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

Abstract

Exercise modulates both brown adipose tissue (BAT) metabolism and white adipose tissue (WAT) browning in murine models. Whether this is true in humans, however, has remained unknown. An unblinded randomized controlled trial (ClinicalTrials.gov ID: NCT02365129) was therefore conducted to study the effects of a 24-week supervised exercise intervention, combining endurance and resistance training, on BAT volume and activity (primary outcome). The study was carried out in the Sport and Health University Research Institute and the Virgen de las Nieves University Hospital of the University of Granada (Spain). One hundred and forty-five young sedentary adults were assigned to either (i) a control group (no exercise, n = 54), (ii) a moderate intensity exercise group (MOD-EX, n = 48), or (iii) a vigorous intensity exercise group (VIG-EX n = 43) by unrestricted randomization. No relevant adverse events were recorded. 97 participants (34 men, 63 women) were included in the final analysis (Control; n = 35, MOD-EX; n = 31, and VIG-EX; n = 31). We observed no changes in BAT volume (Δ Control: −22.2 ± 52.6 ml; Δ MOD-EX: −15.5 ± 62.1 ml, Δ VIG-EX: −6.8 ± 66.4 ml; P = 0.771) or 18F-fluorodeoxyglucose uptake (SUVpeak Δ Control: −2.6 ± 3.1 ml; Δ MOD-EX: −1.2 ± 4.8, Δ VIG-EX: −2.2 ± 5.1; p = 0.476) in either the control or the exercise groups. Thus, we did not find any evidence of an exercise-induced change on BAT volume or activity in young sedentary adults.

Acute and long-term exercise differently modulate plasma levels of oxylipins, endocannabinoids, and their analogues in young sedentary adults: A sub-study and secondary analyses from the ACTIBATE randomized controlled-trial

“…Increases of 10% and 20% were anticipated in activated BAT volume in the MOD-EX and VIG-EX groups respectively (rising from a baseline level of 50–70 mL), along with a standard deviation of 50–60 mL. 29 Differences of at least 10% in BAT volume could be detected with a power of >80% and an α of 0.05 in a group of 34 participants per study group. 29 Therefore, assuming a maximum loss to follow-up of 30%, 150 participants were targeted (i.e., 50 per group).…”

“… 29 Differences of at least 10% in BAT volume could be detected with a power of >80% and an α of 0.05 in a group of 34 participants per study group. 29 Therefore, assuming a maximum loss to follow-up of 30%, 150 participants were targeted (i.e., 50 per group). 29 The IBM-SPSS Sample power software (version 22) was used for calculations.…”

“…However, these changes were not correlated with initial BAT volume or activity, nor any changes therein. 29 …”

“… 29 Therefore, assuming a maximum loss to follow-up of 30%, 150 participants were targeted (i.e., 50 per group). 29 The IBM-SPSS Sample power software (version 22) was used for calculations. 29 Since the current study is based on a sub-study and secondary analysis from the ACTIBATE randomized controlled trial, no specific power calculation was performed.…”

“… 29 The IBM-SPSS Sample power software (version 22) was used for calculations. 29 Since the current study is based on a sub-study and secondary analysis from the ACTIBATE randomized controlled trial, no specific power calculation was performed. Participants with blood sample determinations were included in this sub-study and secondary analyses.…”