Supraclavicular Skin Temperature as a Measure of Brown Adipose Tissue Temperature in Normal and Obese Young Adults of Male

Abstract

Background: Brown adipose tissue (BAT) takes part in non-shivering thermogenesis and plays an important role in regulating metabolism. Since direct measurements of BAT are often invasive or expensive, supraclavicular skin temperature (SCT) has been described in literature as a measure as BAT activity.

Objective: This study explored the supraclavicular skin temperature as a possible reflection of BAT activity in young lean and obese adult males

Methods: The study was conducted in 446 young adult males, grouped into, normal weight, overweight, and obese categories based on BMI. SCT was taken as a measure of BAT activity because of high accumulation of BAT in this zone in adults. Using thermistor probe which was attached to Fluke 17B+ multimeter, we measured both SCT (BAT region) and chest skin temperature (non-BAT region). Temperature was recorded in winter months at room temperature of 25-26 ⁰C. Temperature values were compared across BMI groups.

Results: SCT and chest skin temperature were recorded in 446 subjects. The mean temperature recorded from supraclavicular and chest region were 33.3 ±0.8 ⁰C, 32.8±1.0 ⁰C (mean±SD) respectively. The SCT was significantly higher than the chest skin temperature. But when compared with normal weight group,  the SCT in overweight and obese participants showed lower values (32.8±1°C and 32.6±0.6 °C, respectively) and were statistically significant (p < 0.001).

Conclusion: Our study shows that the skin temperature measured over the supraclavicular region is consistently higher than chest skin temperature, reflecting the activity of brown fat. Importantly, this temperature was highest in young men with a normal BMI and gradually declined in those who were overweight and obese. This suggests that BAT activity decreases with increasing BMI reflecting. Measuring SCT therefore offers a simple, non-invasive way to measure BAT activities indirectly in population studies to understand pathophysiology of obesity.