Baseline clinical and pathological characteristics stratified by the International Clinical Diabetic Retinopathy Disease Severity Scale
| Total | No DR | Mild NPDR | Moderate NPDR | Severe NPDR | PDR | ||
| (n=232) | (n=55) | (n=23) | (n=42) | (n=41) | (n=71) | P value | |
| Clinical characteristics | |||||||
| Age (years) | 59 (50, 67) | 60 (43, 69) | 64 (55, 72) | 65 (58, 69) | 59 (53, 66) | 52 (42, 62) | <0.001 |
| Male (%) | 78 | 85 | 70 | 90 | 68 | 72 | 0.037 |
| BMI (kg/m2) | 24 (22, 27) | 25 (22, 28) | 24 (22, 28) | 25 (22, 27) | 23 (21, 24) | 24 (22, 26) | 0.11 |
| Diabetes duration (years) | 14 (10, 21) | 11 (4, 19) | 17 (11, 25) | 14 (8, 23) | 16 (10, 25) | 15 (11, 20) | 0.052 |
| History of CVD (%) | 24 | 24 | 39 | 29 | 24 | 15 | 0.18 |
| Ever having smoked (%) | 61 | 67 | 57 | 69 | 59 | 56 | 0.53 |
| RAAS use (%) | 66 | 49 | 87 | 81 | 49 | 72 | <0.001 |
| Glucose-lowering agents use (%) | 81 | 60 | 87 | 83 | 88 | 89 | <0.001 |
| Statin use (%) | 29 | 24 | 40 | 29 | 14 | 38 | 0.23 |
| Systolic blood pressure (mm Hg) | 145 (132, 160) | 140 (126, 148) | 141 (131, 150) | 150 (140, 167) | 152 (140, 170) | 148 (135, 163) | 0.0053 |
| Diastolic blood pressure (mm Hg) | 80 (72, 90) | 80 (73, 90) | 80 (69, 87) | 80 (71, 87) | 80 (74, 90) | 81 (72, 90) | 0.68 |
| Hemoglobin A1c (%) | 7.3 (6.4, 8.9) | 7.2 (6.4, 8.9) | 7.0 (6.3, 8.5) | 7.1 (6.3, 8.2) | 8.1 (6.8, 10.2) | 7.1 (6.1, 9.1) | 0.20 |
| (mmol/mol) | 56 (46, 74) | 55 (46, 74) | 53 (45, 69) | 54 (45, 66) | 65 (51, 88) | 54 (43, 76) | 0.20 |
| Total cholesterol (mmol/L) | 5.4 (4.5, 6.6) | 5.5 (4.6, 6.3) | 5.3 (4.6, 5.9) | 5.2 (4.3, 5.6) | 5.5 (4.4, 7.0) | 5.7 (4.5, 7.2) | 0.27 |
| Triglycerides (mmol/L) | 1.8 (1.3, 2.4) | 2.2 (1.4, 3.4) | 1.8 (1.3, 2.6) | 1.7 (1.4, 2.2) | 1.5 (1.2, 2.0) | 1.9 (1.1, 2.6) | 0.032 |
| LDL-C (mmol/L) | 3.2 (2.6, 4.4) | 3.1 (2.6, 4.2) | 3.0 (2.8, 3.8) | 3.2 (2.5, 3.6) | 3.9 (2.6, 4.7) | 3.5 (2.9, 4.9) | 0.11 |
| HDL-C (mmol/L) | 1.0 (0.9, 1.3) | 1.0 (0.8, 1.2) | 1.0 (0.7, 1.3) | 1.0 (0.9, 1.4) | 1.2 (1.0, 1.4) | 1.1 (0.9, 1.4) | 0.38 |
| Uric acid (µmol/L) | 393 (333, 446) | 387 (309, 422) | 387 (315, 488) | 399 (357, 422) | 399 (351, 470) | 405 (321, 458) | 0.33 |
| eGFR (mL/min/1.73 m2) | 39 (25, 61) | 53 (37, 75) | 46 (36, 67) | 36 (29, 57) | 29 (16, 47) | 36 (23, 55) | <0.001 |
| UACR (g/g) | 1.4 (0.5, 3.2) | 0.7 (0.2, 1.5) | 1.2 (0.7, 3.3) | 1.2 (0.3, 2.3) | 1.8 (1.0, 3.2) | 2.1 (1.0, 4.4) | <0.001 |
| Pathological characteristics | |||||||
| RPS Diabetic Nephropathy Classification | <0.001 | ||||||
| Class I | 6 | 22 | 0 | 0 | 2 | 0 | |
| Class IIa | 20 | 40 | 35 | 19 | 5 | 8 | |
| Class IIb | 28 | 20 | 17 | 33 | 20 | 41 | |
| Class III | 32 | 11 | 39 | 34 | 44 | 38 | |
| Class IV | 14 | 7 | 9 | 14 | 29 | 13 | |
| IFTA | <0.001 | ||||||
| 0 | 6 | 22 | 4 | 0 | 0 | 1 | |
| 1 | 28 | 44 | 48 | 31 | 17 | 14 | |
| 2 | 33 | 20 | 22 | 31 | 41 | 42 | |
| 3 | 33 | 14 | 26 | 38 | 42 | 43 | |
| Interstitial inflammation | |||||||
| 0 | 10 | 25 | 18 | 5 | 0 | 4 | <0.001 |
| 1 | 77 | 71 | 78 | 79 | 83 | 76 | |
| 2 | 13 | 4 | 4 | 16 | 17 | 20 | |
| Arteriolar hyalinosis | <0.001 | ||||||
| 0 | 6 | 20 | 0 | 0 | 2 | 1 | |
| 1 | 13 | 22 | 22 | 10 | 7 | 10 | |
| 2 | 81 | 58 | 78 | 90 | 91 | 89 | |
| Arteriosclerosis | 0.009 | ||||||
| 0 | 7 | 14 | 13 | 7 | 0 | 3 | |
| 1 | 47 | 53 | 26 | 45 | 39 | 56 | |
| 2 | 46 | 33 | 61 | 48 | 61 | 41 | |
| Diffuse | <0.001 | ||||||
| 0 | 6 | 23 | 0 | 0 | 5 | 0 | |
| 1 | 15 | 41 | 11 | 14 | 5 | 7 | |
| 2 | 33 | 27 | 33 | 48 | 19 | 36 | |
| 3 | 46 | 9 | 56 | 38 | 71 | 57 | |
| Exudative | 66 | 32 | 78 | 62 | 81 | 80 | 0.002 |
| Subendothelial space widening | 67 | 27 | 88 | 81 | 81 | 78 | <0.001 |
| Mesangiolysis/microaneurysm | 46 | 14 | 56 | 38 | 62 | 60 | 0.005 |
| Perihilar neovascularization | 81 | 59 | 89 | 81 | 86 | 90 | 0.062 |
Data are expressed as mean (SD), median (25th, 75th percentiles), or percentage.
RPS Diabetic Nephropathy Classification: I, mild or non-specific light microscopy changes and electron microscopy-proven glomerular membrane thickening; IIa, mild mesangial expansion; IIb, severe mesangial expansion; III, nodular sclerosis (Kimmelstiel-Wilson lesion); IV, advanced diabetic glomerulosclerosis.
BMI, body mass index; CVD, cardiovascular disease; DR, diabetic retinopathy; eGFR, estimated glomerular filtration rate; HDL-C, high-density lipoprotein cholesterol; IFTA, interstitial fibrosis and tubular atrophy; LDL-C, low-density lipoprotein cholesterol; NPDR, non-proliferative diabetic retinopathy; PDR, proliferative diabetic retinopathy; RAAS, renin-angiotensin-aldosterone system blockade; RPS, Renal Pathology Society; UACR, urine albumin to creatinine ratio.