Table 5.
Proportion of the Difference in CAC between South Asians and Each of the 4 MESA Racial/Ethnic Groups Groups Explained by PFVa
| Effect of Racial/Ethnic Group Before PFV Adjustmentb | Effect of Racial/Ethnic Group After PFV Adjustmentb | Proportion of the Effect Explained (PE %)c | ||
|---|---|---|---|---|
| Any CAC Models, All Participants | ||||
| Racial/Ethnic Group | N | Risk Difference % (95% CI) | Risk Difference % (95% CI) | PE % (95% CI) |
| South Asian (referent) | 779 | — | — | — |
| White | 2534 | 4.0 (0.2 to 7.7) | 3.3 (−0.5 to 6.9) | 19 (9 to 102) |
| Black | 1824 | −11.7 (−15.5 to −8.0) | −11.2 (−15.0 to −7.3) | 5 (4 to 7) |
| Latino | 1450 | −7.3 (−11.2 to −3.5) | −7.9 (−11.7 to −4.0) | −8 (−16 to −5) |
| Chinese American | 776 | 1.5 (−2.9 to 5.7) | 0.6 (−3.8 to 4.9) | 61 (−503 to 793) |
| Ln(CAC) Models, Participants With CAC >0 | ||||
|---|---|---|---|---|
| Racial/Ethnic Group | N | ß (95% CI) | ß (95% CI) | PE % (95% CI) |
| South Asian (referent) | 349 | — | — | — |
| White | 1441 | 0.02 (−0.19 to 0.23) | −0.03 (−0.25 to 0.17) | 270 (−1014 to 691) |
| Black | 796 | −0.38 (−0.61 to −0.16) | −0.35 (−0.58 to −0.13) | 8 (5 to 20) |
| Latino | 657 | −0.34 (−0.57 to −0.12) | −0.38 (−0.61 to −0.16) | −11 (−32 to −7) |
| Chinese American | 391 | −0.25 (−0.50 to −0.01) | −0.32 (−0.56 to −0.07) | −26 (−167 to −12) |
CAC indicates coronary artery calcium; MESA, Multi‐Ethnic Study of Atherosclerosis; PFV, pericardial fat volume.
All models adjusted for body mass index, age, sex, heart disease in first‐degree relative, exercise, alcohol use, current smoking, hypertension, cholesterol medication use, low‐density lipoprotein, and diabetes mellitus.
For the presence of “Any CAC,” effects are shown as risk differences on the proportion scale, shown in percentage points. For effects on CAC severity, effects are shown as adjusted differences in average ln(CAC), or betas, between each comparison group and South Asians.
The proportion of the effect explained (PE) is calculated as the percent difference between the residual adjusted association of race/ethnicity with presence or severity of CAC after adjustment for PFV, and the overall adjusted association, before adjustment for PFV. Note that PE may be negative, if the direct effect is larger than the overall effect; it can also exceed 100% if the direct and overall effects have opposite signs. Please note that for PE estimates, 95% CIs were obtained as the 25th and 95th percentiles of PE estimates based on 1000 simulations of unobserved potential outcomes and therefore may not be symmetric about the point estimate.