Table 3.
Demographics and outcomes (change from baseline (12 weeks minus baseline)) for capsaicin responders (capsaicin pain rated ≥2; 0-10 NPRS)
| Variable | Placebo (n=30) | 0.1% Clonidine (n=33) | p-value | ||
|---|---|---|---|---|---|
| Baseline (BL) | Δ from BL to 12 week visit | Baseline (BL) | Δ from BL to 12 week visit | ||
| Duration of diabetes (in years), mean (SD), | 8.8 (5.9) | 12.2 (9.3) | 0.10 | ||
| Duration of foot pain (in years), mean (SD) | 2.7 (1.3) | 2.8 (1.2) | 0.57 | ||
| Nerve fiber density (in fiber/mm), mean (SD); (n) | 4.3 (4.2); (18) | 2.9 (3.0); (24) | 0.20 | ||
| Capsaicin pain rating, mean (SD) NPRS | 5.2 (2.0) | 4.5 (2.0) | 0.20 | ||
| Average pain severity from diary, mean (SD) NPRS | 6.3 (1.4) | -1.4 (1.8) | 6.3 (1.5) | -2.6 (2.0) | 0.01§ |
| HbA1c, mean (SD) | 7.3 (1.5) | 0.26 (0.6) | 7.4 (1.8) | 0.0 (0.6) | 0.17§ |
| BPI – Severity scale, sum (SD) | 25.4 (5.8) | -5.3 (7.8) | 25.1 (7.3) | -7.8 (7.2) | 0.18§ |
| BPI – Average pain, mean (SD) | 6.3 (1.5) | -1.3 (1.7) | 6.5 (1.6) | -2.2 (1.9) | 0.06§ |
| BPI-Functional Interference Scale, sum (SD) | 37.2 (17.1) | -8.7 (13.2) | 37.1 (17.5) | -13.0 (15.2) | 0.43§ |
| CPSI -Overall sleep quality, mean (SD); (increase = improvement) | 37.7 (26.9) | 4.4 (32.7) | 44.5 (21.5) | 13.4 (30.4) | 0.03§ |
| HADS – Anxiety Scale, sum (SD) | 7.8 (4.5) | -0.2 (2.2) | 6.4 (4.4) | -0.6 (2.7) | 0.30§ |
| HADS – Depression Scale, sum (SD) | 6.1 (4.5) | -0.8 (2.1) | 4.8 (3.5) | -0.4 (1.8) | 0.60§ |
Brief Pain Inventory (BPI; Severity range 0-40, Average pain range 0-10, Functional Interference range 0-70); Chronic Pain Sleep Inventory (CPSI, range 0-100); Hospital Anxiety and Depression Scale (HADS Anxiety range 0-21, Depression range 0-21; <8 is normal, threshold for moderate is 11).
§
p-values represent analyses of differences from week 12 to baseline in the active compared to placebo group; no changes were observed at baseline between groups.