Daily Cold Water Immersion: A 10-Day Pilot Study on Insulin Sensitivity, Brown Adipose Tissue Activation, and Cold Acclimatisation in Prediabetic Individuals
Tim Hollstein
Background
Diabetes mellitus and prediabetes are on the rise globally, posing significant health challenges. In Germany, approximately 33 million people are affected. One promising method for preventing and treating these metabolic disorders is activating brown adipose tissue (BAT), which increases energy expenditure and improves glucose and fat metabolism through thermogenic activity. Cold exposure, specifically through daily cold-water immersion (CWI), has shown potential in stimulating BAT activation and improving metabolic health, including glucose regulation and insulin sensitivity. Previous studies suggest that cold exposure may also affect muscle metabolism by enhancing GLUT4 translocation, contributing to whole-body glucose uptake.
Study Objective
This pilot study aims to investigate the effectiveness of daily cold-water immersion (CWI) on the activation and expansion of BAT, improvement of insulin sensitivity, and cold acclimatization in individuals with prediabetes. Additionally, it will examine psychological responses to cold exposure, variability in cold tolerance, and reduction of shivering activity. The goal is to develop a practical protocol for cold exposure and evaluate its long-term effects on metabolic health, particularly the potential impact on preventing type 2 diabetes.
Fig. 1: Representative positron emission tomography/computed tomography (PET/CT) images of two participants undergoing cold exposure (16°C for 2 hours) for brown adipose tissue (BAT) activation assessment: The left image (A) shows an individual with minimal BAT activation, while the right image (B) displays significant BAT activation, indicated by increased radiotracer uptake. These findings highlight the variability in BAT responsiveness to cold exposure. (Adapted from Hollstein et al. Metabolism 2021)
Methods
A total of 10 prediabetic participants will undergo a daily cold water immersion protocol for 30 minutes in 16°C cold water over ten days. Participants will receive neoprene gloves and boots to protect their hands and feet. The study will compare baseline to post-intervention values to assess the effects. The primary outcome is the improvement in insulin sensitivity, measured by the oral glucose tolerance test with the oral minimal model (OGTT-OMM). Secondary outcomes include BAT activity, measured using FDG-PET/CT, cold acclimatization, and muscle glucose uptake. Shivering activity and cold-induced thermogenesis (CIT) will be monitored weekly to track cold adaptation.
Outlook
This study could provide groundbreaking insights into how cold exposure can be utilized to prevent and treat prediabetes. Should the intervention show significant improvements in BAT activation, insulin sensitivity, and muscle glucose uptake, it could lead to new, cost-effective, non-pharmacological approaches in metabolic therapy. In the long term, such interventions could help reduce the prevalence of type 2 diabetes and enhance overall metabolic health. Collaboration with international partners, including data sharing with Sherbrooke University, will help expand research and refine cold exposure protocols.
Related links
- Becher T, Palanisamy S, Kramer DJ et al.: Brown adipose tissue is associated with cardiometabolic health. Nature Medicine 2021; 27(1): 58-65. mehr lesen
- Chondronikola M, Volpi E, Børsheim E et al.: Brown Adipose Tissue Improves Whole-Body Glucose Homeostasis and Insulin Sensitivity in Humans. Diabetes 2014; 63(12): 4089-4099. mehr lesen
- Hanssen MJW, Hoeks J, Brans B et al.: Short-term cold acclimation improves insulin sensitivity in patients with type 2 diabetes mellitus. Nature Medicine 2015; 21(8): 863-865. mehr lesen
Author
Priv.-Doz. Dr. Tim Hollstein
Universitätsklinikum Schleswig-Holstein, Campus Kiel
Institut für Diabetologie und klinische Stoffwechselforschung
Düsternbrooker Weg 17, 24105 Kiel
E-Mail: Tim.Hollstein@uksh.de