Table 1 showed the basic demographics of all study subjects. In our study, the mean age of the entire cohort was 48.61 ± 13.63 years; 57.2% were male, 16.9% had diabetic mellitus (DM), the median duration of PD was 21 months, 22.7% low education, 71.9% lose of residual kidney function, 95.3% anemia, and 15.8% peritonitis during 3 years follow-up, the ratio of positive bacteria was 27.3% (12/44 patients).
Table 1
Baseline demographic and laboratory characteristics of patients
Clinical characteristics and laboratory parameters | Mean ± SD/ Median | n,% |
Ages (years) (Min - Max) | 48.61 ± 13.63 | N/A |
Number of males (n,%) | N/A | 159 (57.2) |
PD duration (month) | 21 (10–40,25) | N/A |
Low Education (n,%) | N/A | 63 (22.7) |
Hypertension (n,%) | N/A | 228 (82) |
Diabetic mellitus (n,%) | N/A | 47 (16.9) |
BMI - Mean - < 18.5 - 18.5–22.9 - ≥ 23 - Min - Max | 21.16 ± 2.93 N/A N/A N/A 14.4–33.3 | N/A 46 (16.5) 168 (60.4) 64 (23) N/A |
OH (L) | 1.27 ± 0.18 | N/A |
Residual kidney function - 24 hours urine volume (ml) - No (n,%) - Yes (n,%) | 180 (130–500) N/A N/A | N/A 200 (71.9) 78 (28.1) |
PET - Mean (D4/P) - H (n,%) - HA (n,%) - LA (n,%) - L (n,%) | 0.7 ± 0.08 N/A N/A N/A N/A | N/A 20 (7.2) 175 (62.9) 80 (28.8) 3 (1.1) |
Blood ure (mmol/L) | 19.29 ± 6.11 | N/A |
Creatinine (µmol/L) | 772.16 (654.9–955.8) | N/A |
Kt/V | 1.98 ± 0.3 | N/A |
Total CCr (L/week/1.73 m2) | 62.65 ± 9.3 | N/A |
Hemoglobin - Mean (g/L) - Anemia (n,%) | 100.55 ± 16.9 N/A | N/A 265 (95.3) |
WBC (G/L) | 6.86 ± 1.48 | N/A |
Neutrophil (G/L) | 61.38 ± 8.44 | N/A |
CRP-hs (mg/L) | 2 (1–4) | N/A |
Gluocose (mmol/L) | 4.22 (3.77–4.83) | N/A |
Acid Uric (µmol/L) | 414.63 ± 83.78 | N/A |
Na+ (mmol/L) | 136.93 ± 3.76 | N/A |
K+ (mmol/L) | 3.67 ± 0.78 | N/A |
Ca++ (mmol/L) | 2.05 ± 0.29 | N/A |
Protein (g/dL) | 6.51 ± 0.69 | N/A |
Albumin (g/dL) | 3.69 ± 0.48 | N/A |
Prealbumin (mg/dL) | 34.35 ± 8.49 | N/A |
Peritonitis (n,%) | N/A | 44 (15.8) |
Culture bacteria (+), (n,%) | N/A | 12 (27.3) |
PD: Peritoneal Dialysis; BMI: Body Mass Index; OH: Overhydration; PET: Peritoneal Equilibration Test; H: High; HA: High-Average; LA: Low-Average; L: Low; WBC: White Blood Cell; hs-CRP: high sensitive C Reactive Protein. |
As the results in Table 2, in peritonitis patients, the average age was older, the ratio of low education and DM were higher, the average OH and CRP-hs level were higher, and serum average albumin and prealbumin concentration were lower significantly than those of non-peritonitis group, p < 0.001.
Table 2
Comparison of demographic and laboratory characteristics of peritonitis and non-peritonitis group
Clinical characteristics and laboratory parameters | Peritonitis (n = 44) | Non-peritonitis (n = 234) | p |
Ages (years) (Min - Max) | 54.57 ± 12.25 | 47.49 ± 13.61 | 0.001 |
Number of male (n,%) | 25 (56.8) | 134 (57.3) | 0.956 |
PD duration (month) | 18.5 (8–37.5) | 23 (10–41) | 0.516 |
Low Education (n,%) | 27 (61.4) | 36 (15.4) | < 0.001 |
Hypertension (n,%) | 36 (81.8) | 192 (82.1) | 0.971 |
Diabetic mellitus (n,%) | 23 (52.3) | 24 (10.3) | < 0.001 |
BMI - Mean - < 18.5 - 18.5–22.9 - ≥ 23 - Min - Max | 22.15 ± 3.43 5 (11.4) 21 (47.7) 18 (40.9) 15.4–31.2 | 20.97 ± 2.79 41 (17.5) 147 (62.8) 46 (19.7) 14.4–33.3 | 0.036 0.009 N/A |
OH (L) | 1.49 ± 0.21 | 1.23 ± 0.14 | < 0.001 |
Residual kidney function - 24 hours urine volume (ml) - No (n,%) - Yes (n,%) | 195 (146.25–637.5) 28 (63.6) 16 (36.5) | 175 (128.75–500) 172 (73.5) 62 (26.5) | 0.12 0.181 |
PET - Mean (D4/P) - H (n,%) - HA (n,%) - LA (n,%) - L (n,%) | 0.73 ± 0.08 6 (13.6) 28 (63.6) 10 (22.7) 0 (0) | 0.7 ± 0.08 14 (6) 147 (62.8) 70 (29.9) 3 (1.3) | 0.024 0.236 |
Blood ure (mmol/L) | 19.16 ± 6.89 | 19.31 ± 5.97 | 0.88 |
Creatinine (µmol/L) | 738.97 (608.43–946.95) | 778.8 (657.55–961.99) | 0.372 |
Kt/V | 2.00 ± 0.31 | 1.97 ± 0.3 | 0.597 |
Total CCr (L/week/1.73 m2) | 63.13 ± 9.57 | 62.57 ± 9.27 | 0.713 |
Hemoglobin - Mean (g/L) - Anemia (n,%) | 95.98 ± 15.06 | 101.41 ± 17.12 | 0.051 |
WBC (G/L) | 6.94 ± 1.37 | 6.85 ± 1.5 | 0.711 |
Neutrophil (%) | 61.29 ± 10.77 | 61.39 ± 7.96 | 0.94 |
CRP-hs (mg/L) | 3.95 (2–5.27) | 2 (1–3.7) | < 0.001 |
Gluocose (mmol/L) | 4.47 (3.94–5.34) | 4.16 (3.76–4.79) | 0.024 |
Acid Uric (µmol/L) | 427.04 ± 101.02 | 412.3 ± 80.16 | 0.285 |
Na+ (mmol/L) | 136.17 ± 3.38 | 137.07 ± 3.81 | 0.145 |
K+ (mmol/L) | 3.52 ± 0.58 | 3.7 ± 0.81 | 0.164 |
Ca++ (mmol/L) | 2.04 ± 0.23 | 2.05 ± 0.31 | 0.83 |
Protein (g/dL) | 6.45 ± 0.8 | 6.53 ± 0.67 | 0.515 |
Albumin (g/dL) | 3.36 ± 0.61 | 3.75 ± 0.42 | < 0.001 |
Prealbumin (mg/dL) | 26.34 ± 5.54 | 35.86 ± 8.1 | < 0.001 |
PD: Peritoneal Dialysis; BMI: Body Mass Index; OH: Overhydration; PET: Peritoneal Equilibration Test; H: High; HA: High-Average; LA: Low-Average; L: Low; WBC: White Blood Cell; hs-CRP: high sensitive C Reactive Protein. |
There are many independent factors associated significantly with peritonitis, including low education, PD duration, loss of residual kidney function, anemia, CRP-hs, albumin, prealbumin, and OH, p < 0.05 (Table 3).
Table 3
Univariate logistic regression analysis between peritonitis and clinical variables in studied patients
Variable | Adjusted hazard ratio | 95% Cl | p |
Male sex | 0.237 | 0.049–1.142 | 0.073 |
Low education | 5.710 | 1.527–21.35 | 0.01 |
PD duration (month) | 0.949 | 0.912–0.988 | 0.011 |
Urine 24-hour volume (ml) | 1.002 | 1.000–1.004 | 0.021 |
Kt/V | 0.050 | 0.003–0.869 | 0.04 |
Hemoglobin | 0.927 | 0.881–0.976 | 0.004 |
CRP-hs | 1.366 | 1.036–1.800 | 0.027 |
Protein | 3.255 | 0.891–11.891 | 0.074 |
Albumin | 0.043 | 0.007–0.27 | 0.001 |
Prealbumin | 0.813 | 0.741–0.892 | < 0.001 |
OH | 3998.651 | 95.531–167372.356 | < 0.001 |
PD: Peritoneal Dialysis; hs-CRP: high sensitive C Reactive Protein; OH: Overhydration |
Based on the results of ROC curve analysis in Fig. 1, there were many factors prediction of the first peritonitis, in which prealbumin level and OH had strong value (AUC of prealbumin level = 0.838, of OH = 0.851, p < 0.001)
The Kaplan-Meier analysis in Fig. 2 showed that patients in the high OH (OH ≥ 1.33 L: blue line) exhibited a significantly higher peritonitis rate compared to that with lower OH (OH < 1.33 L: violet line) (Log-rank test, p < 0.001).
Oppositely, as the results of Kaplan-Meier analysis in Fig. 3, patients in the lower prealbumin level (Serum prealbumin ≤ 32.5 mg/dL: blue line) exhibited a significantly higher peritonitis rate compared to that with higher serum prealbumin level (Serum prealbumin > 32.5 mg/dL: violet line) (Log-rank test, p < 0.001).