Physical Activity, Exercise and ‘FreeLiving’ Glycaemic Control in Individuals with Insulin Resistance

Supervisors

Dr Richard Metcalfe Dr Conor McClean Dr Ben Fitzpatrick Prof Gareth Davison

Overview

With the worldwide prevalence of type 2 diabetes (T2D) predicted to reach 592 million in 2035 [1], and ~30% of the population estimated to be living with ‘prediabetes’ [2], it is clear that these conditions represent an increasingly significant and global challenge to public health. The United Kingdom is not exempt [3], with a recent report estimating the direct economic cost of T2D to the NHS at ~£8.8 billion in 2011 [4]. As such, finding effective and inexpensive methods to both prevent and treat T2D is a key public health objective, and is indeed essential if public funded health care systems are to remain a viable proposition [5].
Improving insulin sensitivity and glycemic control is the basis of diabetic care, and the key target for interventions aimed at prevention of disease development. The postprandial period and, in particular, periods of elevated postprandial hyperglycemia (≥10 mmol/L), is increasingly considered to be an important target for therapeutic intervention [6]. The development of continuous glucose monitoring technology (CGM) allows detailed assessment of these postprandial glycemic responses and can provide clinically important information over and above traditional laboratory based assessments. For example, cross-sectional studies using CGM have revealed that, despite pharmacological intervention, patients with T2D still spend large portions of the day in hyperglycaemia [7].
CGM can also be a useful tool to assess the effects of physical activity and exercise (which are considered cornerstones in both treatment and prevention of T2D) on postprandial glycaemia over several days under ‘free-living’ conditions. Several studies over the past 10 years have shown that single sessions of aerobic, resistance and interval based exercise can be effective for reducing mean 24-hour glucose levels, and the prevalence of hyperglycaemia, in patients with T2D [8-10]. However, it is currently not clear what type and timing of exercise or physical activity is most effective. In the Centre for Physical Activity and Health Research at Ulster University, we are embarking on a program of research which aims to address this question. For example, we are currently examining the effects of different high-intensity interval training (HIT) protocols in patients with T2D (https://www.ulster.ac.uk/aboutus/news/2016/october/ulster-university-exercise-research-totransform-diabetes-management). This PhD studentship will build on this research and will examine – with the overarching aim of optimising - the impact different modes, durations, intensities and timings
of physical activity or structured exercise on ‘free-living’ glycemic control in populations with insulin resistance (pre-diabetes, diabetes etc). CGM assessments would be supported with laboratory and/or biochemical measurements where relevant.
Aims and Objectives of the Research:

The aim of this PhD project is to examine the effects of different modes, durations, intensities and timings of physical activity or exercise on ‘free-living’ glycemic control in individuals with insulin resistance.

Methods to be used:

This PhD studentship will investigate specific research questions using both acute exercise and exercise training approaches in the laboratory and/or field settings. The ‘free-living’ assessments using CGM may be supported – where relevant – with laboratory and/or biochemical based assessments, such as venous blood sampling, in order to investigate potential underlying mechanisms and exercise responses.

Skills required of applicant:

This PhD studentship would suit a graduate from the areas of Physical Activity, Exercise and Health, Health Science or Sport and Exercise Sciences. The successful applicant should have a good knowledge of the physiological and biochemical responses to exercise, an understanding of the role of physical activity in prevention of treatment of disease, and in the complexities of physical activity measurement and manipulation. Previous experience in undertaking a range of physiological and/or health based assessments is important, as is experience in quantitative research methods. Knowledge of exercise biochemistry and previous experience in wet laboratory techniques would be an advantage, but is not essential as training will be provided. The ability to communicate clearly and effectively through oral and written means is also a desirable quality.

Costs:

The CGM devices are available in the Centre for Exercise and Health Research Laboratories, and the cost of the single use sensors and other consumables would be covered by the PhD studentship.