Pesticides and the Epidemic of CKD in Central America

Abstract

In a recently published article in AJKD, Dr Correa-Rotter and colleagues1Correa-Rotter R. Wesseling C. Johnson R.J. CKD of unknown origin in Central America: the case for a Mesoamerican nephropathy.Am J Kidney Dis. 2014; 63: 506-520Abstract Full Text Full Text PDF PubMed Scopus (231) Google Scholar attempt to disentangle the causes of an epidemic of chronic kidney disease (CKD) of unknown origin that is devastating farming communities in Central America, reviewing potential risk factors and causes and summarizing evidence for and against each. We believe the method used to assess the evidence was flawed; consequently, the authors’ proposed priorities for future research are misguided. Specifically, the authors conclude that heat stress likely is a leading risk factor in this CKD epidemic and should be a high priority for future research.1Correa-Rotter R. Wesseling C. Johnson R.J. CKD of unknown origin in Central America: the case for a Mesoamerican nephropathy.Am J Kidney Dis. 2014; 63: 506-520Abstract Full Text Full Text PDF PubMed Scopus (231) Google Scholar However, they also state that “[a]n etiologic role of pesticides in MeN [Mesoamerican nephropathy] is not likely but cannot be completely ruled out.”1Correa-Rotter R. Wesseling C. Johnson R.J. CKD of unknown origin in Central America: the case for a Mesoamerican nephropathy.Am J Kidney Dis. 2014; 63: 506-520Abstract Full Text Full Text PDF PubMed Scopus (231) Google Scholar(p513) We contend that heat stress cannot explain cases of CKD found in non–sugarcane workers and women. Moreover, CKD of unknown origin, which has been documented in Sri Lanka2Jayatilake N. Mendis S. Maheepala P. Mehta F.R. on behalf of the CKDu National Research Project TeamChronic kidney disease of uncertain aetiology: prevalence and causative factors in a developing country.BMC Nephrol. 2013; 14: 180Crossref PubMed Scopus (238) Google Scholar and Central America, is virtually absent in other countries with similar weather conditions and long traditions of sugarcane cultivation. Unfortunately, Central America has a long-standing and well-documented history of agrochemical misuse.3McConnell R. Pacheco A. Magnotti R. Crop duster aviation mechanics: high risk for pesticide poisoning.Am J Public Health. 1990; 80: 1236-1239Crossref PubMed Scopus (29) Google Scholar, 4Aragon A. Aragón C. Thörn Å. Pests, peasants, and pesticides on the northern Nicaraguan Pacific plain.Int J Occup Environ Health. 2001; 7: 295-302Crossref PubMed Scopus (32) Google Scholar, 5Wesseling C. Corriols M. Bravo V. Acute pesticide poisoning and pesticide registration in Central America.Toxicol Appl Pharmacol. 2005; 207: S697-S705Crossref PubMed Scopus (102) Google Scholar, 6Rosenthal E. Who's afraid of national laws? Pesticide corporations use trade negotiations to avoid bans and undercut public health protections in Central America.Int J Occup Environ Health. 2005; 11: 437-443Crossref PubMed Scopus (18) Google Scholar, 7Bravo V. Rodriguez T. Van Wendel de Joode B. et al.Monitoring pesticide use and associated health hazards in Central America.Int J Occup Environ Health. 2011; 17: 258-269Crossref PubMed Scopus (35) Google Scholar The mere fact that some pesticides used regularly in Central America are clearly nephrotoxic8Bhupindervir Kaur B. Khera A. Sandhir R. Attenuation of cellular antioxidant defense mechanisms in kidney of rats intoxicated with carbofuran.J Biochem Mol Toxicol. 2012; 26: 393-398Crossref PubMed Scopus (39) Google Scholar, 9Li Q. Peng X. Yang H. Wang H. Shu Y. Deficiency of multidrug and toxin extrusion 1 enhances renal accumulation of paraquat and deteriorates kidney injury in mice.Mol Pharm. 2011; 8: 2476-2483Crossref PubMed Scopus (42) Google Scholar, 10Siddharth M. Datta S.K. Bansal S. et al.Study on organochlorine pesticide levels in chronic kidney disease patients: association with estimated glomerular filtration rate and oxidative stress.J Biochem Mol Toxicol. 2012; 26: 241-247Crossref PubMed Scopus (42) Google Scholar should be sufficient reason to take them into account in the research agenda for this epidemic. Underestimating the role of pesticides in this epidemic could seriously undermine efforts to develop effective—and urgently needed—public health interventions for the CKD epidemic in Central America and other health problems that could be related to pesticide misuse. Financial Disclosure: The authors declare that they have no relevant financial interests. CKD of Unknown Origin in Central America: The Case for a Mesoamerican NephropathyAmerican Journal of Kidney DiseasesVol. 63Issue 3PreviewAn epidemic of chronic kidney disease of unknown origin has emerged in the last decade in Central America and has been named Mesoamerican nephropathy. This form of chronic kidney disease is present primarily in young male agricultural workers from communities along the Pacific coast, especially workers in the sugarcane fields. In general, these men have a history of manual labor under very hot conditions in agricultural fields. Clinically, they usually present with normal or mildly elevated systemic blood pressure, asymptomatic yet progressive reduction in estimated glomerular filtration rate, low-grade non-nephrotic proteinuria, and often hyperuricemia and or hypokalemia. Full-Text PDF In Reply to ‘Pesticides and the Epidemic of CKD in Central America’American Journal of Kidney DiseasesVol. 64Issue 3PreviewWe thank Drs Orduñez and Silva1 for their letter. We maintain that research-based evidence for pesticides as causal agents is weak. Although it is true that ubiquitous use exposes agricultural workers and communities to pesticides,2 this does not indicate causality. New studies have results consistent with toxic environmental exposures, yet lack data on pesticides specifically.3,4 Although some weak associations have been reported,5,6 other studies have found no associations.2,7 As stated in our review, toxic pesticides constitute a major hazard for public health and may be implicated in Mesoamerican nephropathy. Full-Text PDF