Table 1.
Baseline characteristics
| Characteristic | Overall | Lowest Quartile of Skin AF | Second Quartile of Skin AF | Third Quartile of Skin AF | Highest Quartile of Skin AF | P Value |
|---|---|---|---|---|---|---|
| Sexa | ||||||
| Men | 671 (39.3) | 156 (36.4) | 161 (35.9) | 164 (38.5) | 190 (47.1) | 0.001 |
| Women | 1036 (60.7) | 273 (63.6) | 288 (64.1) | 262 (61.5) | 213 (52.9) | |
| Age, yra | ||||||
| <60 | 125 (7.3) | 55 (12.8) | 39 (8.7) | 19 (4.5) | 12 (3.0) | <0.001 |
| 60–69 | 439 (25.7) | 137 (31.9) | 123 (27.4) | 98 (23.1) | 81 (20.1) | |
| 70–79 | 738 (43.2) | 164 (38.2) | 196 (43.7) | 190 (44.6) | 122 (46.7) | |
| 80+ | 405 (23.7) | 73 (17.0) | 91 (20.3) | 119 (27.9) | 188 (30.3) | |
| Age, yr | 73±9 | 70±10 | 72±9 | 74±8 | 75±8 | |
| Ethnicity | ||||||
| White | 1681 (98.5) | 416 (97.0) | 448 (99.8) | 419 (98.4) | 398 (98.8) | 0.11 |
| Other | 26 (1.5) | 13 (3.0) | 1 (0.2) | 7 (1.6) | 5 (1.2) | |
| Qualificationsa | ||||||
| No formal qualifications | 935 (54.8) | 188 (43.9) | 234 (52.1) | 258 (60.6) | 255 (63.4) | <0.001 |
| School or equivalent qualifications | 459 (26.9) | 132 (30.8) | 129 (28.7) | 110 (25.8) | 88 (21.9) | |
| Degree or equivalent qualifications | 311 (18.2) | 108 (25.2) | 86 (19.2) | 58 (13.6) | 59 (14.7) | |
| IMD quintilesa | ||||||
| 1 (most deprived) | 139 (8.1) | 35 (8.2) | 34 (7.6) | 31 (7.3) | 39 (9.7) | 0.01 |
| 2 | 426 (25.0) | 93 (21.8) | 109 (24.3) | 117 (27.5) | 107 (26.6) | |
| 3 | 320 (18.7) | 71 (16.6) | 83 (18.5) | 95 (22.4) | 71 (17.6) | |
| 4 | 441 (25.8) | 123 (28.8) | 117 (26.1) | 92 (21.6) | 109 (27.0) | |
| 5 (least deprived) | 378 (22.1) | 105 (24.6) | 106 (23.6) | 90 (21.2) | 77 (19.1) | |
| History of cardiovascular diseasea | 580 (34.0) | 113 (26.3) | 140 (31.2) | 151 (35.4) | 176 (43.7) | <0.001 |
| Diabetesa | 284 (16.6) | 37 (8.6) | 49 (10.9) | 76 (17.8) | 122 (30.3) | <0.001 |
| Hypertension | 1495 (87.6) | 369 (86.0) | 387 (86.2) | 380 (89.2) | 359 (89.1) | 0.09 |
| Average systolic BP, mmHgb | 134±18 | 133±17 | 133±18 | 134±17 | 136±20 | 0.04 |
| Average diastolic BP, mmHgb | 72±11 | 74±11 | 74±11 | 72±10 | 71±11 | <0.001 |
| Smokinga | ||||||
| Current | 79 (4.6) | 16 (3.7) | 13 (2.9) | 17 (4.0) | 33 (8.2) | <0.001 |
| Ex-smoker | 849 (49.7) | 183 (42.7) | 214 (47.7) | 215 (50.5) | 237 (58.8) | |
| Never | 779 (45.6) | 230 (53.6) | 222 (49.4) | 194 (45.5) | 133 (33.0) | |
| Body mass index, kg/m2 | 29.0±5.1 | 28.6±4.5 | 29.4±5.5 | 29.1±5.0 | 29.1±5.4 | 0.19 |
| Waist-to-hip ratiob | 0.9±0.1 | 0.9±0.1 | 0.9±0.1 | 0.9±0.1 | 0.9±0.1 | <0.001 |
| Total-to-HDL cholesterol ratio | 3.5±1.2 | 3.6±1.2 | 3.6±1.3 | 3.5±1.1 | 3.4±1.2 | 0.20 |
| uACR, mg/gc | 3.0 (0.0–13.3) | 1.5 (0.0–7.7) | 2.4 (0.0–9.4) | 3.8 (0.0–13.9) | 6.2 (0.0–28.9) | <0.001 |
| eGFR groups, ml/min per 1.73 m2a | ||||||
| ≥60 | 410 (24.0) | 130 (30.3) | 127 (28.3) | 87 (20.4) | 66 (16.4) | <0.001 |
| 45–59 | 892 (52.3) | 242 (56.4) | 242 (53.9) | 218 (51.2) | 190 (47.1) | |
| 30–44 | 379 (22.2) | 54 (12.6) | 78 (17.4) | 112 (26.3) | 135 (33.5) | |
| <30 | 26 (1.5) | 3 (0.7) | 2 (0.4) | 9 (2.1) | 12 (3.0) | |
| eGFR, ml/min per 1.73 m2b | 52.5±10.4 | 57.0±10.9 | 55.6±11.2 | 52.0±11.9 | 49.1±11.9 | <0.001 |
| Hemoglobin, g/dlb | 13.2±1.4 | 13.6±1.3 | 13.4±1.3 | 13.0±1.4 | 12.8±1.5 | <0.001 |
| Skin autofluorescence, AUb | 2.7±0.6 | 2.0±0.2 | 2.5±0.1 | 2.9±0.1 | 3.57±0.4 | <0.001 |
Data are number (%), mean±SD, or median (interquartile range). AF, autofluorescence; IMD, Index of Multiple Deprivation; uACR, albumin-to-creatinine ratio; AU, arbitrary unit.
a
Test for trend across quartiles (P<0.05).
b
One-way ANOVA (P<0.05).
c
Log uACR used as uACR not normally distributed. One-way ANOVA (P<0.05).