Association of Serum Cystatin C Level With Carotid Arterial Wall Elastic Resistance as a Potential Marker for Detection of Early Stage Atherosclerosis

Background: Early diagnosis of atherosclerosis is exigent in patients with known cardiovascular disease (CVD) risk factors. During the initial phases of atherosclerosis, appearance of plaques can be detected by the ultrasonic phased tracking method which measures the arterial wall elasticity. However, reliable and easily available biochemical markers are not evaluated in the diagnosis of early-stage atherosclerosis. So the current study was carried out to assess the serum cystatin C level as an atherosclerotic marker, by evaluating its association with carotid arterial elastic modulus using the phased tracking method. Materials and methods: A cross-sectional study was conducted on 115 patients having risk factors for atherosclerosis but not meeting carotid intima-media thickness (IMT) criteria. The early-stage atherosclerosis was detected by using the ultrasonic phased tracking method and the patients were divided based on low and high carotid elastic modulus. Serum levels of cystatin-C were measured in association with IMT, and elastic modulus was calculated using a novel method. This study also put forth the evaluation of the sensitivity and specificity of cystatin C for early diagnosis of atherosclerosis. Results: Cystatin C was strongly related to carotid elasticity (r=0.650). Based on multi-linear regression analysis, cystatin C showed significant association with carotid elasticity (β=0.509; p<0.001). It also displayed significant positive association with high carotid elastic modulus (β=0.511; p=0.02). Cystatin C showed a sensitivity of 85% in the prediction of high carotid elastic modulus. Conclusion: For patients who are at risk to evolve atherosclerosis but are not evident with arterial plaques, cystatin C exhibits a significant association with carotid wall elastic modulus, which eases the detection of atherosclerosis. Thus, cystatin C is a potential biochemical marker for early diagnosis of atherosclerosis.