Table 2.
Main results of Mendelian randomisation analysis using individual level data
| Cases/controls | Causal estimate (odds ratio)b (95% CI) | Overall estimatec | P value | P het d | ||||
|---|---|---|---|---|---|---|---|---|
| Scotland 1 | SOCCS/GS | Croatia | SOCCS/LBC | UK biobank | ||||
| 932/942 | 4551/8804 | 689/441 | 461/1444 | 3301/11382 | ||||
| Univariable model | ||||||||
| Weighted score | 1.92 (0.36–10.27) | 0.84 (0.44–1.62) | 3.69 (0.41–33.34) | 0.59 (0.09–3.99) | 0.67 (0.33–1.38) | 0.85 (0.55–1.33) | 0.481 | 0.531 |
| Unweighted score | 2.20 (0.30–16.19) | 0.89 (0.41–1.93) | 10.71 (0.71–161.41) | 1.02 (0.11–9.84) | 0.85 (0.36–1.96) | 1.03 (0.61–1.73) | 0.920 | 0.440 |
| Multivariable modela | ||||||||
| Weighted score | 6.85 (0.77–60.81) | 0.63 (0.24–1.67) | 3.82 (0.41–35.23) | 0.57 (0.08–3.87) | 0.87 (0.44–1.73) | 1.03 (0.51–2.07) | 0.931 | 0.227 |
| Unweighted score | 4.70 (0.46–48.41) | 0.65 (0.22–1.88) | 11.21 (0.76–164.33) | 0.93 (0.10–8.66) | 0.81 (0.38–1.75) | 1.12 (0.51–2.45) | 0.785 | 0.222 |
aMultivariable regression model adjusted by age, sex and BMI for Scotland 1, SOCCS/GS and UK biobank, age and sex for Croatia, sex for LBC.MD
bChange in CRC risk per unit log-transformed 25-OHD (nmol/L)
cOverall estimates were obtained by meta-analyses under random-effect model
dPhet, P values of χ2 Q test for heterogeneity
25-OHD 25-hydroxyvitamin D, CI confidence interval, CRC colorectal cancer, GRS genetic risk score, LBC Lothian Birth Cohort, SOCCS Scotland Colorectal Cancer Study