Table 1. Clinical Characteristics and Laboratory Data of All Participants According to CKD Stages.
Values for categorical variables are given as number (percentage); values for continuous variables are given as mean ± standard deviation or median (interquartile range). Abbreviations: eGFR, estimated glomerular filtration rate; ESA, erythropoiesis-stimulating agent; HDL, high-density lipoprotein; LDL, low-density lipoprotein; NT-proBNP, N-terminal pro-brain natriuretic peptide; PTH, parathyroid hormone; RAAS, renin-angiotensin-aldosterone system; UPCR, urinary protein to creatinine ratio.
| All participants (n = 95) | CKD stage 3a (n = 34) | CKD stage 3b (n = 26) | CKD stages 4+5 (n = 35) | P for trend | |
|---|---|---|---|---|---|
| Age [years] | 62 ± 11 | 63 ± 11 | 60 ± 11 | 64 ± 12 | 0.750 |
| Sex, male, n (%) | 49 (52) | 14 (42) | 13 (50) | 22 (63) | 0.071 |
| Diabetes mellitus, n (%) | 28 (30) | 6 (18) | 5 (19) | 17 (49) | 0.005 |
| Smoking habits, current/past, n (%) | 9 (9) / 42 (44) | 1 (3) / 9 (26) | 2 (8) / 12 (46) | 6 (17) / 21 (60) | 0.002 * |
| Daily alcohol consumption, n (%) | 44 (46) | 12 (35.3) | 16 (61.5) | 16 (45.7) | 0.393 |
| Previous history of CVD, n (%) | 11 (12) | 2 (6) | 2 (8) | 7 (20) | 0.066 |
| Education of more than 12 years, n (%) | 37 (39) | 9 (27) | 14 (54) | 14 (40) | 0.255 |
| Body mass index [kg/m 2 ] | 24.0 ± 4.0 | 24.5 ± 4.1 | 23.9 ± 3.6 | 23.7 ± 4.2 | 0.704 |
| Systolic blood pressure [mmHg] | 135 ± 17 | 135 ± 17 | 134 ± 18 | 136 ± 17 | 0.878 |
| Diastolic blood pressure [mmHg] | 81 ± 11 | 83 ± 12 | 81 ± 10 | 79 ± 11 | 0.384 |
| Medication | |||||
| Use of RAAS inhibitors, n (%) | 79 (83) | 25 (74) | 22 (85) | 32 (91) | 0.047 |
| Use of calcium antagonists, n (%) | 55 (58) | 17 (50) | 12 (46) | 26 (74) | 0.040 |
| Use of statins, n (%) | 49 (52) | 17 (50) | 14 (54) | 18 (51) | 0.907 |
| Use of ESAs, n (%) | 13 (14) | 0 (0) | 0 (0) | 13 (100) | <0.001 |
| Laboratory data | |||||
| Total protein [g/dL] | 6.8 ± 0.5 | 6.8 ± 0.4 | 6.7 ± 0.4 | 6.8 ± 0.7 | 0.817 |
| Albumin [g/dL] | 3.9 ± 0.4 | 4.1 ± 0.3 | 3.9 ± 0.4 | 3.8 ± 0.5 | 0.021 |
| Serum urea nitrogen [mg/dL] | 30.3 ± 16.4 | 20.2 ± 4.0 | 23.5 ± 6.4 | 45.3 ± 18.0 | <0.001 |
| Creatinine [mg/dL] | 1.72 ± 1.15 | 0.97 ± 0.21 | 1.30 ± 0.18 | 2.75 ± 1.35 | <0.001 |
| Uric acid [mg/dL] | 6.5 ± 1.5 | 5.8 ± 1.4 | 6.7 ± 1.6 | 7.0 ± 1.2 | 0.003 |
| C-reactive protein [mg/dL] | 0.05 (0.03–0.10) | 0.06 (0.03–0.12) | 0.04 (0.03–0.07) | 0.06 (0.03–0.11) | 0.234 |
| Total cholesterol [mg/dL] | 191 ± 40 | 186 ± 34 | 192 ± 38 | 195 ± 47 | 0.669 |
| Triglycerides [mg/dL] | 128 (85–178) | 125 (85–177) | 111 (79–163) | 130 (86–239) | 0.509 |
| HDL cholesterol [mg/dL] | 54 ± 15 | 54 ± 14 | 57 ± 14 | 53 ± 16 | 0.610 |
| LDL cholesterol [mg/dL] | 101 ± 30 | 99 ± 27 | 102 ± 31 | 101 ± 33 | 0.935 |
| Corrected calcium [mg/dL] ** | 9.2 ± 0.5 | 9.3 ± 0.6 | 9.4 ± 0.3 | 9.1 ± 0.6 | 0.137 |
| Phosphate [mg/dL] | 3.5 ± 0.7 | 3.4 ± 0.8 | 3.3 ± 0.5 | 3.8 ± 0.8 | 0.005 |
| Ferritin [ng/mL] | 76 (46–136) | 78 (51–106) | 61 (39–138) | 80 (55–156) | 0.607 |
| β 2 -microglobulin [mg/L] | 3.2 (2.5–5.5) | 2.5 (1.9–2.8) | 3.1 (2.6–3.5) | 5.8 (4.9–8.2) | <0.001 |
| Hemoglobin A1c [%] | 6.0 ± 0.7 | 5.9 ± 0.6 | 5.9 ± 0.5 | 6.1 ± 0.8 | 0.238 |
| Whole PTH [pg/mL] | 36 (26–53) | 27 (22–33) | 33 (25–43) | 64 (45–102) | <0.001 |
| NT-proBNP [pg/mL] | 120 (56–253) | 61 (31–107) | 99 (48–204) | 234 (127–578) | 0.163 |
| eGFR [mL/min/1.73 m 2 ] | 36.9 ± 15.2 | 53.2 ± 5.8 | 38.4 ± 4.5 | 20.0 ± 5.8 | <0.001 |
| UPCR [g/g·creatinine] | 0.37 (0.09–1.64) | 0.11 (0.06–0.50) | 0.30 (0.13–1.40) | 1.3 (0.4–3.6) | 0.002 |
| Hemoglobin [g/dL] | 12.3 ± 1.5 | 12.9 ± 1.2 | 12.8 ± 1.4 | 11.4 ± 1.4 | <0.001 |
* P value was calculated by chi-square test;
** Corrected calcium was calculated by the formula: (4.0 –serum albumin) + actual serum calcium.