T2 mapping and fat quantification of lumbar paraspinal muscle in ankylosing spondylitis: a case control study

Table 1 Demographic and clinical characteristics of AS patients and healthy controls

Variables, N (%) or mean ± SD	AS (n = 37)	HC (n = 37)	P-value
Age, y	27.65 ± 7.32	27.81 ± 3.63	0.610^a
Sex
Female	10 (27.1%)	13 (35.1%)	0.451^b
Male	27 (72.9%)	24 (64.9%)
BMI, kg/m²	20.83 ± 3.21	21.76 ± 2.18	0.149^c
Current smoking
Yes	7 (18.9%)	2 (5.4%)	0.152^d
No	30 (81.1%)	35 (94.6%)
Alcohol consumption
Yes	8 (21.6%)	6 (16.2%)	0.553^b
No	29 (78.4%)	31 (83.8%)
Exercise habit
None	21 (56.8%)	16 (43.2%)	0.319^d
1–2/wk	14 (37.8%)	15 (40.5%)
≥ 3/wk	2 (5.4%)	6 (16.2%)
Disease duration, y	6.24 ± 4.56
ESR^e, mm/H	22.94 ± 28.31
CRP^f, mg/L	20.49 ± 29.33
BASFI Score (0–10)	0.37 ± 0.70
BASDAI Score (0–10)	2.46 ± 2.17
HLA-B27 positive	34 (91.9%)
TNF inhibitor biological therapy	3 (8.1%)

Note: The values are given as frequencies (percentages) or means ± standard deviation; ^a Mann–Whitney U test; ^b Pearson chi-squared test; ^c independent samples t test; ^d Fisher exact test; A p-value of < 0.05 was considered to indicate statistical significance
^eNormal range: 0–15 mm/H for female and 0–20 mm/H for male
^fNormal range: 0–8 mg/L
Y Years, WK Week, ESR Erythrocyte sedimentation rate, CRP C-reactive protein, BMI Body mass index, BASFI Bath AS function index, BASDAI Bath AS disease activity index, AS Ankylosing spondylitis, HC Healthy control, HLA-B27 Human leukocyte antigen-B27, TNF Tumor necrosis factor

ISSN: 1471-2474