Hydration Choices, Sugary Beverages, and Kidney Injury in Agricultural Workers in California

Abstract

Purpose Agricultural workers working in high ambient temperatures are at risk for acute kidney injury. Despite recommendations to maintain hydration, workers likely do not drink enough to protect their renal function. Additionally, new research suggests that rehydration with sugary beverages adds additional risk to kidneys already stressed by high heat and workload. We assessed hydration choices during a work shift and tested associations of rehydration using sugary beverages with acute kidney injury. Methods We recruited a convenience sample of workers on farms over two summers. We estimated acute kidney injury via pre‐ and post‐shift serum creatinine readings from capillary blood samples. We used self‐reported measures of the volume and type of fluids workers consumed during their shifts. We also measured changes in core body temperature, ambient temperature, and workload. We used logistic regression to estimate associations of sugary drinks with acute kidney injury, while controlling for physiologic and occupational variables. Findings In our sample of 445 participants, we found that men drink more than women do overall, including more than a liter of water than women (2.9 L compared to 1.9 L, respectively). The total volume workers drank was associated with increased odds of acute kidney injury (adjusted odds ratio 1.47, 95% confidence interval 1.09–1.99). We found no association of sugary drinks with acute kidney injury. Conclusions These findings provide important information about what men and women use to hydrate during the work day and suggest that they do not drink enough to maintain adequate hydration. Increased fluid intake during the work day may be a result of vigorous workload, which could explain the increased risk for acute kidney injury. Nurses play an important role in educating agricultural workers about the importance of maintaining hydration at work. Clinical Relevance This study advances current knowledge of occupational risk factors for acute kidney injury in agricultural workers. Nurses may be the only point of care for this vulnerable population and are therefore in a unique position to educate on the importance of proper hydration during work.

Longitudinal assessment of kidney function in migrant farm workers

“…However, the association between recent consumption of soda among participants and lower eGFR disappeared after controlling for PSI. The lack of an association with soda consumption and eGFR is similar to the results reported by a recent study conducted in California among agricultural workers, in which there was no association between sugary drinks and AKI ( Moyce et al, 2020 ).…”

“…Our results on water consumption and eGFR are consistent with other studies in which an increase on self-reported water consumption is associated with eGFR decline ( Laws, 2015 ; Sanoff et al, 2010 ; Wesseling et al, 2016 ). This supports the idea that perhaps the workers who drank large amounts may be compensating for working hard ( Moyce et al, 2020 ). It is important to consider the effect of hyperthermia alone or in combination with dehydration, as consequences of the strenuous physical work conducted during high levels of heat stress, which can lead to a reduced renal blood flow ( Cotter et al, 2014 ; Cuddy and Ruby, 2011 ).…”

“…In order to evaluate several factors of interest associated with eGFR, we performed linear mixed effects regression analyses with random intercepts for individuals to account for the repeated measures on the same participant using the data collected during pre-harvest and the late harvest timepoints. Occupational factors, individual behaviors and demographic characteristics known to be risk factors in reduced kidney function were selected a priori based on recent literature and data collection feasibility ( Butler-Dawson et al, 2019 ; Moyce et al 2018 , 2020 ; Sorensen et al, 2019 ).…”

Occupational heat exposure and the risk of chronic kidney disease of nontraditional origin in the United States

“…There are only three reports of the specific outcome of CKDnt in the United States (14)(15)(16). A few studies, although limited by the serum creatinine-defined criteria, have taken the important initial steps in quantifying postshift AKI incidence in US agricultural workers (18)(19)(20)(21)(22). In one study, agricultural workers in California experienced increased serum…”

“…Hotspots of end-stage renal disease of unknown causes have been identified in rural agricultural areas in the United States, including in the Mississippi river valley, southeast, California, and Texas (17). There are also a few preliminary reports of AKI in agricultural workers in California and Florida based on increased serum creatinine (18)(19)(20)(21)(22), and a recent retrospective analysis revealed that 40% of US military service members hospitalized with exertional heat stroke were diagnosed with AKI, but none required dialysis (11). To our knowledge, no study has investigated whether in situ occupational heat exposure increases markers of kidney injury among US workers.…”