Assessment of morphological, biochemical and rheological blood indicators in men after a 24-hour stay in a thermo-climatic chamber -50°C

Abstract

Purpose: The aim of the study was to evaluate morphological, biochemical, and rheological blood indicators in men staying in a cryochamber at a temperature of -50°C for 24 hours. In 2018, a scientific-survival project ‘Taming the Frost’ was conducted at the Technoclimatic Research and Working Machines Laboratory of the Cracow University of Technology, under the scientific patronage of the Rector of the Cracow University of Technology, Prof. Jan Kazior, PhD, as well as the Rector of the University of Physical Education in Krakow, the late Prof. Aleksander Tyka, PhD, and the Vice-Rector for Science, Prof. Anna Marchewka, PhD. Material and methods: The blood for the tests was collected from an ulnar vein in fasting participants by a qualified nurse, in the morning, before entering the cryochamber and after 24 hours, i.e. on leaving the cryochamber. Morphological, biochemical, and rheological blood indicators were evaluated. The study group of the scientific-survival project ‘Taming the Frost’ involved men (n=6) who stayed in a cryochamber at a temperature of -50°C for 24 hours. For each participant, a 5-ml blood sample was placed in a tube (BD Vacutainer) with EDTA K2 anticoagulant for blood morphology and blood rheological evaluations in the Blood Physiology Laboratory of the Central Research and Development Laboratory, University of Physical Education in Krakow. Another 5-ml blood sample was placed in a Vacuette tube with a clotting activator for the remaining biochemical analyses in the Department of Clinical Biochemistry of the Krakow Branch of Maria Skłodowska-Curie National Research Institute of Oncology. Results: After leaving the cryochamber with a temperature of –50°C, the participants presented statistically significant increases in monocyte count and high-density lipoprotein and creatine kinase values, as well as decreases in IgA, total cholesterol, and triglycerides. In the assessment of blood rheological indicators, statistically significant increases in the elongation index at the shear stress of 0.30, 0.58, 1.13, and 2.19 Pa and decreases in the elongation index at the shear stress of 31.03 and 60.3 Pa were observed. For red cell aggregation indicators, a statistically significant increase in total aggregation time was reported. The other indicators exhibited a significance level of p>0.05. Conclusions: Staying in a cryochamber at a temperature of -50°C for 24 hours did not exert a negative impact on morphological, biochemical, or rheological blood indicators, which implies the subjects’ adaptation to the arranged conditions.