Table 2.
Preclinical CVD markers as mediators in the association of BMI with clinical OA
| Independent variable | Dependent variable |
|||
|---|---|---|---|---|
| Total effect C | Indirect effect A | Direct effect C’ Indirect effect B | Mediation % (95% CI) | |
| Clinical hand OA OR (95% CI) | Mediator β (95% CI) | Clinical hand OA OR (95% CI) | ||
| BMI | 1.22 (1.08, 1.37) | 0.21 (0.18, 0.25) | 1.22 (1.08, 1.38) | NA |
| Systolic BP | 0.98 (0.84, 1.14) | |||
| BMI | 1.22 (1.08, 1.37) | 0.28 (0.25, 0.32) | 1.22 (1.08, 1.38) | NA |
| Diastolic BP | 0.98 (0.84, 1.15) | |||
| BMI | 1.21 (1.07, 1.36) | 0.23 (0.19, 0.27) | 1.19 (1.05, 1.34) | 10.6 (6.2, 30.5) |
| Carotid IMT | 1.09 (0.94, 1.25) | |||
| BMI | 1.56 (1.17, 2.08) | 0.01 (−0.06, 0.09) | 1.55 (1.16, 2.07) | NA |
| Popliteal VWT | 1.14 (0.84, 1.55) | |||
| BMI | 1.41 (1.15, 1.73) | 0.05 (−0.01, 0.11) | 1.41 (1.15, 1.73) | NA |
| Aortic PWV | 1.04 (0.81, 1.33) | |||
| Clinical knee OA OR (95% CI) | Mediator β (95% CI) | Clinical knee OA OR (95% CI) | ||
| BMI | 1.46 (1.32, 1.62) | 0.21 (0.17, 0.24) | 1.46 (1.31, 1.62) | NA |
| Systolic BP | 1.02 (0.90, 1.15) | |||
| BMI | 1.46 (1.32, 1.62) | 0.27 (0.24, 0.31) | 1.45 (1.31, 1.62) | 2.1 (1.6, 3.0) |
| Diastolic BP | 1.03 (0.91, 1.15) | |||
| BMI | 1.46 (1.32, 1.62) | 0.24 (0.20, 0.27) | 1.47 (1.33, 1.62) | NA |
| Carotid IMT | 0.97 (0.86, 1.09) | |||
| BMI | 1.20 (0.88, 1.64) | 0.03 (−0.04, 0.11) | 1.21 (0.89, 1.64) | NA |
| Popliteal VWT | 0.95 (0.74, 1.24) | |||
| BMI | 1.37 (1.12, 1.67) | 0.05 (−0.00, 0.11) | 1.37 (1.12, 1.67) | NA |
| Aortic PWV | 0.96 (0.76, 1.21) | |||
Results are based on analyses weighted towards the BMI distribution of the general population. Due to analyses in subpopulation and control definitions, numbers included in the analyses vary; numbers included are provided Supplementary Fig. 1, available at Rheumatology online. Continuous variables were standardized (mean 0, s.d. 1), s.d. BMI=4, s.d. systolic BP=19, s.d. diastolic BP=12, s.d. carotid IMT=0.09, s.d. popliteal VWT=0.05, s.d. aortic PWV=1.30. Analyses were adjusted for age, sex and education. BP: blood pressure; IMT: intima media thickness; NA: not applicable; OR: odds ratio; PWV: pulse wave velocity; VWT: vessel wall thickness.