Table 4.
Risk factors for sleep apnea and RLS among RA patients
| Variable | Sleep Apnea (Berlin Score) |
P-value | RLS (IRLSSG criteria) |
P-Value | ||
|---|---|---|---|---|---|---|
| High risk | Low risk | Yes | No | |||
| Age, years (mean±SD) | 53 (12) | 46 (15) | 0.016 | 48 (14) | 49 (16) | 0.896 |
| Gender | ||||||
| Female | 35 (37) | 60 (63) | 0.873 | 60 (63) | 35 (37) | 0.873 |
| Male | 2 (40) | 3 (60) | 3 (60) | 2 (40) | ||
| BMI (mean±SD, kg/m2) | 34 (9) | 30 (11) | 0.135 | 32 (11) | 32 (9) | 0.694 |
| BMI Classification | ||||||
| Underweight/normal | 2 (10) | 18 (90) | 0.022 | 13 (65) | 7 (35) | 0.611 |
| Overweight | 12 (44) | 15 (56) | 19 (70) | 8 (30) | ||
| Obese | 23 (43) | 30 (57) | 31 (58) | 22 (42) | ||
| Hemoglobin (g/dL) | 12 (2) | 14 (14) | 0.442 | 14 (14) | 12 (1) | 0.497 |
| Serum ferritin (μg/L) | 34 (24) | 40 (48) | 0.451 | 31 (24) | 50 (58) | 0.022 |
| Iron (μmol/L) | 11 (6) | 13 (18) | 0.466 | 13 (18) | 11 (7) | 0.632 |
| TSH (U/mL) | 2 (1) | 4 (7) | 0.216 | 2 (2) | 5 (8) | 0.520 |
| Any comorbidity | 22 (56) | 17 (44) | 0.001 | 21 (54) | 18 (46) | 0.115 |
| Hypertension | 19 (76) | 6 (24) | 0.000 | 15 (60) | 10 (40) | 0.720 |
| Diabetes | 14 (67) | 7 (33) | 0.001 | 10 (48) | 11 (52) | 0.100 |
| Stroke | 1 (50) | 1 (50) | 0.662 | 2 (100) | 0 (0) | 0.270 |
| Ischemic heart disease | 0 (0) | 3 (100) | 0.193 | 2 (67) | 1 (33) | 0.883 |
| GERD | 0 (0) | 7 (100) | 0.042 | 3 (43) | 4 (57) | 0.262 |
| COPD | 0 (0) | 1 (100) | 0.457 | 1 (100) | 0 (0) | 0.437 |
Notes: Bold values indicate statistical significance. Abbreviations: RA, rheumatoid arthritis; TSH, thyroid stimulating hormone; GERD, gastroesophageal reflux disease; IRLSSG, International Restless Leg Syndrome Study Group.