Predictors of carotid intima-media thickness and carotid plaque in young Indian adults: the New Delhi birth cohort

Background: Carotid intima-media thickness (CIMT) and carotid plaques represent preclinical markers of atherosclerosis. We sought to describe predictors of CIMT and carotid plaques, including early life growth, in a young urban Indian cohort free of clinical cardiovascular disease (CVD).

Methods: In 2006-2009, we performed B-mode carotid ultrasound on 600 participants (mean [SD] age 36 [1.1] years; 45% women) from the New Delhi Birth Cohort to evaluate CIMT and carotid plaques (>1mm). Height and weight were recorded at birth, 2 and 11 years of age. Data on CVD risk factors, anthropometry, medical history, socio-economic position, and lifestyle habits were collected in 1998-2002.

Results: Mean (SD) CIMT for men and women was 0.91 (0.12) and 0.86 (0.13) mm, respectively. Carotid plaque was present in 33% of men and 26% of women. Waist circumference in 1998-2002 was positively associated with CIMT (β coefficient 0.26 mm [0.17, 0.36] per SD) and carotid plaque (OR 1.27 [1.06,1.52] per SD) in 2006-2009. Higher triglycerides, PAI-1, insulin resistance, and diastolic blood pressure, metabolic syndrome, and lower HDL-cholesterol and physical activity predicted higher CIMT and/or plaque (p<0.05). Longer length at 2 years was associated with higher CIMT (p<0.05). These associations were attenuated after adjusting for adult waist circumference.

Conclusions: These are the first prospective data from India showing that early life growth, adult socio-demographics, and CVD risk factors predict future CIMT and/or carotid plaque. These relationships appear primarily mediated through central adiposity, highlighting the importance of maintaining a healthy weight in early adulthood to prevent CVD.