Table 1.
General characteristics of the study population (n = 532) according to tertiles of 25-hydroxyvitamin D2 and month-specific tertiles of 25-hydroxyvitamin D3
| 25-hydroxyvitamin D2 | 25-hydroxyvitamin D3 | |||||
|---|---|---|---|---|---|---|
| T1 (n = 177, 0.08-1.19 nmol/L) | T2 (n = 178, 1.20-2.09 nmol/L) | T3 (n = 177, 2.10-20.2 nmol/L) | T1 (n = 177, 8–86 nmol/L)d | T2 (n = 177, 27–100 nmol/L)d | T3 (n = 178, 43–169 nmol/L)d | |
| Age (years) | 40.5 ± 10.5 | 39.0 ± 9.8 | 39.2 ± 10.0 | 40.9 ± 10.4 | 39.5 ± 10.3 | 38.2 ± 9.4 |
| Male sex (%) | 51 | 47 | 55 | 53 | 52 | 49 |
| Body mass index (kg/m2) | 24.5 ± 3.4 | 24.7 ± 3.1 | 24.3 ± 3.3 | 24.7 ± 3.7 | 24.5 ± 3.1 | 24.2 ± 2.8 |
| HbA1c (%) (mmol/mol) | 8.7 ± 1.7 (72 ± 19) | 8.5 ± 1.7 (69 ± 19) | 8.5 ± 1.5 (69 ± 16) | 9.0 ± 1.8 (75 ± 20) | 8.4 ± 1.5 (68 ± 16) | 8.2 ± 1.5 (66 ± 16) |
| Duration of diabetes (years) | 22.9 ± 9.0 | 20.5 ± 9.7 | 20.9 ± 9.3 | 22.8 ± 9.2 | 22.2 ± 9.9 | 19.4 ± 8.8 |
| Total cholesterol (mmol/L) | 5.4 ± 1.4 | 5.4 ± 1.1 | 5.1 ± 1.1 | 5.4 ± 1.3 | 5.2 ± 1.1 | 5.3 ± 1.2 |
| LDL cholesterol (mmol/L) | 3.2 ± 1.2 | 3.1 ± 1.0 | 3.2 ± 1.0 | 3.2 ± 1.1 | 3.1 ± 1.0 | 3.2 ± 1.1 |
| HDL cholesterol (mmol/L) | 1.6 ± 0.5 | 1.6 ± 0.4 | 1.6 ± 0.4 | 1.6 ± 0.4 | 1.6 ± 0.4 | 1.7 ± 0.4 |
| Total-HDL-cholesterol-ratio | 3.7 ± 1.3 | 3.5 ± 1.4 | 3.3 ± 1.0 | 3.7 ± 1.5 | 3.4 ± 1.1 | 3.3 ± 1.1 |
| Triacylglycerols (mmol/L) | 1.0 (0.8-1.4) | 1.0 (0.7-1.4) | 0.9 (0.7-1.2) | 1.0 (0.7-1.5) | 1.0 (0.8-1.4) | 0.9 (0.7-1.2) |
| Smoking (never/ex/current, %) | 39/32/29 | 39/32/29 | 42/24/34 | 37/28/35 | 42/30/28 | 41/30/29 |
| Physical activity (0/≤mediana/>median, %) | 68/17/15 | 59/20/21 | 60/21/19 | 74/14/12 | 63/20/17 | 50/25/25 |
| Alcohol intake (0/≤70 g per wk/>70 g per wk, %) | 16/53/31 | 19/53/28 | 10/57/33 | 21/53/26 | 13/56/31 | 10/55/35 |
| Systolic blood pressure (mmHg) | 127 ± 22 | 121 ± 19 | 120 ± 18 | 125 ± 21 | 121 ± 20 | 123 ± 18 |
| Diastolic blood pressure (mmHg) | 76 ± 11 | 75 ± 12 | 74 ± 11 | 76 ± 12 | 73 ± 11 | 76 ± 11 |
| Use of antihypertensive medication (%) | 45 | 31 | 19 | 36 | 33 | 26 |
| Use of hormone replacement therapy (% women) | 14 | 11 | 10 | 11 | 8 | 15 |
| Use of oral contraceptive therapy (% women) | 39 | 42 | 47 | 27 | 49 | 50 |
| Estimated glomerular filtration rate (mL/min) | 97 (77–109) | 103 (88–114) | 104 (91–113) | 102 (82–112) | 102 (86–112) | 101 (89–112) |
| C-reactive protein (mg/L) | 1.1 (0.5-2.7) | 1.0 (0.4-2.5) | 1.1 (0.4-2.4) | 1.4 (0.5-3.5) | 0.9 (0.4-2.3) | 0.9 (0.4-2.4) |
| Interleukin-6 (pg/mL) | 2.1 (1.5-4.0) | 1.8 (1.1-3.0) | 1.8 (1.2-3.1) | 2.3 (1.5-4.4) | 1.9 (1.2-3.0) | 1.6 (1.1-2.8) |
| Tumour necrosis factor-α (pg/mL) | 3.2 (2.3-4.6) | 2.7 (2.0-3.3) | 2.6 (2.0-3.2) | 3.1 (2.2-4.3) | 2.7 (2.1-3.5) | 2.7 (2.1-3.4) |
| Low-grade inflammation score (SD)b | 0.27 ± 1.00 | −0.13 ± 0.99 | −0.14 ± 0.97 | 0.26 ± 1.10 | −0.11 ± 0.87 | −0.14 ± 0.97 |
| Soluble E-selectin (ng/mL) | 36 ± 20 | 32 ± 11 | 35 ± 12 | 36 ± 16 | 35 ± 16 | 32 ± 13 |
| Soluble vascular cell adhesion molecule-1 (ng/mL) | 451 ± 174 | 391 ± 97 | 387 ± 98 | 438 ± 169 | 399 ± 106 | 393 ± 103 |
| Endothelial dysfunction score (SD)c | 0.30 ± 1.32 | −0.22 ± 0.74 | −0.08 ± 0.76 | 0.21 ± 1.15 | −0.04 ± 0.97 | −0.17 ± 0.82 |
| Albuminuria (normo/micro/macro, %) | 45/13/42 | 65/17/18 | 73/17/10 | 52/14/34 | 58/20/22 | 74/13/13 |
| Retinopathy (none/non-proliferative/proliferative, %) | 34/30/36 | 49/27/24 | 49/25/26 | 34/33/33 | 44/28/28 | 54/21/25 |
| Cardiovascular disease (%) | 21 | 29 | 24 | 28 | 27 | 20 |
| 25-hydroxyvitamin D2 (nmol/L) | 0.8 (0.6-1.0) | 1.5 (1.4-1.8) | 2.8 (2.4-3.9) | 1.4 (0.9-2.5) | 1.6 (1.1-2.4) | 1.6 (1.1-2.4) |
| 25-hydroxyvitamin D3 (nmol/L) | 46 (28–73) | 58 (37–75) | 49 (33–74) | 27 (21–38) | 48 (39–67) | 77 (62–98) |
Data are presented as means ± SD, medians (interquartile range) or percentages, as appropriate. asex-specific medians for physical activity were 11.3 MET-h/week for men and 6.8 MET-h/week for women; bthe low-grade inflammation score was calculated as the mean Z-score of ln-transformed values of C-reactive protein, interleukin-6 and tumour necrosis factor-α; cthe endothelial dysfunction score was calculated as the mean Z-score of soluble E-selectin and soluble vascular cell adhesion molecule-1; dranges of 25-hydroxyvitamin D3 concentrations overlap between tertiles as tertiles were defined month-specifically (see Methods section)