Exercise Effects on Appetite-regulating Hormones and Cardiovascular Risk Factors

Study Overview
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Brief Summary
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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
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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.

Official Title
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Exercise Effects on Appetite-regulating Hormones and Cardiovascular Risk Factors in South Asian and White European Men

Conditions
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Risk Factor, Cardiovascular, Physical Activity, Pre-diabetes

Intervention / Treatment
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* Behavioral: Exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non-smoker Non-dieting Physically well to participant in maximal exercise Male Not taking any anticoagulant or anti-inflammatory medication Between the ages 18-50 White European or South Asian Exclusion Criteria: Those that are taking any anticoagulant or anti-inflammatory medication Those with a known medical condition such as diabetes, cardiovascular disease.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| European males<br>This study will involve a cohort of 15 White European men, between the ages of 18-50 years. Participants will be non-smokers, not dieting, and physically well to participate. Participants will be required to exercise on one occasion. | Behavioral: Exercise<br>* 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.<br>|
| South Asian males<br>This study will involve a cohort of 15 South Asian (India, Pakistan, Sri Lanka, Nepal, Bangladesh, Maldives and Bhutan), men, between the ages of 18-50 years. Participants will be non-smokers, not dieting, and physically well to participate. Participants will be required to exercise on one occasion. | Behavioral: Exercise<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma Acylated ghrelin concentration | Plasma acylated ghrelin will be examined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details). Commercially available enzyme-linked immunosorbent assays (Bertin Bioreagent, Montigny le Bretonneux, France) will be used to measure plasma acylated ghrelin concentration. The sample will be collected from whole blood using venepuncture. | 2 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma TAG concentration | Plasma Insulin will be also examined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details). Commercially available enzyme-linked immunosorbent assays (Mercodia, Uppsala, Sweden) will be used to measure plasma Insulin concentration. The sample will be collected from whole blood using venepuncture. | 2 days | 
| Plasma triacylglycerol (TAG) concentration | Plasma TAG concentration will be determined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details) by enzymatic, colorimetric methods using a bench top analyser (Pentra 400; HORIBA ABX Diagnostics, Montpellier, France). The sample will be collected from whole blood using venepuncture. | 2 days | 
| Plasma high-density lipoprotein (HDL) cholesterol concentration | Plasma HDL concentration will be determined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details) by enzymatic, colorimetric methods using a bench top analyser (Pentra 400; HORIBA ABX Diagnostics, Montpellier, France). The sample will be collected from whole blood using venepuncture. | 2 days | 
| Cardiorespiratory fitness | Cardiorespiratory fitness will be determined during the preliminary test (please refer to study design for details) using an incremental exercise test to volitional exhaustion on an electromagnetically braked cycle ergometer (Lode Excalibur Sport, Groningen, Netherlands). Participants will cycle at a self-selected pedal rate between 70 to 90 revolutions per minute for 3 min at 80 watts (warm up), followed by increments of 30 watts every 3 minutes until volitional fatigue. The sample will be collected from whole blood using venepuncture. | 2 days | 
| Plasma Glucose concentration for impaired glucose tolerance (IGT) | Plasma glucose concentration will be determined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details) by enzymatic, colorimetric methods using a bench top analyser (Pentra 400; HORIBA ABX Diagnostics, Montpellier, France). The sample will be collected from whole blood using venepuncture. | 2 days | 
| Plasma Peptide YY concentration | Plasma PYY will be also examined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details). Commercially available enzyme-linked immunosorbent assays (Millipore, Billerica, USA) will be used to measure plasma PYY concentration. The sample will be collected from whole blood using venepuncture. | 2 days | 
| Plasma Leptin concentration | Plasma leptin will be also examined before and after the standardised breakfast, libitum buffet meal and exercise and before leaving the laboratory (please refer to study design for details). Commercially available enzyme-linked immunosorbent assays (Millipore, Billerica, USA) will be used to measure plasma leptin concentration. The sample will be collected from whole blood using venepuncture. | 2 days |