Table 5.
Multiple regression analyses with fatigue a as a dependent variable including interactions.
| Men | Women | |||||||
|---|---|---|---|---|---|---|---|---|
| Model 1 | Model 2 | Model 1 | Model 2 | |||||
| β b | p | βb | p | β b | p | β b | p | |
| Plasma NOx (μmol/L) | −0.03 | 0.58 | 0.00 | 0.99 | −0.16 | 0.004 | −0.12 | 0.03 |
| Job strain index c | 0.41 | <0.001 | 0.37 | <0.001 | 0.36 | <0.001 | 0.35 | <0.001 |
| Job strain index c × plasma NOx (interaction) | −0.07 | 0.29 | −0.05 | 0.48 | −0.12 | 0.02 | −0.14 | 0.01 |
| Age (years) | −0.06 | 0.36 | 0.04 | 0.53 | ||||
| BMI (kg/m2) | −0.03 | 0.66 | −0.03 | 0.53 | ||||
| Cigarette smoking | ||||||||
| Nonsmoker or ex-smoker d (reference) | ||||||||
| Moderate smoker e | 0.06 | 0.36 | −0.05 | 0.34 | ||||
| Heavy smoker f | −0.07 | 0.30 | 0.03 | 0.62 | ||||
| Alcohol consumption | ||||||||
| None (reference) | ||||||||
| Once per week or less, but not none | −0.09 | 0.22 | −0.07 | 0.22 | ||||
| More than once per week | −0.08 | 0.28 | 0.01 | 0.91 | ||||
| Exercise | ||||||||
| Less than once per week (reference) | ||||||||
| Once per week or more | −0.06 | 0.27 | −0.11 | 0.06 | ||||
| Total vegetable intake (g/day) | −0.05 | 0.38 | −0.17 | 0.004 | ||||
| Job strain index c × total vegetable intake (interaction) | −0.06 | 0.33 | 0.02 | 0.73 | ||||
| Adjusted R2 | 0.143 (p < 0.001) | 0.148 (p < 0.001) | 0.149 (p < 0.001) | 0.175 (p < 0.001) | ||||
a Evaluated using the Profile of Mood States; b Standardized regression coefficient; c Calculated as job demands divided by job control evaluated using the Job Content Questionnaire and logarithmically transformed; d Others than moderate or heavy smokers. e Current smokers with a smoking history of 1 to 20 pack years; f Current smokers with a smoking history of >20 pack years.