Area social characteristics and carotid atherosclerosis.

OBJECTIVES: To explore the effect of social characteristics of residential areas on carotid atherosclerosis prevalence. METHODS AND
RESULTS: The associations among area social characteristics and B-mode ultrasound determined carotid plaque-score (a semi-quantitative scale measuring the degree of atherosclerosis in the carotid bifurcation area) were cross-sectionally investigated in a general population sample of 4033 men and women. Area socioeconomic circumstances were described through a social deprivation index calculated from migration rate, percentage residents with foreign citizenship among those with foreign background, dependency on social welfare support, and employment rate. Living in socially deprived areas was associated with an increased carotid plaque-score in both men (P for trend = 0.004) and women (P for trend = 0.007). These associations were only slightly reduced after adjustment for individual level indicators with a decrease of the absolute mean difference in carotid plaque-score between worse-off and better-off areas of 9% for men and 13% for women, whereas adjustment for risk factors turned the trend non-significant in women, however, not in men.
CONCLUSIONS: Those living in socially deprived areas in general had more extensive carotid atherosclerosis. However, in these areas there were a substantial number of individuals with low degrees of carotid atherosclerosis and vice versa. Thus, with regard to conceptual ideas of causal inference, the social characteristics of an area seem to be associated with the prevalence of carotid atherosclerosis. However, with regard to benefits of prevention, focusing on geographical areas would probably give a restricted benefit, where only some high-risk individuals would be reached.