title: Rationale, description and baseline findings of a community-based prospective cohort study of kidney function amongst the young rural population of Northwest Nicaragua.
abstract: BACKGROUND
  An epidemic of Mesoamerican Nephropathy (MeN) is killing thousands of agricultural workers along the Pacific coast of Central America, but the natural history and aetiology of the disease remain poorly understood. We have recently commenced a community-based longitudinal study to investigate Chronic Kidney Disease (CKD) in Nicaragua. Although logistically challenging, study designs of this type have the potential to provide important insights that other study designs cannot. In this paper we discuss the rationale for conducting this study and summarize the findings of the baseline visit.
  
  
  METHODS
  The baseline visit of the community-based cohort study was conducted in 9 communities in the North Western Nicaragua in October and November 2014. All of the young men, and a random sample of young women (aged 18-30) without a pre-existing diagnosis of CKD were invited to participate. Glomerular filtration rate (eGFR) was estimated with CKD-EPI equation, along with clinical measurements, questionnaires, biological and environmental samples to evaluate participants' exposures to proposed risk factors for MeN.
  
  
  RESULTS
  We identified 520 young adults (286 males and 234 females) in the 9 different communities. Of these, 16 males with self-reported CKD and 5 females with diagnoses of either diabetes or hypertension were excluded from the study population. All remaining 270 men and 90 women, selected at random, were then invited to participate in the study; 350 (97%) agreed to participate. At baseline, 29 (11%) men and 1 (1%) woman had an eGFR <90 mL/min/1.73 m2.
  
  
  CONCLUSIONS
  Conducting a community based study of this type requires active the involvement of communities and commitment from local leaders. Furthermore, a research team with strong links to the area and broad understanding of the context of the problem being studied is essential. The key findings will arise from follow-up, but it is striking that 5% of males under aged 30 had to be excluded because of pre-existing kidney disease, and that despite doing so 11% of males had an eGFR <90 mL/min/1.73 m2at baseline.
authors.affiliation: Research Centre on Health, Work and Environment (CISTA), National Autonomous University of Nicaragua at León (UNAN-León), Campus Médico, Facultad de Ciencias Médica, Edificio C (CISTA), León, Nicaragua. mgonzalez@cm.unanleon.edu.ni.|Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK. mgonzalez@cm.unanleon.edu.ni.|Centre for Nephrology, University College London Medical School, London, UK. mgonzalez@cm.unanleon.edu.ni.
authors.forename: Marvin
authors.initials: M
authors.lastname: González-Quiroz
authors.affiliation: Research Centre on Health, Work and Environment (CISTA), National Autonomous University of Nicaragua at León (UNAN-León), Campus Médico, Facultad de Ciencias Médica, Edificio C (CISTA), León, Nicaragua.
authors.forename: Armando
authors.initials: A
authors.lastname: Camacho
authors.affiliation: Fundación Isla, León, Nicaragua.
authors.forename: Dorien
authors.initials: D
authors.lastname: Faber
authors.affiliation: Research Centre on Health, Work and Environment (CISTA), National Autonomous University of Nicaragua at León (UNAN-León), Campus Médico, Facultad de Ciencias Médica, Edificio C (CISTA), León, Nicaragua.
authors.forename: Aurora
authors.initials: A
authors.lastname: Aragón
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Catharina
authors.initials: C
authors.lastname: Wesseling
authors.affiliation: La Isla Network, Chicago, Illinois, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Glaser
authors.affiliation: Royal School of Mines, Imperial College London, London, UK.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Le Blond
authors.affiliation: Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Liam
authors.initials: L
authors.lastname: Smeeth
authors.affiliation: Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Nitsch
authors.affiliation: Department of Non-Communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.|Centre for Global NCDs, London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Pearce
authors.affiliation: Centre for Nephrology, University College London Medical School, London, UK.
authors.forename: Ben
authors.initials: B
authors.lastname: Caplin
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D007677:Kidney Function Tests / Q000706:statistics & numerical data*; D008297:Male; D009527:Nicaragua / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012016:Reference Values; D015203:Reproducibility of Results; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D055815:Young Adult
keywords: CKDu; Community-based; Follow-up; Mesoamerican nephropathy; Nicaragua