Differences in atherosclerosis according to area level socioeconomic deprivation: cross sectional, population based study

Objectives To examine the relation between area level social deprivation and ultrasound markers of atherosclerosis (common carotid intima-media thickness and plaque score), and to determine whether any differences can be explained by “classic” (currently recognised) or “emerging” (novel) cardiovascular risk factors. Design Cross sectional, population based study. Setting NHS Greater Glasgow Health Board area. Participants 666 participants were selected on the basis of how their area ranked in the Scottish Index of Multiple Deprivation 2004. Approximately equal numbers of participants from the most deprived areas and the least deprived areas were included, as well as equal numbers of men and women and equal numbers of participants from each age group studied (35-44, 45-54, and 55-64 years). Main outcome measures Carotid intima-media thickness and plaque score, as detected by ultrasound. Results The mean age and sex adjusted intima-media thickness was significantly higher in participants from the most deprived areas than in those from the least deprived areas (0.70 mm (standard deviation (SD) 0.16 mm) v 0.68mm(SD 0.12 mm); P=0.015). On subgroup analysis, however, this difference was only apparent in the highest age tertile in men (56.3-66.5 years). The difference in unadjusted mean plaque score between participants from the most deprived and those from the least deprived areas was more striking than the difference in intimamedia thickness (least deprived 1.0 (SD 1.5) v most deprived 1.7 (SD 2.0); P<0.0001). In addition, a significant difference in plaque score was apparent in the two highest age tertiles in men (46.8-56.2 years and 56.3-66. 5 years; P=0.0073 and P<0.001) and the highest age tertile in women (56.3-66.5 years; P<0.001). The difference in intima-media thickness between most deprived and least deprived males remained significant after adjustment for classic risk factors, emerging risk 1.7 (SD 2.0); P<0.0001). In addition, a significant difference in plaque score was apparent in the two highest age tertiles in men (46.8-56.2 years and 56.3-66. 5 years; P=0.0073 and P<0.001) and the highest age tertile in women (56.3-66.5 years; P<0.001). The difference in intima-media thickness between most deprived and least deprived males remained significant after adjustment for classic risk factors, emerging risk factors, and individual level markers of socioeconomic status (P=0.010). Adjustment for classic risk factors and emerging cardiovascular risk factors, either alone or in combination, did not abolish the deprivation based difference in plaque presence (as a binary measure; adjusted odds ratio of 1.73, 95% confidence interval 1.07 to 2.82). However, adjustment for classic risk factors and individual level markers of early life socioeconomic status abolished the difference in plaque presence between the most deprived and the least deprived individuals (adjusted odds ratio 0.94, 95% CI 0.54 to 1.65; P=0.84). Conclusions Deprivation is associated with increased carotid plaque score and intima-media thickness. The association of deprivation with atherosclerosis is multifactorial and not adequately explained by classic or emerging risk factors

Flow chart of subject inclusion.

<p>SCV = prior study center visits, IPAQ = International Physical Activity Questionnaire, PA = physical activity, affected adjustments = body mass index, mean arterial pressure, heart rate, smoking.</p

Characteristics of the study population by sex.

<p>Numbers (N), mean value and standard deviation (SD), median and interquartile range (p25, p75), blood pressure (BP), physical activity (PA).</p><p>Characteristics of the study population by sex.</p

Open and closed segmented calcified surface area measurements for HR and LR carotid arterial wall measurements.

<p>* = p-value for paired t-test between HR scan and LR scan.</p><p>† = p-value for paired t-test between HR rescan and LR rescan using the closed segmentation method.</p><p>‡ = p-value for Levene’s test between HR and LR measurements for the corresponding segmentation. HR = high resolution; LR = low resolution; ICC = intraclass correlation coefficient; CV = coefficient of variation; SD = standard deviation.</p><p>Data are presented as number with percentage or mean with SD. ICCs are given with the corresponding 95% confidence interval.</p

Box plots of distensibility and physical activity (PA) for both sexes across three 10-year age categories.

<p>Box plots of distensibility and physical activity (PA) for both sexes across three 10-year age categories.</p

Open and closed fibrous cap thickness measurements for HR and LR carotid arterial wall measurements.

<p>* = p-value for paired t-test between HR scan and LR scan.</p><p>† = p-value for paired t-test between HR rescan and LR rescan using the closed segmentation method.</p><p>‡ = p-value for Levene’s test between HR and LR measurements for the corresponding segmentation. HR = high resolution; LR = low resolution; ICC = intraclass correlation coefficient; SD = standard deviation.</p><p>Data are presented as mean with ± SD. ICCs are given with the corresponding 95% confidence interval.</p

Within-reader and between-reader reproducibility for the HR and LR carotid arterial wall component measurements.

<p>Data are presented as mean with (95% CI). Last column contains p-value for Levene’s test between HR and LR measurements. HR = high resolution; LR = low resolution.</p

Open and closed segmented loose matrix surface area measurements for HR and LR carotid arterial wall measurements.

<p>* = p-value for paired t-test between HR scan and LR scan.</p><p>† = p-value for paired t-test between HR rescan and LR rescan using the closed segmentation method.</p><p>‡ = p-value for Levene’s test between HR and LR measurements for the corresponding segmentation. HR = high resolution; LR = low resolution; ICC = intraclass correlation coefficient; CV = coefficient of variation; SD = standard deviation.</p><p>Data are presented as mean with ± SD. ICCs are given with the corresponding 95% confidence interval.</p

Scan parameters for the HR and LR carotid arterial wall dimension measurements.

<p>* Scan times at heart rate of 60 min^-1</p><p>HR = high resolution; LR = low resolution; TSE = turbo spin-echo, FFE = fast field echo, FOV = field of view, DIR = double inversion-recovery, NEX = number of excitations.</p

Number of identified carotid plaque components with corresponding scan-rescan mismatch.

<p>Data are presented as number.</p