Cardiovascular risk factors and oxidative stress in young people

Although cardiovascular disease is the leading cause of death in developed countries, the multifactorial origin of this disease makes it difficult to understand and treat. This is why determination of cardiovascular risk factors (CVRFs), such as hypertension, smoking, diabetes, obesity and dyslipidaemias, including hypercholesterolaemia, hypertriglyceridaemia, high levels of low density lipoproteins (LDLs) and low concentrations of high density lipoprotein (HDLs), is fundamental in the early detection and management of cardiovascular diseases.^1,2 As Villalpando Sánchez et al.³ indicate in their article published in this issue of Clínica e Investigación en Arteriosclerosis [Clinical and Research in Arteriosclerosis], early identification of risk factors in populations susceptible to lifestyle changes, such as young adults or adolescents, is a key factor in developing prevention strategies.

There is ample evidence that oxidative stress plays a major role in the development and progression of cardiovascular diseases, including hypertension, diabetes, atherosclerosis or coronary disease.⁴ Oxidative stress is defined as a disturbance in the balance between the production of reactive oxygen species and antioxidant defences, which leads to cell damage due to the oxidation of nucleic acids, lipids and proteins. The oxidation of plasma proteins gives rise to what has been called advanced oxidation protein products (AOPP). AOPPs were initially identified as biomarkers of plasma oxidative stress in patients with chronic kidney disease⁵; later, they were also described as proinflammatory mediators in numerous diseases, including chronic kidney disease,⁶ hypertension and atherosclerosis.⁷ This demonstrated that there is a correlation between plasma AOPP levels and blood pressure.⁸ In addition, several studies have shown an association between elevated plasma AOPP levels and the onset and progression of atherosclerosis, and with the carotid intima-media thickness in patients with carotid atherosclerotic plaques.⁹

In their article, Villalpando Sánchez et al.³ have made a major breakthrough in the early detection of cardiovascular disease by studying for the first time AOPP levels in apparently healthy young individuals and their correlation with CVRFs. Despite the small sample size, significant differences in weight, body mass index, waist circumference and lipids levels, but not blood pressure, were observed between groups, depending on the number of risk factors. This in turn is reflected in the frequency of risk factors, where the highest percentage is observed in obese and overweight (40%) individuals, while the percentage of hypertensive patients was 15%. The study also shows a progressive increase in AOPP levels based on the number of CVRFs, with the highest levels observed in groups with 3 and 4 risk factors. It is also striking to note that, contrary to expectations, a negative correlation was observed between AOPP levels and the atherogenic index and LDL levels, while HDL levels correlated positively with AOPP. This, as the authors suggest, could be due to the limitations of the study, including their failure to quantify oxidised LDL, and the small sample size.

The findings of this study show the need for further research to determine the relationship between AOPPs and CVRFs in a similar population. However, since AOPP levels are rapidly and relatively easily quantified using the method described by Witko-Sarsat et al.,⁵ routine determination of these products could serve as a new early indicator of cardiovascular disease. Therapies that inhibit the formation of AOPPs, therefore, could be beneficial in diseases such as atherosclerosis, coronary artery disease or in cardiac events.

Acknowledgements

RR has received a Sara Borrell grant (CD15/00003). MS's research is funded by MINECO research project grants (SAF2016-80305-P) and ISCIII (CB16/1100286).