The maintenance of core temperature in SCUBA divers: Contributions of anthropometrics, patent foramen ovale, and non-shivering thermogenesis

Objectives

To determine the influence of a patent foramen ovale and fibroblast growth factor-21 on core temperature (Tc) responses in SCUBA divers. Additionally, we aimed to quantify the individual and combined influences of wetsuit thickness and anthropometric data on Tc changes during the dives.

Design

An experimental study comparing the Tc responses between divers with (n = 17) and without a patent foramen ovale (n = 14).

Methods

A total of 31 divers participated in the study. Tc was measured pre- and post-dive in 17–18 °C sea water using a telemetric pill. Additionally, blood was drawn pre-dive and ~ 1–2 h post-dive for measurement of fibroblast growth factor-21.

Results

There was no influence of a patent foramen ovale on the Tc responses during SCUBA diving in either dive profile (p > 0.05). Additionally, there was no influence of SCUBA diving on fibroblast growth factor-21 concentrations (p > 0.05). The strongest positive and significant associations with the ∆ Tc/min were found when multiplying wetsuit thickness in millimeters by body mass (r² = 0.3147, p = 0.0010), BMI (r² = 0.3123, p = 0.0011), and body surface area (r² = 0.2877, p = 0.0019). There was a significant, negative linear relationship between the body surface area to mass ratio and ∆ Tc/min (r² = 0.2812, p = 0.0032).

Conclusions

These data suggest that Tc regulation during recreational SCUBA diving can be facilitated in part by the appropriate choice of wetsuit thickness for a given set of anthropometric characteristics.