8279820 Workload, Age, Sex, and Core Body Temperature as Predictors of Short Term Kidney Injury in Nicaraguan Sugarcane Workers

<h3>Objective</h3> To examine workload related and other factors as predictors of change in serum creatinine (SCr) and acute kidney injury (AKI) among Nicaraguan sugarcane workers. <h3>Material and Methods</h3> During the 2023–2024 sugarcane harvest, demographic data and SCr levels were collected pre- and post-shift from 300 workers across 12 job types. AKI was defined as an increase in SCr ≥0.3 mg/dL across the shift. In a subset of 140 workers from 3 jobs, heart rate (HR) was collected and core temperature estimated (eCT). Workload intensity was classified by%HRmax using data collected over several years. Linear mixed-effects models assessed associations between log-transformed post-shift SCr, adjusting for time-by-workload and time-by-age interactions and examining eCT. Logistic regression estimated the odds of AKI in SCr models, while penalized logistic regression assessed odds of AKI with eCT, adjusting for age, sex, and workload category. Beta coefficients were exponentiated to obtain odds ratios (OR). <h3>Results</h3> Significant changes in SCr across shift were observed overall (p &lt; 0.01) and by age, sex, and workload (p &lt; 0.01). Age and sex were significant predictors, with higher SCr among those in heavier workload categories. In the adjusted logistic regression, female workers had lower odds of AKI compared to males (OR = 0.22, p = 0.05), while age and workload were not significant predictors although sample size was small. Interaction terms between age and sex or workload were not significant. The models are being examined for an association between eCT and cross-shift SCr or AKI as well as interactions with workload and these results also will be presented. <h3>Conclusion</h3> Age, sex, and workload were associated with cross-shift changes in kidney function among sugarcane workers, with female workers showing lower odds of AKI, highlighting the need for targeted protective measures—especially for older individuals and those performing high-intensity labor in hot environments.