UvA-DARE (Digital Academic Repository) The role of sleep in ethnic inequalities in health: Cardiovascular disease and risk factors Anujuo, K.O. Publication date 2018 Document Version Other version License Other Link to publication Citation for published version (APA): Anujuo, K. O. (2018). The role of sleep in ethnic inequalities in health: Cardiovascular disease and risk factors. General rights It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: https://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. UvA-DARE is a service provided by the library of the University of Amsterdam (https://dare.uva.nl) Download date:24 Sep 2021 CHAPTER 4 RELATIONSHIP BETWEEN SHORT SLEEP DURATION AND CARDIOVASCULAR RISK FACTORS IN A MULTI-ETHNIC COHORT – THE HELIUS STUDY Published Kenneth Anujuo, Karien Stronks, Marieke B. Snijder, Girardin Jean-Louis, Femke Rutters, Bert-Jan van den Born, Ron J. Peters, Charles Agyemang. Relationship between short sleep duration and cardiovascular risk factors in a multi-ethnic cohort – the HELIUS study. Sleep Med. 2015;16:1482-1488. Anujuo_binnenwerk_FINAL.indd 73 30/07/2018 21:19 Chapter 4 ABSTRACT Objective: To investigate the association between short sleep duration and CVD risk factors including hypertension, diabetes, obesity, and lipid profile among various ethnic groups (South-Asian Surinamese, African Surinamese, Ghanaians, Turks, Moroccans and Dutch) living in the Netherlands. We also examined the contribution of social economic status (SES) and lifestyle factors to this association. Method: 12805 participants (aged 18-70 years) from the multi-ethnic HELIUS cohort. Short sleep duration was defined as <7 hours/night. The association between short sleep and CVD risk factors, and the contribution of SES and lifestyle factors were assessed using prevalence ratios (PRs). Results: Short sleep was significantly associated with obesity in four out of six ethnic groups, with the socio-demographic adjusted PR of 1.45 (95% CI, 1.07-1.95) in Dutch, 1.21 (1.01-1.44) in South-Asian Surinamese, 1.25 (1.09-1.43) in African Surinamese and 1.16 (1.04-1.29) in Turks. Short sleep was significantly associated with diabetes in African Surinamese (1.45, 1.14-1.84), Turks (1.59, 1.26-2.02), and Moroccan (1.29, 1.02-1.63). By contrast, the associations between other cardiovascular risk factors and short sleep were not significant in most ethnic groups, with the exception of the association with hypertension in Dutch and Turks, and dyslipidaemia in South-Asians Surinamese (reduced HDL cholesterol and triglyceride) and Moroccans (raised total cholesterol). SES and lifestyle factors contributed little to the observed associations. Conclusion: Our findings indicate that short sleep is associated with obesity and diabetes in most ethnic groups. The associations for other risk factors vary between ethnic groups. Further studies are needed to establish the potential factors that might lead to the observed differences across populations. 74 Anujuo_binnenwerk_FINAL.indd 74 30/07/2018 21:19 Association of sleep with CVD risk factors in adults INTRODUCTION Cardiovascular disease (CVD) is the leading cause of global mortality. Several prospective and retrospective studies have shown that hypertension, diabetes, obesity and dyslipidaemia are important risk factors for CVD [1,2]. As the prevalence of these risk factors (especially obesity and diabetes) is increasing in adult populations in most countries [3], the necessity to identify potential modifiable risk factors increases, in order to reduce adverse CVD outcomes. Recently, several studies have shown conflicting reports on the association between sleep duration and cardiovascular risk factors including hypertension [4,5], diabetes [6-9], obesity [10-12] and dyslipidaemia [13- 19]. The fact that two independent studies showed an association between short sleep and cardiovascular mortality is supportive of the hypothesis that short sleep is related to CVD risk factors [20,21]. Recent studies indicated that the relationship between sleep duration and CVD risk factors varies between study populations [22-23]. This suggests the potential importance 4 of contextual factors such as sociocultural and lifestyle factors which may influence the association. Previous studies suggested that the association between sleep duration and CVD risk may be mediated by SES, lifestyle factors and other covariates, they were therefore recommended to be included in future studies [24]. Studies investigating the relationship between sleep duration and cardiovascular risk factors have not considered differences among ethnic minority groups with different migration backgrounds. In addition, CVD and risk factors also differ between ethnic groups [25-29]. For instance, Surinamese people in Netherlands have higher incidence rates of stroke than the European Dutch. By contrast, Moroccans have lower incidence rates of stroke compared with Dutch [30]. Also, ethnic minority groups tend to experience shorter sleep duration compared to their host European majority populations [29]. Given the variation in the association between short sleep and CVD risk factors between populations, it is important to elucidate how short sleep is related to CVD risk factor in different ethnic groups. Furthermore, the data on the relationship between short sleep and CVD risk factors across ethnic minority groups are lacking particularly in Europe. Using data from the Healthy Life in an Urban Setting (HELIUS) study, the aim of this study was to investigate whether there are differences in the association of sleep duration with cardiovascular risk factors between 75 Anujuo_binnenwerk_FINAL.indd 75 30/07/2018 21:19 Chapter 4 various ethnic minority groups living in the Netherlands. In addition, the contribution of SES and lifestyle factors to these associations was examined. STUDY POPULATION AND METHODS Study population This study was based on baseline data from the HELIUS study. The aims and design of the HELIUS study have been described elsewhere [30]. In brief, HELIUS is a large-scale prospective cohort study on health and health care among different ethnic groups living in Amsterdam. The study started in 2011 and it includes individuals aged between 18 and 70 years from the six major ethnic groups in Amsterdam (African-Surinamese, South-Asian Surinamese, Turks, Moroccan, Ghanaian, and Dutch origin). This study focuses on three major disease categories: cardiovascular disease, mental health and infectious diseases. Participants were randomly sampled from the municipal registers and stratified by ethnicity. The study protocols were approved by the Academic Medical Center (AMC) Ethical Review Board. All participants provided written informed consent. This study used baseline data that were collected until June 2014. The study included 13,316 participants from whom data from both questionnaire and the physical examination were available. Participants with a Javanese Surinamese background (n=137), other/unknown Suriname background (n=141) or other/unknown background (n=26) were excluded because of the small sample sizes. In addition, individuals with no data on sleep duration (n=207) were also excluded from the analysis. This resulted in a dataset of 12,805 participants, including 2146 Dutch, 2158 African-Surinamese, 2262 South-Asian Surinamese, 1795 Ghanaians, 2242 Turks and 2202 Moroccans. Measurements Sleep duration Participants were asked to provide information on their average hours of sleep at night. Sleep duration was assessed using the item, `How many hours do you sleep on average per night?` Short sleep was defined as having <=6 hours of sleep per night according to National Sleep Foundation (NSF), American Academy of Sleep Medicine (AASM), and Sleep Research Society 76 Anujuo_binnenwerk_FINAL.indd 76 30/07/2018 21:19 Association of sleep with CVD risk factors in adults (SRS) which recommend 7 to 8 hours as the basal sleep need for healthy adults [31, 32]. We focused on short sleep only because in our previous study, we previously demonstrated that short sleep was the major problem for the ethnic minority groups [29], and because previous studies found that short sleep was more consistently related to CVD risk factors compared to long sleep [22-23], [33-35]. Ethnicity Participant’s ethnicity was defined according to the country of birth of the participant as well as that of their parents. Specifically, a participant is considered to be of ethnic minority origin if he/she fulfils either of the following criteria: 1) he or she was born abroad and has at least one of his/ her parents born abroad; or 2) he or she was born in the Netherlands but has both his/her parents born abroad [30]. The Surinamese population is made up of several ethnic subgroups including those of Africa Surinamese, South- Asian Surinamese, Javanese, Amerindian, and Chinese origin. Therefore,