Heavy metal exposure and renal impairment: A systematic review of observational studies

ABSTRACT

Background: Environmental exposure to toxins has been strongly implicated in its multi-faceted etiology of chronic kidney disease, a serious public health problem affecting individuals, families, and communities. There is a need to synthesize available studies on the effect of heavy metal exposure on renal function, considering the rising global burden of kidney disease. The objective of this study is to determine the association between exposure to heavy metals and renal disease. Methods: The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) were used to conduct the review. A comprehensive independent search, title, abstract, and full-text screening of available literature on Google Scholar, PubMed, and OAREScience was done between March 2021 and May 2021. The criteria for study inclusion were full-text articles published in English language in the last 20 years (2001-2020), and observational primary human studies reporting the association between heavy metal exposure and renal disease. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of the included studies. Results: A total of 552 studies were identified following the search from the different databases. A total of 13 studies were finally included in the review. Heavy metals implicated in the studies include cadmium, lead, mercury, and arsenic, with ten studies showing environmental exposure as the primary source. Ten (10) studies showed an association between heavy metal exposure and renal impairment (p<0.05) while only 3 studies reported no association. Conclusion: Environmental monitoring is needed to stem the tide of heavy metal exposure in view of the growing burden of chronic kidney disease.