Relevance of heat stress and dehydration to chronic kidney disease (CKDu) in Sri Lanka

Abstract

Chronic kidney disease in the absence of hypertension and diabetes is a growing problem among agricultural laborers in tropical and subtropical regions. It is unclear if heat stress and dehydration are risk factors for this form of chronic kidney disease (CKDu). To investigate this relationship, agricultural workers in four villages (n = 261) in North Central Province, Sri Lanka completed the US National Institute for Occupational Safety and Health (NIOSH) health hazard evaluation of heat stress, translated into Sinhalese (July 2017). We constructed a heat stress/dehydration index based on the frequency of 16 symptoms (range 0–32; reliability, 0.84). Workers provided a urine sample for dipstick assessment of urine albumin-creatinine ratio (ACR) and refractometer analysis of urine concentration. Of 261 respondents, 41 participants reported diabetes or chronic kidney disease. They scored higher on the heat stress-dehydration index (10.78 vs. 8.03, p < .01) and were more likely to have ACR > 30 (85.4% vs. 69.4%, p < .05). Among 216 non-pregnant agricultural workers without diabetes or kidney disease (mean age, 46.6; 37% male), villagers in the high-CKDu prevalence area were more likely to show signs of dehydration (for example, greater urine concentration, 1.015 vs. 1.012, p < .05, among males); however, the heat stress-dehydration index overall was not associated with ACR or urine concentration. Because an elevated ACR (proteinuria) is not a reliable marker of early CKDu, additional studies are needed to assess the association between heat stress-dehydration symptoms and risk of CKDu.

Acute Kidney Injury Biomarker Responses to Short-Term Heat Acclimation

“…This difference in findings may relate to our more intense testing protocol resulting in greater exertion and a smaller range of responses than the previous study, with all subjects reporting at least a 4/10 on our 0-10 perceived exertion scale at the end of exercise, compared to subjects in the previous work reporting a range from the lowest to the highest possible values for exertion (6-20 on the Borg rating of perceived exertion scale) [49]. It is possible that perceived exertion may be predictive during lower-intensity work, but it should be considered that AKI is more likely to occur during higher intensity work such as our protocol in which perceived exertion was not predictive of clinical biomarkers of AKI [40,50,51].…”

Risk Factors Associated with Chronic Kidney Disease of Unknown Origin (Ckdu) in North Central Province (NCP) of Sri Lanka: An Analysis of Evidence to Date

“…The most recent findings about CKDu has helped several countries burdened by hypotheses" worldwide and shows incident rates in the region. Change in agricultural practices and providing an alternative way of farming will increase the likelihood of farmers being less exposed by the disease, although these methods have been suggested there has been no continuous monitoring carried out which questions the reliability of the methods [33,34]. A study carried out by the World Health Organization in 2014 stated that residents of the NCP exposed to agricultural activities are at high risk of contracting CKDu if protective measures are not taken [35].…”

Public health interventions for chronic diseases: cost–benefit modelizations for eradicating chronic kidney disease of multifactorial origin (CKDmfo/ CKDu) from tropical countries

“…There are a number of factors that have not been investigated, including the effects of chronic infections (e.g., hantavirus and leptospirosis), changes of dietetic constituents (predominantly carbohydrate-rich (fructose) diets with insufficient proteins, antioxidants, and micronutrients), use of illicitly brewed alcohol, chronic dehydration, excessive use of over-the counter nephrotoxic medications (e.g., NSAIDs), and a host of recently acquired unhealthy behaviours [4, 6, 14, 18]. Current data strongly support a multifactorial aetiology for this disease; thus, the terminology of CKDmfo.…”

“…Current investigations in Sri Lanka are continuing on the effects of geochemical and occupation exposure, such as agrochemicals; climate change-associated issues, such as chronic dehydration and frequent exhaustion; and the combined effects of fluoride- and magnesium-rich hardwater, etc. [11, 12, 13, 14].…”

“…In Bangladesh, the disease is triggered by ingestion of groundwater-based arsenic that predominantly cause genitourinary tract malignancies [13]. In the Balkan region (Serbia, Bulgaria, Romania, Croatia, and Bosnia) [14] and in China, aristolochic acid ( Aristolochia indica ) is suspected as a cause for this renal tubular disease [14, 15]. No cause has been identified in other countries, including ones in Mesoamerica (Nicaragua, El Salvador, etc.…”