Table 1.
Characteristics of the included studies.
| First author | Year | Country | Study design | Number | Follow-up period | Average age | Average eGFR(ml/min) | Low versus high sKlotho level | Outcomes | HR and 95% CI |
|---|---|---|---|---|---|---|---|---|---|---|
| Liu (Ref [25]) | 2018 | China | Cross-sectional Prospective | 112 | 20.1 ± 10.1 months | 50.1 ± 14.0 | 38.2 ± 7.3 22.1 ± 6.3 10.8 ± 2.2 |
Median sKlotho level | Scr doubling RRT Death |
Direct |
| Bob (Ref [21]) | 2018 | Romania | Cross-sectional Retrospective | 63 | 12 months | 58.13 ± 12 | 65.2 ± 32.5 | Overall sKlotho | Δdecline of eGFR | — |
| Fountoulakis (Ref [23]) | 2018 | UK | Cross-sectional Prospective | 101 | 9 (2-13) years | 60 (40-82) | 90.7 ± 20.0 | Median sKlotho level | 50% decline of eGFR Death |
Indirect (estimated HR) |
| Qian (Ref [16]) | 2018 | China | Cross-sectional Prospective | 112 | 1.5 years | 64.5 ± 12.7 | — | ΔsKlotho level | RRT Cardio-cerebrovascular events |
— |
| Drew (Ref [22]) | 2017 | America | Prospective | 2496 | 3 or 10 years | 75 ± 3 | 73 ± 18 | sKlotho quartile level | eGFR decline ≥ 30% or >3 ml/min per year | Indirect (estimated OR) |
| Kim (Ref [24]) | 2017 | Korea | Prospective | 147 | 32 (12-52) months | 56.4 ± 10.8 | 93.0 ± 23.2 | sKlotho tertile level | Annual eGFR decline Albuminuria |
Direct |
| Kim (Ref [13]) | 2013 | Korea | Cross-sectional Prospective | 243 | 29.7 (6.0-62.1) months | 45.7 ± 15.7 | 55.4 ± 36.5 | Median sKlotho level | Scr doubling RRT Death |
Direct |
| Seiler (Ref [18]) | 2013 | Germany | Cross-sectional Prospective | 312 | 2.2 ± 0.8 years | 65.5 ± 12.1 | 43.8 ± 15.6 | sKlotho tertile level | RRT Death |
Direct |
Abbreviation: RRT: renal replacement therapy; Scr: serum creatinine; HRs: hazard ratios; CI: confidence interval; eGFR: estimated glomerular filtration rate; Ref: reference.