Table 1.

Baseline characteristics of 1232 hemodialysis patients, overall and by race

CharacteristicRace
OverallWhitesBlacksP Value
N1232431801
Trimethylamine oxide (µM)
 Mean±SD.101.9±63.998.4±57.0103.8±67.30.15
 Median [25th to 75th percentiles]88 [62–124]87 [63–120]88 [62–125]
Demographics
 Age, yr57.7±13.858.5±14.957.3±13.20.12
 Female sex699 (56.7)205 (47.6)494 (61.7)<0.001
Clinical characteristics
 ICED score2.0±0.82.1±0.91.9±0.8<0.001
 Diabetes555 (45.0)181 (42.0)374 (46.7)0.12
 Cardiac disease976 (79.2)330 (76.6)646 (80.6)0.11
 Gastrointestinal disease466 (37.8)183 (42.5)283 (35.3)0.02
 Attributed cause of ESRD<0.001
  Diabetes463 (37.96)159 (36.9)304 (38.0)
  Hypertension397 (32.2)74 (17.2)323 (40.3)
  Polycystic kidney disease32 (2.6)18 (4.2)14 (1.7)
  Other316 (25.6)169 (39.2)147 (18.4)
 Residual kidney urea clearance >0413 (33.5)166 (38.5)247 (30.8)0.01
Dialysis characteristicsa
 Years of prior dialysis3.5±4.23.5±4.53.5±4.00.74
 Predialysis systolic BP, mmHga152.2±25.7151.1±25.8152.8±25.70.27
 Postdialysis weight, Kg70.3±15.269.9±15.970.5±14.80.53
 Body mass index, Kg/m225.8±5.425.7±5.725.8±5.30.73
 Relative volume removed, %4.1±1.74.1±1.74.1±1.70.95
 High-dose group613 (49.8)223 (51.7)390 (48.7)0.32
 High-flux group620 (50.3)222 (51.5)398 (49.7)0.55
Predialysis laboratory testsa
 BUN, mg/dl59.4±18.761.5±17.858.3±19.00.004
 Single-pool Kt/V1.5±0.31.5±0.31.5±0.30.15
 Serum albumin, g/dl3.6±0.43.6±0.43.6±0.40.78
 Serum β2-microglobulin, mg/L36.7±14.334.8±12.437.7±15.2<0.001
 enPCR, g/kg/day1.0±0.31.1±0.21.0±0.3<0.001
Dietary recall at baseline
 Total protein, g/kg-ABW/day0.9±0.30.9±0.30.9±0.40.62
 Fat%35.6±7.534.8±7.736.1±7.30.003
 Carbohydrates%48.3±9.249.4±9.347.7±9.10.002
Dietary recall at yr 1
 Total protein, g/kg-ABW/day0.9±0.40.9±0.40.9±0.40.32
 Fat, %36.5±7.835.7±7.936.9±7.70.02
 Carbohydrates, %47.2±9.348.5±9.346.5±9.20.001
  • Values for categorical variables are given as number (percentage); values for continuous variables are given as mean±SD.

  • enPCR, equilibrated normalized protein catabolic rate. ABW, adjusted body weight.

  • a Data from the same date as the TMAO sample.