Cross‐shift Body Mass Change and Associated Health Outcomes Related to Chronic Kidney Disease in Sugarcane Workers in Guatemala

Abstract

A new form of kidney disease, chronic kidney disease of an unknown origin (CKDu), has developed in Central America and other parts of the world. One group that is disproportionately affected are sugarcane workers potentially because of chronic dehydration and exercise heat stress.PURPOSEThe aim was to evaluate if changes in kidney health outcomes for three groups of sugarcane workers [highland sugarcane cutters (HC), local sugarcane cutters (LC), production workers (PW)] were related to the frequency of cross‐shift body mass change (> 1% of body mass = dehydrated, body mass loss of ≤ 1% = hydrated).METHODS418 male sugarcane workers (HC n = 137, 28 ± 7 y, 159 ± 1 cm, 58.5 ± 6.0 kg, 0.88 ± 0.14 mg·dL‐1 whole blood creatinine (WBCr); LC n = 190, 32 ± 8 y, 161 ± 1 cm, 59.7 ± 8.4 kg, 0.92 ± 0.16 mg· dL‐1 WBCr; PW n = 91, 32 ± 11 y, 158 ± 1 cm, 60.1 ± 7.5 kg, 0.88 ± 0.16 mg· dL‐1 WBCr) participated in the study. The study included pre‐employment baseline data and three single day cross‐shift data collections. At each time point, bodyweight, a urine sample, and a point‐of‐care creatinine measure were collected from participants before and after work. Workers were not hired if they had an estimated glomerular filtration rate (eGFR) < 60 ml□min‐1□1.73m‐2. To evaluate chronic hydration status, workers were divided into four groups (pre‐ to post‐shift body mass loss < 1% at three, two, one, or zero of the time points). One‐way ANOVAs comparing change in WBCr and eGFR were completed to evaluate pre‐ to post‐season change for the different groups of workers based on hydration status. Statistical significance was set at α < .05.RESULTSThere was a significant difference among worker group season change in eGFR ml□min‐1□1.73m‐2 (HC 2.05 ± 1.5, LC −5.47 ± 1.3, PW −0.30 ± 1.9, F‐score = 7.6, P = <0.01) There was a significant difference in change of WBCr from pre‐season to post‐season between worker groups (HC −0.07 ± 0.19, LC 0.03 ± 0.27, PW −0.04 ± 0.15, F‐score = 7.72, P = <0.01). Thirteen participants developed an eGFR <90 ml□min‐1□1.73m‐2 and two participants developed an eGFR <60 ml□min‐1□1.73m‐2 during the season. Self‐reported water consumptions during the work shift at the first time point was 17.6 ± 5.0 L for HC, 14.8 ± 2.5 L for LC, and 4.9 ± 1.4 L for PW. Among each work group, there was no significant difference in change in eGFR between workers who were hydrated at 3, 2, 1, or 0 time points (HC F‐score = 0.09, P = 0.92; LC F‐score = 1.44, P = 0.23; PW F‐score =1.07, P = 0.37).CONCLUSIONSChronic hydration status based on frequency of cross‐shift body mass >1% did not relate to workers' risk of developing kidney damage over the course of a 6‐month sugarcane harvest. Only 13 and 2 participants developed an eGFR <90 and <60 ml□min‐1□1.73m‐2, respectively, possibly indicating that drinking large amounts of water and not hiring workers with a pre‐season eGFR < 60 ml□min‐1□1.73m‐2 may help prevent the development of CKDu. However, there are likely other contributing factors such as work intensity and/or lifestyle.Support or Funding InformationInvestigation funded by Colorado School of Public Health and PantaleonThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.