Diane was successful in her application to the Irish Research Council for Science, Engineering and Technology (IRCSET) to fund her PhD work with Dr Donal O'Gorman in DCU. For the PhD Diane looked at the impact of different types of diet and exercise interventions on novel biomarkers of insulin resistance in individuals who were overweight and sedentary. At that time the novel biomarkers included FGF21, IL-13, Fetuin-A, Visfatin, Omentin and Chemerin.
Brief overview of study 1: The purpose of this study was to compare the effect of isocaloric diet and exercise interventions on body composition and metabolic health in participants who were sedentary and overweight. Participants were randomly assigned to either a diet (calorie deficit of 2,500kcal per week) or aerobic exercise (energy expenditure of 2,500kcal per week) group for a 12 week intervention. Pre and post tests included VO2max test + ECG, Oral Glucose Tolerance Test (OGTT), muscle biopsy, DEXA, food diaries, anthropometrics. The paper is currently in progress.
Brief overview of study 2: The purpose of this study was to investigate the impact of 12 weeks of concurrent training on energy expenditure and metabolism in participants who were sedentary and overweight. Participants were randomly assigned to concurrent training incorporating aerobic exercise and regular resistance training, or concurrent training incorporating aerobic exercise and eccentric resistance training only. The pre and post tests included VO2max + ECG, DEXA, OGTT, muscle biopsy, resting metabolic rate, MRI, 3 repetition maximum. The paper is currently in progress.
Brief overview of findings: The key findings were that isocaloric diet and exercise interventions lead to similar reductions in body weight, but exercise training may lead to greater improvements in body composition and metabolic health. Importantly, aerobic fitness was the single best predictor of improvements in metabolic health in this population. Resistance training is important for improving lean tissue mass, fat oxidation and resting metabolic rate. The novel biomarkers of insulin resistance are differentially regulated by diet, exercise and different modes of exercise training. Improvements in body composition and fitness drive improvements in insulin sensitivity and the circulating concentration of the biomarkers, and there is a cyclical relationship between the biomarkers and metabolic health. It is important to study the biomarkers for better understanding of metabolic processes but larger scale studies may be required to determine their role. A combination of calorie restriction, aerobic exercise and resistance training will optimise improvements in insulin resistance and body composition in these individuals.
Link to PhD document: The PhD document can be accessed HERE
Cooper, D and O’Gorman, D.J. Exercise and type 2 diabetes: the metabolic benefits and challenges. Diabetes Management Vol. 1, issue 6 pg 575-587, 2011. Paper can be accessed HERE.
Hernández-Alvarez, M,I, Díaz-Ramos, A., Berdasco, M, Cobb, J, Planet, E, Cooper, D, Pazderska, A, Wanic, K, O’Hanlon, D, Gomez, A, R. de la Ballina, L, Esteller, M, Palacin, M, O’Gorman, D.J. Nolan, J.J, and Zorzanocorresponding, A. Early-onset and classical forms of type 2 diabetes show impaired expression of genes involved in muscle branched-chain amino acids metabolism. Scientific Reports 7, 13850, 2017. Paper can be accessed HERE.