Prevalence and risk factors of asymptomatic carotid artery stenosis in Indian population: An 8-year follow-up study.

Background: Asymptomatic carotid artery stenosis (ACAS) is a marker for cerebrovascular disease, coronary atherosclerosis, and death.

Aim: To investigate the prevalence of ACAS in the Indian population, and to correlate ACAS with other vascular risk factors.

Materials And Methods: We prospectively recruited 1500 individuals who were older than 40 years and asymptomatic for cerebrovascular disease between June 2003 and December 2014. Evaluation of vascular risk factors was done for all the participants. Color Doppler of bilateral carotid arteries was performed for all the participants. Carotid stenosis of 1-49% and ≥50% was considered to be mild and significant stenosis, respectively.

Results: There were 1016 (67.7%) men, with a mean age of 58.1 ± 10.6 years (age range: 40-98 years). The prevalence of significant carotid stenosis was 5.2%. After adjustment using multiple regression analysis, age >70 years (OR: 2.0; 95% CI: 1.48-2.74), hypertension (OR: 1.8; 95% CI: 1.11-2.96), diabetes (OR: 2.3; 95%CI: 1.45-3.89), smoking (OR: 3.6; 95% CI: 2.18-6.03), dyslipidemia (OR: 4.0; 95% CI: 2.52-6.63), history of migraine (OR: 3.6; 95% CI: 2.54-9.13), history of periodontitis (OR: 3.2; 95% CI: 1.90-5.68), and family history of stroke (OR: 7.1; 95% CI: 4.20-12.2) were significantly associated with >50% stenosis. Duration (>15 years) of hypertension (OR: 2.5; 95% CI: 1.33-6.43), diabetes (OR: 6.2; 95% CI: 3.41-11.3), and smoking (OR: 5.2; 95% CI: 2.20-12.1) markedly worsened the risk. During the 8-year follow up, 14 participants (1.4%) with mild stenosis and 3 participants (4.7%) with significant stenosis developed stroke.

Conclusions: Our study suggests that 5.2% of asymptomatic individuals > 40 years of age harbor significant extracranial carotid artery disease. Presence of multiple vascular risk factors markedly increases the risk of carotid stenosis.