Relationships between cardiorespiratory fitness/muscular strength and 18F-fluorodeoxyglucose uptake in brown adipose tissue after exposure to cold in young, sedentary adults

Abstract

Humans have metabolically active brown adipose tissue (BAT). However, what is the relation between exercise or physical activity with this tissue remains controversial. Therefore, the main aim of the present study is to examine whether cardiorespiratory fitness and muscular strength are associated with brown adipose tissue (BAT) volume and activity after exposure to cold in young, sedentary adults. Cardiorespiratory fitness was determined in 119 young, healthy, sedentary adults (68% women, age 21.9 ± 2.1 years, body mass index 25 ± 4.8 kg/m 2 ) via the maximum treadmill exercise test, and their muscular strength assessed by the handgrip strength test and the 1-repetition maximum bench and leg press tests. Some days later, all subjects were exposed to 2 h of personalized exposure to cold and their cold-induced BAT volume and activity determined by a combination of 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography and computed tomography scan. Cardiorespiratory fitness was associated with neither the BAT volume nor BAT activity (P ≥ 0.05). However, handgrip strength with respect to lean body mass was positively (though weakly) associated with BAT activity as represented by the 18 F-FDG mean standardised uptake value (SUV) (β = 3.595, R 2 = 0.039, P = 0.031) and SUVpeak value (β = 15.314, R 2 = 0.037, P = 0.035). The above relationships remained after adjusting for several confounders. No other associations were found. Handgrip strength with respect to lean body mass is positively associated with BAT activity (SUVmean and SUVpeak) in young adults after exposure to cold - but only weakly. Further studies are needed to reveal the relationship between muscular fitness and human BAT characteristics.

No evidence of brown adipose tissue activation after 24 weeks of supervised exercise training in young sedentary adults in the ACTIBATE randomized controlled trial

“…The lack of evidence of BAT volume, 18 F-FDG uptake or mean radiodensity modification after exercise training is in line with the results of cross-sectional studies that show no association of BAT-related outcomes with objectively measured free-living physical activity 51 or muscular or cardiorespiratory fitness 52 . Case-control studies have revealed, however, that endurance-trained athletes show lower BAT volumes and 18 F-FDG uptakes than their sedentary counterparts 53 , 54 .…”

Vigorous-Intensity Physical Activities Are Associated with High Brown Adipose Tissue Density in Humans

“…In this study, participants, especially men, performing VPA, showed high BAT-d in the supraclavicular region. Information is sparse from human studies investigating the relationship between exercise and BAT; previous studies have focused on aerobic exercise [19,50], vigorous-intensity exercise [25], and muscle strength [64]. This study was the first to observe a relationship between VPA and BAT-d.…”

“…On the other hand, two weeks of high intensity interval training and moderate training interventions did not alter 18 F-FDG uptake [25]. A cross-sectional report on the relationship between muscle strength and BAT activity showed a positive correlation between grip strength and BAT activity [64]. The concentration of blood myokine, a marker for promoting WAT browning, has been reported to be higher in an 8-week resistance training group than in control and endurance training groups [75,76].…”

Association Between Hospital Anxiety Depression Scale and Autonomic Recovery Following Exercise

“…Thus, exercise has been proven to provide a beneficial effect in animals (Rossi et al 2011) and humans (Martinez-Tellez et al 2019). Exercise treatments for anxiety or depression have been considered a helpful intervention (Wegner et al 2014).…”