Febuxostat for treating allopurinol-resistant hyperuricemia in patients with chronic kidney disease

Figures & data

Table 1. Baseline characteristics of the study population.

Baseline characteristics	All patients n = 60	Male patients n = 44 (73%)	Female patients n = 16 (27%)
Age (years)
Mean (±SD)	63.1 ± 16.6	62.8 ± 16.4	63.9 ± 17.7
Range	29–98	30–89	29–98
Serum uric acid concentration (mg/dL)
Mean (±SD)	8.4 ± 1.4	8.5 ± 1.4	8.2 ± 1.6
Range	6.2–13.1	6.3–13.1	6.2–12.1
<7 mg/dL (n, %)	6 (10.0)	4 (9.1)	2 (12.5)
7–8 mg/dL (n, %)	16 (26.7)	10 (22.7)	6 (37.5)
8–9 mg/dL (n, %)	25 (41.7)	20 (45.5)	5 (31.3)
≥9 mg/dL (n, %)	13 (21.7)	10 (22.7)	3 (18.8)
eGFR (ml/min/1.73 m^2)
Mean ( ± SD)	27.2 ± 19.2	29.8 ± 20.7	20.2 ± 12.0
Range	3.1–89.8	4.0–89.8	3.1–43.7
<15 mL/min/1.73 m^2 (n, %)	18 (30.0)	12 (27.3)	6 (37.5)
15–29 mL/min/1.73 m^2 (n, %)	22 (36.7)	15 (34.1)	7 (43.8)
30–44 mL/min/1.73 m^2 (n, %)	11 (18.3)	8 (18.2)	3 (18.8)
45–59 mL/min/1.73 m^2 (n, %)	4 (6.7)	4 (9.1)	0
≥60 mL/min/1.73 m^2 (n, %)	5 (8.3)	5 (11.4)	0
Underlying morbidity
Hypertension	15 (25.0)	11 (25.0)	4 (25.0)
Chronic glomerulonephritis (n, %)	21 (35.0)	16 (36.4)	5 (31.3)
IgA nephropathy (n, %)	12 (20.0)	8 (18.2)	4 (25.0)
Membranous nephropathy (n, %)	7 (11.7)	6 (13.6)	1 (6.3)
Focal segmental glomerulosclerosis (n, %)	1 (1.7)	1 (2.3)	0
Biopsy not performed (n, %)	1 (1.7)	1 (2.3)	0
Diabetic nephropathy (n, %)	10 (16.7)	6 (13.6)	4 (25.0)
Gouty nephropathy (n, %)	4 (6.7)	4 (9.1)	0
Polycystic kidney (n, %)	4 (6.7)	3 (6.8)	1 (6.3)
Interstitial nephritis (n, %)	2 (3.3)	1 (2.3)	1 (6.3)
Rheumatoid arthritis (n, %)	2 (3.3)	1 (2.3)	1 (6.3)
MRSA nephropathy (n, %)	1 (1.7)	1 (2.3)	0
Renal cell carcinoma (n, %)	1 (1.7)	1 (2.3)	0

Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; SD, standard deviation.

Figure 1. Change in serum uric acid concentration (mean ± SD) before and after the start of febuxostat treatment (number in parentheses indicates number of patients). ***p < 0.001 versus Month 0 (paired t-test).

Figure 2. Change in serum uric acid concentrations (mean ± SD) during febuxostat treatment stratified by (a) gender and (b) baseline eGFR (mL/min/1.73 m²). ***p < 0.001 versus Month 0 (paired t-test).

Figure 3. Change in eGFR (mean ± SD) before and after the start of febuxostat treatment in patients with a baseline eGFR <15 mL/min/1.73 m² (number in parentheses indicates number of patients). *p < 0.05 versus Month 0 (paired t-test).

Table 2. Change from baseline in eGFR (mL/min/1.73 m²) after the start of febuxostat treatment.

	Total			Male			Female
	n	Mean ± SD	p Value*	n	Mean ± SD	p Value*	n	Mean ± SD	p Value*
Baseline (Month 0)	60	27.2 ± 19.2	–	44	29.8 ± 20.7	–	16	20.2 ± 12.0	–
Month 1	54	1.2 ± 4.1	0.0416	40	0.9 ± 4.1	0.1672	14	1.8 ± 4.0	0.1076
Month 2	59	1.8 ± 6.0	0.0252	44	1.9 ± 6.7	0.0650	15	1.5 ± 3.6	0.1294
Month 3	53	0.7 ± 4.3	0.2308	38	0.6 ± 4.9	0.4638	15	1.1 ± 2.4	0.1082
Month 4	59	0.6 ± 5.7	0.4354	44	0.6 ± 6.2	0.5420	15	0.6 ± 3.7	0.5525
Month 5	52	0.8 ± 4.4	0.2008	38	0.7 ± 4.7	0.3588	14	1.0 ± 3.7	0.3165
Month 6	58	2.3 ± 5.6	0.0027	42	2.5 ± 5.8	0.0074	16	1.7 ± 5.1	0.1998

Symbols: *versus Month 0 (paired t-test).

Table 3. Correlation between the change in serum uric acid concentrations and change in eGFR at 6 months after the start of febuxostat treatment.

Patient group	Pearson correlation coefficient (r)	p Value
Total (n = 58)	−0.10	0.4747
Male (42)	−0.02	0.8860
Female (16)	−0.29	0.2696
eGFR at Month 0: <15 mL/min/1.73 m^2 (18)	−0.70	0.0013
eGFR at Month 0: 15–30 mL/min/1.73 m^2 (21)	0.21	0.3694
eGFR at Month 0: 30–45 mL/min/1.73 m^2 (11)	−0.52	0.1022
eGFR at Month 0: 45–60 mL/min/1.73 m^2 (3)	−0.97	0.1685
eGFR at Month 0: ≥60 mL/min/1.73 m^2 (5)	0.71	0.1835

Figure 4. Change in eGFR slope (mean ± SD) before (a) and after (b) the start of febuxostat treatment (number in parentheses indicates number of patients). *p < 0.05 versus Month 0 (paired t-test).

Figure 5. Change in eGFR slope (mean ± SD) before and after febuxostat treatment stratified by (a) gender and (b) baseline eGFR (mL/min/1.73 m²). *p < 0.05 and **p < 0.01 versus before treatment (paired t-test).