Slow nocturnal body cooling during sleep increases interbeat intervals and is tightly coupled to high-frequency heart rate variability in healthy men.

ABSTRACT: During nocturnal sleep, core body temperature (CBT) decreases and cardiac inter-beat intervals (IBI) increase. This study used a non-disturbing cooling intervention during sleep to investigate additional effects of CBT reduction on IBI and heart rate variability. Sleep on a high heat-capacity cooling gel mattress (HM) was compared to a low heat-capacity mattress (LM) in 32 healthy males (age 46 ± 4 years). Electroencephalography, electrocardiography, CBT, skin, mattress, and air temperatures were recorded under constant conditions. Power in the low- (LF) and high-frequency (HF) bands and the LF/HF ratio were calculated from one-minute IBI intervals. Sleep on HM led to greater CBT decline and showed increased IBI and HF in all sleep stages. Mediation analyses indicate HF is not directly inf

SUBMITTER: Krauchi K 

PROVIDER: S-EPMC12329345 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature