Clinical Phenotype of Diabetic Peripheral Neuropathy and Relation to Symptom Patterns: Cluster and Factor Analysis in Patients with Type 2 Diabetes in Korea
Table 2
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 already diagnosed patients ().
Variable
Cluster 1 ()
Cluster 2 ()
Cluster 3 ()
value
Age, years
61.2 ± 10.7
62.7 ± 10.9
60.3 ± 11.2
0.030
Female, n (%)
267 (49.3)
245 (60.2)
79 (63.7)
<0.001
Diabetes treatment, n (%)
<0.001
Diet and exercise
12 (2.2)
4 (1.0)
0 (0.0)
OHA
347 (64.0)
203 (49.9)
49 (39.5)
Insulin
54 (10.0)
67 (16.5)
26 (21.0)
Insulin and OHA
129 (23.8)
133 (32.7)
49 (39.5)
BMI, kg/m2
24.8 ± 3.4
25.0 ± 3.7
25.5 ± 3.8
0.165
FPG, mg/dL
141.6 ± 49.8
141.7 ± 52.0
164.2 ± 89.6
0.001
HbA1c, %
7.6 ± 1.5
7.7 ± 1.5
8.3 ± 2.1
<0.001
HbA1c, mmol/mol
60.0 ± 16.6
60.5 ± 16.4
67.0 ± 22.5
<0.001
Hypertension
339 (62.6)
277 (68.1)
87 (70.2)
0.107
Dyslipidemia
294 (54.2)
217 (53.3)
61 (49.2)
0.596
Obesity
42 (7.8)
19 (4.7)
12 (9.7)
0.070
Diabetic retinopathy, n (%)
162 (29.9)
155 (38.1)
55 (44.4)
0.002
Diabetic nephropathy
109 (20.1)
112 (27.5)
33 (26.6)
0.021
MNSI score
1.8 ± 1.6
3.6 ± 1.9
5.8 ± 2.4
<0.001
Pain severity items
Worst
0.6 ± 1.4
4.9 ± 2.8
7.8 ± 1.9
<0.001
Weakest
0.1 ± 0.3
1.2 ± 1.6
2.8 ± 2.1
<0.001
Average
0.3 ± 0.7
2.8 ± 1.9
5.4 ± 1.8
<0.001
Pain interference items
General activity
0.2 ± 0.7
2.2 ± 2.8
6.2 ± 2.8
<0.001
Mood
0.3 ± 1.1
3.0 ± 3.0
7.0 ± 2.2
<0.001
Walking
0.1 ± 0.7
2.1 ± 2.9
5.7 ± 3.1
<0.001
Normal work
0.1 ± 0.7
2.0 ± 2.8
6.0 ± 3.0
<0.001
Relationship
0.1 ± 0.5
1.0 ± 2.1
4.2 ± 3.4
<0.001
Sleep
0.2 ± 0.9
2.2 ± 3.0
5.9 ± 3.3
<0.001
Enjoyment of life
0.1 ± 0.6
1.7 ± 2.6
5.4 ± 3.3
<0.001
Pain interference index
0.9 ± 2.3
10.4 ± 6.5
20.4 ± 6.2
<0.001
MOS-SS†
Sleep quantity
4.8 ± 1.5
3.7 ± 1.8
2.5 ± 1.5
<0.001
Respiratory problem during sleep
5.9 ± 0.4
5.7 ± 0.8
5.0 ± 1.5
<0.001
Sleep initiation problem
5.2 ± 1.4
4.1 ± 1.9
3.1 ± 1.8
<0.001
Sleep maintenance problem
5.1 ± 1.4
4.1 ± 1.8
3.3 ± 1.8
<0.001
Somnolence
5.7 ± 0.8
5.1 ± 1.3
4.5 ± 1.5
<0.001
Sleep adequacy
5.0 ± 1.4
4.0 ± 1.8
3.0 ± 1.8
<0.001
Sleep problem index
31.7 ± 4.6
26.6 ± 6.2
21.4 ± 6.2
<0.001
EQ-5D§
Mobility
1.1 ± 0.3
1.4 ± 0.5
1.9 ± 0.5
<0.001
Self-care
1.0 ± 0.1
1.1 ± 0.4
1.4 ± 0.5
<0.001
Usual activity
1.0 ± 0.2
1.3 ± 0.5
2.0 ± 0.5
<0.001
Pain discomfort
1.1 ± 0.3
1.7 ± 0.5
2.4 ± 0.5
<0.001
Anxiety/depression
1.2 ± 0.4
1.4 ± 0.6
2.1 ± 0.7
<0.001
EQ-5D index§
5.4 ± 0.8
7.0 ± 1.5
9.7 ± 1.5
<0.001
EQ-5D VAS‡
77.9 ± 12.8
64.0 ± 16.1
44.2 ± 19.0
<0.001
Medications for DPN
None
142 (26.2)
79 (19.4)
21 (16.9)
0.013
Antidepressants
50 (9.2)
60 (14.7)
17 (13.7)
0.027
Anticonvulsants
67 (12.4)
99 (24.3)
31 (25.0)
<0.001
α-Lipoic acid
148 (27.3)
91 (22.4)
27 (21.8)
0.154
γ-Linoleic acid
47 (8.7)
29 (7.1)
14 (11.3)
0.323
Others
113 (20.9)
80 (19.7)
26 (21.0)
0.891
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. 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.
