1. Metabolic derangements and cardiac functional assessment in Type 2 Diabetes
- Author
-
Athithan, Lavanya
- Subjects
Metabolic derangements ,Cardiac Functional Assessment ,type 2 diabetes ,Cardiovascular Sciences ,thesis - Abstract
Background: Impaired metabolic flexibility may contribute to the development of cardiac dysfunction in T2D. Evidence has shown ethnic differences in baseline cardiac structure and function. Liver fat fraction is an important noninvasive measure of non-alcoholic fatty liver disease in T2D. Aims: 1. Compare the effect of adenosine vs dobutamine on myocardial blood flow (MBF) in asymptomatic controls. 2. Evaluate myocardial substrate preferences in response to acute increases in cardiac workload in T2D. 3. Assess for an ethnicity driven differential response to a low-calorie diet (LCD) in compliance, and cardiac structure and function. 4. Determine the agreement between volumetric liver fat fraction (VLFF) measurements using the HepaFat-Scan® technique at 1.5T and 3T. Methods: Firstly, we assessed MBF on cardiac magnetic resonance (CMR) comparing adenosine against dobutamine stress in 11 healthy controls. In the CardioMET Study, 8 eligible participants underwent transmyocardial arteriovenous blood sampling to calculate concentration of metabolites in paired coronary sinus and arterial samples at rest and during dobutamine stress. We assessed cardiac response to dobutamine stress on CMR. Additionally, we compared the cardiovascular structural and functional effects in 15 Western Europeans (WE) and 12 South Asians (SA) with T2D on a LCD. Sixty T2D participants were scanned same day using the HepaFat-Scan® gradient echo protocol to assess for agreement and bias in VLFF. Results and Conclusions: 1. There is no significant difference in myocardial blood flow between adenosine and dobutamine stress. 2. 3HBA extraction fraction was significantly increased in T2D compared to controls at peak stress. Therefore, in T2D, cardiac metabolism shifts to ketones during stress as a significant fuel source. 3. WE were more compliant to a LCD than SA with better cardiometabolic profile improvement but no significant difference in change in cardiac function. 4. There is minimal bias and excellent agreement between the measures of VLFF using the HepaFat-Scan® at 1.5 and 3T.
- Published
- 2022
- Full Text
- View/download PDF