Table 1.
Characteristics of 15,573 incident PD patients (2007–2011) who have data on both BMI and renal clearances of urea and creatinine at baseline across six BMI categories.
| <20 kg/m2 | 20 – <25 kg/m2 | 25 – <30 kg/m2 | 30 – <35 kg/m2 | 35 – <40 kg/m2 | ≥40 kg/m2 |
P for trend |
|
|---|---|---|---|---|---|---|---|
| Variable | (n=861) | (n=3,971) | (n=4,869) | (n=3,121) | (n=1,487) | (n=820) | |
| BMI (kg/m2) | 19 (18 to 20) | 23 (22 to 24) | 27 (26 to 29) | 32 (31 to 33) | 37 (36 to 38) | 43 (41 to 46) | <0.001 |
| Age (years) | 54±19 | 57±17 | 58±15 | 56±14 | 54±13 | 51±12 | <0.001 |
| Male sex | 37% | 59% | 64% | 60% | 49% | 39% | <0.001 |
| Race | |||||||
| Non-Hispanic white | 56% | 59% | 59% | 58% | 57% | 55% | 0.1 |
| Non-Hispanic black | 19% | 18% | 21% | 24% | 27% | 31% | <0.001 |
| Hispanic | 10% | 12% | 14% | 13% | 11% | 12% | 0.7 |
| Other races | 15% | 11% | 7% | 5% | 4% | 3% | <0.001 |
| Cause of ESRD | |||||||
| Diabetes | 18% | 29% | 41% | 49% | 53% | 55% | <0.001 |
| Hypertension | 30% | 29% | 28% | 25% | 23% | 21% | <0.001 |
| Other causes | 51% | 42% | 30% | 26% | 25% | 24% | <0.001 |
| Dialysis vintage (months) | 2 (1 to 5) | 1 (1 to 5) | 1 (0 to 5) | 1 (1 to 5) | 1 (1 to 6) | 2 (1 to 7) | 0.08 |
| Comorbid conditions | |||||||
| Diabetes | 38% | 51% | 64% | 72% | 73% | 76% | <0.001 |
| Congestive heart failure | 8% | 9% | 8% | 8% | 8% | 9% | 0.9 |
| Myocardial infarction | 11% | 14% | 13% | 13% | 12% | 12% | 0.2 |
| Other cardiac diseases | 15% | 14% | 14% | 13% | 12% | 13% | 0.03 |
| Hypertension | 53% | 54% | 53% | 51% | 51% | 48% | 0.001 |
| COPD | 3% | 3% | 2% | 3% | 3% | 2% | 0.9 |
| No. of 5-year cumulative incident PD patients | 31 (17 to 49) | 32 (19 to 54) | 33 (18 to 54) | 32 (18 to 54) | 32 (18 to 53) | 32 (17 to 57) | 0.5 |
| Weekly CLcr (L/1.73m2) | |||||||
| Renal | 52 (28 to 87) | 55 (30 to 91) | 61 (34 to 96) | 64 (36 to 100) | 63 (34 to 101) | 62 (35 to 101) | <0.001 |
| Peritoneal | 37±13 | 37±12 | 36±11 | 34±11 | 34±11 | 35±10 | <0.001 |
| Total | 90 (67 to 122) | 94 (69 to 125) | 97 (72 to 130) | 99 (73 to 133) | 97 (71 to 132) | 95 (71 to 134) | <0.001 |
| Weekly Kt/V | |||||||
| Renal | 0.9 (0.5 to 1.5) | 0.9 (0.5 to 1.5) | 1.0 (0.5 to 1.5) | 1.0 (0.5 to 1.5) | 0.9 (0.5 to 1.5) | 0.9 (0.5 to 1.4) | 0.5 |
| Peritoneal | 1.7±0.5 | 1.6±0.4 | 1.5±0.4 | 1.4±0.4 | 1.3±0.4 | 1.3±0.4 | <0.001 |
| Total | 2.6 (2.1 to 3.2) | 2.5 (2.1 to 3.0) | 2.4 (2.0 to 3.0) | 2.4 (2.0 to 2.9) | 2.3 (1.9 to 2.8) | 2.2 (1.8 to 2.7) | <0.001 |
| Normalized PNA (g/kg/d) | 1.05±0.30 | 1.01±0.26 | 0.98±0.26 | 0.94±0.25 | 0.92±0.24 | 0.88±0.23 | <0.001 |
| Laboratory variables | |||||||
| Hemoglobin (g/dL) | 11.9±1.5 | 11.8±1.3 | 11.8±1.3 | 11.7±1.3 | 11.6±1.2 | 11.4±1.2 | <0.001 |
| Albumin (g/dL) | 3.5±0.5 | 3.6±0.5 | 3.6±0.5 | 3.7±0.4 | 3.7±0.4 | 3.6±0.4 | <0.001 |
| Creatinine (mg/dL) | 5.6 (4.2 to 8.1) | 6.0 (4.5 to 8.4) | 6.1 (4.5 to 8.4) | 6.1 (4.6 to 8.3) | 6.2 (4.6 to 8.5) | 6.2 (4.5 to 8.5) | <0.001 |
| Corrected calcium (mg/dL) | 9.2±0.6 | 9.1±0.6 | 9.1±0.6 | 9.1±0.6 | 9.1±0.6 | 9.1±0.6 | <0.001 |
| Phosphorus (mg/dL) | 4.9±1.3 | 4.8±1.3 | 4.9±1.2 | 4.9±1.2 | 5.0±1.3 | 5.0±1.3 | 0.01 |
| Intact PTH (pg/mL) | 258 (143 to 440) | 268 (165 to 433) | 284 (180 to 439) | 315 (195 to 488) | 334 (218 to 510) | 331 (209 to 567) | <0.001 |
Note: Values for categorical variables are given as percentages; values for continuous variables, as mean ± standard deviation or median [interquartile range]. Baseline refers to first 91 days of PD. Trends across BMI categories were evaluated by non-parametric trend tests. Conversion factors for units: calcium in mg/dL to mmol/L, ×0.2495; creatinine in mg/dL to µmol/L, ×88.4; phosphorus in mg/dL to mmol/L, ×0.3229.
Abbreviations: BMI, body mass index; CLcr, creatinine clearance; ESRD, end-stage renal disease; COPD, chronic obstructive pulmonary disease; PD, peritoneal dialysis; PNA, protein nitrogen appearance; PTH, parathyroid hormone