Heavy metals as environmental risk factors for cardiovascular diseases: from the perspective of the renin angiotensin aldosterone system and oxidative stress

Abstract

Cardiovascular diseases (CVDs) are a group of disorders of the heart and blood vessels. CVDs were responsible for approximately 31% of all global deaths in 2016, and 85% of all CVD deaths are due to heart attack and stroke. The underlying process in the blood vessels that results in heart attack and stroke is atherosclerosis. A recent study indicated that exposure to environmental toxic heavy metals is associated with an increased risk of CVDs. In this review, we focus on several heavy metals as environmental risk factors for CVDs: arsenic, lead, cadmium, mercury, chromium and iron. The pathological contribution of these heavy metals to the alternation of two molecular mechanisms: the renin angiotensin aldosterone system (RAAS) and oxidative stress has been discussed. The etiology of heavy metal-induced CVDs is viewed from the perspective of RAAS and oxidative stress. The significance of environmental improvement for better health will also be considered. low Recently, Chowdhury conducted a systematic review and meta-analysis of epidemiological studies that investigated the association of five metals (As, Pb, Cd, Hg and Cu) with the risk of CVDs. The authors identified 37 unique studies comprising 348,259 non-overlapping participants, with 13,033 cases of coronary heart disease (heart attack), 4,205 cases of stroke, and 15,274 cases of composite CVDs (comprising heart attack and stroke). This study indicates that exposure to As, Pb, Cd and Cu is associated with an increased risk of coronary heart disease (heart attack) and overall CVDs, but Hg is not associated with cardiovascular risk. In addition, the authors carried out a dose-response meta-analysis and observed a linear association (a) between As level in well water and the risk for overall CVDs, (b) between blood Pb level and the risk of heart attack, (c) between urine Cd level and the risk for overall CVDs, and (d) between urine Cd level and the risk of heart attack. This analysis indicates that there is a link between exposure to these metals and risk of CVDs even at low concentrations highlighting the importance of environmental toxic metals in enhancing cardiovascular risks. significant positive correlation (r= 0.3418, p< 0.001) was found between the levels of TBARS (mean 0.66 ± 0.63 nmol/mL) (Akther et al ., 2016) and GST activity (mean = 1.73 ± 0.35 U/L) (Akther et al ., 2016) in the healthy individuals. However, a negative correlation (r= -0.06151, p> 0.05) between these two parameters was observed in the tannery workers though statistically not significant. Here, the negative correlation means that as one of the variables increases, the other tends to decrease. The data were obtained from the study of Akther et al . (2016) and analyzed by GraphPad Prism 7.0 software.