Strong association between subclinical atherosclerosis and type of occupation in 3711 high risk European individuals

The relation between socio-economical status (SES) and cardiovascular diseases has been extensively addressed. We assessed the association between the main lifelong occupation reported by the participants of the IMPROVE study (3711 subjects from 5 European countries, age 55-70) and their carotid intima-media thickness (c-IMT) measurement. Jobs were ranked in 5 categories in a scale of SES (labourers, housewives, service workers, white collars, professionals). This scale was highly correlated with education level (r=0.46, P<.0001) and the categories were associated with different grades of physical activity (P<.0001). Mean c-IMT was strongly associated with job type, exhibiting an inverse relation with SES (p-anova = 0.0008; p-trend <0.0001). This association remained highly significant after adjustment for relevant confounders, with a difference of -8.3% from the lowest to the highest job category (P for trend <.0001). The negative trend was observed in both genders and was independent from education level, diet, alcohol intake and latitude. Of interest, employment in manual jobs, although characterized by a high level of physical activity, was associated with the highest IMT measures. In analogy to what observed for other important pathologies, our results show that the type of job is a strong determinant of subclinical atherosclerosis. This relation is not completely explained neither by differences in conventional risk factors among job categories, nor by the major life-style or cultural variables (education, smoke, diet and physical activity).