Comparison of brown adipose tissue activation detected by infrared thermography in men with vs without metabolic syndrome

Abstract

BackgroundBrown adipose tissue (BAT) high density of mitochondria and its thermogenic characteristics promote the dissipation of chemical energy in the form of heat, increasing body caloric expenditure, decreasing plasma levels of lipids and glucose (GL). This makes BAT a potential therapeutic target of Metabolic Syndrome (MetS). Position Emission Tomography Scanning (PET-CT) is the gold standard for estimating BAT, but it has several limitations, including high cost and high emission of radiation. On the other hand, Infrared Thermography (IRT) is considered a simpler, cheaper and non-invasive method to detect BAT. ObjectiveThe aim of this study was to compare BAT activation through IRT and cold stimulation in men diagnosed without and with MetS. MethodsSample of 124 (35.3 ± 9.4 years old) men was evaluated of body composition, anthropometric measurements and dual X-ray absorptiometry (DXA) hemodynamics, biochemical tests and body skin temperature acquisition. The Student t-test with subsequent effect size by (d) Cohen and two-way repeated measures ANOVA with Tukey post-hoc comparisons were conducted. Level of significance was p < 0.05. ResultsThere was significant interaction between group factor (MetS) vs group moment (BAT activation) in supraclavicular skin temperatures right side (maximum (F(1,122) = 10.4, p < 0.002, η2 = 0.062), mean (F(1.122) = 13.0, p < 0.001, η2 = 0.081) and minimal (F(1,122) = 7.9, p < 0.006, η2 = 0.052)) and left side maximum (F(1,122) = 7.7, p < 0.006, η2 = 0.048), mean (F(1.122) = 13.0, p < 0.037, η2 = 0.007) and minimal (F(1,122) = 9.8, p < 0.002, η2 = 0.012)). The MetS risk factor group didn't present significant increase of SCV temperature BAT after cold stimulation. ConclusionMen diagnosed with MetS risk factors seem to activate less BAT, when exposed to cold stimulation, compared to group without MetS risk factor.