Markers of central and peripheral vascular functions among young men with coronary artery disease risk factors

Abstract

In Malaysia, there is an increase in prevalence of coronary artery disease (CAD) especially among young men. This is due to increase in the prevalence of risk factors of CAD. The measurement of high sensitivity C-reactive protein (hs-CRP) as a marker of inflammation, pulse wave velocity (PWV) and augmentation index (AI) as a marker of vascular function and carotid intima media thickness (CIMT) as an atherosclerotic marker may help in early identification of vascular damage due to CAD risk factors. Recently, a low cost and robust vascular marker that may identify those with CAD risk factors namely finger photoplethysmography fitness index (PPGF) was introduced. The objectives of this study were to compare the PPGF value and other markers of CAD among the young men with and without CAD risk factors, to determine the associations between PPGF with other CAD markers and their associations with future cardiovascular disease (CVD) risk [Framingham risk score (FRS)] and lastly to assess the sensitivity of vascular risk prediction index (VRPI, obtained from PPGF) in identifying those with CAD risk factors. Screening activities involved young men aged 20 to 40 years old with and without CAD risk factors. Risk factors were systolic or diastolic blood pressure (BP)>140/90 mmHg, waist circumference (WC)>90 cm, smoker, dyslipidemia [total cholesterol (TC)>6.2 mmol/L, triglyceride (TG)≥1.7 mmol/L, high density lipoprotein (HDL)<1.04 mmol/L and low density lipoprotein (LDL)≥4.2 mmol/L] and family history of premature CVD. Their body mass index (BMI), WC, peripheral and central BP, lipid profiles, hs-CRP, PWV, AI and CIMT were measured. FRS (short and long term) were calculated. Data were analysed via Statistical Package of Social Science (SPSS) version 16. Subjects (N=218) were divided into those with no risk factor (HG, N=63), those with one risk factor (G1, N=59) and those with two or more risk factors (G2, N=96). The mean age was 27.09±5.30 years old. As the risk factors increased, there was significant increase in age, BMI, WC, peripheral and central BP, TC, TG, LDL, hs-CRP and FRS (P<0.05 for all). In addition, there were also significant increment for AI (HG=6.56±3.96%, G1=7.39±4.90%, G2=10.09±4.97%, P<0.01) and right CIMT (HG=0.5201±0.08 mm, G1=0.5467±0.09 mm, G2=0.5698±0.11 mm, P<0.05). There was no significant difference for PPGF (HG=61.20±8.64%, G1=59.69±6.89%, G2=60.10±8.81%, P=0.88) and PWV (HG=7.29±0.88 m/s, G1=7.36±0.74 m/s, G2=7.45±0.78 m/s, P=0.90) between groups. AI had significant moderate association with short and long term FRS (P<0.01 for all). PPGF was associated with PWV (r=-0.27, P<0.01). The sensitivity of VRPI in identifying those with CAD risk factors was 82.02%. In conclusion, hs-CRP, AI and right CIMT may be the early markers of vascular damage among the young men with CAD risk factors. PPGF is related with PWV and VRPI is sensitive as a screening tool to identify those with CAD risk factors.