Table 2.
Associations Between Smoking Status and Quadriceps Properties
| Men (n = 1888) | Women (n = 2581) | All sample (n = 4469) | ||||||
|---|---|---|---|---|---|---|---|---|
| Parameter | Coef. | 95% CI | p Value | Coef. | 95% CI | p Value | Coef. (95% CI) | p Value for sex interaction |
| Muscle CSAa, cm2 | ||||||||
| Never smokers | Ref. | Ref. | Ref. | |||||
| Former smokers | –0.10 | –0.17 to –0.03 | .003 | –0.04 | –0.11 to 0.03 | .26 | –0.10 (–0.15 to –0.05) | .39 |
| Current smokers | –0.19 | –0.33 to –0.05 | .009 | –0.07 | –0.17 to 0.03 | .18 | –0.09 (–0.17 to –0.01) | .003 |
| Muscle attenuationb, HU | ||||||||
| Never smokers | Ref. | Ref. | Ref. | |||||
| Former smokers | –0.08 | –0.16 to –0.01 | .038 | 0.02 | –0.05 to 0.10 | .54 | –0.09 (–0.14 to –0.04) | .031 |
| Current smokers | –0.17 | –0.34 to –0.01 | .045 | –0.24 | –0.34 to –0.13 | <.001 | –0.23 (–0.32 to –0.14) | .42 |
| Peak torqueb, Nm | ||||||||
| Never smokers | Ref. | Ref. | Ref. | |||||
| Former smokers | 0.02 | –0.05 to 0.09 | .59 | 0.05 | –0.03 to 0.12 | .22 | –0.06 (–0.11 to –0.01) | .73 |
| Current smokers | 0.08 | –0.08 to 0.24 | .31 | –0.06 | –0.16 to 0.04 | .25 | –0.04 (–0.13, to 0.05) | .08 |
| Maximum RTDb, Nm/s | ||||||||
| Never smokers | Ref. | Ref. | Ref. | |||||
| Former smokers | –0.02 | –0.11 to 0.07 | .67 | 0.03 | –0.05 to 0.11 | .42 | –0.03 (–0.09 to 0.03) | .27 |
| Current smokers | –0.06 | –0.25 to 0.14 | .58 | –0.04 | –0.16 to 0.08 | .49 | –0.05 (–0.16 to 0.05) | .90 |
Models were adjusted for age, BMI, % weight change from age 50, physical activity level, impaired mobility, health status, alcohol consumption, cognitive function, and depressive symptoms. BMI = body mass index; CSA = cross-sectional area; Coef.= coefficient; CI = confidence interval; RTD = rate of torque development.
aAdditionally adjusted to % IMAT (intramuscular adipose tissue) area calculated as quadriceps fat area (cm2)/total quadriceps cross-sectional area (cm2) ×100, and muscle attenuation;
bAdditionally adjusted to % IMAT, and muscle area. Outcomes were expressed in z-scores.