Table 3.
Association of baseline Lp(a) levels with annual changes in CAC volume and density
| Parameter | Mean change (SD) in CAC volume/density | Model 1 | Model 2 | p-value for race/ ethnicity interaction | ||
|---|---|---|---|---|---|---|
| B (95% CI) | p-value | B (95% CI) | p-value | |||
| CAC volume | ||||||
| Absolute change (mm3/year, n=5975) | ||||||
| Lp(a) (per SD in ln-transformed unit) | 20.4 (48.0) | 0.66 (−0.66, 1.98) | 0.33 | 0.83 (−0.51, 2.17) | 0.23 | 0.02 |
| Lp(a) ≥30 mg/dL | ||||||
| No | 19.9 (46.0) | - | - | - | - | 0.02 |
| Yes | 21.4 (51.9) | 3.43 (0.77, 6.09) | 0.01 | 3.21 (0.56, 5.87) | 0.02 | |
| Lp(a) ≥50 mg/dL | ||||||
| No | 19.6 (45.5) | - | - | - | - | 0.03 |
| Yes | 23.7 (57.0) | 5.67 (2.24, 9.11) | 0.001 | 4.45 (0.97, 7.92) | 0.01 | |
| Relative change (%/year, n=2902)a | ||||||
| Lp(a) (per SD in ln-transformed unit) | 47.4 (99.3) | 0.54 (−3.13, 4.21) | 0.77 | 0.54 (−3.72, 4.80) | 0.80 | 0.48 |
| Lp(a) ≥30 mg/dL | ||||||
| No | 45.0 (97.8) | - | - | - | - | 0.51 |
| Yes | 52.6 (102.4) | 3.15 (−4.59, 10.89) | 0.42 | 3.28 (−5.25, 11.81) | 0.45 | |
| Lp(a) ≥50 mg/dL | ||||||
| No | 46.6 (100.3) | - | - | - | - | 0.88 |
| Yes | 50.7 (95.2) | 2.16 (−7.06, 11.38) | 0.65 | 1.36 (−9.00, 11.73) | 0.80 | |
| CAC density | ||||||
| Absolute change (Hu category unit/year, n=5975) | ||||||
| Lp(a) (per SD in ln-transformed unit) | 0.069 (0.229) | 0.001 (−0.005, 0.006) | 0.83 | 0.002 (−0.005, 0.008) | 0.58 | 0.79 |
| Lp(a) ≥30 mg/dL | ||||||
| No | 0.067 (0.236) | - | - | - | - | 0.97 |
| Yes | 0.073 (0.213) | 0.002 (−0.010, 0.015) | 0.70 | 0.007 (−0.006, 0.021) | 0.31 | |
| Lp(a) ≥50 mg/dL | ||||||
| No | 0.068 (0.232) | - | - | - | - | 0.73 |
| Yes | 0.074 (0.218) | 0.004 (−0.011, 0.018) | 0.62 | 0.008 (−0.007, 0.024) | 0.31 | |
| Relative change (%/year, n=2902)a | ||||||
| Lp(a) (per SD in ln-transformed unit) | 1.72 (11.42) | 0.08 (−0.33, 0.49) | 0.70 | 0.09 (−0.34, 0.52) | 0.68 | 0.80 |
| Lp(a) ≥30 mg/dL | ||||||
| No | 1.68 (11.71) | - | - | - | - | 0.82 |
| Yes | 1.80 (10.78) | 0.14 (−0.76, 1.04) | 0.76 | 0.15 (−0.79, 1.10) | 0.75 | |
| Lp(a) ≥50 mg/dL | ||||||
| No | 1.82 (11.86) | - | - | - | - | 0.32 |
| Yes | 1.30 (9.39) | −0.55 (−1.52, 0.42) | 0.27 | −0.48 (−1.50, 0.53) | 0.35 | |
For continuous Lp(a) levels, regression coefficient (B) is expressed as change in CAC volume or density related to one SD unit (1.144) increase in ln-transformed Lp(a) levels (mg/dL).
Model 1: Adjusted for demographic and lifestyle factors, including age, sex, race/ethnicity, education, smoking, pack-years of smoking, current alcohol use and physical activity at baseline.
Model 2: Further adjusted for cardiovascular risk factors, including BMI, ln-transformed fasting glucose, SBP, HDL cholesterol, LDL cholesterol, ln-transformed triglycerides, use of lipid-lowering medication, use of hypertensive medication, use of glucose lowering medication, family history of heart attack, and eGFR at baseline. For change in CAC density, data were further adjusted for baseline CAC volume and change in CAC volume.
Abbreviations: BMI, body mass index; CAC, coronary artery calcification; eGFR, estimated glomerular filtration rate; HDL, high-density lipoprotein; LDL, low-density lipoprotein; Lp(a), lipoprotein(a); SBP, systolic blood pressure; SD, standard deviation.
For relative change, analysis was performed among participants with CAC at baseline.