Biomarkers of Kidney Injury Among Nicaraguan Sugarcane Workers

Abstract

Background In Central America, an epidemic of chronic kidney disease of unknown etiology disproportionately affects young, male agricultural workers. Study Design Longitudinal cohort study. Setting & Participants 284 sugarcane workers in seven jobs were recruited from one company in northwestern Nicaragua. Blood and urine samples were collected before and near the end of the six-month harvest season. Predictors Job category (cane cutter, seeder, seed cutter, agrichemical applicator, irrigator, driver, factory worker); self-reported water and electrolyte solution intake. Outcomes & Measurements Change in urinary kidney injury biomarkers normalized to urine creatinine, including neutrophil gelatinase-associated lipocalin (NGAL), interleukin 18 (IL-18), N-acetyl-β-d-glucosaminidase (NAG), and albumin; serum creatinine–based estimated glomerular filtration rate (eGFR). Results Mean eGFR was 113 mL/min/1.73 m2 and less than 5% of workers had albuminuria, field workers had increases in NGAL and IL-18 that were 1.49 (95% CI, 1.06-2.09) and 1.61 (95% CI, 1.12-2.31) times as high, respectively, as in non-field workers. Cane cutters and irrigators had the greatest increase in NGAL during the harvest, while cane cutters and seeders had the greatest increase in IL-18. Consumption of electrolyte solution was associated with lower mean NGAL and NAG among cane cutters and lower mean IL-18 and NAG among seed cutters; however, there was no overall effect of hydration among all workers. On average, workers with the largest increases in NGAL and NAG during the harvest had declines in eGFR of 4.6 (95% CI, −8.2 to −1.0) and 3.1 (95% CI, −6.7 to 0.6) mL/min/1.73 m2, respectively. Limitations Surrogate exposure measure, loss-to-follow-up. Conclusions Results are consistent with the hypothesis that occupational heat stress and volume depletion may be associated with development of kidney disease, and future studies should directly measure these occupational factors. The presence of urine tubular injury markers supports a tubulointerstitial disease that could occur with repeated tubular injury.

Calculated Serum Osmolality, Acute Kidney Injury, and Relationship to Mortality after Percutaneous Coronary Intervention

“…In a large-scale retrospective analysis including 13,201 patients without renal disease, elevated sOsmo independently predicted the development of CKD over a follow-up period of 5 years [8]. In addition, sOsmo has been linked to the development of CKD in the absence of classic risk factors (e.g., DM and hypertension) [9, 10]. In contrast to these earlier reports, we demonstrate similar associations with respect to short-term renal injury after PCI.…”

Climate Change and the Emergent Epidemic of CKD from Heat Stress in Rural Communities: The Case for Heat Stress Nephropathy

“…The theory that this was a result of direct exposure to pesticides in the fields, however, is weakened by the presence of the disease in occupations not involving farming, by reports that there is a greater risk for renal injury in the sugarcane fields among the cane cutters as opposed to the pesticide applicators, and because the frequency of the disease is lower in sugarcane cutters working at higher altitudes where it is significantly cooler than at lower altitudes, despite similar agrochemical exposure (32,36,47). Nevertheless, it remains possible that toxins, for example, could be concentrating in well water that could affect the populations as a whole.…”

Intervention to diminish dehydration and kidney damage among sugarcane workers

“…Several studies suggest a causal association between MeN and chronic heat stress and dehydration (8)(9)(10)(11)(12)(13) and experimental data have shown that repeated dehydration can induce CKD in mice (14,15). Heat exposure, strenuous exercise and dehydration pose a significant challenge to the cardiovascular system, and the transport of oxygen to exercising muscles and vital organs, such as the kidney (16).…”