Article Text

This article has a correction. Please see:

PDF

Heat stress, hydration and uric acid: a cross-sectional study in workers of three occupations in a hotspot of Mesoamerican nephropathy in Nicaragua

Abstract

Objectives To study Mesoamerican nephropathy (MeN) and its risk factors in three hot occupations.

Design Cross-sectional.

Setting Chinandega and León municipalities, a MeN hotspot on the Nicaraguan Pacific coast, January–February 2013.

Participants 194 male workers aged 17–39 years: 86 sugarcane cutters, 56 construction workers, 52 small-scale farmers.

Outcome measures (1) Differences between the three occupational groups in prevalences/levels of socioeconomic, occupational, lifestyle and health risk factors for chronic kidney disease (CKD) and in biomarkers of kidney function and hydration; (2) differences in prevalences/levels of CKD risk factors between workers with reduced estimated glomerular filtration rate (eGFRCKD-EPI <80 mL/min/1.73 m2) and workers with normal kidney function (eGFRCKD-EPI ≥80 mL/min/1.73 m2).

Results Sugarcane cutters were more exposed to heat and consumed more fluid on workdays and had less obesity, lower blood sugar, lower blood pressure and a better lipid profile. Reduced eGFR occurred in 16%, 9% and 2% of sugarcane cutters, construction workers and farmers, respectively (trend cane > construction > farming, p=0.003). Significant trends (cane > construction > farming) were also observed for high serum urea nitrogen (blood urea nitrogen (BUN) >20 mg/dL), high serum creatinine (SCr >1.2 mg/dL), low urinary pH (≤5.5) and high BUN/SCr ratio (>20) but not for high urinary specific gravity (≥1.030). Sugarcane cutters also more often had proteinuria and blood and leucocytes in the urine. Workers with eGFR <80 mL/min/1.73 m2 reported a higher intake of water and lower intake of sugary beverages. Serum uric acid levels related strongly and inversely to eGFR levels (adj β −10.4 mL/min/1.73 m2, 95% CI −12.2 to −8.5, p<0.001). No associations were observed for other metabolic risk factors, pesticides, non-steroidal anti-inflammatory drugs or alcohol. Among cane cutters, consumption of electrolyte hydration solution appeared preventive (adj β 8.1 mL/min/1.73 m2, p=0.09).

Conclusions Heat stress, dehydration and kidney dysfunction were most common among sugarcane cutters. Kidney dysfunction also occurred to a lesser extent among construction workers, but hardly at all among small-scale farmers. High serum uric acid was associated with reduced kidney function.

  • NEPHROLOGY
  • PUBLIC HEALTH
  • OCCUPATIONAL & INDUSTRIAL MEDICINE
  • EPIDEMIOLOGY

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/

Statistics from Altmetric.com

Footnotes

  • Contributors Concept and design: AA, CW, MG, RJJ, JG, RC-R. Data collection and biological analyses: AA, MG, IW, CR-J, CJR. Data analysis: CW. Data interpretation: All authors. Manuscript preparation: CW, RJJ. Critical revision and approval of manuscript: All authors.

  • Funding Danone Research, Palaiseau, France. The funder did not participate in study design, data collection or reporting of results.

  • Competing interests None declared.

  • Patient consent Obtained.

  • Ethics approval Ethical Review Board of the National Autonomous University of Nicaragua, León, Nicaragua.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement No additional data are available.

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Linked Articles

  • Correction
    British Medical Journal Publishing Group