Table 1. Demographics and clinical characteristics of the included patients with chronic exposure to HCQ.
| Parameters | All patients | HCQ retinopathy | No HCQ retinopathy | P value* |
|---|---|---|---|---|
| No. of subjects | 310 | 9 | 301 | NA |
| No. of patients whose duration ≥ 5 yr | 175 (31.3) | 9 (100.0) | 166 (55.1) | NA |
| Age, yr | 44.5 ± 12.4 | 48.7 ± 15.3 | 44.4 ± 12.4 | 0.308 |
| Female | 286 (92.3) | 8 (88.9) | 278 (92.4) | 0.701 |
| Body weight, kg | 56.2 ± 8.5 | 53.0 ± 7.8 | 56.3 ± 8.5 | 0.251 |
| BMI, kg/m2 | 22.3 ± 3.1 | 21.6 ± 3.2 | 22.3 ± 3.1 | 0.527 |
| Duration of use, mon | 71.7 ± 40.4 (range, 2–174) | 108.9 ± 31.9 (range, 76–174) | 70.5 ± 40.1 (range, 2–160) | 0.005 |
| Cumulative dose, g | 625.5 ± 376.2 (range, 24–2,088) | 952.0 ± 519.2 (range, 558–2,088) | 615.1 ± 368.1 (range, 24–1,680) | 0.008 |
| Daily dose, mg | 302.9 ± 83.3 | 284.1 ± 96.3 | 303.3 ± 83.1 | 0.495 |
| Daily dose per real body weight, mg/kg | 5.5 ± 1.8 | 5.6 ± 2.6 | 5.5 ± 1.7 | 0.84 |
| No. of patients whose cumulative dose ≥ 1,000 g | 44 (14.2) | 2 (22.2) | 42 (14.0) | 0.485 |
| No. of patients whose daily dose ≥ 6.5 mg/kg real body weight | 103 (33.2) | 3 (33.3) | 100 (33.2) | 0.841 |
| Diagnosis of patients† | ||||
| SLE | 224 (72.3) | 5 (55.6) | 219 (72.6) | NA |
| Sjögren syndrome | 45 (14.5) | 1 (11.1) | 44 (14.6) | NA |
| RA | 32 (10.3) | 3 (33.3) | 29 (9.6) | NA |
| APLS | 10 (3.2) | 1 (11.1) | 9 (3.0) | NA |
| Others | 13 (4.2) | 0 (0) | 13 (4.3)‡ | NA |
| Systemic disease | ||||
| Kidney dysfunction | 10 (3.2) | 0 (0) | 10 (3.3) | NA |
| Liver dysfunction | 0 (0) | 0 (0) | 0 (0) | NA |
Data are shown as mean ± SD or number (%).
HCQ = hydroxychloroquine, BMI = body mass index, SLE = systemic lupus erythematosus, RA = rheumatoid arthritis, APLS = antiphospholipid antibody syndrome, NA = not applicable, SD = standard deviation.
*Mann-Whitney U test, which compared the 2 patient groups, “HCQ retinopathy” and “No HCQ retinopathy” group. †Fourteen patients were diagnosed with more than 1 disease. ‡Twelve patients were diagnosed with mixed connective tissue disease and one of them had vasculitis.