A critical review of a hidden epidemic: examining the occupational and environmental risk factors of chronic kidney disease of unknown etiology (CKDu)

The global burden of chronic kidney disease (CKD) in terms of mortality and disability-adjusted life years has increased, and this trend is expected to worsen over the next few decades. The primary cause of CKD is known to be due to hypertension and diabetes, however, over the last three decades, a form of CKD has been described in people without any known risk factors. These cases can be described as chronic kidney disease of an unknown etiology (CKDu). Cases of CKDu are rising primarily among rural agricultural communities in affected regions and occur mostly among young male farmers. There is no agreement on whether CKDu in these emerging clusters represents a single disease or a group of different diseases. As such, hypothesized causes of CKDu development include chronic occupational heat stress and dehydration, as well as exposure to environmental contaminants and agrochemicals, such as heavy metals and pesticides. The purpose of this critical review is to bring together the current literature on proposed CKDu etiologies, specifically those related to work in the agricultural sector. This review examines what is known about these occupational and environmental factors and their potential impact on the widespread epidemics of CKDu.