Table 2.
Baseline characteristics of the study cohort by geographic region
| Overall | West | Mid-West | North-West | Midlands | East | South-East | P-value | ||
|---|---|---|---|---|---|---|---|---|---|
| n | (n = 530) | (n = 120) | (n = 103) | (n = 70) | (n = 52) | (n = 150) | (n = 35) | ||
| Demographic | |||||||||
| Age (years), mean (SD) | 510 | 57.1 (18.3) | 56.5 (19.6) | 57.2 (17.5) | 59.0 (15.6) | 63.9 (18.7) | 54.2 (18.8) | 55.4 (17.5) | 0.216 |
| Men (%) | 293 | 55.3 | 49.6 | 56.3 | 63.8 | 49.0 | 56.0 | 65.7 | 0.309 |
| Race (%) | |||||||||
| White Irish | 492 | 92.8 | 93.3 | 96.0 | 94.3 | 96.1 | 96.5 | 94.3 | 0.123 |
| White Irish traveller | 2 | 0.4 | 0.8 | 0.0 | 0.0 | 0.0 | 0.7 | 0 | 0.127 |
| White other | 12 | 2.3 | 4.2 | 1.0 | 5.7 | 3.9 | 0.0 | 0.0 | 0.125 |
| Asian | 2 | 0.4 | 0.8 | 0.0 | 0.0 | 0.0 | 0.7 | 0.0 | 0.130 |
| Other | 9 | 1.7 | 0.8 | 3.3 | 0.0 | 0.0 | 2.1 | 5.7 | 0.123 |
| Cause of CKD (%) | |||||||||
| Hypertension | 144 | 27.2 | 21.7 | 9.7 | 32.9 | 23.1 | 42.0 | 28.6 | <0.001 |
| Diabetes | 67 | 12.6 | 14.2 | 6.8 | 12.9 | 32.7 | 8.7 | 11.4 | 0.001 |
| Glomerulonephritis | 94 | 17.7 | 30.0 | 19.4 | 12.9 | 13.5 | 9.3 | 22.9 | 0.001 |
| Autosomal dominant PKD | 33 | 6.2 | 5.0 | 7.8 | 8.6 | 3.8 | 5.3 | 8.6 | 0.759 |
| Hereditary | 14 | 2.6 | 1.7 | 4.9 | 7.1 | 3.8 | 0.0 | 0.0 | 0.007 |
| Other | 172 | 32.5 | 23.3 | 27.2 | 48.6 | 42.3 | 33.3 | 28.6 | 0.006 |
| Not known | 71 | 13.4 | 14.2 | 30.1 | 7.1 | 13.5 | 6.7 | 2.9 | <0.001 |
| Kidney biopsy (%) | 79 | 14.9 | 17.5 | 25.2 | 7.1 | 13.5 | 10.7 | 11.4 | 0.011 |
| Comorbid conditions (%) | |||||||||
| Diabetes | 111 | 20.9 | 22.4 | 20.6 | 21.7 | 44.7 | 17.8 | 25.0 | 0.017 |
| Hypertension | 382 | 72.1 | 86.9 | 67.6 | 64.1 | 87.2 | 74.8 | 83.3 | 0.006 |
| Cancer | 34 | 6.4 | 1.9 | 3.9 | 8.7 | 21.3 | 7.4 | 8.3 | 0.002 |
| Heart failure | 22 | 4.2 | 4.7 | 6.9 | 8.8 | 0.0 | 0.0 | 16.7 | <0.001 |
| Thyroid disease | 49 | 9.2 | 10.3 | 8.8 | 8.7 | 21.3 | 6.7 | 16.7 | 0.107 |
| Stroke/TIA | 22 | 4.2 | 7.5 | 4.9 | 7.2 | 8.5 | 0.0 | 0.0 | 0.005 |
| COPD | 22 | 4.2 | 5.6 | 5.9 | 10.1 | 0.0 | 2.2 | 0.0 | 0.072 |
| Peripheral vascular disease | 38 | 7.2 | 3.7 | 11.8 | 8.7 | 10.6 | 5.2 | 16.7 | 0.078 |
| Coronary heart disease | 76 | 14.3 | 15.9 | 20.6 | 13.0 | 27.7 | 8.2 | 20.8 | 0.014 |
| Obesity | 29 | 5.5 | 0.0 | 5.9 | 18.8 | 8.5 | 3.7 | 4.2 | <0.001 |
| Gout | 59 | 11.1 | 16.8 | 19.6 | 4.3 | 17.0 | 5.2 | 13.0 | 0.001 |
| Hypercholesterolaemia | 131 | 24.7 | 38.1 | 14.7 | 42.9 | 42.6 | 16.3 | 17.4 | <0.001 |
| Depression | 20 | 3.8 | 6.5 | 3.9 | 1.4 | 6.4 | 3.7 | 0.0 | 0.550 |
| Arthritis | 29 | 5.5 | 4.7 | 3.9 | 15.9 | 17.0 | 0.7 | 0.0 | <0.001 |
| Osteoporosis | 31 | 5.8 | 3.7 | 7.8 | 18.8 | 10.6 | 0.7 | 0.0 | <0.001 |
| Current or ex-smoker | 53 | 10.0 | 0.0 | 19.6 | 14.5 | 21.3 | 9.6 | 0.0 | <0.001 |
| Physical measurements, mean (SD) | |||||||||
| Weight (kg) | 408 | 80.6 (17.4) | 79.5 (18.4) | 81.3 (16.0) | 80.7 (17.6) | 81.7 (19.0) | 80.2 (17.5) | 79.2 (20.0) | 0.641 |
| Pulse | 301 | 75.1 (16.2) | 71.5 (14.9) | 77.5 (17.3) | 76.5 (16.7) | 73.8 (15.5) | 76.1 (15.8) | 73.1 (14.0) | 0.743 |
| Systolic BP (mmHg) | 495 | 137.7 (19.6) | 136.4 (17.9) | 137.6 (20.1) | 139.5 (18.8) | 143.0 (23.3) | 135.0 (19.7) | 142.5 (17.2) | 0.331 |
| Diastolic BP (mmHg) | 495 | 77.5 (13.3) | 78.5 (11.3) | 77.0 (11.7) | 76.8 (11.6) | 75.3 (15.1) | 78.4 (16.4) | 77.0 (10.5) | 0.429 |
| Laboratory parameters, mean (SD) | |||||||||
| eGFRa (mL/min/1.73 m2) | 464 | 48.5 (27.9) | 43.9 (24.2) | 45.8 (29.3) | 46.7 (23.8) | 46.0 (28.8) | 52.1 (30.2) | 64.1 (28.5) | 0.118 |
| Haemoglobin (g/dL) | 461 | 12.6 (1.9) | 12.5 (2.1) | 12.7 (1.9) | 13.1 (1.7) | 12.6 (1.8) | 12.3 (1.8) | 12.3 (1.8) | 0.166 |
| Ferritin (ng/L) | 163 | 251.6 (334.6) | 272.0 (303.4) | 210.2 (223.5) | 375.5 (488.7) | 139.3 (192.0) | 179.4 (236.5) | 269.5 (187.4) | 0.730 |
| TSAT ratio (%) | 132 | 26.6 (13.2) | 23.3 (11.8) | 24.1 (7.7) | 31.1 (10.2) | 20.8 (20.3) | 27.8 (14.4) | 25.4 (18.4) | 0.327 |
| Folate (nmol/L) | 97 | 39.6 (142.3) | 72.8 (207.9) | 13.8 (8.5) | 8.8 (4.7) | 8.7 (5.1) | 44.1 (152.4) | 44.0 (NA) | 0.548 |
| Vitamin B12 (nmol/L) | 124 | 451.5 (271.1) | 445.4 (168.8) | 510 (244.1) | 603.8 (426.0) | 384.5 (154.4) | 376.2 (244.5) | 575.0 (NA) | 0.113 |
| Calcium (mmol/L) | 417 | 2.4 (0.2) | 2.3 (0.1) | 2.3 (0.2) | 2.3 (0.2) | 2.4 (0.1) | 2.4 (0.2) | 2.4 (0.2) | <0.001 |
| Albumin (g/L) | 364 | 41.1 (5.6) | 41.6 (7.1) | 36.4 (5.2) | 43.2 (4.2) | 43.5 (3.4) | 41.0 (3.3) | 41.1 (6.4) | <0.001 |
| Phosphate (mmol/L) | 388 | 1.1 (0.3) | 1.1 (0.3) | 1.3 (0.3) | 1.1 (0.3) | 1.1 (0.2) | 1.1 (0.3) | 1.2 (0.1) | <0.001 |
| PTH (pg/mL) | 166 | 131.7 (128.6) | 130.2 (95.3) | 207.8 (189.5) | 89.0 (50.4) | 108.3 (137.2) | 117.3 (106.2) | NaN (NA) | 0.004 |
| Total cholesterol (mmol/L) | 199 | 4.6 (1.4) | 4.7 (1.9) | 5.2 (1.5) | 4.3 (0.8) | 4.1 (0.9) | 4.6 (1.3) | 5.1 (0.9) | 0.110 |
| LDL cholesterol (mmol/L) | 126 | 2.6 (1.2) | 2.5 (1.6) | 2.8 (1.4) | 2.5 (0.7) | 2.3 (0.8) | 2.7 (1.3) | 2.8 (0.6) | 0.739 |
| HDL cholesterol (mmol/L) | 128 | 1.4 (0.5) | 1.4 (0.6) | 1.4 (0.6) | 1.4 (0.4) | 1.2 (0.3) | 1.0 (0.2) | 1.5 (0.6) | 0.066 |
| Triglycerides (mmol/L) | 196 | 3.9 (21.2) | 1.6 (0.8) | 1.5 (0.8) | 1.6 (0.8) | 2.1 (1.4) | 8.0 (35.1) | 1.7 (1.3) | 0.232 |
| HbA1c (mmol/mol) | 89 | 48.4 (23.4) | 46.5 (15.2) | 55.9 (25.8) | 32.0 (26.7) | 57.4 (19.1) | 53.1 (37.4) | 55.0 (14.2) | 0.770 |
| Urine tests | |||||||||
| Protein:creatinine ratio | 139 | 139.3 (246.6) | 302.6 (406.2) | 173.1 (171.7) | 67.2 (134.2) | NA (NA) | 120.8 (176.1) | 67.9 (28.8) | 0.566 |
| Albumin:creatinine ratio | 53 | 101.4 (211.3) | 170.6 (276.9) | 0.6 (NA) | 3.4 (3.0) | 51.4 (70.1) | 37.7 (47.7) | 37.4 (52.8) | 0.874 |
| Medications (%) | |||||||||
| ACE-I | 121 | 22.8 | 25.8 | 15.5 | 35.7 | 17.3 | 20.7 | 25.7 | 0.044 |
| ARB | 96 | 18.1 | 24.2 | 10.7 | 14.3 | 21.2 | 16.7 | 28.6 | 0.057 |
| ACE-I and ARB | 12 | 2.3 | 1.7 | 0.0 | 4.3 | 1.9 | 3.3 | 2.9 | 0.300 |
| Aspirin | 181 | 34.2 | 31.7 | 30.1 | 35.7 | 46.2 | 31.3 | 45.7 | 0.165 |
| Iron therapy (oral or i.v.) | 54 | 10.2 | 11.7 | 13.6 | 8.6 | 13.5 | 6.7 | 8.6 | 0.435 |
| ESA therapy | 25 | 4.7 | 5 | 2.9 | 5.7 | 7.7 | 4 | 5.7 | 0.749 |
PKD, polycystic kidneys; TIA, transient ischaemic attack; COPD, chronic obstructive pulmonary disease; BP, blood pressure; LDL, low-density lipoprotein; HDL, high-density lipoprotein; ACE-I, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker, ESA, erythropoietin stimulating agent, NA = not available.
a
eGFR (estimated glomerular filtration rate per CKD-EPI equation) was available for 464 patients. NA = not available.