Table 2.
Baseline characteristics across quarters of global DNA methylation.
| Characteristic | Global DNA methylation | p difference∗ | p-trend | r (p value)∗∗ | β (p value)∗∗∗ | |||
|---|---|---|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | |||||
| n | 141 | 141 | 140 | 142 | ||||
| Actual% 5mc | ||||||||
| Median | 0.14 | 2.14 | 3.97 | 7.27 | ||||
| Women, n (%) | 100 (70.9) | 109 (77.3) | 115 (82.1) | 114 (80.3) | 0.117 | 0.036 | 0.076 (0.070) | 0.543 (0.063) |
| Any diabetes | 31 (22.0) | 38 (26.9) | 36 (25.7) | 53 (37.3) | 0.028 | 0.008 | 0.101 (0.016) | 0.621 (0.036) |
| Diabetes status, n (%) | 0.0007 | 0.145 | 0.082 (0.052) | |||||
| None | 110 (78.0) | 103 (73.0) | 104 (74.3) | 89 (62.7) | Reference | |||
| Screen-detected | 15 (10.6) | 23 (16.3) | 17 (12.1) | 42 (29.6) | 1.069 (0.004) | |||
| Known diabetes | 16 (11.3) | 15 (10.6) | 19 (13.6) | 11 (7.7) | −0.026 (0.947) | |||
| Current smoking, n (%) | 55 (39.0) | 60 (42.5) | 59 (42.1) | 50 (35.2) | 0.562 | 0.519 | −0.038 (0.367) | −0.162 (0.505) |
| Current drinking, n (%) | 40 (28.4) | 37 (26.2) | 37 (26.4) | 36 (25.3) | 0.950 | 0.594 | −0.019 (0.648) | 0.211 (0.494) |
| Age (years) | 51 (41–64) | 52 (44–60) | 53 (44–62) | 53 (44–64) | 0.883 | 0.523 | 0.036 (0.391) | 0.007 (0.443) |
| Body mass index (kg/m2) | 29.1 (24.4–33.4) | 28.8 (23.6–34.7) | 28.6 (24.3–34.3) | 31.0 (26.3–34.9) | 0.209 | 0.051 | 0.090 (0.033) | 0.015 (0.464) |
| Waist circumference (cm) | 96.0 (85.5–104.0) | 96.5 (85.1–108.0) | 97.0 (87.5–106.4) | 99.5 (88.4–108.2) | 0.256 | 0.053 | 0.090 (0.033) | 0.007 (0.444) |
| Hip circumference (cm) | 107.8 (98.0–116.5) | 108.0 (99.2–118.0) | 109.2 (100.2–117.5) | 110.0 (101.5–121.0) | 0.385 | 0.083 | 0.083 (0.050) | 0.004 (0.685) |
| Waist-to-hip ratio | 0.87 (0.82–0.93) | 0.87 (0.83–0.93) | 0.87 (0.84–0.92) | 0.88 (0.83–0.93) | 0.871 | 0.477 | 0.031 (0.465) | 1.265 (0.470) |
| Systolic blood pressure (mmHg) | 121 (109–137) | 120 (109–134) | 119 (108–129) | 120 (109–133) | 0.570 | 0.514 | −0.025 (0.557) | −0.012 (0.090) |
| Diastolic blood pressure (mmHg) | 75 (66–82) | 74 (67–83) | 73 (66–79) | 73 (67–82) | 0.529 | 0.379 | −0.039 (0.357) | −0.013 (0.207) |
| Fasting blood glucose (mmol/L) | 5.4 (4.9–6.0) | 5.7 (5.0–6.3) | 5.4 (5.0–6.3) | 6.0 (5.0–7.1) | 0.006 | 0.003 | 0.126 (0.029) | 0.066 (0.225) |
| 2-hour glucose (mmol/L) | 6.6 (5.4–9.0) | 6.9 (6.0–8.8) | 7.0 (5.6–8.6) | 7.8 (6.0–10.0) | 0.002 | 0.0003 | 0.167 (0.0002) | 0.011 (0.824) |
| HbA1c (%) | 5.7 (5.5–6.1) | 5.8 (5.5–6.3) | 5.9 (5.6–6.3) | 5.9 (5.5–6.3) | 0.519 | 0.195 | 0.057 (0.181) | −0.039 (0.782) |
| Fasting insulin (μU/mL) | 7.3 (3.7–11.7) | 6.1 (2.1–12.9) | 6.7 (2.9–12.4) | 8.3 (3.0–12.8) | 0.435 | 0.961 | −0.005 (0.900) | −0.016 (0.133) |
| 2-hour insulin (μU/mL) | 36.3 (19.9–64.3) | 38.7 (18.3–68.4) | 39.7 (10.2–68.1) | 44.1 (19.5–89.4) | 0.485 | 0.131 | 0.070 (0.120) | 0.0004 (0.860) |
| C-reactive protein (mg/L) | 3.6 (0.9–9.2) | 4.4 (1.1–9.6) | 2.8 (0.9–9.4) | 5.3 (1.7–11.7) | 0.091 | 0.121 | 0.080 (0.059) | 0.005 (0.641) |
| Cotinine (ng/mL) | 10.0 (9.0–282.1) | 10 (9–310) | 10 (9–270) | 10.0 (9.0–197.2) | 0.417 | 0.323 | −0.059 (0.160) | −0.002 (0.109) |
| Gamma-glutamyltransferase (IU/L) | 27.0 (18.0–40.0) | 28.0 (20.0–45.7) | 27.5 (19.0–39.2) | 28.0 (20.2–44.5) | 0.820 | 0.625 | 0.0005 (0.991) | −0.002 (0.081) |
| Triglycerides (mmol/L) | 1.23 (0.93–1.74) | 1.24 (0.90–1.69) | 1.27 (0.87–1.81) | 1.34 (1.06–1.92) | 0.096 | 0.048 | 0.079 (0.061) | −0.065 (0.642) |
| HDL-cholesterol (mmol/L) | 1.28 (1.11–1.46) | 1.22 (0.99–1.45) | 1.24 (1.03–1.45) | 1.16 (0.99–1.44) | 0.138 | 0.058 | −0.081 (0.055) | −0.509 (0.130) |
| LDL-cholesterol (mmol/L) | 3.49 (2.84–4.28) | 3.43 (2.80–4.05) | 3.62 (3.00–4.26) | 3.68 (2.90–4.39) | 0.279 | 0.136 | 0.079 (0.062) | 0.078 (0.538) |
| Total cholesterol (mmol/L) | 5.52 (4.70–6.40) | 5.33 (4.59–6.05) | 5.59 (4.75–6.37) | 5.54 (4.93–6.46) | 0.183 | 0.275 | 0.061 (0.147) | −0.009 (0.933) |
∗ p values from Kruskal-Wallis and chi square tests for the differences across quarters of global DNA methylation.
∗∗Spearman correlation coefficients and p values for the continuous associations of global DNA methylation with covariates.
∗∗∗Beta coefficients and p values from age, gender, and status for hyperglycemia and smoking adjusted robust linear regressions for the prediction of global DNA methylation by various traits.