Diagnostic Biomarkers for Heat Stroke and Heat Exhaustion: A Scoping Review

Objectives: As the global incidence of heat-related illnesses escalates in the wake of climate change-induced heat waves, the critical necessity for reliable diagnostic tools becomes apparent. This scoping review aimed to summarize the existing body of published evidence on biomarkers that could potentially be utilized for the diagnosis of heat-related illness in the clinical setting. Methods: We conducted a thorough search of 3 databases, including Embase, MEDLINE, on Ovid, and The Cochrane Library (Wiley) databases from October 11, 2022 up until January 15, 2024. We also manually included studies by searching the reference lists of the included articles. Studies that performed statistical validation were summarized in detail. Results: 2877 citations were identified and screened, with 228 studies reviewed as full text. 56% of these studies were conducted within China or North America. The studies identified 113 biomarkers. Most common biomarkers studied were troponin I, IL-6, platelets, and ALT. The studies exhibited considerable variation, reflecting the diverse range of investigated biomarkers and the absence of standardized statistical validation for the biomarkers. Conclusions: Numerous biomarkers have been evaluated in the literature, but none have been studied to impact clinical practice. There is significant variation in the methodology and statistical validation. There is a need for further research to identify clinically relevant biomarkers for heat related illnesses.