Table 2. Means (SD) of study variables by SHS exposure status.
| Not Exposed (n=138) | Exposed in Adulthood only (n=45) | Exposed in childhood only (n=135) | Exposed in Both (n=97) | |
|---|---|---|---|---|
| Whites (n, %) | 96 (69.6) | 31 (68.9) | 106 (78.5) | 68 (70.1) |
| Males (n, %)a | 59 (42.8) | 11 (24.4) | 48 (35.6) | 26 (26.8) |
| Age (year) | 36.3 (4.5) | 36.9 (4.6) | 36.7 (4.0) | 35.2 (4.3) |
| Education (n, %) | ||||
| Elementary school | 0 | 1 (2.2) | 0 | 3 (3.1) |
| Middle school | 1 (0.7) | 0 | 2 (1.5) | 0 |
| High school | 64 (46.4) | 15 (33.3) | 54 (40.0) | 50 (51.5) |
| College and above | 73 (52.9) | 29 (64.4) | 79 (58.5) | 44 (45.4) |
| Income/year (n, %)b | ||||
| <=$15000 | 27 (19.6) | 2 (4.4) | 16 (11.9) | 27 (27.8) |
| $15001-$30000 | 18 (13.0) | 17 (37.8) | 18 (13.3) | 22 (22.7) |
| $30001-$45000 | 21 (15.2) | 5 (11.1) | 24 (17.8) | 7 (7.2) |
| >$45000 | 72 (52.2) | 21 (46. 7) | 77 (57.0) | 41 (42.3) |
| BMI (kg/m2) | 28.5 (6.1) | 31.3 (9.0)** | 28.8 (6.1) | 29.8 (6.7) |
| Systolic BP (mmHg) | 116.0 (15.1) | 115.7 (13.2) | 113.4 (11.9) | 117.3 (15.4) |
| LDL-C (mg/dL) | 121.9 (33.4) | 121.8 (35.2) | 128.6 (31.3) | 128.5 (32.9) |
| TG/HDL-C | 3.0 (3.0) | 2.8 (2.0) | 2.9 (2.9) | 2.7 (3.1) |
| Common IMT (μm) | 735 (118) | 754 (122) | 749 (128) | 747 (129)* |
| Bulb IMT (μm) | 901 (170) | 916 (204) | 964 (275)** | 960 (318)** |
| Internal IMT (μm) | 677 (163) | 703 (135.2) | 728 (220)** | 772 (386)** |
| Composite IMT (μm) | 771 (111) | 791 (128) | 814 (161)** | 826 (202)** |
SHS=secondhand smoke; BMI=body mass index; BP=blood pressure; L(H)DL-C=low(high)-density lipoprotein cholesterol; TG=triglycerides; IMT=intima-media thickness
a
p<0.05;
b
p<0.01 by Chi-square tests
Difference in continuous variables between three SHS exposure groups and the non-exposure group was tested in GLM models, adjusted for sex, age, education, income and/or race;
*
P<0.05;
**
P<0.01