Exercise Effects on Appetite-regulating Hormones and Cardiovascular Risk Factors
Condition: Risk Factor, Cardiovascular; Physical Activity; Pre-diabetes
MeSH terms: Prediabetic State
Study type: Observational

Summary: 
      The aim of this study is to examine the effect of a single bout of moderate exercise,
      standardized breakfast and buffet meal on appetite-related hormones, type two diabetes and
      cardiovascular risk factors with a comparison between healthy South Asian and white European
      men. It is of interest to see if any factor differences occur in appetite-regulating hormones
      and cardiovascular disease risk factors whilst exercising. If so strategies may be used to
      alter regulation in diet and exercise to reduce risk cardiovascular disease as this is the
      number one cause of death globally.
    

Detailed description: 
      Cardiovascular diseases are recognised as the number one cause of death globally.
      Furthermore, diabetes is a major risk factor for cardiovascular disorders with abundant
      evidence showing that patients with type 2 diabetes (T2D) are at higher risk of
      cardiovascular disease (CVD) than those with a normal glycaemia.

      In contrast to the declining numbers in the Western world, the prevalence of CVD and T2D is
      growing in low - and middle - income countries accompanied by a rapid increase of mortality
      and morbidity. Of interest, a rise in CVD prevalence has been particularly observed in people
      of South Asian origin including India, Bangladesh, Pakistan, Sri Lanka or Nepal with a
      projection showing that in this population deaths attributed to CVD will rise globally to
      nearly 36 % in 2030 compared to 29 % in 2005. South Asians collectively form 20% of the
      global population while in the UK they are the largest ethnic minority group representing
      over 5% of the total UK population .

      Although the majority of research has been conducted mainly on White individuals, recent
      studies have revealed that traditional CVD risk factors such as hypertension, dyslipidaemia,
      insulin resistance and diabetes are higher in South Asians than other ethnicities. The
      factors underlying the high CVD risk in this population remain largely unexplained even
      though genetic predisposition and physical inactivity could play a key role. In contrast to
      European counterparts, sedentary lifestyles or physical inactivity have been identified as an
      important coronary heart disease (CHD) risk factor in South Asians. A systematic review from
      the United Kingdom (U.K.) showed that South Asians are participating in up to 50-75% less
      physical activity compared to their European counterparts.

      In addition to the traditional risk factors there are emerging biomarkers which could
      represent meaningful predictors of metabolic disorders and related complications.
      Specifically, appetite hormones secreted mainly by the gastrointestinal tract, such as
      Acylated Ghrelin or Peptide YY (PYY) have shown potential effects on glucose homeostasis and
      cardiovascular system. Current experimental studies suggest beneficial cardiovascular,
      anti-inflammatory and anti-apoptotic effects of ghrelin in the cardiovascular system.

      Although evidence suggests that ghrelin may be a potential metabolic risk factor and is
      important in appetite regulation, no studies to the researcher's knowledge have examined
      changes of this peptide in South Asians despite the fact that CVD and T2D burden in the South
      Asian population is growing. Likewise, although studies have investigated the effects of
      exercise on ghrelin and other appetite hormones, no study has taken in consideration the
      effects of exercise on appetite gut hormones in South Asian populations.

      Therefore, this research project aims to examine specific appetite hormones in response to a
      single bout of exercise, standardised meal and ad libitum buffet meal, with a comparison
      between South Asians and White Europeans identifying potential relationships with genetic and
      other metabolic risk factors.
    

Intervention name(s): Exercise
Intervention type(s): Behavioral
Intervention description(s): Participants will be required to complete two, 8-hours trials (exercise & control) in a randomised order, preceded by 2 hours of preliminary testing (baseline) with no more than 14 days between conditions.
Observational model: Cohort
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        This study will involve a cohort of 15 White European and 15 South Asian (India, Pakistan,
        Sri Lanka, Nepal, Bangladesh, Maldives and Bhutan), men, between the ages of 18-50 years
        with no known underlying disease.
      
Biospecimen description: 
      Plasma and serum stored according to Human Tissue Act for maximum of 6 years