Table 2.
Mean levels of cardiovascular risk factors at entry by Chlamydia pneumoniae IgA antibody titre. Values are number (percentage) unless stated otherwise
| Risk factor | IgA antibody titre
|
P value (trend) | ||
|---|---|---|---|---|
| Zero (n=1411) |
Trace (n=255) |
⩾1 in 16 (n=107) | ||
| Age (years) | 52.1 | 52.7 | 52.2 | 0.17 |
| Standing height (m) | 1.71 | 1.71 | 1.72 | 0.32 |
| FEV1/height2 (l/m2) | 0.90 | 0.89 | 0.88 | 0.28 |
| Body mass index (kg/m2) | 26.1 | 26.5 | 26.3 | 0.18 |
| Systolic blood pressure (mm Hg) | 139.9 | 140.5 | 141.4 | 0.40 |
| Total cholesterol (mmol/l) | 5.72 | 5.74 | 5.55 | 0.30 |
| High density lipoprotein cholesterol (mmol/l) | 1.12 | 1.09 | 1.14 | 0.88 |
| Low density lipoprotein cholesterol (mmol/l) | 3.84 | 3.86 | 3.71 | 0.41 |
| Fibrinogen (g/l) | 3.78 | 3.89 | 3.81 | 0.31* |
| Leucocytes (×109/l) | 6.94 | 6.97 | 7.11 | 0.52* |
| Viscosity (cP) | 1.705 | 1.719 | 1.722 | 0.009* |
| C reactive protein (g/l) | 2.58 | 3.08 | 3.48 | 0.08* |
| Heat shock protein antibody† | 0.82 | 0.77 | 0.71 | 0.07* |
| Current smokers | 763/1405 (54.3) | 140/254 (55.1) | 59/107 (55.1) | 0.79 |
| Manual worker | 940/1385 (67.9) | 170/247 (68.8) | 72/103 (69.9) | 0.66‡ |
| Father manual worker | 1101/1257 (87.6) | 201/223 (90.1) | 81/96 (84.4) | 0.93‡ |
Column totals vary slightly owing to missing data for each variable.
*
Significance test based on log transformed data.
†
Optical density, measured in 230 men with undetectable IgA antibodies and 68 men with detectable IgA antibodies.
‡
Based on Spearman’s rank correlation between social class and IgA antibody titre.