title: CKD of Uncertain Etiology: A Systematic Review.
abstract: OBJECTIVE
  Epidemics of CKD of uncertain etiology (CKDu) are emerging around the world. Highlighting common risk factors for CKD of uncertain etiology across various regions and populations may be important for health policy and public health responses.
  
  
  METHODS
  We searched PubMed, Embase, Scopus and Web of Science databases to identify published studies on CKDu. The search was generated in January of 2015; no language or date limits were used. We used a vote-counting method to evaluate exposures across all studies.
  
  
  RESULTS
  We identified 1607 articles, of which 26 met inclusion criteria. Eighteen (69%) were conducted in known CKDu-endemic countries: Sri Lanka (38%), Nicaragua (19%), and El Salvador (12%). The other studies were from India, Japan, Australia, Mexico, Sweden, Tunisia, Tanzania, and the United States. Heavy metals, heat stress, and dietary exposures were reported across all geographic regions. In south Asia, family history, agrochemical use, and heavy metal exposures were reported most frequently, whereas altitude and temperature were reported only in studies from Central America. Across all regions, CKDu was most frequently associated with a family history of CKDu, agricultural occupation, men, middle age, snake bite, and heavy metal exposure.
  
  
  CONCLUSIONS
  Studies examining etiologies of CKDu have reported many exposures that are heterogeneous and vary by region. To identify etiologies of CKDu, designing consistent and comparative multisite studies across high-risk populations may help elucidate the importance of region-specific versus global risk factors.
authors.affiliation: Duke Global Health Institute, josephlunyera@gmail.com.
authors.forename: Joseph
authors.initials: J
authors.lastname: Lunyera
authors.affiliation: Departments of Medicine and.
authors.forename: Dinushika
authors.initials: D
authors.lastname: Mohottige
authors.affiliation: Duke Medical Center Library.
authors.forename: Megan
authors.initials: M
authors.lastname: Von Isenburg
authors.affiliation: Duke Global Health Institute, Sanford School of Public Policy, and Institute of Water Policy, Lee Kwan Yew School of Public Policy, National University of Singapore, Singapore.
authors.forename: Marc
authors.initials: M
authors.lastname: Jeuland
authors.affiliation: Duke Global Health Institute, Departments of Medicine and Pediatrics, Duke Clinical Research Institute, Duke University, Durham, North Carolina; and.
authors.forename: Uptal D
authors.initials: UD
authors.lastname: Patel
authors.affiliation: Duke Global Health Institute, Departments of Medicine and Duke Clinical Research Institute, Duke University, Durham, North Carolina; and.
authors.forename: John W
authors.initials: JW
authors.lastname: Stanifer
mesh_terms: D000367:Age Factors; D000382:Agricultural Workers' Diseases / Q000453:epidemiology; D004032:Diet / Q000009:adverse effects; D004781:Environmental Exposure / Q000009:adverse effects; D000067565:Farmers; D005260:Female; D020022:Genetic Predisposition to Disease; D014943:Global Health; D000075322:Heavy Metal Poisoning; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects; D010375:Pedigree; D011041:Poisoning / Q000453:epidemiology; D051436:Renal Insufficiency, Chronic / Q000175:diagnosis / Q000453:epidemiology*; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D012909:Snake Bites / Q000453:epidemiology
keywords: chronic kidney disease; global health; humans; low- and middle-income countries; nephrotoxicity; occupations; public health; renal insufficiency, chronic; risk factors; temperature