Changes of cortisol and immunoglobulins in the saliva of naval divers during decompression of the 330 m saturation dive in the open sea

Abstract

Listen

Translate article

Objective To observe the change pattern of cortisol, IgA, IgG and IgM in the saliva of the naval divers during decompression of the 330 m saturation dive in the open sea, and also to explore the practicability of monitoring the stress level of divers under hyperbaric pressure by using the saliva indicators, so as to provide scientific evidence for the screening of stress-related indicators under hyperbaric environment. Methods During decompression of the 330 m saturation dive, saliva samples of the divers were collected at set time. The cortisol level was detected by using radioimmunoassay and IgA, IgG and IgM levels were monitored by using enzyme-linked immunosorbent assay (ELISA). Results As compared with the baseline data[Cortisol: (117.0±35.4)μg/L], all the parameters including cortisol, IgA, IgG and IgM concentrations decreased at day 2 (at the initial decompression phase), and at day 8 (at the medium decompression stage) IgA concentration also decreased(129.5±114.8)μg/L]. However, salivary cortisol concentration at other time points was higher than the baseline data, and salivary cortisol concentration at day 12 (207.7±85.9)μg/L] approached the significant level (t=3.014, P=0.057), and on day 13 [(208.1±15.4)μg/L] it reached significant level (t=8.424, P=0.014). Nevertheless, the levels of IgA, IgG and IgM failed to reach significant levels. Results indicated that the two salivary indicators were positively correlated. It was shown from the graph that various indicators decreased at the initial decompression stage at the early stage, and their levels remained relatively stable at medium decompression stage, while these levels increased slightly at the late stage of decompression. Conclusions Under hyperbaric environment, salivary cortisol could be used as a stress indicator and could provide scientific evidence for the intervention of stress during saturation diving. Key words: Diver; Saliva; Cortisol; Decompression