Table I.
Basic characteristics of eligible studies included in the present systematic review and meta-analysis.
| First author (year) | Ethnicity | Study design | Cases (FX/control) | Age (mean ± SD, years) | M/F | Time-points of measurement (months) | Inclusion criteria | Intervention | NOS scale | (Refs.) |
|---|---|---|---|---|---|---|---|---|---|---|
| Sezai (2014) | Asian | Prospective, randomized, controlled | 56/53 | FX: 69.4±10.0; Con: 69.1±9.2 | 85/24 | 6 | Patients with eGFR <60 ml/min/ 1.73 m2 prior to treatment | A maximum of 60 mg/day for FX or 300 mg/day for allopurinol; in patients with an eGFR <30 ml/min/1.73 m2, the maximum daily dose was 40 mg for FX and 200 mg for allopurinol. | 7 | (14) |
| Sofue (2014) | Asian | Retrospective observational study | 26/25 | FX: 48.6; Con: 54.1 | 43/8 | 1, 3, 6, 12 | UA >7.0 mg/dl or requirement for treatment with conventional UA-lowering drugs | FX started at 10 mg/day and increased to 20 mg/day if serum UA levels remained >7 mg/dl. | 6 | (19) |
| Tanaka (2014) | Asian | Prospective, randomized, controlled | 21/19 | FX: 70.1±9.5; Con: 66.1±7.0 | 35/5 | 1, 2, 3 | Adult subjects with hyperuricemia (serum UA ≥7.0 mg/dl) who were known to have CKD stage 3. | FX was allowed to be increased to 40 mg/day. | 8 | (21) |
| Tsuruta (2014) | Asian | Retrospective observational study | 51/22 | FX: 67.4±12.3; Con: 72.9±10.7 | 45/28 | 3, 6, 9, 12 | Presence of CKD as manifested by an eGFR <45 ml/min; current UA-lowering therapy with allopurinol; stable renal function; stable clinical condition. | NA | 7 | (22) |
| Tsuruta (2015) | Asian | Prospective, randomized, controlled | 27/26 | FX: 67.7±12.4; Con: 68.9±12.7 | 34/29 | 1 | Outpatients on maintenance hemodialysis; age of >20 years; serum UA levels of ≥7.0 mg/dl; stable clinical condition | FX (10 mg/day) or control group using the minimization method for age and UA levels | 8 | (20) |
| Beddhu (2016) | Caucasian | Prospective, randomized, controlled | 37/39 | 68±10 | 52/28 | 2 weeks, 1, 3, 6 | Serum UA levels ≥327 µmol/l in males and ≥274 µmol/l in females; adults with diagnosis of type 2 diabetes and kidney disease defined as eGFR 30–59 ml/min/1.73 m2 (body surface area) or eGFR ≥60 ml/min/1.73 m2 with urine dipstick ≥1+ proteinuria or urine albumin/creatinine ≥3.4 mg/mmol | Oral FX 80 mg/day or matching placebo for 24 weeks | 8 | (18) |
Values are expressed in n or the mean ± standard deviation. FX, febuxostat; NOS, Newcastle-Ottawa Scale; UA, uric acid; eGFR, estimated glomerular filtration rate; CKD, chronic kidney disease; Con, control; SD, standard deviation; M, male; F, female.