Brain‐Derived Neurotrophic Factor and Substrate Utilization Following Acute Aerobic Exercise in Obese Individuals

Abstract

Brain-derived neurotrophic factor (BDNF) serves as a vital regulator of neuronal proliferation and survival, and has been shown to regulate energy homeostasis, glucose metabolism and body weight maintenance. Elevated concentrations of plasma BDNF have been associated with obesity and type 2 diabetes mellitus. Acute aerobic exercise transiently increases circulating BDNF, potentially correcting obesity-related metabolic impairment. The present study aimed to compare acute aerobic exercise elicited BDNF responses in obese and normal-weight subjects. Furthermore, we aimed to investigate whether acute exercise-induced plasma BDNF elevations would be associated with improved indices of insulin resistance, as well as substrate utilization [carbohydrate oxidation (CHOoxi) and fat oxidation (FAToxi)]. Twenty-two healthy, untrained subjects [11 obese (four men and seven women; age = 22.91 ± 4.44 years; body mass index = 35.72 ± 4.17 kg/m(2)) and 11 normal-weight (five men and six women; age = 23.27 ± 2.24 years; body mass index = 21.89 ± 1.63 kg/m(2))] performed 30 min of continuous submaximal aerobic exercise at 75% maximal oxygen consumption. Our analyses showed that the BDNF response to acute aerobic exercise was similar in obese and normal-weight subjects across time (time: P = 0.015; group: P = not significant) and was not associated with indices of IR. Although no differences in the rates of CHOoxi and FAToxi were found between both groups, total relative energy expenditure was significantly lower in obese subjects compared to normal-weight subjects (3.53 ± 0.25 versus 5.59 ± 0.85; P < 0.001). These findings suggest that acute exercise-elicited BDNF elevation may not be sufficient to modulate indices of IR or the utilization of either carbohydrates or fats in obese individuals.

Association between Obesity and Circulating Brain-Derived Neurotrophic Factor (BDNF) Levels: Systematic Review of Literature and Meta-Analysis

“…According to other studies [30,31], we did not find a significant difference among the analyzed groups.…”

“…Therefore, smokers should be excluded from studies assessing circulating levels of the protein. Interestingly, only in one study [30] was it clearly declared that smoke history represented one of the exclusion criteria used.…”

“…However, in the last few years this relationship was called into question. Indeed, different studies have shown either that circulating BDNF levels are higher in obese subjects than in controls [9,30] or that there are no differences between the two groups [31]. In order to disentangle these controversies regarding the association between circulating levels of BDNF and obesity, we performed a systematic review and meta-analysis of the literature.…”

The effect of acute exercise on blood concentrations of brain‐derived neurotrophic factor in healthy adults: a meta‐analysis

“…Forty‐two studies measured BDNF in serum only, nine studies (Zoladz et al ., ; Rasmussen et al ., ; Correia et al ., ; Seifert et al ., ; Babaei et al ., ; Coelho et al ., ; Slusher et al ., ; Church et al ., ; Schild et al ., ) measured BDNF in plasma only, and four studies (Currie et al ., ; Cho et al ., ; Gilder et al ., ; Pareja‐Galeano et al ., ) measured BDNF in both serum and plasma. In subgroup analysis, a significantly greater increase in BDNF was found in plasma compared to serum (Serum: SMD = 0.55, 95% CI: 0.41–0.68, P < 0.001; Plasma: SMD = 0.99, 95% CI: 0.58–1.40, P < 0.001; Test for subgroup differences: χ 2 = 4.12, df = 1, P = 0.04).…”

The Potential Role of Contraction-Induced Myokines in the Regulation of Metabolic Function for the Prevention and Treatment of Type 2 Diabetes

“…Chronic intracerebroventricular BDNF administration is also shown to decrease body weight, fat mass, adipocyte size, and serum triglycerides and promote lipolysis (70). Exercise induced increases in plasma BDNF are equivalent in obese and non-obese individuals but are not associated with increases in either whole-body glucose or FA oxidation (71). Further work is required to determine the effect of contraction-induced BDNF on fat metabolism in muscle, adipose, and liver.…”