Table 1. Characteristics of the study participants.
| Characteristics | PM and DM (n=60) | Healthy controls (n=65) | P value* | Acute stage (n=21) | Chronic stage (n=39) | P value* |
|---|---|---|---|---|---|---|
| Female/male | 39/21 | 44/21 | 0.750 | 12/9 | 27/12 | 0.349 |
| Age (year) | 44.25±12.51 | 43.80±11.64 | 0.835 | 48.33±10.66 | 42.05±13.00 | 0.063 |
| BMI (kg/m2) | 21.18±2.76 | 21.82±2.03 | 0.146 | 21.04±2.34 | 21.26±2.99 | 0.763 |
| Disease duration (months) | 9 (5, 15) | – | – | 3 (2, 5.5) | 13 (9, 23) | – |
*, a P value below 0.05 indicates a significant difference. Continuous variables were tested using the independent samples t test or the Mann-Whitney test. Categorical variables were tested using the chi-squared test. Data of age and BMI are expressed as the mean ± standard deviation. Disease duration is expressed as the median (upper quartile, lower quartile). BMI, body mass index; PM, polymyositis; DM, dermatomyositis.