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Independent effects of diet and exercise training on fat oxidation in non-alcoholic fatty liver disease

View Article: PubMed Central - PubMed

ABSTRACT

Aim: To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on whole-body and hepatic fat oxidation of patients with non-alcoholic fatty liver disease (NAFLD).

Methods: Participants were randomised into either circuit exercise training (EX; n = 13; 3 h/wk without changes in dietary habits), or dietary energy restriction (ER) without changes in structured physical activity (ER; n = 8). Respiratory quotient (RQ) and whole-body fat oxidation rates (Fatox) were determined by indirect calorimetry under basal, insulin-stimulated and exercise conditions. Severity of disease and steatosis was determined by liver histology; hepatic Fatox was estimated from plasma β-hydroxybutyrate concentrations; cardiorespiratory fitness was expressed as VO2peak. Complete-case analysis was performed (EX: n = 10; ER: n = 6).

Results: Hepatic steatosis and NAFLD activity score decreased with ER but not with EX. β-hydroxybutyrate concentrations increased significantly in response to ER (0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L, P = 0.03) but remained unchanged in response to EX (0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L, P = 0.39). Basal RQ decreased (P = 0.05) in response to EX, while this change was not significant after ER (P = 0.38). VO2peak (P < 0.001) and maximal Fatox during aerobic exercise (P = 0.03) improved with EX but not with ER (P > 0.05). The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis (r = -0.56, P = 0.04).

Conclusion: ER and EX lead to specific benefits on fat metabolism of patients with NAFLD. Increased hepatic Fatox in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.

No MeSH data available.


Consort diagram describing the flow of patients through the randomised controlled trial.
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Figure 1: Consort diagram describing the flow of patients through the randomised controlled trial.

Mentions: Participants were randomised into either a dietary energy restriction intervention (ER; n = 8) or an exercise training intervention (EX; n = 13). A consort diagram describing the flow of patients through the randomised controlled trial is presented in Figure 1. Outcome measures were assessed prior to randomisation (pre-intervention) and after 6 mo of intervention. At both time-points participants undertook three testing sessions within a 7-d period. Patients had stable body weight for at least 2 wk before the post intervention testing.


Independent effects of diet and exercise training on fat oxidation in non-alcoholic fatty liver disease
Consort diagram describing the flow of patients through the randomised controlled trial.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5037327&req=5

Figure 1: Consort diagram describing the flow of patients through the randomised controlled trial.
Mentions: Participants were randomised into either a dietary energy restriction intervention (ER; n = 8) or an exercise training intervention (EX; n = 13). A consort diagram describing the flow of patients through the randomised controlled trial is presented in Figure 1. Outcome measures were assessed prior to randomisation (pre-intervention) and after 6 mo of intervention. At both time-points participants undertook three testing sessions within a 7-d period. Patients had stable body weight for at least 2 wk before the post intervention testing.

View Article: PubMed Central - PubMed

ABSTRACT

Aim: To investigate the independent effects of 6-mo of dietary energy restriction or exercise training on whole-body and hepatic fat oxidation of patients with non-alcoholic fatty liver disease (NAFLD).

Methods: Participants were randomised into either circuit exercise training (EX; n = 13; 3 h/wk without changes in dietary habits), or dietary energy restriction (ER) without changes in structured physical activity (ER; n = 8). Respiratory quotient (RQ) and whole-body fat oxidation rates (Fatox) were determined by indirect calorimetry under basal, insulin-stimulated and exercise conditions. Severity of disease and steatosis was determined by liver histology; hepatic Fatox was estimated from plasma β-hydroxybutyrate concentrations; cardiorespiratory fitness was expressed as VO2peak. Complete-case analysis was performed (EX: n = 10; ER: n = 6).

Results: Hepatic steatosis and NAFLD activity score decreased with ER but not with EX. β-hydroxybutyrate concentrations increased significantly in response to ER (0.08 ± 0.02 mmol/L vs 0.12 ± 0.04 mmol/L, P = 0.03) but remained unchanged in response to EX (0.10 ± 0.03 mmol/L vs 0.11 ± 0.07 mmol/L, P = 0.39). Basal RQ decreased (P = 0.05) in response to EX, while this change was not significant after ER (P = 0.38). VO2peak (P < 0.001) and maximal Fatox during aerobic exercise (P = 0.03) improved with EX but not with ER (P > 0.05). The increase in β-hydroxybutyrate concentrations was correlated with the reduction in hepatic steatosis (r = -0.56, P = 0.04).

Conclusion: ER and EX lead to specific benefits on fat metabolism of patients with NAFLD. Increased hepatic Fatox in response to ER could be one mechanism through which the ER group achieved reduction in steatosis.

No MeSH data available.