Table 1. Baseline characteristics, outcomes and comparisons between responders and non-responders to the first ACTH stimulation test during glucocorticoid (GC) treatment for giant cell arteritis (GCA).

Characteristics	Total	Responders (n=76)	Non-responders (n=74)	P
Median age at diagnosis of GCA (years)	74 ± 7	74 ± 7.5	74 ± 7.2	0.7
Gender (male/female)	49/101	20/56	29/45	0.09
Median weight at GCA diagnosis (kg)	62 ± 12	61 ± 13	63.5 ± 12	0.16
Treatment
Starting dosage of GCs (mg/day)	51 ± 16	50 ± 15	52 ± 16	0.28
Initial pulse methylprednisolone (%)	25	31	19	0.1
GC dosage after 3 months (mg/day)	19 ± 5	17.6 ± 4.9	20.1 ± 5.6	0.003
GC dosage after 6 months (mg/day)	13 ± 4	11.9 ± 3.3	14.7 ± 4.8	0.0003
GC dosage after 12 months (mg/day)	8 ± 4	6.63 ± 3.2	8.9 ± 4.4	0.0007
Time from diagnosis to the first ACTH test (months)	17 ± 8	15.7 ± 7	18.6 ± 9	0.004
Total amount of GCs at the first ACTH test (mg)	7740 ± 3390	6800 ± 2729	8697 ± 3743	0.0007
Basal cortisol concentration (nmol/L)	392 ± 163	488 ± 121	295 ± 143	< 0.0001
Stimulated cortisol concentration (nmol/L)	566 ±212	728 ± 135	397 ± 124	< 0.0001
Initial presentation
Symptomology (%)	75	80	69	0.16
Fatigue (%)	67	74	60	0.07
Fever (%)	43	42	47	0.6
Associated PMR (%)	32	33	31	0.8
ESR (mm)	87 ± 27	87.7 ± 29.3	86.3 ± 25.1	0.8
CRP (mg/mL)	97 ± 58	96.9 ± 59.4	98 ± 56.7	0.7
Haemoglobin (g/dL)	11.5 ± 1.8	11.4 ± 1.8	11.6 ± 1.7	0.6
Evolution
Relapse (%)	50	52	48	0.7
Recurrence (%)	33	37	28	0.4
Other GC-induced adverse events (%)	60	63	59	0.7
Diabetes mellitus (%)	15	15	16	0.8
Myopathy (%)	25	24	27	0.7
Bone involvement (%)	15	15	15	1
Infection (%)	26	26	27	0.8

ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; PMR: polymyalgia rheumatica