TABLE 2.
Details of the selected studies and baseline characteristics of the participants in the comparisons of circulating TMAO concentrations between patients with CKD and healthy subjects1
| First author | Year | Journal | Country | Design | Subjects, n | Age,2 y | Male, % | Disease status | Sample | Assay | Main results |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Kim et al. (45) | 2016 | Kidney Int | Canada | Cohort | 2529 | 68.2 ± 12.7 | 62.5 | CKD | Plasma | LC-MS/MS | Stage 4 patients with severe CKD had higher TMAO concentrations than stage 3b patients with moderate CKD (P <0.001) |
| Missailidis et al. (28) | 2016 | PLoS One | Sweden | Cohort | 259 | 57.2 ± 13.8 | 66.8 | CKD and healthy subjects | Plasma | LC-MS/MS | Plasma TMAO concentrations increased with decreasing kidney function. CKD5 patients had a 13-fold increase in TMAO compared with healthy subjects (P < 0.001) |
| Xu et al. (44) | 2017 | Sci Rep | China | Cross-sectional | 64 | 54.2 ± 12.5 | 50 | CKD and healthy subjects | Plasma | LC-MS/MS | Patients with CKD had obviously higher TMAO concentrations than healthy subjects (P < 0.001) |
| Stubbs et al. (27) | 2016 | J Am Soc Nephrol | USA | Cohort | 104 | 57.6 ± 14.1 | 50 | CKD, ESKD, and healthy subjects | Serum | UHPLC-MS/MS | Serum TMAO concentrations increased with advancing CKD stage, with median concentrations in dialysis-dependent patients with ESKD ∼30-fold higher than in controls (P < 0.001) |
| Kaysen et al. (32) | 2015 | J Ren Nutr | USA | Cohort | 235 | 61.8 ± 14.2 | 55.3 | ESKD and healthy subjects | Plasma | UPLC-MS | Serum TMAO concentrations were elevated in patients undergoing hemodialysis compared with individuals with normal or near-normal kidney function (P < 0.05) |
| Pelletier et al. (31) | 2019 | Toxins | France | Cross-sectional | 124 | ≥18 | 54 | CKD, ESKD, and healthy subjects | Plasma | LC-MS/MS | Plasma TMAO concentrations were increased in patients with CKD (P < 0.05) |
| Bain et al. (29) | 2006 | Nephrol Dial Trans | USA | Cross-sectional | 20 | 45.5 ± 17.3 | 60 | ESKD and healthy subjects | Plasma | GC-MS | Plasma TMAO concentrations in predialysis patients were significantly higher than corresponding concentrations in healthy subjects (P < 0.05) |
| Hai et al. (24) | 2015 | PLoS One | USA | Cross-sectional | 13 | ≥18 | NR | ESKD and healthy subjects | Plasma | LC-MS/MS | Patients with ESKD had much higher peak predialysis plasma TMAO concentrations (P < 0.05) |
| Al-Obaide et al. (46) | 2017 | J Clin Med | USA | Cross-sectional | 40 | 59.35 ± 5.8 | NR | CKD and healthy subjects | Serum | LC-MS | TMAO concentrations in the serum of patients with type 2 DM and CKD were higher than those in healthy subjects (P < 0.0001) |
1
CKD, chronic kidney disease; DM, diabetes mellitus; ESKD, end-stage kidney disease; LC-MS/MS, LC-tandem MS; NR, not reported; TMAO, trimethylamine N-oxide; UHPLC, ultra-high-performance LC; UPLC, ultra-performance LC.
2
Values are mean ± SD or range.