Whole-Body Cryotherapy Reduces Systemic Inflammation in Healthy Adults: Pilot Cohort Study.

Background: Chronically elevated inflammation is implicated in many conditions, including obesity, metabolic syndrome, and cardiovascular disease, and has been associated with increased mortality risk. Whole-body cryotherapy (W-BC) is a promising modality to treat inflammation with demonstrated benefits for clinical subpopulations including those with arthritis, obesity, and type 2 diabetes. However, it is unclear whether the benefit from W-BC extends to healthy individuals prior to chronic disease-related inflammation. In addition, the long-term durability of W-BC effect is unknown.

Objective: This study investigates the inflammatory response to W-BC in healthy adults with a biomarker of inflammation, high-sensitivity C-reactive protein (hsCRP), and clinical biomarkers of metabolism including fasting glucose, hemoglobin A_1c (HbA_1c), low-density lipoprotein (LDL) and high-density lipoprotein (HDL), and triglycerides.

Methods: Fifteen individuals (n=9 female) participated in frequent recreational W-BC (3 minutes of cold exposure at -110 ℃) over approximately 9 months and had blood draws at baseline plus follow-up visits. Biomarkers were modeled as linear functions of W-BC sessions received in the month prior to blood draw.

Results: The mean amount of W-BC received was 6.78 (SD 4.26) times per month with the cumulative total ranging from 13 to 157 W-BC sessions over the course of the study. On average, participants completed 1-2 sessions per week throughout the intervention. The number of W-BC sessions were associated with decreased hsCRP (-0.14 mg/L in hsCRP per W-BC session; P<.01) and with durability of up to 9 months. Increased W-BC was also associated with a downward trend in fasting glucose. This trend failed to reach significance at 1 month (-0.73 mg/dL in fasting glucose per W-BC session; P<.10) but was significant for 2- and 3-month windows (P<.05). HbA_1c was increased significantly after 9 months (P<.01); however, the change occurred within normal ranges (difference=0.13% and <5.7%) and was not clinically significant. There was no association between W-BC and LDL cholesterol, HDL cholesterol, or triglycerides (P>.10), although LDL trended lower over the time period examined (P=.07).

Conclusions: These results suggest that W-BC beneficially impacts systemic inflammation by lowering hsCRP levels in healthy individuals and may also have some modulating effect on fasting glucose.