.58 |
14.33 |
0.15 |
Hyperesthesia/DPN (+) |
−124.22 |
27.2 |
−0.58b
|
6.33 |
3.71 |
0.26 |
−107.05 |
23.3 |
−0.63b
|
−67.49 |
11.42 |
−0.63b
|
Age, yr |
0.45 |
1.08 |
0.05 |
−0.23 |
0.15 |
−0.22 |
−1.62 |
0.95 |
−0.22 |
−0.69 |
0.46 |
−0.15 |
Duration of diabetes, yr |
0.14 |
1.81 |
0.01 |
0.43 |
0.25 |
0.25 |
0.85 |
1.53 |
0.07 |
−0.59 |
0.75 |
−0.08 |
Female sex |
46.52 |
25.12 |
0.21 |
−3.84 |
3.43 |
−0.15 |
18.17 |
21.5 |
0.11 |
27.63 |
10.54 |
0.26a
|