Biochemical markers of cell death: Forensic implications for differentiating primary and secondary hypothermia

Background: Primary hypothermia occurs when the body is exposed to extremely low temperatures in an environment with no underlying health conditions. Secondary hypothermia, on the other hand, results from disruptions in thermoregulation due to diseases, trauma, surgery, drugs, alcohol, or infections. Postmortem biochemistry has become a crucial factor in forensic examinations, offering valuable apprehension into tissue of and organ dysfunction associated with the process of dying. Aim: This research aims to explore various biochemical markers and their significance in distinguishing primary from secondary hypothermia. Methods: This study involved 21 Wistar rats, which were separated into three experimental groups: CG (n = 7), which were exposed only to hypothermic conditions; AHG (n = 7); and BHG (n = 7). We tested these parameters in each rat: glucose, urea, creatinine, blood urea nitrogen to creatinine ratio, phosphorus, calcium, sodium, potassium, sodium to potassium ratio, chloride, and calculated osmolality. Results: Distinct biochemical differences were noted between primary and secondary hypothermia. Glucose and creatinine levels exhibited significant variations (p < 0.001). Urea concentrations also manifested notable differences between the groups (p < 0.001). Phosphorus levels demonstrated significant differences (p = 0.004), with post hoc analyses revealing significant contrasts between the AHG and BHG (p = 0.014) and between the BHG and CG (p = 0.014). Potassium levels and the sodium-to-potassium ratio differed significantly (p < 0.001). Osmolality also varied significantly across experimental groups (p < 0.001), with post hoc tests confirming significant differences between the AHG and CG (p = 0.013) and between the BHG and CG (p = 0.002). Conclusion: The calculated osmolality exhibited significant variation among the different groups, indicating a notable impact of the substances on the biochemical profile related to hypothermia. This study focused on the effectiveness of biochemical markers in distinguishing primary hypothermia from secondary hypothermia.