8290742 Kidney injury in Nicaraguan sugarcane workers – prevention and consequences

<h3>Objectives</h3> To study the effect of enhancing rest-shade-hydration-hygiene (RSHH) interventions on kidney injury and inflammation biomarkers, and rates of clinical acute kidney injury (AKI) in Nicaraguan sugarcane workers with a very high rate of chronic kidney disease of non-traditional origin (CKDnt), and the long-term estimated glomerular filtration rate (eGFR) trends in workers with kidney injury. <h3>Methods</h3> We analyzed serum creatinine and C-reactive protein (CRP) and leukocyturia from samples obtained before and at the end of four harvest seasons (H1-4). An increase in creatinine ≥0.30 mg/dL over the harvest was considered incident kidney injury (IKI). Clinically diagnosed AKI were obtained from medical records. Each season the RSHH intervention included progressively longer and more frequent rest periods with improved access to shade and hydration, implementation monitoring, and health outcome assessments. Changes in eGFR during 2-4 years of followup were calculated for workers with and without kidney injury respectively. <h3>Results</h3> 1,044 workers were followed for 1,938 person-harvests. Among burned cane cutters, the workgroup with with the highest workload and worst outcomes initially, rates of IKI (21% in H1 to 1% in H4, p&lt;0.01), AKI (20/1000 worker-months to 8/1000 worker-months, p&lt;0.01), end-harvest leukocyturia (26% to 1%, p&lt;0.01), and cross-harvest CRP rises (median 1.75 fold-increase in H1 to 1.00 in H4, p&lt;0.01) decreased. Workers experiencing kidney injury had lost approximately 10 ml/min/1.73m2 more eGFR during follow-up than workers who had not experienced kidney injury. <h3>Conclusion</h3> A structured RSHH intervention supported by implementation monitoring and commitment from workplace management reduced AKI rates and improved markers of kidney injury and inflammation among heat-stressed workers at high risk of CKDnt. The findings support a causal relationship between heat stress, kidney injury and ultimately CKDnt.