Table 5.
Phenotypic correlations (rp) for body mass index and blood pressure in all twin participants (n = 1,235)
| BP and BMI | rp | t a | P valuea |
|---|---|---|---|
| Measured SBP | 0.18 | -- | -- |
| Fixed addition SBP | 0.24 | −7.92 | <0.001 |
| Stepped addition SBP | 0.26 | −7.89 | <0.001 |
| Drug class addition SBP | 0.29 | −7.06 | <0.001 |
| Random addition of 14–38mm Hg to SBPb | 0.2785±0.006 (0.278–0.279) | -- | -- |
| Random addition of 14–50mm Hg to SBPb | 0.2784±0.008 (0.262–0.295) | -- | -- |
| Addition of 20mm Hg to all medicated SBPc | 0.275 | ||
| Measured DBP | 0.21 | -- | -- |
| Fixed addition DBP | 0.26 | −7.93 | <0.001 |
| Stepped addition DBP | 0.29 | −6.86 | <0.001 |
| Drug class addition DBP | 0.32 | −6.59 | <0.001 |
| Random addition of 9–27mm Hg to DBPb | 0.3046±0.006 (0.304–0.305) | -- | -- |
| Random addition of 9–40mm Hg to DBPb | 0.297±0.01 (0.279–0.318) | -- | -- |
| Addition of 14mm Hg to all medicated DBPc | 0.308 |
Data in parentheses are 95% confidence intervals.
Abbreviations: BMI, body mass index; BP, blood pressure; DBP, diastolic blood pressure; SBP, systolic blood pressure.
aThe rp of each imputed SBP and DBP was compared with the rp of the measured SBP and DPB, respectively; t statistic and P value from 2-tailed significance test of the difference between dependent correlations.
bAddition of mm Hg to SBP or DBP in medicated individuals. For these, the rp represents the mean phenotypic correlation of 500 simulations.
c The average mm Hg added to the DBP/SBP of medicated individuals in the drug class addition was 14mm Hg/20mm Hg.