Table 1.

Baseline comparison of demographic, anthropometric, comorbidity, biochemical, and nutritional characteristics across categories of prescribed dietary phosphate

First Quartile (n = 300)aSecond Quartile (n = 314)aThird Quartile (n = 307)aFourth Quartile (n = 297)aNo Phosphate Prescription (n = 533)aGlobal P Value for Differences among Groupsb
PDP (mg/d)800 (600 to 870)900 (871 to 999)1000 (1000 to 1000)1200 (1001 to 2000)NANA
Age (years)57.3 ± 14.859.1 ± 13.458.6 ± 13.556.8 ± 13.257.2 ± 14.60.14
Female genderc79.7%57.0%54.4%36.4%55.7%<0.001
Black racec69.7%76.4%65.8%54.2%54.6%<0.001
Vintage0.008
    ≤1 year24.3%25.8%22.5%21.9%18.6%
    1 to 2 years19%25.2%22.2%27.6%20.6%
    2 to 4 years23.3%17.8%26.1%25.3%29.1%
    >4 years33.3%31.2%29.3%25.3%31.7%
Accessc<0.001
    graft68.7%63.7%65.2%52.5%53.9%
    fistula23.7%27.7%28.7%41.8%40.5%
    catheter7.7%8.6%6.2%5.7%5.6%
Diabetes42.7%47.1%45.0%43.1%45.0%0.81
Arterial diseasec53.3%58.0%57.7%58.3%52.7%0.34
CHFc42.7%40.8%37.5%41.4%35.8%0.25
EDW (kg)
    femalec60.4 ± 12.470.6 ± 13.668.9 ± 15.271.7 ± 15.668.0 ± 16.0<0.001
    malec65.2 ± 12.571.2 ± 12.273.8 ± 15.477.0 ± 13.670.5 ± 12.8<0.001
MAMC (cm)
    femalec22.9 ± 3.524.3 ± 4.324.3 ± 4.025.3 ± 4.723.6 ± 4.70.001
    male24.4 ± 3.325.6 ± 2.825.6 ± 3.926.2 ± 3.425.2 ± 4.10.02
TSF (mm)
    femalec18.7 ± 10.022.7 ± 13.421.7 ± 10.921.7 ± 9.223.5 ± 15.2<0.001
    male12.5 ± 8.511.3 ± 6.713.8 ± 8.714.2 ± 8.314.4 ± 11.80.004
Alb (g/dl)c3.59 ± 0.363.61 ± 0.373.59 ± 0.333.65 ± 0.353.67 ± 0.360.006
Cr (mg/dl)c9.69 ± 2.8410.76 ± 3.0410.44 ± 3.1010.63 ± 2.8010.05 ± 2.690.001
eKt/V1.50 ± 0.271.49 ± 0.311.49 ± 0.311.46 ± 0.301.49 ± 0.310.21
Corrected Ca (mg/dl)9.62 ± 1.059.51 ± 1.029.62 ± 0.959.52 ± 0.979.70 ± 0.890.004
(n = 313)
Phos (mg/dl)5.90 ± 1.995.73 ± 1.895.63 ± 1.826.01 ± 1.905.72 ± 1.880.05
(n = 313)
PTH (pg/ml)c<0.001
    ≤15031.3%30.6%42.7%39.4%44.3%
    151 to 30022.0%20.4%20.9%21.9%21.6%
    >30038.0%33.4%27.7%30.3%28.0%
    missing8.7%15.6%8.8%8.4%6.2%
nPCR (g/kg/d)1.01 ± 0.251.02 ± 0.251.05 ± 0.241.00 ± 0.271.04 ± 0.270.004
Vitamin D use53.7% (n = 298)54.1%49.0% (n = 306)58.3%55.4% (n = 531)0.23
Nutritional supplement usec27.3%33.1%25.7%15.5%14.6%<0.001
Appetitec0.004
    very good21.3%36.0%26.4%32.0%32.3%
    good41.0%32.2%43.7%34.7%37.7%
    fair26.0%21.7%21.2%25.6%22.7%
    poor8.3%8.9%6.2%6.4%6.4%
    very poor3.3%1.3%2.6%1.4%0.9%
Observed protein1.01 ± 0.420.93 ± 0.440.96 ± 0.400.94 ± 0.400.92 ± 0.420.03
intake (g/kg/d)c(n = 287)(n = 309)(n = 304)(n = 293)(n = 528)
Observed caloric intake24.9 ± 9.722.1 ± 9.322.6 ± 9.123.5 ± 9.822.2 ± 9.5<0.001
(kcal/kg/d)c(n = 287)(n = 309)(n = 304)(n = 293)(n = 528)
Observed phosphate820 ± 380810 ± 390840 ± 380910 ± 430830 ± 3800.02
intake (mg/d)(n = 288)(n = 309)(n = 304)(n = 293)(n = 528)
  • The values are expressed as the means ± standard deviation or proportion, except for PDP, which is expressed as median (range). EDW, estimated dry weight; MAMC, midarm muscle circumference; TSF, triceps skin-fold thickness; CHF, congestive heart failure; Alb, serum albumin; Cr, serum creatinine; eKT/V, equilibrated Kt/V; Corrected Ca, corrected serum calcium; Phos, serum phosphate; nPCR, normalized protein catabolic rate; NA, not applicable.

  • a Except where indicated.

  • b P value for global comparisons among groups by Kruskal Wallis and χ2 tests for continuous and categorical variables, respectively.

  • c P < 0.05 for two-way comparison between first quartile and no-prescription groups by Wilcoxon rank sum test.