Table 1. Baseline patient characteristics by BMI groupsa

Low BMI (<18.5 kg/m2; n = 4,052)Normal BMI (18.5–24.9 kg/m2; n = 23,299)High BMI (≥25 kg/m2; n = 23,381)
a BMI, body mass index.
Demographics
    age (yr; mean ± SD)72.6 ± 11.272.2 ± 10.869.5 ± 10.3
    male gender (n [%])1,789 (44)12,514 (54)10,099 (43)
    race (n [%])
        white2,815 (70)17,383 (75)16,822 (72)
        black974 (24)4,401 (19)5,351 (23)
        other263 (6)1,515 (6)1,208 (5)
Comorbid conditions
    diabetes as cause of renal failure (n [%])1,097 (27)8,941 (38)12,526 (54)
    coronary artery disease (n [%])1,502 (37)9,588 (41)9,097 (39)
    cerebrovascular disease (n [%])605 (15)3,361 (14)2,845 (12)
    peripheral vascular disease (n [%])949 (23)5,382 (23)4,863 (21)
    history of cardiac arrest (n [%])43 (1)294 (1)248 (1)
    heart failure (n [%])1,860 (46)10,742 (46)10,974 (47)
    current smoker (n [%])374 (9)1,334 (6)877 (4)
    hypertension (n [%])3,031 (75)17,686 (76)18,379 (78)
Nutritional parameters
    body mass index (kg/m2; mean ± SD)17.1 ± 1.222.0 ± 1.829.9 ± 4.6
    24-h urine creatinine (g/d)0.63 ± 0.290.72 ± 0.310.81 ± 0.35
    serum albumin (g/dl; mean ± SD)3.1 ± 0.63.2 ± 0.63.2 ± 0.6
Anemia
    hematocrit (%; mean ± SD)29.1 ± 5.229.4 ± 5.029.4 ± 4.8
    predialysis erythropoietin use (n [%])1,033 (25)6,227 (27)6,300 (27)