scholarly journals Cold-activated brown adipose tissue in human adults: methodological issues

2014 ◽  
Vol 307 (2) ◽  
pp. R103-R113 ◽  
Author(s):  
Anouk A. J. J. van der Lans ◽  
Roel Wierts ◽  
Maarten J. Vosselman ◽  
Patrick Schrauwen ◽  
Boudewijn Brans ◽  
...  

The relevance of functional brown adipose tissue (BAT) depots in human adults was undisputedly proven approximately seven years ago. Here we give an overview of all dedicated studies that were published on cold-induced BAT activity in adult humans that appeared since then. Different cooling protocols and imaging techniques to determine BAT activity are reviewed. BAT activation can be achieved by means of air- or water-cooling protocols. The most promising approach is individualized cooling, during which subjects are studied at the lowest temperature for nonshivering condition, probably revealing maximal nonshivering thermogenesis. The highest BAT prevalence (i.e., close to 100%) is observed using the individualized cooling protocol. Currently, the most widely used technique to study the metabolic activity of BAT is deoxy-2-[18F]fluoro-d-glucose ([18F]FDG)-positron emission tomography/computed tomography (PET/CT) imaging. Dynamic imaging provides quantitative information about glucose uptake rates, whereas static imaging reflects overall BAT glucose uptake, localization, and distribution. In general, standardized uptake values (SUV) are used to quantify BAT activity. An accurate determination of total BAT volume is hampered by the limited spatial resolution of the PET image, leading to spillover. Different research groups use different SUV threshold values, which make it difficult to directly compare BAT activity levels between studies. Another issue is the comparison of [18F]FDG uptake in BAT with respect to other tissues or upon with baseline values. This comparison can be performed by using the “fixed volume” methodology. Finally, the potential use of other relatively noninvasive methods to quantify BAT, like magnetic resonance imaging or thermography, is discussed.

2014 ◽  
Vol 170 (3) ◽  
pp. 359-366 ◽  
Author(s):  
Zhaoyun Zhang ◽  
Aaron M Cypess ◽  
Qing Miao ◽  
Hongying Ye ◽  
Chong Wee Liew ◽  
...  

ObjectivePrevious studies have shown that active brown adipose tissue (BAT) is present in adults and may play important roles in the regulation of energy homeostasis. However, nearly every study has been carried out in patients undergoing scanning for cancer surveillance (CS), whose metabolism and BAT activity may not reflect those of healthy individuals. The objective of this study was to investigate the prevalence and predictors of active BAT in Chinese adults, particularly in healthy individuals.DesignA total of 31 088 consecutive subjects aged ≥18 years who had undergone positron emission tomography/computed tomography (PET/CT) scanning of BAT were evaluated in this study.MethodsWe measured BAT activity via18F-fluorodeoxyglucose PET/CT in subjects who had undergone scanning for either a routine medical checkup (MC) or CS in Shanghai. Then, we investigated the predictors of active BAT, particularly in healthy individuals.ResultsIn both groups, the prevalence of BAT was higher in women than in men. Using a multivariate logistic analysis, we found age, sex, BMI, and high thyroid glucose uptake to be significant predictors of BAT activity in the MC group. Similarly, we found age, sex, and BMI to be significant predictors of BAT activity, but not thyroid high glucose uptake, in the CS group.ConclusionsIn Chinese adults, BAT activity inversely correlates with BMI and thyroid high glucose uptake, which reinforces the central role of brown fat in adult metabolism and provides clues to a potential means for treating the metabolic syndrome.


2016 ◽  
Vol 120 (8) ◽  
pp. 825-832 ◽  
Author(s):  
Laura Ernande ◽  
Kristin I. Stanford ◽  
Robrecht Thoonen ◽  
Haihua Zhang ◽  
Maëva Clerte ◽  
...  

Brown adipose tissue (BAT) activation increases glucose and lipid consumption; as such, it is been considered as a potential therapy to decrease obesity. BAT is highly vascularized and its activation is associated with a necessary increase in blood flow. However, whether increasing BAT blood flow per se increases BAT activity is unknown. To examine this hypothesis, we investigated whether an isolated increase in BAT blood flow obtained by β2-adrenoreceptor (β2-AR) stimulation with salbutamol increased BAT activity. BAT blood flow was estimated in vivo in mice using contrast-enhanced ultrasound. The absence of direct effect of salbutamol on the function of isolated brown adipocytes was assessed by measuring oxygen consumption. The effect of salbutamol on BAT activity was investigated by measuring BAT glucose uptake in vivo. BAT blood flow increased by 2.3 ± 0.6-fold during β2-AR stimulation using salbutamol infusion in mice ( P = 0.003). β2-AR gene expression was detectable in BAT but was extremely low in isolated brown adipocytes. Oxygen consumption of isolated brown adipocytes did not change with salbutamol exposure, confirming the absence of a direct effect of β2-AR agonist on brown adipocytes. Finally, β2-AR stimulation by salbutamol increased BAT glucose uptake in vivo (991 ± 358 vs. 135 ± 49 ng glucose/mg tissue/45 min in salbutamol vs. saline injected mice, respectively, P = 0.046). In conclusion, an increase in BAT blood flow without direct stimulation of the brown adipocytes is associated with increased BAT metabolic activity. Increasing BAT blood flow might represent a new therapeutic target in obesity.


Endocrinology ◽  
2017 ◽  
Vol 158 (10) ◽  
pp. 3090-3096 ◽  
Author(s):  
Jo E Lewis ◽  
Ricardo J Samms ◽  
Scott Cooper ◽  
Jeni C Luckett ◽  
Alan C Perkins ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Rongcai Ye ◽  
Chunlong Yan ◽  
Huiqiao Zhou ◽  
Yuanyuan Huang ◽  
Meng Dong ◽  
...  

Polycystic ovary syndrome (PCOS) is a common endocrine disease accompanied by energetic metabolic imbalance. Because the etiology of PCOS is complex and remains unclear, there is no effective and specific treatment for PCOS. It is often accompanied by various metabolic disorders such as obesity, insulin resistances, and others. Activated brown adipose tissue (BAT) consumes excess energy via thermogenesis, which has positive effects on energy metabolism. Our previous research and that of others indicates that BAT activity is decreased in PCOS patients, and exogenous BAT transplantation can improve PCOS rodents. Notably however, it is difficult to apply this therapeutic strategy in clinical practice. Therapeutic strategies of enhancing endogenous BAT activity and restoring whole-body endocrine homeostasis may be more meaningful for PCOS treatment. In the current study, the dehydroepiandrosterone-induced PCOS rat was exposed to low temperature for 20 days. The results show that cold treatment could reverse acyclicity of the estrous cycle and reduce circulating testosterone and luteinizing hormone in PCOS rats by activating endogenous BAT. It also significantly reduced the expression of steroidogenic enzymes as well as inflammatory factors in the ovaries of PCOS rats. Histological investigations revealed that cold treatment could significantly reduce ovary cystic follicles and increase corpus luteum, indicating that ovulation was recovered to a normal level. Concordant with these results, cold treatment also improved fertility in PCOS rats. Collectively, these findings suggest that cold treatment could be a novel therapeutic strategy for PCOS.


2019 ◽  
Vol 181 (5) ◽  
pp. 473-480 ◽  
Author(s):  
Oliveira Flávia R ◽  
Marcelo Mamede ◽  
Mariana F Bizzi ◽  
Rocha Ana Luiza L ◽  
Cláudia N Ferreira ◽  
...  

Objective To evaluate whether brown adipose tissue (BAT) activity is altered in women with polycystic ovary syndrome (PCOS), and whether BAT activity correlates with plasma levels of irisin, a myokine that can induce BAT formation. Design We performed a cross-sectional study including women with PCOS (n = 45) and a healthy control group (n = 25) matched by age and body mass index (BMI). Methods BAT activity was measured using 18F-FDG positron emission tomography-computed tomography (PET-CT) and plasma irisin levels were measured by a validated enzyme immunoassay. Results Total BAT activity was significantly reduced in women with PCOS (maximal standardized uptake value (SUVmax): median 7.4 g/mL, interquartile range 0.9–15.4) compared to controls (median 13.0 g/mL, interquartile range 4.7–18.4, P = 0.047). However, this difference was no longer significant after adjustment for waist circumference, a surrogate marker of central adiposity. In the PCOS group, BAT activity correlated negatively with BMI (Spearman’s r = −0.630, P = 0.000) and waist circumference (r = −0.592, P = 0.000) but not with plasma irisin levels. Conclusions BAT activity was reduced in women with PCOS possibly due to increased central adiposity. In PCOS women, BAT activity did not correlate with plasma irisin levels.


Nutrients ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2752
Author(s):  
Kelsey A. Heenan ◽  
Andres E. Carrillo ◽  
Jacob L. Fulton ◽  
Edward J. Ryan ◽  
Jason R. Edsall ◽  
...  

Background: Brown adipose tissue (BAT) provides a minor contribution to diet-induced thermogenesis (DIT)—the metabolic response to food consumption. Increased BAT activity is generally considered beneficial for mammalian metabolism and has been associated with favorable health outcomes. The aim of the current systematic review was to explore whether nutritional factors and/or diet affect human BAT activity. Methods: We searched PubMed Central, Embase and Cochrane Library (trials) to conduct this systematic review (PROSPERO protocol: CRD42018082323). Results: We included 24 eligible papers that studied a total of 2785 participants. We found no mean differences in standardized uptake value of BAT following a single meal or after 6 weeks of L-Arginine supplementation. Resting energy expenditure (REE), however, was increased following a single meal and after supplementation of capsinoid and catechin when compared to a control condition (Z = 2.41, p = 0.02; mean difference = 102.47 (95% CI = 19.28–185.67)). Conclusions: Human BAT activity was not significantly affected by nutrition/diet. Moreover, REE was only increased in response to a single meal, but it is unlikely that this was due to increased BAT activity. BAT activity assessments in response to the chronic effect of food should be considered along with other factors such as body composition and/or environmental temperature.


2019 ◽  
Vol 50 (4) ◽  
pp. 1160-1168 ◽  
Author(s):  
Gani Gashi ◽  
Philipp Madoerin ◽  
Claudia I. Maushart ◽  
Regina Michel ◽  
Jaël‐Rut Senn ◽  
...  

Author(s):  
Rahel Catherina Loeliger ◽  
Claudia Irene Maushart ◽  
Gani Gashi ◽  
Jaël Rut Senn ◽  
Martina Felder ◽  
...  

Objective Human brown adipose tissue (BAT) is a thermogenic tissue activated by the sympathetic nervous system in response to cold. It contributes to energy expenditure (EE) and takes up glucose and lipids from the circulation. Studies in rodents suggest that BAT contributes to the transient rise in EE after food intake, so called diet-induced thermogenesis (DIT). We investigated the relationship between human BAT activity and DIT in response to glucose intake in 17 healthy volunteers. Methods We assessed DIT, cold induced thermogenesis (CIT) and maximum BAT activity at three separate study visits within two weeks. DIT was measured by indirect calorimetry during an oral glucose tolerance-test. CIT was assessed as the difference in EE after cold exposure of two hours duration as compared to warm conditions. Maximal activity of BAT was assessed by 18F-FDG-PET/MRI after cold exposure and concomitant pharmacological stimulation with Mirabegron. Results 17 healthy men (mean age 23.4 years, mean BMI 23.2 kg/m2) participated in the study. EE increased from 1908 (±181) kcal/24 hours to 2128 (±277) kcal/24 hours (p<0.0001, +11.5%) after mild cold exposure. An oral glucose load increased EE from 1911 (±165) kcal/24 hours to 2096 (±167) kcal/24 hours at 60 minutes (p<0.0001, +9.7%). The increase in EE in response to cold was significantly associated with BAT activity (R2=0.43, p=0.004). However, DIT was not associated with BAT activity (R2=0.015, p=0.64). Conclusion DIT after an oral glucose load was not associated with stimulated 18F-FDG uptake into BAT suggesting that DIT is independent from BAT activity in humans.


Metabolites ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 388
Author(s):  
Angie S. Xiang ◽  
Corey Giles ◽  
Rebecca K.C. Loh ◽  
Melissa F. Formosa ◽  
Nina Eikelis ◽  
...  

Brown adipose tissue (BAT) activation is a possible therapeutic strategy to increase energy expenditure and improve metabolic homeostasis in obesity. Recent studies have revealed novel interactions between BAT and circulating lipid species—in particular, the non-esterified fatty acid (NEFA) and oxylipin lipid classes. This study aimed to identify individual lipid species that may be associated with cold-stimulated BAT activity in humans. A panel of 44 NEFA and 41 oxylipin species were measured using mass-spectrometry-based lipidomics in the plasma of fourteen healthy male participants before and after 90 min of mild cold exposure. Lipid measures were correlated with BAT activity measured via 18F-fluorodeoxyglucose ([18F]FDG) positron emission tomography/computed tomography (PET/CT), along with norepinephrine (NE) concentration (a surrogate marker of sympathetic activity). The study identified a significant increase in total NEFA concentration following cold exposure that was positively associated with NE concentration change. Individually, 33 NEFA and 11 oxylipin species increased significantly in response to cold exposure. The concentration of the omega-3 NEFA, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) at baseline was significantly associated with BAT activity, and the cold-induced change in 18 NEFA species was significantly associated with BAT activity. No significant associations were identified between BAT activity and oxylipins.


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