A Study to derive distribution of carotid intima media thickness and to determine its COrrelation with cardiovascular Risk factors in asymptomatic nationwidE Indian population (SCORE-India)

BACKGROUND: There is presently no data to describe normal distribution of carotid intima-media thickness (CIMT), an established measure of subclinical atherosclerosis, in Indian subjects. METHODS: In this multi-centric study, 1229 subjects with age ≥30 years and no previous cardiovascular disease (CVD) underwent CVD risk factor assessment and CIMT measurement. Mean far wall common carotid artery IMT was measured on both sides and averaged. RESULTS: Mean age of the subjects was 48.0 ± 12.0 years and 54.2% were men. CIMT measurement was feasible in 1157 subjects. Mean, median and 75th percentile values of CIMT for different age-groups were derived for men and women separately. There was a progressive increase in CIMT with increasing age (P < 0.001) and men had higher CIMT values than women (0.608 ± 0.12 mm vs. 0.579 ± 0.11 mm, P < 0.001). The CIMT values were also higher in diabetics (0.635 ± 0.10 mm) and hypertensives (0.624 ± 0.10 mm) as compared to non-diabetics (0.589 ± 0.12 mm, P < 0.001) and non-hypertensives (0.592 ± 0.12, P 0.02) respectively. Among continuous variables, age, systolic blood pressure and fasting blood glucose had strong to modest correlation with CIMT (Pearson's r 0.524, 0.282 and 0.192 respectively, all P values <0.001), whereas body mass index, diastolic blood pressure and serum triglycerides exhibited weak but still statistically significant relationship (Pearson's r 0.069, P 0.019; Pearson's r 0.065, P 0.026; and Pearson's r 0.094, P 0.001, respectively). CONCLUSIONS: This is the first study to provide age- and gender-specific distribution of CIMT in Indian subjects free from CVD. This information should help facilitate further research and clinical work involving CIMT in India.