High intensity intermittent exercise improves cardiac structure and function and reduces liver fat in patients with type 2 diabetes: a randomised controlled trial

Abstract

Aims/hypothesisCardiac disease remains the leading cause of mortality in type 2 diabetes, yet few strategies to target cardiac dysfunction have been developed. This randomised controlled trial aimed to investigate high intensity intermittent training (HIIT) as a potential therapy to improve cardiac structure and function in type 2 diabetes. The impact of HIIT on liver fat and metabolic control was also investigated.MethodsUsing an online random allocation sequence, 28 patients with type 2 diabetes (metformin and diet controlled) were randomised to 12 weeks of HIIT (n = 14) or standard care (n = 14). Cardiac structure and function were measured by 3.0 T MRI and tagging. Liver fat was determined by 1H-magnetic resonance spectroscopy and glucose control by an OGTT. MRI analysis was performed by an observer blinded to group allocation. All study procedures took place in Newcastle upon Tyne, UK.ResultsFive patients did not complete the study and were therefore excluded from analysis: this left 12 HIIT and 11 control patients for the intention-to-treat analysis. Compared with controls, HIIT improved cardiac structure (left ventricular wall mass 104 ± 17 g to 116 ± 20 g vs 107 ± 25 g to 105 ± 25 g, p < 0.05) and systolic function (stroke volume 76 ± 16 ml to 87 ± 19 ml vs 79 ± 14 ml to 75 ± 15 ml, p < 0.01). Early diastolic filling rates increased (241 ± 84 ml/s to 299 ± 89 ml/s vs 250 ± 44 ml/s to 251 ± 47 ml/s, p < 0.05) and peak torsion decreased (8.1 ± 1.8° to 6.9 ± 1.6° vs 7.1 ± 2.2° to 7.6 ± 1.9°, p < 0.05) in the treatment group. Following HIIT, there was a 39% relative reduction in liver fat (p < 0.05) and a reduction in HbA1c (7.1 ± 1.0% [54.5 mmol/mol] to 6.8 ± 0.9% [51.3 mmol/mol] vs 7.2 ± 0.5% [54.9 mmol/mol] to 7.4 ± 0.7% [57.0 mmol/mol], p < 0.05). Changes in liver fat correlated with changes in HbA1c (r = 0.70, p < 0.000) and 2 h glucose (r = 0.57, p < 0.004). No adverse events were recorded.Conclusions/interpretationThis is the first study to demonstrate improvements in cardiac structure and function, along with the greatest reduction in liver fat, to be recorded following an exercise intervention in type 2 diabetes. HIIT should be considered by clinical care teams as a therapy to improve cardiometabolic risk in patients with type 2 diabetes.Trial registration:www.isrctn.com 78698481Funding:Medical Research Council.

Systematic review assessing the effectiveness of dietary intervention on gut microbiota in adults with type 2 diabetes

“…Furthermore, interventions targeting physical activity/exercise have also been shown to improve glucose control [41], body composition and liver fat in humans with fatty liver disease [53] and type 2 diabetes mellitus [54], irrespective of weight loss. The exact mechanisms behind how physical activity/exercise modulates the gut microbiota and risk factors for type 2 diabetes mellitus in combination remain unknown.…”

Exercise Reduces Liver Lipids and Visceral Adiposity in Patients With Nonalcoholic Steatohepatitis in a Randomized Controlled Trial

“…Exercise was supervised by an accredited exercise specialist and recorded to ensure adherence 3 times per week on nonconsecutive days for 12 weeks 18, 19. The exercise program consisted of aerobic (cycling) and resistance training, and is detailed in Supplementary Methods.…”

“…Exercise was supervised and performed 3 times per week on nonconsecutive days for 12 weeks, a program we have used successfully for patients with NAFLD 10 and type 2 diabetes 11 . The exercise program consisted of aerobic (cycling) and resistance training and is detailed in the Supplementary Clinical Trial Study Protocol.…”

High-Intensity Exercise Reduces Cardiac Fibrosis and Hypertrophy but Does Not Restore the Nitroso-Redox Imbalance in Diabetic Cardiomyopathy

“…For instance, while moderate-intensity exercise did not improved cardiac function in type 2 diabetic patients [21], a similar study but with a high-intensity interval training showed improved cardiac function and remodeling [22]. Another study showed no difference between moderate- and high-intensity exercises [23], although this later did not include the assessment of cardiac parameters.…”