Highlights
- Hand heating significantly reduced postprandial blood glucose (PBG) compared to sham.
- Decreases were observed in peak PBG, area under the curve (AUC), and incremental AUC (iAUC).
- No effects were seen on fasting blood glucose (FBG).
- Tympanic temperature remained stable across all trials, confirming localized thermal action.
Objective
This study aimed to investigate whether localized hand heating — with or without negative pressure — could influence fasting (FBG) and postprandial blood glucose (PBG) levels in healthy individuals.
Why It Matters
Postprandial hyperglycemia, or elevated blood sugar after meals, is a known risk factor for metabolic diseases such as type 2 diabetes and cardiovascular disorders. Identifying simple, non-invasive methods to reduce PBG could represent a major step in preventive and complementary healthcare.
Study Design
A double-blind, randomized controlled crossover trial was conducted with 17 healthy participants for the FBG test and 13 for the PBG test.
Three devices were tested:
- Heat only,
- Heat + negative pressure,
- Sham (control).
Each intervention was applied to one hand for 30 minutes (FBG) or 1 hour during an Oral Glucose Tolerance Test (PBG). Blood samples were collected to assess FBG, peak PBG, AUC, and iAUC.
Results
- No changes were detected in fasting blood glucose.
- For postprandial glucose, both active devices significantly lowered peak PBG compared to the sham: Heat only: ↓18 mg/dL (p=0.039); Heat + vacuum: ↓16 mg/dL (p=0.092).
- AUC and iAUC were also reduced in the active conditions, especially with heat only.
- Tympanic temperature changes remained minimal (≤0.15°C).
Interpretation
Localized hand heating, even without vacuum assistance, improved glucose metabolism following meal ingestion. These effects may be associated with enhanced peripheral blood flow or increased glucose uptake in heated tissues, suggesting a potential physiological mechanism involving thermal modulation.
Why This Is Important
This study demonstrates that a simple, localized heating intervention can lower postprandial blood glucose levels in healthy adults, indicating potential benefits for metabolic control. Such findings open new possibilities for non-pharmacological strategies to manage glucose levels and support overall metabolic health.
Reference: Moore, J., Kressler, J., & Buono, M. J. (2020). Hand heating lowers postprandial blood glucose concentrations: A double-blind randomized controlled crossover trial. Complementary therapies in medicine, 49, 102280. doi: 10.1016/j.ctim.2019.102280.
Figure 1 – Mean (SD) blood glucose concentration before and immediately following 30 min of treatment for the 3 conditions. N=17. * Indicates statistical significance (p≤0.05). ^ Indicates a trend towards statistical significance (p≤0.10)
Figure 2 – Mean (SD) blood glucose concentrations before and 120 min following ingestion of 75 g of dextrose for the 3 different conditions. N=13.
Figure 3 – Mean (SD) 1 h post ingestion area under the curve for the 3 different conditions. * Indicates statistical significance (p≤0.05). ^ Indicates a trend towards statistical significance (p≤0.10)
Figure 4 – Mean (SD) 1 h post ingestion integrated area under the curve for the 3 different conditions.
* Indicates statistical significance (p≤0.05). ^ Indicates a trend towards statistical significance (p≤0.10)