Table 1. Comparison of clinical characteristics and neurological functions between two diabetic groups divided based on GPx‐1 genotype (n = 173).
| Pro/Leu type | Pro/Pro type | P‐value | |
|---|---|---|---|
| n | 24 | 149 | |
| Clinical characteristics | |||
| Age (year) | 55.6 ± 13.0 | 54.9 ± 10.3 | 0.8503 |
| Gender (Male/Female) | 13/11 | 85/64 | 0.7916 |
| Duration of diabetes (years) | 12.9 ± 7.8 | 11.3 ± 7.7 | 0.3433 |
| Therapy (insulin/OHA/diet and exercise) | 1/5/18 (4.2/20.8/75.0) | 6/42/101 (4.0/28.2/67.8) | 0.7524 |
| BMI (kg/m2) | 23.1 ± 4.2 | 23.9 ± 3.9 | 0.3163 |
| Hypertension | 10/24 (41.7) | 67/149 (45.0) | 0.7627 |
| Dyslipidemia | 10/24 (41.7) | 72/149 (48.3) | 0.5445 |
| HbA1c (%) | 9.83 ± 2.22 | 9.11 ± 2.06 | 0.1134 |
| Proteinuria (no/intermittent/persistent) | 16/4/4 (66.6/16.7/16.7) | 102/19/28 (68.5/12.7/18.8) | 0.8614 |
| Retinopathy (no/simple/pre‐, proliferative) | 10/4/10 (41.7/16.6/41.7) | 78/22/49 (52.4/14.7/32.9) | 0.6124 |
| History of macrovascular disease (MVD) | 5/24 (20.8) | 12/149 (8.1) | 0.0510 |
| Subjective symptoms and Achilles tendon reflex (ATR) | |||
| Numbness in toes and soles | 9/24 (37.5) | 52/149 (34.9) | 0.8045 |
| Pain in feet | 3/24 (12.5) | 16/149 (10.7) | 0.7978 |
| Painful leg cramp | 14/24 (58.3) | 36/149 (24.2) | 0.0006 |
| Orthostatic dizziness | 4/24 (16.7) | 27/149 (18.4) | 0.8411 |
| Frequent constipation/diarrhea | 1/24 (4.2) | 13/149 (8.7) | 0.4429 |
| Diminished ATRs | 19/24 (79.2) | 94/149 (64.8) | 0.1669 |
| Subtypes of diabetic neuropathy and quantitative nerve functions | |||
| DSPN (Distal symmetric polyneuropathy) | 17/24 (70.8) | 62/149 (41.6) | 0.0076 |
| DAN (diabetic autonomic neuropathy) | 3/24 (12.5) | 22/149 (14.8) | 0.7696 |
| QVP (dB) | 26.0 ± 7.2 | 20.4 ± 10.3 | 0.0114 |
| Prevalence of impaired QVP | 17/24 (70.8) | 56/149 (37.6) | 0.0022 |
| CVR‐R (%) | 1.98 ± 0.92 | 1.96 ± 1.06 | 0.9591 |
| Prevalence of impaired CVR‐R | 13/24 (56.5) | 68/149 (46.9) | 0.3908 |
| ΔBP (mmHg) | 7.79 ± 12.49 | 11.02 ± 14.51 | 0.3057 |
| Orthostatic hypotension | 4/24 (16.7) | 35/149 (23.5) | 0.4579 |
| MCV (m/s) | 50.9 ± 3.9 | 50.4 ± 6.8 | 0.7506 |
| Prevalence of impaired MCV | 5/24 (20.8) | 50/149 (33.6) | 0.2141 |
| CMAP (mV) | 7.12 ± 3.36 | 7.10 ± 2.74 | 0.9734 |
| Prevalence of impaired CMAP | 5/24 (20.8) | 16/149 (10.7) | 0.1599 |
| SCV (m/s) | 56.4 ± 5.2 | 57.3 ± 5.9 | 0.5187 |
| Prevalence of impaired SCV | 10/24 (41.7) | 58/149 (38.9) | 0.7987 |
| SNAP (μV) | 18.4 ± 14.9 | 21.1 ± 14.3 | 0.3993 |
| Prevalence of impaired SNAP | 8/24 (33.3) | 39/149 (26.2) | 0.4644 |
Numbers in parenthesis indicate the percentage. OHA, oral hypoglycemic agents; BMI, body mass index; ATR, Achilles tendon reflex; QVP, quantitative vibratory perception thresholds; CVR‐R, correlation coefficient of R‐R intervals in electrocardiogram; BP, blood pressure; CMAP, compound muscle action potential; SCV, sensory nerve conduction velocity; SNAP, sensory nerve action potential; Pro/Leu type, genotype with Pro/Leu at the codon 198 of glutathione peroxidase 1 gene; Pro/Pro type, genotype with Pro/Pro at the codon 198 of glutathione peroxidase 1 gene. The value for HbA1c (%) was estimated as an NGSP equivalent value (%) calculated by the formula HbA1c (%) = HbA1c (JDS) (%) + 0.4%. Statistically significant P‐value was shown by boldfaced type.