Table 4.

Univariate and multivariate cross-sectional associations of TMAO

CharacteristicsModelingUnivariate AnalysisMultivariate Analysis
TMAO (SEM)P ValueTMAO (SEM)P Value
Demographic
 Age, yrPer 10 years higher1.3 (1.3)0.29
 Sex, female %Female versus male0.1 (3.6)0.98
 Race, black %Black versus non-black4.4 (3.7)0.238.0 (3.7)0.03
Clinical Characteristics
 Diabetes, %Yes versus no8.1 (3.6)0.027.9 (3.6)0.03
 Cardiac disease, %Yes versus no3.6 (4.4)0.42
 ICED score, %<3 versus 31.1 (3.8)0.77
 Gastrointestinal disease, %Yes versus no8.5 (3.7)0.0210.5 (3.8)0.01
 Residual kidney urea clearance, ml/min/35L TBWPer 0.5 ml/min/35 L TBW higher−5.4 (1.8)0.003−5.0 (1.8)0.01
 Body mass index, Kg/m2≥25 Kg/m2 versus <25 Kg/m24.3 (3.6)0.23
 Body surface area, m2Per 0.5 m2 higher6.8 (4.5)0.13
 Dialysis Characteristics
 Years of prior dialysisPer 1 yr higher0.6 (0.4)0.18
 Predialysis systolic BP, mmHgPer 10 mmHg higher−0.2 (0.7)0.81
 Post Dialysis Weight, KgPer 1 kg higher0.3 (0.1)0.04
 Relative volume removed, %Per 1% higher1.6 (1.1)0.13
 Dose interventionHigh dose versus standard dose−9.3 (3.6)0.01
 Flux interventionHigh flux versus low flux3.9 (3.6)0.27
 Treatment time, minPer 30 minute higher−3.0 (1.9)0.11
 Blood flow rate, ml/minPer 50 ml/min higher−1.3 (1.5)0.37
 Dialysate flow rate, ml/minPer 100 ml/min higher−0.1 (1.4)0.94
Predialysis laboratory tests
 BUN, mg/dlPer 10 mg/dl higher7.8 (0.9)<0.0018.4 (1.0)<0.001
 Single-pool Kt/VUREAPer 0.2 higher−1.9 (1.3)0.14
 Serum albumin, g/dlPer 0.5 g/dl higher2.9 (2.3)0.22
 Serum β2-microglobulin, mg/LPer 10 mg/L higher2.2 (1.3)0.09
 Equilibrated nPCR, g/kg/dayPer 0.2 g/kg/day higher9.7 (1.4)<0.001
  • Results are from linear regression of TMAO (on natural scale) on predictors in separate models (univariate associations) and in a forward selection model with model entry based on P ≤0.05 (multivariate model). For the multivariate model, R2=7.4% and root mean squared error (RMSE) = 62.1. TBW, total body water; nPCR, normalized protein catabolic rate.