Effects of a Single Bout of Walking on Postprandial Triglycerides in Men of Chinese, European and Japanese Descent: a Multisite Randomised Crossover Trial
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Open access Protocol BMJ Open Sport Exerc Med: first published as 10.1136/bmjsem-2020-000928 on 16 December 2020. Downloaded from Effects of a single bout of walking on postprandial triglycerides in men of Chinese, European and Japanese descent: a multisite randomised crossover trial Chihiro Nagayama ,1 Stephen F Burns ,2 David J Stensel ,3,4 Alice E Thackray ,3,4 Masaki Takahashi ,5 Masashi Miyashita 6 To cite: Nagayama C, Burns SF, ABSTRACT to the progression of atherosclerosis over Stensel DJ, et al. Effects of Introduction Elevated non- fasting triglyceride (TG) the lifespan.3 Systematic reviews and meta- a single bout of walking on concentrations are a risk factor for cardiovascular diseases postprandial triglycerides in analyses show that exercise is an effective 4–6 men of Chinese, European and but can be reduced after acute exercise. Ethnic- based strategy for reducing postprandial TG. Japanese descent: a multisite differences in the magnitude of postprandial lipaemia Much of the reduction is from the acute and the extent that acute exercise reduces postprandial randomised crossover trial. BMJ effect of exercise with rapid increases in post- Open Sport & Exercise Medicine TG are poorly characterised across some ethnicities 2020;6:e000928. doi:10.1136/ prandial TG apparent in the absence of any including those of East Asian origin. This paper describes 4–6 bmjsem-2020-000928 the protocol of a multisite randomised crossover study recent exercise. comparing the effect of acute walking on postprandial TG The prevalence of cardiovascular disease Protected by copyright. varies considerably across different countries Accepted 23 November 2020 in two groups of East Asian men with European men. Methods and analysis Twenty Japanese, 20 and ethnicities.7 Direct ethnic comparisons Singaporean Chinese and 20 white British healthy men of postprandial metabolic responses to acute (21–39 years) recruited from Japan, Singapore and the exercise are sparse, but two notable excep- © Author(s) (or their UK, respectively, will complete two, 2- day trials. Fasted tions from the UK compared responses in employer(s)) 2020. Re- use and postprandial venous blood samples and arterial blood individuals of South Asian and white Euro- permitted under CC BY- NC. No pressure measurements will be taken over 6 hours the day pean descent.8 9 This work highlighted that commercial re- use. See rights after either: (1) 60- min treadmill walking; or (2) a rest day and permissions. Published by of normal living. The primary outcome is the difference South Asian individuals—a population with BMJ. in postprandial TG among ethnic groups after rest and an increased susceptibility to coronary heart 1 10 11 Graduate School of Sport walking. Secondary outcomes include cholesterol, glucose, disease (CHD) and type 2 diabetes —exhib- Sciences, Waseda University, insulin, ketone bodies, preheparin lipoprotein lipase, C- ited markedly higher postprandial TG and Tokorozawa, Japan 2Physical Education and Sports reactive protein and systolic/diastolic blood pressure. insulin than their white European counter- Ethics and dissemination The study was approved parts. Furthermore, a single bout of running Science Academic Group, http://bmjopensem.bmj.com/ National Institute of Education, by the Ethics Review Committee on Research with reduced postprandial TG to a greater extent Nanyang Technological Human Subjects of Waseda University and the Nanyang in the South Asian compared with the white University, Singapore Technological University Institutional Review Board. European men,9 whereas acute brisk walking 3School of Sport, Exercise and Relevant approval will be obtained from the UK site. Health Sciences, Loughborough induced an equivalent reduction in postpran- Research findings will be disseminated through peer- 8 University, Loughborough, UK dial TG and insulin between the ethnicities. 4 reviewed journal publication and health conferences. National Institute for Health Trial registration number UMIN000038625. Evidence has also demonstrated that South Research (NIHR) Leicester Asian men have higher skeletal muscle Biomedical Research Centre, expression of genes involved in oxidative University Hospitals of Leicester NHS and University of Leicester, metabolism and a greater capacity for mito- 12 on September 30, 2021 by guest. Leicester, UK chondrial ATP production. However, at the 5Comprehensive Research INTRODUCTION same time whole-body fat oxidation during Organization, Waseda University, Triglyceride (TG) is the predominant form submaximal exercise appears lower than Singapore 13 6 of lipid in the circulation and concentra- in Europeans. Whether such differences Faculty of Sport Sciences, Waseda University, Tokorozawa, tions are highest in the postprandial period impact exercise- induced reductions in post- Japan (after eating). There is strong evidence from prandial TG between ethnicities is uncertain. prospective cohort studies that postpran- Examining differences in CHD risk factors Correspondence to dial TG concentrations are a risk factor for by ethnicity is important as current exercise 1 2 Masashi Miyashita; cardiovascular diseases, and disturbances guidelines do not distinguish recommen- m. miyashita@ waseda. jp in postprandial lipid metabolism contribute dations based on ethnicity.14–18 This should Nagayama C, et al. BMJ Open Sp Ex Med 2020;6:e000928. doi:10.1136/bmjsem-2020-000928 1 Open access BMJ Open Sport Exerc Med: first published as 10.1136/bmjsem-2020-000928 on 16 December 2020. Downloaded from include investigations in more diverse and understudied 2. Ketone bodies (3-hydroxybutyrate (3- OHB), acetoace- ethnic groups such as those of East Asian origin. This is tic acid, total ketone body). because previous studies have shown that the absolute 3. Preheparin lipoprotein lipase (LPL). value of some risk markers (eg, insulin sensitivity, body fat 4. Glucose and insulin. percentage, body mass index (BMI) cut-offs for detecting 5. C- reactive protein (CRP). metabolic abnormalities) for CHD differ between East 6. Resting brachial arterial blood pressure. Asian and white European groups,19 20 and even between 7. Ratings of perceived appetite. South Asian and East Asian groups.21 In addition, phys- The secondary aim of this study is to investigate ethnic- ical activity guidelines in East Asian countries are based based differences between Singaporean Chinese, on data derived mainly from Western countries16 17 even Japanese and white British men in: though the response to physical activity may not be the 1. Body adiposity (sum of five skinfold thicknesses, waist same in East Asians. The importance of diversifying ethnic- circumference, BMI). based research to East Asian populations is underscored 2. Treadmill- based maximum oxygen uptake. by the upward trajectory in adverse CHD risk factors 3. Whole- body substrate oxidation during submaximal including dyslipidaemia, diabetes and obesity apparent exercise. in these populations in recent years.22 23 The rationale 4. Habitual levels of physical activity using accelerometry. is strengthened further by evidence demonstrating that levels of physical inactivity are high in high-income East METHODS AND ANALYSIS Asian countries including Singapore and Japan as well as Study design and setting in European countries.24 This will be a multisite laboratory-based randomised Low- intensity to moderate-intensity walking is crossover study conducted in accordance with the frequently advocated as a strategy to augment physical Standard Protocol Items: Recommendations for Inter- activity engagement and to promote metabolic health 33 14–18 25 ventional Trials statement. The study schedule is shown benefits at the population level. Furthermore, in figure 1. Research will take place at three institutions: walking, particularly briskly, is associated with a lower risk 26 Waseda University (Japan), Nanyang Technological Protected by copyright. of cardiovascular disease, and favourable reductions in University (Singapore) and Loughborough University postprandial TG have been reported after acute bouts (UK). Ethical permission for the study will be obtained of walking in studies involving individuals exclusively of 27 28–30 31 32 at each site of research. Eligible participants who have Singaporean, Japanese or European ancestry. completed informed consent, screening and prelimi- However, further work is required to directly compare nary testing will be invited to complete two, 2-day trials the acute effects of walking on postprandial CHD risk in a random order. The lead investigator (CN) will enrol factors in individuals of East Asian and European descent. participants to the study and randomly assign the trial This study aims to expand the current evidence base by sequence in a counterbalanced manner at each study adopting an international multisite approach. This will site using computer- generated random numbers to avoid allow direct comparison of fasting and postprandial order effects. Due to the nature of the study design, it will cardiometabolic risk markers in response to acute exer- cise between men of Singaporean Chinese, Japanese and not be possible to blind researchers or participants to the white British descent. trial order allocation. Each trial will be separated by ≥5 days to eliminate any potential carry-over effects. http://bmjopensem.bmj.com/ AIMS AND OBJECTIVES Aim Participants The aim of this multisite randomised crossover study is Inclusion criteria to compare the acute effects of walking on fasting and Individuals