Table 1.

The characteristics of the DM and PM patients who underwent a biopsy of the fasciae and muscles. The values indicate the number of patients (%) or the mean ± SD.

Variables	DM, n = 24	PM, n = 8	Total, n = 32	p
Age, yrs	53 ± 12.33	58.88 ± 10.47	54.47 ± 12.01	NS^*
Sex, M/F	10/14	2/6	12/20	NS^**
Myalgia	17 (70.83)	2 (25)	19 (59.38)	< 0.05^**
MMT8	76.38 ± 3.321	79.5 ± 0.9258	77.16 ± 3.204	< 0.05^*
CK, IU/l^a	1491 ± 2416	1961 ± 1699	1608 ± 2242	NS^*
Aldolase (IU/l)^b	23.46 ± 33.01	28.86 ± 27.60	24.06 ± 31.44	NS^*
Anti-Jo1	4 (16.67)	1 (12.5)	5 (15.63)	NS^**
ILD	20 (83.33)	3 (37.5)	23 (71.88)	< 0.05^**
Malignancy	4 (16.67)	2 (25)	6 (18.75)	NS^**

↵a Normal range, 25–200 IU/l.
↵b Normal range, 2.1–6.1 IU/l.
↵* Mann-Whitney U test;
↵** Fisher’s exact test. DM: dermatomyositis; PM: polymyositis; CK: creatine kinase; MMT: manual muscle testing; anti-Jo1: anti-Jo1 antibody; ILD: interstitial lung disease; NS not significant.