TABLE 3.
Characteristics and outcomes from studies that reported the effect of pharmacological agents on TMAO concentrations1
| Reference and country | Participant characteristics | Study design | Intervention compared with control | Duration and follow-up | Baseline TMAO concentration (μM)2 | Outcome3 | Dietary intake4 |
|---|---|---|---|---|---|---|---|
| Huo et al. (34) China | n = 15:205 Female: 53% Age: 57.2 ± 10.76 y BMI: 28.8 ± 2.39 Subjects with DM | Open-label, nonrandomized metabonomic study | Metformin Compared with no treatment | 3 mo | Serum NR | ↑** | Uncontrolled7 |
| Cadeddu et al. (31) Italy | n = 20 Female: 45% Age: 47 ± 13 y BMI: 30.8 ± 5.2 Subjects with DM | Open-label, nonrandomized, non-placebo-controlled study | Metformin (850 mg bid) | 3 mo | Serum NR | ↑** | Uncontrolled |
| Dambrova et al. (32) Latvia | n = 8 Female: 50% Healthy subjects | Open-label, nonrandomized interventional study | Meldonium (500 mg bid) + TMA-rich diet (seafood) | 3 wk | Plasma 4.9 ± 1.3 | ↓** | Controlled |
| Tang et al. (3) United States | n = 40 Healthy subjects | Prospective, nonrandomized clinical trial | Metronidazole (500 mg bid) plus ciprofloxacin (500 mg OD) + phosphatidylcholine diet | 4 wk | Plasma 4.2 ± 2.0 | ↓↓*** | Controlled |
| Lever et al. (35) United Kingdom | n = 26 Female: 42% Age: 50 ± 15 y Healthy subjects | Open-label, nonrandomized, non-placebo-controlled interventional study | Fenofibrate tablet (145 mg OD) | 6 wk | Urine8 38.9 (21.4–49.0) | NC* | Uncontrolled |
| Velebova et al. (39) Prague, Czech Republic | n = 40 Subjects with DM | Randomized, placebo-controlled, double-blind, crossover study | Metformin (2 g OD) Compared with placebo (not specified) | 6 mo | Serum 1.03 ± 1.29 | NC* | Uncontrolled |
| Hazen (33) United States | n = 7: 95 | Nonrandomized, non-placebo-controlled, crossover study | Aspirin (81 mg OD) + choline diet Compared with choline diet only | 12 mo | Plasma I: 2.6 ± 0.3 C: 2.8 ± 0.4 | ↓↓*** | Controlled |
n = 7. bid, twice daily; C, control; DM, diabetes mellitus; HD, hemodialysis; I, intervention; NC, no change; NR, not reported; OD, once daily; tab, tablet; TMA, trimethylamine; TMAO, trimethylamine N-oxide.
Baseline TMAO concentration in micromolar (μM) = μmol/L unless otherwise indicated.
Outcome denotes effect of intervention on TMAO levels (increase or decrease).
Dietary intake of trimethylamine dietary precursors including seafood, fish, choline, l-carnitine, and betaine.
n = intervention: control groups.
Values are means ± SDs unless otherwise indicated.
“Controlled” indicates dietary intake of TMAO precursors was controlled; “uncontrolled” indicates dietary intake of TMAO precursors was not controlled.
Median (interquartile range) urine excretions (mmol/mol creatinine).
P > 0.05.
P < 0.05.
P < 0.001.