Clinical Phenotype of Diabetic Peripheral Neuropathy and Relation to Symptom Patterns: Cluster and Factor Analysis in Patients with Type 2 Diabetes in Korea
Table 1
Comparison of the demographic and clinical characteristics and the clinical impacts of diabetic peripheral neuropathy on pain, sleep, and quality of life in three clustered groups in the entire patients ().
Variable
Cluster 1 ()
Cluster 2 ()
Cluster 3 ()
value
Age, years
61.7 ± 9.9
62.6 ± 11.5
62.7 ± 10.5
0.3058
Female, n (%)
202 (45.1) ∫,¶
345 (61.4)
198 (60.4)
<0.001
Diabetes treatment, n (%)
<0.001
Diet and exercise
14 (3.1)∫,¶
4 (0.7)¶
6 (1.8)
OHA
297 (66.3) ∫,¶
321 (57.1)¶
143 (43.6)
Insulin
40 (8.9)∫,¶
76 (13.5)¶
70 (21.3)
Insulin and OHA
97 (21.7)∫,¶
161 (28.7)¶
109 (33.2)
BMI, kg/m2
24.9 ± 3.4
24.9 ± 3.5¶
25.5 ± 4.1
0.0394
FPG, mg/dL
137.8 ± 44.3∫,¶
141.9 ± 54.3¶
153.0 ± 71.1
0.0048
HbA1c, %
7.5 ± 1.3∫,¶
7.8 ± 1.6¶
8.2 ± 4.0
0.002
HbA1c, mmol/mol
58.6 ± 14.6∫,¶
61.3 ± 17.6¶
65.6 ± 43.5
0.002
Hypertension
276 (61.6)
383 (68.15)
220 (67.1)
0.0781
Dyslipidemia
242 (54.0)
301 (53.6)
161 (49.1)
0.334
Obesity
29 (6.5)
33 (5.9)
18 (5.5)
0.8408
Diabetic retinopathy, n (%)
122 (27.2)∫,¶
178 (31.7)¶
125 (38.1)
0.0057
Diabetic nephropathy
83 (18.5)∫,¶
133 (23.7)¶
85 (25.9)
0.0353
MNSI score
1.6 ± 1.2∫,¶
3.1 ± 1.7¶
5.4 ± 2.1
<0.001
Pain severity items
Worst
0.39 ± 1.01∫,¶
3.20 ± 2.99¶
7.04 ± 2.41
<0.001
Weakest
0.03 ± 0.20∫,¶
0.60 ± 1.03¶
2.37 ± 2.10
<0.001
Average
0.14 ± 0.46∫,¶
1.76 ± 1.78¶
4.63 ± 2.08
<0.001
Pain interference items
General activity
0.10 ± 0.47∫,¶
1.23 ± 2.19¶
4.96 ± 3.24
<0.001
Mood
0.21 ± 0.91∫,¶
1.82 ± 2.53¶
5.63 ± 3.10
<0.001
Walking
0.09 ± 0.51∫,¶
1.06 ± 2.16¶
4.82 ± 3.29
<0.001
Normal work
0.08 ± 0.56∫,¶
1.10 ± 2.13¶
4.73 ± 3.35
<0.001
Relationship
0.04 ± 0.31∫,¶
0.54 ± 1.45¶
3.07 ± 3.38
<0.001
Sleep
0.13 ± 0.60∫,¶
1.52 ± 2.57¶
4.22 ± 3.59
<0.001
Enjoyment of life
0.08 ± 0.42∫,¶
1.01 ± 2.09¶
3.99 ± 3.53
<0.001
Pain interference index
0.6 ± 1.5∫,¶
6.3 ± 6.0¶
17.3 ± 7.3
<0.001
MOS-SS†
Sleep quantity
5.08 ± 1.26∫,¶
3.54 ± 1.76
3.67 ± 1.88
<0.001
Respiratory problem during sleep
5.96 ± 0.23∫,¶
5.67 ± 0.83
5.39 ± 1.23
<0.001
Sleep initiation problem
5.46 ± 1.10∫,¶
3.95 ± 1.94
4.00 ± 1.94
<0.001
Sleep maintenance problem
5.41 ± 1.12∫,¶
3.92 ± 1.81
4.05 ± 1.85
<0.001
Somnolence
5.77 ± 0.64∫,¶
5.09 ± 1.32
4.92 ± 1.40
<0.001
Sleep adequacy
5.29 ± 1.17∫,¶
3.84 ± 1.79
4.00 ± 1.83
<0.001
Sleep problem index
33.0 ± 3.1∫,¶
26.0 ± 6.3
26.0 ± 7.2
EQ-5D§
Mobility
1.07 ± 0.25¶
1.26 ± 0.45¶
1.80 ± 0.50
<0.001
Self-care
1.01 ± 0.13¶
1.09 ± 0.30¶
1.33 ± 0.54
<0.001
Usual activity
1.03 ± 0.17¶
1.21 ± 0.43¶
1.76 ± 0.55
<0.001
Pain discomfort
1.08 ± 0.29¶
1.51 ± 0.53¶
2.17 ± 0.51
<0.001
Anxiety/depression
1.11 ± 0.31¶
1.40 ± 0.51¶
1.79 ± 0.67
<0.001
EQ-5D index§
5.3 ± 0.7¶
6.5 ± 1.4¶
8.8 ± 1.8
<0.001
EQ-5D VAS‡
81.8 ± 9.6∫,¶
65.9 ± 16.1¶
51.4 ± 19.3
<0.001
Medications for DPN
None
164 (36.6)
191 (34.0)
111 (33.8)
0.625
Antidepressants
30 (6.7)∫,¶
68 (12.1)¶
33 (10.1)
0.016
Anticonvulsants
47 (10.5)∫,¶
81 (14.4)¶
72 (22.0)
<0.001
α-Lipoic acid
107 (23.9)∫,¶
116 (20.6)
54 (16.5)
0.042
γ-Linoleic acid
34 (7.6)
33 (5.9)
27 (8.2)
0.351
Others
83 (18.5)
102 (18.2)
54 (16.5)
0.739
Data are expressed as means ± SD for continuous variables and frequency (%) for categorical variables. Items were derived from the BPI-SF. A 0–10 numeric rating scale was anchored at 0 for “no pain” and 10 for “pain as bad as you can imagine.” †Item response on a 6-point scale ranging from 1 for “all of the time” to 6 for “none of the time;” dimensions of sleep quantity, “get the amount of sleep you needed;” and sleep adequacy, “get enough sleep to feel rested upon waking in the morning” were calculated backwards. §Items were from three levels indicating “no problem” (or 1), “some problems” (or 2), and “severe problems” (or 3), and EQ-5D index was the sum of scores of 5 dimensions. ‡Values from 0 to 100, where 0 represents the worst imaginable health state and 100 represents the best imaginable health state. ∫ versus ≤cluster 2 and ¶ versus cluster 3. OHA: oral hypoglycemic agent(s); BMI: body mass index; FPG: fasting plasma glucose; MNSI: Michigan Neuropathy Screening Instrument questionnaire; MOS-SS: medical outcomes study sleep scale; EQ-5D: EuroQol, 5-dimensions; VAS: visual analog scale.
