Relationships between plasma lipidomic profiles and brown adipose tissue density in humans

Abstract

Background/objectives The thermogenic function of brown adipose tissue (BAT) is generally activated in winter and tightly regulated through various metabolic processes. However, the mechanisms mediating these changes have not been elucidated in humans. Here, we investigated the relationships between BAT density (BAT-d) and lipid metabolites in plasma from men and women in the winter and summer. Subjects/methods In total, 92 plasma samples were obtained from 23 men and 23 women, aged 21–55 years, on two different occasions (summer and winter). Lipid metabolites were comprehensively quantified using liquid chromatography-time-of-flight-mass spectrometry. BAT-d was evaluated by measuring total hemoglobin concentrations in the supraclavicular region using near-infrared time-resolved spectroscopy. Anthropometric parameters, such as the percentage of whole body fat and visceral fat area (VFA), were evaluated. Factors influencing BAT-d were investigated by univariate and multivariate regression analyses. Results A variety of metabolite peaks, such as glycerophospholipids (168 peaks), steroids and derivatives (78 peaks), fatty acyls (62 peaks), and glycerolipids (31 peaks), were detected. Univariate regression analysis, corrected by false discovery rate to yield Q values, revealed significant correlations in BAT-d and phosphatidylethanolamine (PE(46:2), r = 0.62, Q = 4.9 × 10−2) in the summer, androgens (r = 0.75, Q = 7.0 × 10−3) in the winter, and diacylglycerol (DG(36:1), r = −0.68, Q = 4.9 × 10−2) in the summer in men, but not in women. Multivariate regression analysis in the winter revealed a significant correlation between BAT-d and plasma androgens (P = 5.3 × 10−5) in men and between BAT-d and VFA (P = 2.2 × 10−3) in women. Conclusions Certain lipids in plasma showed unique correlations with BAT-d depending on sex and season. BAT-d showed a specific correlation with plasma androgens in men in the winter.

Near-Infrared Time-Resolved Spectroscopy for Assessing Brown Adipose Tissue Density in Humans: A Review

“…BAT characteristics are related to unique profiles of lipid metabolites, such as the concentration of lysophosphatidylcholine-acyl (LysoPC-acyl) C16:0 in humans (63), and the concentration of phosphatidylethanolamine (PE) in the BAT and WAT was decreased in high-fat diet-fed mice (14). The relationships have been examined in the winter and summer between [total-Hb] sup , a parameter for evaluating BAT-d, measured using NIR TRS and plasma lipids in humans (38). showed a significant correlation with androgens in men and VFA in women in winter.…”

“…The purpose of this article is to provide evidence concerning the ability of NIRS to evaluate BAT characteristics in humans. In this review, we included studies examining BAT characteristics using NIRS in humans: most studies used NIR TRS (29,(33)(34)(35)(36)(37)(38)(39), a technology to quantify both absolute tissue absorption and scattering characteristics, while some utilized NIR continuous wave spectroscopy (NIR CWS ), an inexpensive technology that only provides relative values of tissue oxygenation (32,40). First, we present how NIRS functions to evaluate tissue oxygenation and blood volume.…”

Serum Metabolomic Profiling of Patients with Non-Infectious Uveitis

“…The LC-MS instrument has previously been described in detail [24]. Briefly, Agilent Technologies 1290 Infinity LC system and G6230B time-of-flight MS (TOF-MS) (Agilent Technologies, Santa Clara, CA, USA) were used.…”

Effects of Capsinoid Intake on Brown Adipose Tissue Vascular Density and Resting Energy Expenditure in Healthy, Middle-Aged Adults: A Randomized, Double-Blind, Placebo-Controlled Study

“…The probes were placed on the skin of the supraclavicular region, an area that contains BAT. Participants were required to remain in the sitting position, wearing light clothing, such as T-shirts, during measurements, as previously described [2,7,[24][25][26][27]. Compared to visible light wavelengths, NIR wavelengths (700-3000 nm) show less scattering and, consequently, better penetration into the biological tissue.…”