Table 3:
Association of Race- and Sex-Specific Lp(a) Quartiles with Incident Stroke
| First Quartile HR (95% CI) |
Second Quartile HR (95% CI) |
Third Quartile HR (95% CI) |
Fourth Quartile HR (95% CI) |
Interaction P value |
|
|---|---|---|---|---|---|
| All | |||||
| N cases | 99 | 114 | 174 | 160 | |
| N controls | 215 | 241 | 265 | 246 | |
| Model 1 | 1.0 (ref) | 1.05 (0.72, 1.53) | 1.43 (1.01, 2.03) | 1.38 (0.96, 1.98) | |
| Model 2 | 1.0 (ref) | 1.24 (0.81, 1.92) | 1.49 (0.98, 2.25) | 1.45 (0.96, 2.19) | |
| Blacks | |||||
| N Cases | 39 | 43 | 66 | 79 | |
| N Controls | 104 | 124 | 122 | 128 | |
| Model 1 | 1.0 (ref) | 0.90 (0.51, 1.59) | 1.47 (0.87, 2.49) | 1.74 (1.03, 2.94) | |
| Model 2 | 1.0 (ref) | 0.95 (0.50, 1.81) | 1.48 (0.82, 2.67) | 1.96 (1.10, 3.46) | |
| Whites | |||||
| N Cases | 60 | 71 | 108 | 81 | |
| N Controls | 111 | 117 | 143 | 118 | |
| Model 1 | 1.0 (ref) | 1.14 (0.70, 1.86) | 1.36 (0.86, 2.14) | 1.16 (0.72, 1.87) | |
| Model 2 | 1.0 (ref) | 1.59 (0.87, 2.90) | 1.39 (0.79, 2.47) | 1.14 (0.64, 2.04) | |
| Race Interaction, Model 1/2 | 0.37/0.12 | ||||
| Women | |||||
| N Cases | 49 | 57 | 86 | 73 | |
| N Controls | 107 | 117 | 137 | 127 | |
| Model 1 | 1.0 (ref) | 0.97 (0.58, 1.63) | 1.27 (0.78, 2.07) | 1.17 (0.71, 1.94) | |
| Model 2 | 1.0 (ref) | 1.10 (0.61, 2.01) | 1.32 (0.75, 2.31) | 1.23 (0.68, 2.21) | |
| Men | |||||
| N Cases | 50 | 57 | 88 | 87 | |
| N Controls | 108 | 124 | 128 | 119 | |
| Model 1 | 1.0 (ref) | 1.11 (0.66, 1.86) | 1.55 (0.95, 2.52) | 1.63 (0.99, 2.67) | |
| Model 2 | 1.0 (ref) | 1.33 (0.73, 2.42) | 1.61 (0.91, 2.86) | 1.62 (0.90, 2.92) | |
| Sex Interaction, Model 1/2 | 0.88/0.96 | ||||
| Black Women | |||||
| N Cases | 24 | 25 | 29 | 47 | |
| N Controls | 52 | 60 | 62 | 68 | |
| Model 1 | 1.0 (ref) | 0.94 (0.44, 1.99) | 1.12 (0.54, 2.32) | 1.55 (0.77, 3.13) | |
| Model 2 | 1.0 (ref) | 1.00 (0.40, 2.50) | 1.27 (0.56, 2.92) | 1.90 (0.86, 4.17) | |
| Black Men | |||||
| N Cases | 15 | 18 | 37 | 32 | |
| N Controls | 52 | 64 | 60 | 60 | |
| Model 1 | 1.0 (ref) | 0.98 (0.42, 2.28) | 2.21 (1.02, 4.77) | 2.17 (0.98, 4.78) | |
| Model 2 | 1.0 (ref) | 0.66 (0.23, 1.93) | 1.93 (0.81, 4.65) | 2.04 (0.79, 5.32) | |
| White Women | |||||
| N Cases | 25 | 32 | 57 | 26 | |
| N Controls | 55 | 57 | 75 | 59 | |
| Model 1 | 1.0 (ref) | 1.01 (0.49, 2.07) | 1.35 (0.69, 2.64) | 0.84 (0.40, 1.76) | |
| Model 2 | 1.0 (ref) | 1.79 (0.69, 4.67) | 1.31 (0.54, 3.20) | 0.78 (0.30, 2.02) | |
| White Men | |||||
| N Cases | 35 | 39 | 51 | 55 | |
| N Controls | 56 | 60 | 68 | 59 | |
| Model 1 | 1.0 (ref) | 1.22 (0.63, 2.38) | 1.28 (0.68, 2.39) | 1.41 (0.75, 2.65) | |
| Model 2 | 1.0 (ref) | 1.76 (0.75, 4.11) | 1.34 (0.61, 2.96) | 1.53 (0.64, 3.65) |
Hazard ratios are compared to those in the first quartile (reference).
Legend: CI = confidence interval; HR = hazard ratio; N = number; ref = reference.
*
Model 1. Adjusted for age, race, sex, and age*race. Interaction terms for Lp(a) quartiles, model 1: age=0.82, race=0.37, sex=0.88.
Model 2. Adjusted for age, sex, and Framingham stroke risk factors (atrial fibrillation, smoking, prior cardiovascular disease, left ventricular hypertrophy, and use of any antihypertensive medication). Interaction terms for Lp(a) quartiles: age=0.77, race=0.12, sex=0.96.