Table 1.
Demographics, Clinical and Metabolic Characteristics, Cognitive Assessment Scores, and Olfactory Test Scores of T2DM Patients by DPN Status
| HCs | NDPN | DPN | P value of All | P value of Diabetes | |
|---|---|---|---|---|---|
| n=36 | n=36 | n=28 | |||
| Demographic factors | |||||
| Age (years) | 52.0±8.1 | 53.1±8.1 | 53.9±8.3 | 0.632 | 0.684 |
| Sex (male, n, %) # | 17, 47 | 19, 53 | 16, 57 | 0.728 | 0.803 |
| Education (years) | 12.3±3.2 | 11.6±2.5 | 12.0±3.0 | 0.580 | 0.592 |
| Alcohol consumption (%)# | 9, 25 | 10, 28 | 8, 29 | 0.942 | 1.000 |
| Smoking habits (%)# | 12, 33 | 14, 38 | 11, 39 | 0.752 | 1.000 |
| Diabetes-related characteristics | |||||
| Duration of diabetes (years) | - | 9.8±6.3 | 11.5±6.7 | - | 0.287 |
| HbA1c (%) | 5.6±0.1 | 8.3±1.7a | 9.2±1.9bc | 0.000 | 0.042 |
| Fasting glucose (mmol/L) | 5.0±0.4 | 8.3±2.6a | 7.8±2.5b | 0.027 | 0.424 |
| 2h postprandial glucose (mmol/L) | 6.6±1.5 | 14.5±4.9a | 13.9±5.2b | 0.005 | 0.647 |
| Fasting insulin (mIU/mL) | 7.0±2.1 | 11.8±8.6 | 11.2±18.8 | 0.773 | 0.877 |
| 2h postprandial insulin (mIU/mL) | 62.6±35.4 | 37.6±35.8 | 37.1±78.8 | 0.705 | 0.973 |
| Fasting C-peptide (pmol/L) | 630.6±167.1 | 754.1±424.2 | 576.8±376.5 | 0.209 | 0.081 |
| 2h postprandial C-peptide (pmol/L) | 2933.6±1651.3 | 1748.2±901.3 | 1287.1±1388.4b | 0.044 | 0.123 |
| Clinical variables | |||||
| BMI (kg/m2) | 23.9±2.7 | 26.2±3.7a | 25.1±3.6 | 0.025 | 0.208 |
| Waist (cm) | 84.1±6.8 | 92.8±9.4a | 90.8±11.7b | 0.001 | 0.406 |
| WHR | 0.8±0.1 | 0.9±0.1a | 0.9±0.1b | 0.000 | 0.260 |
| Systolic Blood Pressure (mmHg) | 123.3±16.6 | 134.2±15.5a | 129.2±15.8 | 0.020 | 0.220 |
| Diastolic Blood Pressure (mmHg) | 79.3±14.5 | 82.1±10.6 | 80.3±12.9 | 0.645 | 0.564 |
| Triglycerides (mmol/L) | 1.5±0.5 | 1.9±0.9 | 1.9±1.2 | 0.308 | 0.963 |
| Total cholesterol (mmol/L) | 4.8±0.8 | 4.7±1.3 | 4.8±0.9 | 0.710 | 0.501 |
| HDL cholesterol (mmol/L) | 1.2±0.4 | 1.1±0.3a | 1.2±0.4 | 0.075 | 0.073 |
| LDL cholesterol (mmol/L) | 2.7±0.7 | 2.9±1.2 | 2.9±0.8 | 0.964 | 0.951 |
| Neuropathy parameters | |||||
| MCV | |||||
| Median nerve | 57.6±2.6 | 55.6±3.5 | 50.6±6.3 bc | 0.000 | 0.000 |
| Ulnar nerve | 62.8±4.4 | 57.4±3.2 | 52.8±5.7bc | 0.000 | 0.000 |
| Common peroneal nerve | 46.3±3.3 | 45.3±2.8 | 39.6±6.7 bc | 0.000 | 0.000 |
| Tibial nerve | 47.3±3.1 | 45.1±2.4 | 39.5±6.0 bc | 0.000 | 0.000 |
| SCV | |||||
| Median nerve | 51.8±6.0 | 50.4±10.7 | 46.5±6.3 bc | 0.146 | 0.000 |
| Ulnar nerve | 57.2±3.1 | 55.5±5.2 | 52.4±4.4 bc | 0.000 | 0.000 |
| Sural nerve | 49.8±3.7 | 47.8±3.1 | 42.2±5.4 bc | 0.000 | 0.000 |
| Cognitive assessment | |||||
| MoCA < 26 (n, %)# | 1, 2.8 | 11, 30.6 a | 8, 28.6 b | 0.005 | 1.000 |
| MMSE | 29.2±0.8 | 28.9±1.2 | 28.4±1.5b | 0.032 | 0.109 |
| MoCA | 28.0±1.6 | 26.5±2.0a | 26.2±2.1b | 0.000 | 0.505 |
| Memory | 206.9±22.6 | 155.2±15.2a | 142.±20.0bc | 0.000 | 0.042 |
| AVLT-immediate recall | 59.8±7.7 | 39.4±6.1 | 35.4±7.3 | 0.159 | 0.257 |
| AVLT-delayed recall (30 min) | 17.1±3.1 | 17.2±4.3 | 15.2±4.1b | 0.081 | 0.043 |
| AVLT-recognition | 57.4±1.9 | 57.4±2.4 | 56.8±2.8 | 0.429 | 0.278 |
| WASI-immediate recall | 19.3±5.8 | 17.8±4.5 | 15.8±5.0b | 0.029 | 0.126 |
| WASI -delayed recall (30 min) | 15.5±6.5 | 14.6±4.6 | 13.1±5.0b | 0.217 | 0.284 |
| WASI –recognition | 9.6±1.6 | 8.8±1.9a | 8.8±1.8 | 0.068 | 0.911 |
| Working memory | 14.2±1.9 | 13.1±1.8a | 13.1±2.4b | 0.035 | 0.967 |
| DST-forward | 8.5±0.6 | 8.3±0.9 | 8.1±0.9b | 0.063 | 0.562 |
| DST-backward | 5.7±1.8 | 4.8±1.2a | 5.0±1.8 | 0.072 | 0.731 |
| Visual attention and task switching (processing speed) | 20.7±4.3 | 102.3±37.9a | 134.2±69.2bc | 0.000 | 0.004 |
| TMT-A | 11.6±5.3 | 13.9±6.4 | 18.±10.1bc | 0.003 | 0.030 |
| TMT-B | 87.7±35.9 | 88.4±33.2 | 116.2±61.6bc | 0.019 | 0.014 |
| Word fluency and retrieval performance | |||||
| ANT | 20.8±4.5 | 18.5±4.8a | 19.2±3.7 | 0.090 | 0.537 |
| BNT | 57.3±3.5 | 56.6±2.6 | 55.9±4.1 | 0.264 | 0.395 |
| Executive functions (time) | 66.7±20.1 | 79.5±20.4a | 86.6±22.8b | 0.041 | 0.056 |
| SCWT-color | 17.4±5.1 | 19.2±7.8 | 22.0±6.2b | 0.023 | 0.085 |
| SCWT-word | 20.2±7.8 | 18.9±7.4 | 24.1±10.0bc | 0.013 | 0.005 |
| SCWT-color word | 29.0±9.0 | 38.4±13.2a | 43.4±13.6 | 0.016 | 0.187 |
| Olfactory test | |||||
| Total score | 50.2±5.4 | 47.2±8.7 | 43.5±6.0bc | 0.001 | 0.036 |
| Olfactory threshold | 10.6±2.5 | 8.6±3.1a | 8.4±3.0b | 0.004 | 0.859 |
| Odor identification test | 24.1±2.3 | 23.6±4.3 | 21.4±3.3bc | 0.008 | 0.013 |
| Task A (10 odors) | 8.6±1.1 | 8.1±1.5 | 7.6±1.7b | 0.040 | 0.177 |
| Task B (20 odors) | 15.5±1.8 | 15.5±3.1 | 13.8±2.1bc | 0.011 | 0.007 |
| Odor memory test | 15.6±2.2 | 15.0±3.1 | 13.6±2.6bc | 0.015 | 0.041 |
| Old 10 odors | 8.0±1.6 | 7.7±1.6 | 6.8±1.8bc | 0.011 | 0.029 |
| New 10 odors | 7.6±1.6 | 7.3±2.1 | 6.9±2.0 | 0.348 | 0.349 |
Notes: Data are mean ± standard deviation. Independent samples t-test between two groups. #Pearson chi-square analysis for dichotomous variables. aIndicates P <0.05 between NDPN compared with HCs; bindicates P <0.05 between DPN compared with HCs and cindicates P <0.05 between DPN compared with NDPN.
Abbreviations: HbA1c, glycated hemoglobin; BMI, body mass index; WHR, waist-hip ratio; MMSE, Mini-Mental State Examination; MoCA, Montreal Cognitive Assessment. ANT, Animal Naming Test; AVLT, Auditory Verbal Learning Test; BNT, Boston Naming Test; DST, Digit Span Task; SCWT, Stroop Color and Word Test; TMT, Trail Making Test; WASI, Wechsler Abbreviated Scale of Intelligence.