Table 2.
Demographics, clinical characteristics, and outcomes at baseline, and 12 weeks minus baseline
| Variable | Placebo (n=90) | 0.1% Clonidine (n=89) | p-value |
|---|---|---|---|
| Baseline (BL) | Baseline (BL) | ||
| Age (in years), mean (SD) | 57.6 (9.5) | 59.4 (9.9) | 0.22 |
| Sex, n (%) | |||
| Female | 48 (53) | 45 (51) | 0.77 |
| Male | 42 (47) | 44 (49) | |
| Race, n (%) | |||
| Non-Hispanic white | 46 (51) | 56 (63) | 0.19 |
| Hispanic | 17 (19) | 7 (8) | |
| African descent | 24 (27) | 24 (27) | |
| Other | 3 (3) | 2 (2) | |
| Type of diabetes mellitus, n (%) | |||
| Type 1 | 4 (4) | 5 (6) | 0.56 |
| Type 1.5 | 0 (0) | 1 (1) | |
| Type 2 | 86 (96) | 83 (93) | |
| Duration of diabetes (in years), mean (SD) | 9.6 (7.8) | 10.7 (8.0) | 0.35 |
| Duration of foot pain (in years), mean (SD) | 2.9 (1.3) | 3.0 (1.3) | 0.55 |
| Nerve fiber density (in fibers/mm), mean (SD); (n) | 3.2 (3.5); (44) | 2.3 (2.6); (53) | 0.14 |
| Concomitant medications (%) | 48 | 39 | 0.25 |
| Capsaicin pain rating, mean (SD) (at Screening; 0-10 NPRS, average of right and left foot) | 1.8 (2.7) | 1.8 (2.4) | 0.97 |
| Baseline (BL) | Change (12 week minus BL) | Baseline (BL) | Change (12 week minus BL) | ||
|---|---|---|---|---|---|
| Average pain severity from diary, daily mean (SD, 0-10 NPRS) | 6.4 (1.4) | -1.7 (1.9) | 6.5 (1.5) | -2.3 (2.2) | 0.07§ |
| Experienced >30% reduction in pain, n (%) | 36 (40.0) | 43 (48.3) | 0.34 | ||
| Experienced >50% reduction in pain, n (%) | 26 (28.9) | 31 (34.8) | 0.49 | ||
| HbA1c, mean (SD) | 7.5 (1.6) | 0.1 (0.7) | 7.4 (1.6) | 0.03 (0.6) | 0.47§ |
| BPI - Severity Scale, sum (SD) | 25.3 (5.8) | -6.0 (8.2) | 25.4 (6.4) | -7.7 (8.9) | 0.23§ |
| BPI – Average pain, mean (SD) | 6.3 (1.4) | -1.6 (1.9) | 6.5 (1.5) | -2.2 (2.2) | 0.06§ |
| BPI - Functional Interference Scale, sum (SD) | 38.8 (15.1) | -11.8 (14.9) | 36.4 (16.9) | -13.5 (17.2) | 0.53§ |
| CPSI - Overall sleep quality, mean (SD); (increase = improvement) | 37.9 (23.4) | 15.9 (32.1) | 39.7 (24.7) | 18.1 (30.7) | 0.40§ |
| HADS – Anxiety Scale, sum (SD) | 7.0 (4.1) | -0.5 (2.5) | 6.2 (4.1) | -0.7 (3.0) | 0.30§ |
| HADS – Depression Scale, sum (SD) | 5.9 (4.1) | -0.4 (2.4) | 5.0 (3.7) | -0.8 (2.1) | 0.11§ |
Concomitant medications included anticonvulsants, antidepressants, and opioids; 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.