title: Kidney function in sugarcane cutters in Nicaragua--A longitudinal study of workers at risk of Mesoamerican nephropathy.
abstract: BACKGROUND
  Chronic kidney disease is common among sugarcane workers in Central America. The main risk factor seems to be repeated high-intensity work in hot environments. Several cross-sectional studies have been performed but few longitudinal studies.
  
  
  OBJECTIVE
  The aim of the study was to examine whether kidney function changes over a few months of work during the harvest period.
  
  
  METHODS
  A group of male sugarcane cutters in Nicaragua (N=29, aged 17-38 years) was examined with renal biomarkers before and after shift on the first day at the start of harvest, on the sixth day during acclimatization, and then in mid-harvest 9 weeks later. A reference group (N=25, mainly office workers) was examined with the same biomarkers at start of harvest, and then at end of harvest 5 months later.
  
  
  RESULTS
  The pre-shift renal function decreased significantly during 9 weeks of work in the cane cutters. Mean serum creatinine increased (20%), mean estimated glomerular filtration rate decreased (9%, 10mL/min), serum urea N (BUN) increased (41%), and mean urinary neutrophil gelatinase-associated lipocalin (NGAL) increased (four times). The cane cutters also developed cross-shift increases in these biomarkers, in particular serum creatinine and BUN, and in urinary uric acid. The longitudinal decrease in eGFR tended to be associated with the cross-shift increase in serum creatinine.
  
  
  CONCLUSIONS
  There was a remarkable decrease of glomerular kidney function, after only 9 weeks of harvest. The cross-shift increase in serum creatinine may be caused by dehydration (pre-renal dysfunction), and when repeated on a daily basis this may cause permanently reduced GFR.
authors: Unit of Occupational Medicine, Institute of Environmental Medicine (IMM), Karolinska Institutet, Stockholm, Sweden. Electronic address: inekewesseling@gmail.com.
authors: Catharina
authors: C
authors: Wesseling
authors: Research Center on Health, Work and Environment (CISTA), Autonomous University of Nicaragua at León (UNAN-León), León, Nicaragua. Electronic address: auroraragon@gmail.com.
authors: Aurora
authors: A
authors: Aragón
authors: Research Center on Health, Work and Environment (CISTA), Autonomous University of Nicaragua at León (UNAN-León), León, Nicaragua; Department of Non-communicable Disease Epidemiology of London School of Hygiene and Tropical Medicine, London, UK. Electronic address: marvin99_00@yahoo.es.
authors: Marvin
authors: M
authors: González
authors: La Isla Foundation, Chicago, IL, USA. Electronic address: ilana@laislafoundation.org.
authors: Ilana
authors: I
authors: Weiss
authors: La Isla Foundation, Chicago, IL, USA. Electronic address: jason@laislafoundation.org.
authors: Jason
authors: J
authors: Glaser
authors: Department Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubirán, Mexico City, Mexico; Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico. Electronic address: nab@biomedicas.unam.mx.
authors: Norma A
authors: NA
authors: Bobadilla
authors: Division of Renal Diseases and Hypertension, University of Colorado, Aurora, CO, USA. Electronic address: tamara.harra@ucdenver.edu.
authors: Carlos
authors: C
authors: Roncal-Jiménez
authors: Department Nephrology and Mineral Metabolism, Instituto Nacional de Ciencias Médicas y Nutrición, Salvador Zubirán, Mexico City, Mexico. Electronic address: correarotter@gmail.com.
authors: Ricardo
authors: R
authors: Correa-Rotter
authors: Division of Renal Diseases and Hypertension, University of Colorado, Aurora, CO, USA. Electronic address: Richard.Johnson@ucdenver.edu.
authors: Richard J
authors: RJ
authors: Johnson
authors: Occupational and Environmental Medicine, Sahlgrenska University Hospital and University of Gothenburg, Sweden. Electronic address: lars.barregard@amm.gu.se.
authors: Lars
authors: L
authors: Barregard
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000032:analysis; D000067565:Farmers; D006801:Humans; D007668:Kidney / Q000502:physiology*; D007677:Kidney Function Tests; D008137:Longitudinal Studies; D008297:Male; D009527:Nicaragua; D031786:Saccharum; D012621:Seasons; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: BUN; Chronic kidney disease; Heat stress; Hsp72; KIM-1; NGAL; Occupational; eGFR