Table 1.
Baseline characteristics of patient groups and non‐diabetes controls
| Type 1 diabetes with proliferative retinopathy | Type 1 diabetes without proliferative retinopathy | Non‐diabetes controls | Overall P value | |
|---|---|---|---|---|
| N | 51 | 53 | 49 | – |
| Age (yr) | 44.5 ± 7.2a, b | 37.8 ± 9.2 | 36.7 ± 11.2 | <0.001 |
| Sex (men/women; % men) | 21/30 (41.2) | 20/33 (37.7) | 19/30 (38.8) | 0.935 |
| Estimated IQc | 110.2 ± 13.4 | 106.9 ± 11.2 | 108.5 ± 11.7 | 0.399 |
| Depressive symptomsd | 8.0 (0–42)a, b | 5.0 (0–31) | 4.0 (0–37) | 0.005 |
| BMI (km/m2) | 25.6 ± 4.1 | 24.8 ± 3.5 | 24.3 ± 3.5 | 0.189 |
| A1C (mmol/mol) | 64.7 ± 14.1a | 61.7 ± 9.8a | 34.2 ± 2.6 | <0.001 |
| A1C (%) | 8.1 ± 1.3a | 7.8 ± 0.9a | 5.3 ± 0.2 | <0.001 |
| Systolic blood pressure (mm Hg) | 133.6 ± 17.3a | 129.1 ± 14.7 | 123.6 ± 11.3 | 0.004 |
| Diastolic blood pressure (mm Hg) | 76.0 ± 8.7 | 78.2 ± 9.5 | 77.4 ± 7.2 | 0.426 |
| Total cholesterol (mmol/l) | 4.5 ± 0.7 | 4.7 ± 0.7 | 4.5 ± 0.9 | 0.217 |
| Current smoking (%) | 6 (11.8) | 10 (18.9) | 11 (22.4) | 0.371 |
| Cholesterol medication (%) | 11 (20.8) | 16 (31.4) | – | 0.226 |
| Blood pressure medication (%) | 32 (62.7)b | 6 (11.3) | – | <0.001 |
| Hypertension (%)e | 33 (64.7)b | 13 (24.5) | – | <0.001 |
| Albumin:creatinine ratio (mg/mmol; min‐max) | 0.91 (0–33.17)b | 0.39 (0–3.19) | – | 0.003 |
| BG before MRI (mmol/l) | 9.2 ± 3.7 | 10.5 ± 4.7 | – | 0.124 |
| BG before NPA (mmol/l) | 8.6 ± 4.0 | 8.4 ± 4.0 | – | 0.777 |
| Diabetes duration (yrs) | 34.3 ± 7.9† | 21.6 ± 9.3 | – | <0.001 |
| Diabetes onset age (yrs) | 10.2 ± 7.2† | 16.2 ± 9.7 | – | 0.001 |
| Diabetes early onset age (%)f | 18 (35.3) | 10 (18.9) | – | 0.077 |
| Severe hypoglycemic events (min‐max)g | 2.0 (0–40) | 2.0 (0–50) | – | 0.701 |
| Neuropathy (%)h | 25 (49) | – | – | – |
| Albuminuria (%)i | 14 (27.5) | – | – | – |
| Mean global gray matter volume (mm3) | 614.08 ± 81.4 | 614.97 ± 74.0 | 639.23 ± 91.0 | 0.282 |
| Network sizej | 7,473 ± 688 | 7,439 ± 746 | 7,591 ± 757 | 0.994 |
| Network degreek | 1,102 ± 115 | 1,108 ± 120 | 1,151 ± 120 | 0.356 |
| Connectivity densityl | 14.81 ± 0.68 | 14.97 ± 0.69 | 15.24 ± 0.80 | 0.163 |
Data are means ± standard deviation, median with minimum and maximum or absolute numbers with percentages. NPA: neuropsychological assessment. BG: blood glucose.
Statistically different from controls.
Statistically different from patients without proliferative retinopathy.
Estimated IQ was measured using the Dutch version of the National Adult Reading Test (NART).
Depressive symptoms were measured using the Center for Epidemiological Studies scale for Depression.
Hypertension was defined as a systolic blood pressure of ≥140 mm Hg, a diastolic blood pressure of ≥90 mm Hg or the user of antihypertensive drugs. Controls with hypertension were excluded from the study.
Diabetes early onset age was defined as an onset age below the age of 7 years.
Severe hypoglycemic events were self‐reported and defined as events for which the patient needs assistance from a third person to recuperate as a result of loss of consciousness or seriously deranged functioning, coma, or seizure owing to low glucose levels.
Neuropathy was based on medical records or, in case they were not available, based on self‐report.
Albuminuria was defined as an albumin:creatinine ratio >2.5 mg/mmol for men and >3.5 mg/mmol for women.
Size is defined as the number of nodes of a network.
Degree is defined as average number of edges per node.
Connectivity density is defined as the percentage of existing edges out of the total number of possible edges.