General characteristics and retinal and skin measures for the retinal study population according to glucose metabolism status
| Characteristics | NGM (n = 1,040) | Prediabetes (n = 276) | T2D (n = 475) |
|---|---|---|---|
| Age (years) | 58.0 ± 8.2 | 61.5 ± 7.2 | 62.9 ± 7.6 |
| Women | 596 (57.3) | 130 (47.1) | 147 (30.9) |
| Diabetes duration (years)* | — | — | 6.0 (3.0–12.0) |
| Diabetes medication use | |||
| Any type | — | — | 359 (75.6) |
| Insulin | — | — | 86 (18.1) |
| Oral glucose-lowering medication | — | — | 338 (71.2) |
| BMI (kg/m2) | 25.5 ± 3.4 | 27.5 ± 4.0 | 29.5 ± 4.5 |
| Waist circumference (cm) | |||
| Men | 96.3 ± 9.1 | 101.6 ± 9.4 | 106.7 ± 11.6 |
| Women | 85.6 ± 9.7 | 92.7 ± 12.1 | 100.9 ± 13.6 |
| Smoking | |||
| Never/former/current, n | 409/502/116 | 75/161/33 | 136/264/62 |
| Never/former/current, % | 39.8/48.9/11.3 | 27.9/59.9/12.3 | 29.4/57.1/13.4 |
| History of cardiovascular disease | 116 (11.4) | 30 (11.2) | 118 (25.8) |
| eGFR (mL/min/1.73 m2) | 89.9 ± 13.0 | 87.2 ± 14.0 | 85.3 ± 17.2 |
| eGFR <60 mL/min/1.73 m2 | 18 (1.7) | 10 (3.6) | 45 (9.5) |
| (Micro)albuminuria† | 47 (4.6) | 15 (5.4) | 77 (16.2) |
| Retinopathy | 1 (0.1) | 1 (0.4) | 18 (3.9) |
| Composite indices of potential mediators‡ | |||
| Markers of hyperglycemia | |||
| HbA1c (%)‡ | 5.4 ± 0.4 | 5.7 ± 0.4 | 6.8 ± 0.9 |
| HbA1c (mmol/mol) | 35.8 ± 3.7 | 38.4 ± 4.5 | 50.6 ± 9.9 |
| Fasting glucose (mmol/L)‡ | 5.2 ± 0.4 | 5.9 ± 0.6 | 7.7 ± 1.7 |
| 2-h postload glucose (mmol/L)‡§ | 5.4 ± 1.1 | 8.2 ± 1.7 | 14.2 ± 3.9 |
| Skin autofluorescence (AU)‡ | 2.3 ± 0.5 | 2.4 ± 0.5 | 2.6 ± 0.6 |
| Markers of blood pressure | |||
| Ambulatory 24-h SBP (mmHg)‡ | 117.3 ± 11.1 | 120.1 ± 11.9 | 122.4 ± 11.7 |
| Ambulatory 24-h DBP (mmHg)‡ | 73.6 ± 7.2 | 74.5 ± 7.3 | 73.0 ± 7.0 |
| Antihypertensive medication use‡ | 226 (21.7) | 113 (40.9) | 333 (70.1) |
| Markers of lipid profile | |||
| Total-to-HDL cholesterol ratio | 3.5 ± 1.1 | 3.9 ± 1.3 | 3.7 ± 1.1 |
| LDL cholesterol (mmol/L) | 3.3 ± 0.9 | 3.3 ± 1.1 | 2.4 ± 0.9 |
| Total cholesterol (mmol/L)‡ | 5.6 ± 1.0 | 5.5 ± 1.2 | 4.4 ± 1.1 |
| HDL cholesterol (mmol/L)‡ | 1.7 ± 0.5 | 1.5 ± 0.4 | 1.3 ± 0.4 |
| Triglycerides (mmol/L)‡ | 1.2 ± 0.6 | 1.6 ± 1.0 | 1.8 ± 0.9 |
| Lipid-modifying medication use‡ | 178 (17.1) | 93 (33.7) | 350 (73.7) |
| Markers of insulin resistance | |||
| HOMA2-IRInsulin (AU)‡ | 1.3 ± 0.7 | 1.9 ± 1.1 | 2.4 ± 1.4 |
| HOMA2-IRC-peptide (AU)‡ | 1.3 ± 0.5 | 1.7 ± 0.7 | 2.1 ± 0.9 |
| Markers of low-grade inflammation | |||
| hs-CRP (mg/L)‡ | 1.1 (0.6–2.2) | 1.8 (0.8–3.5) | 1.5 (0.7–3.3) |
| Serum amyloid A (mg/L)‡ | 3.0 (1.9–5.0) | 3.6 (2.3–5.7) | 3.5 (2.2–6.0) |
| Soluble ICAM-1 (ng/mL)‡ | 338.6 ± 80.2 | 365.8 ± 103.2 | 383.8 ± 115.9 |
| Interleukin-6 (pg/mL)‡ | 0.5 (0.4–0.8) | 0.6 (0.4–0.9) | 0.8 (0.6–1.1) |
| Interleukin-8 (pg/mL)‡ | 3.7 (3.0–4.6) | 4.3 (3.3–5.3) | 4.8 (4.0–6.1) |
| Tumor necrosis factor-α (pg/mL)‡ | 2.1 (1.8–2.4) | 2.2 (1.9–2.6) | 2.5 (2.1–2.9) |
| Markers of arterial stiffness | |||
| Carotid-femoral pulse wave velocity (m/s)‡ | 8.4 ± 1.7 | 9.2 ± 2.1 | 9.9 ± 2.3 |
| Carotid distensibility coefficient (103/kPa)‡ | 15.1 ± 5.2 | 13.7 ± 4.8 | 13.3 ± 4.9 |
| Microvascular outcomes | |||
| Baseline arteriolar diameter (MU) | 115.3 ± 15.3 | 114.8 ± 15.9 | 116.0 ± 15.9 |
| Arteriolar average dilation (%) | |||
| Mean ± SD | 3.4 ± 2.8 | 3.1 ± 2.8 | 2.4 ± 2.7 |
| Median [interquartile range] | 3.0 (1.1–5.3) | 2.8 (0.8–5.0) | 1.6 (0.4–3.9) |
| Baseline skin blood flow (PU)‖ | 10.8 ± 6.4 | 11.7 ± 7.2 | 11.0 ± 5.7 |
| Skin hyperemic response (%)‖ | |||
| Mean ± SD | 1,252.6 ± 813.4 | 1,107.4 ± 710.8 | 941.7 ± 701.1 |
| Median [interquartile range] | 1,104.0 (668.7–1,656.9) | 1,006.9 (604.9–1,536.9) | 821.2 (479.0–1,209.8) |
Data are reported as mean ± SD, median [interquartile range], or number (%) as appropriate. AU, arbitrary units; DBP, diastolic blood pressure; eGFR, estimated glomerular filtration rate; HOMA2-IR, HOMA of insulin resistance; ICAM, intercellular adhesion molecule; MU, measurement units; PU, perfusion units; SBP, systolic blood pressure.
↵* Available in 313 individuals with type 2 diabetes.
↵† (Micro)albuminuria was defined as a urinary albumin excretion of >30 mg per 24 h.
↵‡ Indicates that the individual marker is part of the corresponding composite index.
↵§ Available in 389 individuals with T2D, as the oral glucose tolerance test was not performed in individuals who were on insulin treatment.
↵‖ Heat-induced skin hyperemia measures were available in a different subset of n = 1,281.