Kidney function impairment amongst industrial agricultural workers in Central America

Hart, Ellon (2022). Kidney function impairment amongst industrial agricultural workers in Central America. University of Birmingham. M.Sc.

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Abstract

In several regions of Central America an epidemic of chronic kidney disease exists that is unrelated to conventional risk factors such as hypertension and diabetes. The impact of this disease, now termed chronic kidney disease of non-traditional origin (CKDnt), is devastating, accounting for tens of thousands of fatalities. The exact aetiology of CKDnt is still unknown, although there is strong evidence to favour the involvement of high occupational workloads and heat stress, due to prolonged strenuous work in hot climates. It is believed that frequent exposure to strenuous work under heat stress can cause repeat episodes of acute kidney injury or kidney strain, which can potentially lead to a chronic functional and structural damage, especially when recovery time between work shifts is minimal.
There is therefore an urgent need to understand more about CKDnt pathophysiology, in order to develop effective strategies to mitigate the risk. In addition, more research is warranted to help improve the diagnosis and monitoring of at-risk workers, through more consistent and standardised field-based testing protocols, and the potential implementation of more sensitive biomarkers. This thesis will aim to address some of these issues. Firstly, a protocol chapter (Chapter 2) is presented that assesses methods of measuring kidney function/injury, their advantages, and disadvantages, as well as some recommendations on how to best use these measures in field-based occupational studies. The latter part of this thesis presents a data chapter (Chapter 3) comparing the recovery of blood and urine biomarkers at the end of a working week (17 hours recovery) to that at the beginning of a working week, after a day off (41 hours recovery). This chapter also examines how these two different recovery periods affect cross-shift changes in blood and urine biomarkers. The study presented in Chapter 3 was conducted at the sugarcane mill Ingenio San Antonio (ISA) in Chinandega, Nicaragua, over the course of 4 days during the mid-harvest season (including three workdays (Friday, Saturday, and Monday), and one rest day (Sunday). Biomarkers of kidney function, hydration status, inflammation and muscle damage were collected in 20 male burned sugarcane cutters (aged 33 ± 7 years) at 5 timepoints across the course of the study (End of work week: Friday post-shift, Saturday pre- and post-shift; and Beginning of work week: Monday pre- and post-shift). Our results showed that recovery of blood and urine biomarkers was not significantly different following 41 hours (Saturday post- to Monday pre-shift), compared to 17 hours, (Friday post- to Saturday pre-shift). In addition, cross-shift reductions in kidney function were significantly greater after this longer 41-hour recovery period, compared to a 17-hour recovery period. However, it is possible that any significant benefits from a longer recovery period may be dampened by the high degree of individual variability in our results

Type of Work:

Thesis (Masters by Research > M.Sc.)

Award Type:

Masters by Research > M.Sc.

Supervisor(s):