review article

Hamdan Medical Journal 2017 (http://dx.doi.org/10.7707/hmj.755)

REVIEW ARTICLE Prevalence and risk factors of cardiovascular disease in the United Arab Emirates Hira Abdul Razzak, Alya Harbi, Wael Shelpai and Ahmad Qawas Statistics and Research Center, Ministry of Health and Prevention, Dubai, United Arab Emirates

Abstract Non-communicable diseases are a cause of great concern in developing countries, particularly cardiovascular disease (CVD). CVD is most commonly attributable to risk factors such as obesity, high blood pressure (BP), lack of physical activity and smoking. This study aims to summarize previous research on the prevalence and risk factors of CVD in the United Arab Emirates (UAE). Search engines and databases such as PubMed, Scopus and Science Direct, as well as several local journals, were utilized to identify relevant literature. Inclusion was limited to studies published between 2007 and 2016 in the English language and conducted with UAE participants (citizens and/or expatriates). Twenty-one relevant studies were found, including cross-sectional studies (n=11), population-based studies (n=3), literature reviews (n=2) and a case–control study (n=1). Estimates of the prevalence of CVD are considerably high, though there is insufficient information available on prevalence in the UAE as a whole. Primary determinants of CVD include obesity, smoking and diabetes mellitus. The prevalence of risk factors associated with CVD has increased in the UAE and will continue to increase, as made clear by the reviewed studies and as predicted by projections and future estimates. Some risk factors can be controlled, treated and prevented. Further attention must be given to developing preventative and curative strategies in order to reduce BP, increase physical activity, improve dietary habits and reduce smoking.

Introduction Cardiovascular disease (CVD) and the associated burden are increasing in developing countries, particularly in the United Arab Emirates (UAE), and represent a key challenge in health care. The World Health Organization (WHO) reports that CVD is the primary cause of death worldwide, accounting for 17.5 million deaths (31% of all deaths) in 2012, of which 80% occurred in low- and middle-income Correspondence: Hira Abdul Razzak, Statistics and Research Center, Ministry of Health and Prevention, Dubai, United Arab Emirates. Email: [email protected] and [email protected]

countries.1 Globally, 85% of disability is attributable to CVD.2 CVD includes stroke, coronary heart disease (CHD) and peripheral vascular disease. CVD also accounts for a significant proportion of global deaths caused by non-communicable diseases among individuals aged under 70 years (37%). If intervention is not improved, global annual CVD deaths will increase from 17.5 million in 2012 to 22.2 million by the year 2030.3 A Ministry of Health and Prevention report4 has revealed that CVD is a leading cause of mortality in the UAE. Of CVD deaths, 22% were attributable to acute myocardial infarction (AMI), 16% to cerebrovascular disease, 6% to ischaemic heart disease and 5% to hypertension. WHO has reported5 on the most effective interventions, which include drug therapy, the regulation of alcohol and tobacco, health counselling and public awareness programmes that promote regular physical activity and a healthy diet. Greater understanding of the epidemiology, prevalence and risk factors of CVD is understood to be the basis for designing, implementing and monitoring effective prevention strategies. A Framingham heart study6 found an association between CHD mortality and congestive heart failure (HF), high blood pressure (BP), metabolic disorders, abdominal adiposity and diabetes mellitus (DM). According to Assmann et al.7 and Hense et al.,8 both prevalence and prognosis are important in the development of risk prediction scores for CHD. Yusuf et al.9 and Rosengren et al.10 have reported on the INTERHEART study and the nine risk factors (excessive alcohol intake, lack of exercise, psychosocial index, abdominal obesity, hypertension, DM, smoking, apolipoprotein A-I and apolipoprotein B) associated

© 2017 The Author(s) Journal Compilation © 2017 Sheikh Hamdan Bin Rashid Al Maktoum Award for Medical Sciences

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with AMI, suggesting that risk of AMI is the same for both sexes and is consistent throughout all ethnic groups and regions across the globe. Teo et al.11 and Yusuf et al.12 describe the low prevalence of healthy lifestyle behaviours across countries of all income levels, with particularly low prevalence – along with a lower rate of use of cardioprotective drugs during secondary prevention – in low-income countries. The MONICA (MONItoring trends and determinants in CArdiovascular disease) project13,14 found that smoking rates had decreased in men and increased in women after a 10-year period, whereas cholesterol levels and systolic BP rates had decreased in both sexes. Furthermore, body mass index (BMI) had significantly increased in about half of the studied population. The project demonstrated the important relationship between CHD and serum cholesterol. Bearing this trend in mind – increasing CVD-related mortality in the UAE – there is an evident need to further investigate CVD prevalence and risk factors across the UAE. This systematic review is intended to offer a comprehensive understanding of CVD in the UAE and highlight gaps in existing knowledge, summarizing previous research with UAE participants on CVD prevalence and risk factors.

Methodology A systematic review of the literature was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for reviewing epidemiological studies. Relevant articles were identified by searching data sources such as PubMed, Scopus, ScienceDirect and local journals. Search terms, including keywords and medical subject headings, were related to CVD (cerebrovascular disease; stenosis; peripheral arterial disease; myocardial infarction; stroke; vascular; cardiovascular event; cardiovascular risk; CVD; angiography; coronary artery disease; CHD; atherosclerosis) and the UAE (Dubai; Ajman; Al-Ain; Abu Dhabi; Fujairah; Sharjah; Ras al-Khaimah; Umm al-Quwain). A standardized approach was adopted by the authors and the literature search and data extraction were undertaken independently. Research articles were similarly searched for in local journals and cross-reference lists to ensure that a thorough search had been conducted. Inclusion and exclusion criteria We included studies that directly concerned potential risk factors of CVD. Extracted articles were

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limited to original research conducted in English and published in peer-reviewed journals between 2007 and 2016. The articles focused predominantly on the prevalence and risk factors of CVD in the UAE. Studies with insufficient information on risk factors and studies that did not address the high-risk UAE population were excluded. Selection and data extraction Overall, 177 records were identified, of which 40 remained after the removal of duplicates. Abstracts and titles were then reviewed in order to exclude non-relevant articles. The full text of each of the remaining 21 articles was retrieved for evaluation. Data were extracted into Excel 2013 (Microsoft Corporation, Redmond, WA, USA), including the names of the first author, publication year, sample, location and specific outcomes. A research strategy flow chart is presented in Figure 1.

Results Following a systematic search to identify epidemiological studies on the prevalence and risk factors of CVD in the UAE, 21 studies met the inclusion criteria, including cross-sectional studies (n=11), population-based studies (n=3), literature reviews (n=2) and a case–control study (n=1). Of these, 16 studies15–30 reported on CVD risk factors and five studies20,21,24,30,31 reported on CVD prevalence. Prevalence of cardiovascular disease All five studies reporting on CVD prevalence were conducted in the UAE. One study was conducted at a national level,24 two were multicentre studies20,31 and two were conducted in Abu Dhabi.21,30 All were cross-sectional with the exception of one review21 (Table 1). Two studies20,24 focused on HF and demonstrated that HF is significantly associated with inpatient mortality: the first involved a multivariate logistic regression analysis, which found that DM, heart rate, hyperlipidaemia and age were associated with higher inpatient HF;20 the second reported that the prevalence of HF was higher in women than in men.24 Almahmeed et al.21 focused on the lack of detailed, nationally representative epidemiological data and the need for registry development to reveal the nature of coronary disease. Shah et al.30 evaluated the association between CVD risk factors, acculturation and obesity among men; hypertension was found in 30.5% (419) of the sample along with DM in 9.0% (9) of the subsample. Another



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FIGURE 1 Schematic representation of the selection of studies for the systematic literature review.

prospective multicentre study31 offered detailed information on post-discharge GRACE (Gulf Registry of Acute Coronary Events) risk scores in patients from the Arabian Gulf with acute coronary syndrome (ACS). The results demonstrated that this score can be used to stratify 1-year mortality risk among the Arab population; it does not need additional calibration and often has great discriminatory aptitude. Risk factors of cardiovascular disease All 21 studies present data on risk factors. Ten studies were cross-sectional,15,19,20,24–30 one was a case–control study,23 two were literature reviews18,21 and three were population-based studies16,17,22 (Table 2). Five studies were multicentre studies;19,26–29 seven were conducted in Al-Ain15–18,20,24,25 and three were conducted in Abu Dhabi.21,22,30 CVD is largely caused by risk factors that can be modified, treated or controlled, for example obesity and overweight,15,22,30 high BP,15,16,20–23,28,30 DM,15–17,19,22,26,28 lack of physical activity21,22 and smoking.16,17,19,23,26

The findings suggest that a high prevalence of overweight, in addition to obesity, further increases CVD risk. A population-wide study reported the following risk factor prevalence rates: obesity, 35%; central obesity, 55%; overweight, 32%; DM, 18%; preDM, 27%; dyslipidaemia, 44%; and hypertension, 23.1%.22 On the other hand, Baynouna et al.15 found that 37.3% were obese, and an abnormal lipid profile was found in 53.9% of women and 64.0% of men, largely owing to high triglyceride levels and low high-density lipoproteins. Hypertension is the most significant risk factor for premature CVD and is more common than other major risk factors such as DM, dyslipidaemia and smoking.15,16,20–23,28,30 As evidenced by a Framingham heart study, stroke in women and coronary disease in men are the principal primary cardiovascular events subsequent to the onset of hypertension.6 The risk of both stroke and coronary disease rises gradually with incremental escalation in BP above 115/75mmHg, as demonstrated in several epidemiological studies.23,30 Smoking is a major cause


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TABLE 1 Papers published between 2007 and 2016 on the prevalence of CVD in the UAE

Study

Year

Study design

Study population

Key findings

Shehab et al.20

2012

Patients with ACS

Almahmeed et al.21

2012

Prospective multinational multicentre registry, GRACE Literature review

Shehab et al.24 Shah et al.30

2013

GRACE

Results indicate that HF is significantly linked with inpatient mortality. In multivariate logistic regression, DM, heart rate, hyperlipidaemia and age were associated with higher in-hospital HF Lack of current, detailed, nationally representative epidemiological data in the majority of countries. Development of national registries is required to reveal the nature of CHD. Beta-blockers are important for prevention Prevalence of HF is higher in women than in men

2015

Cross-sectional

Thalib et al.31

2016

Prospective multicentre study, GRACE

Patients with CHD

18 UAE hospitals; patients with ACS Random sampling from health screening centre, Abu Dhabi

Six Gulf countries (Bahrain, Saudi Arabia, Qatar, Oman, UAE and Yemen); 65 hospitals

Overall prevalence of BMI-derived obesity and overweight and ‘waist-to-hip-derived central obesity’ was calculated to be 44.7% in women and 66.7% in men. Hypertension was reported in 30.5% (419) of the sample and DM in 9.0% (9) of the subsample Results suggest that discrimination, goodness of fit and calibration were excellent. Post-discharge GRACE risk scores can be utilized for stratifying the 1-year mortality risk across the Arabian Gulf population; it does not need additional calibration and has great discriminatory aptitude

ACS, acute coronary syndrome; GRACE, Gulf Registry of Acute Coronary Events.

TABLE 2 Papers published between 2007 and 2016 on CVD risk factors in the UAE

Study

Year

Study design

Study population

Key findings

Baynouna et al.15

2008

Cross-sectional, community-based

Al-Ain, UAE (February 2004 – February 2005)

Abdulle et al.16

2008

Health survey stratified by self-reported hypertension

Al-Ain, UAE; included 641 normotensive subjects of various ethnicities

Baynouna et al.17

2009

Al-Ain, UAE; 817 national residents

Binbrek et al.18

2010

Community-based; conventional CVD risk factors Six-study meta-analysis

Risk factor prevalence rates: obesity, 37.3%; hypertension, 20.8%; DM, 23.3%; metabolic syndrome, 22.7%; Framingham risk assessment score >20%, 28.4%; smoking, 19.6% in men. Abnormal lipid profile was observed in 53.9% of women and 64% of men, mainly owing to high triglyceride levels and low high-density lipoproteins Smoking prevalence was similar in two groups (normotensives 14.2%, hypertensives 13.2%). Prevalence rates of obesity and overweight, dyslipidaemia and DM, and thus the 10-year Framingham risk assessment score, were significantly higher in hypertensives Smoking was associated with DM. Few metabolic syndrome adjustments were reduced, while numerous others remained

Yusufali et al.19

2010

Prospective registry

Shehab et al.20

2012

Prospective multinational multicentre registry, GRACE

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Six studies conducted in the UAE (1995 – 2009); 1262 patients with MI Four tertiary care hospitals; three major UAE cities (December 2003 – December 2006) Patients with ACS

Patients admitted and treated after acute ST-segment elevation MI onset at an early age; recanalization induced via thrombolysis was a useful therapeutic approach. Patients’ characteristics in the six studies were very similar Prevalence rates: smoking, 46.4%; DM, 38.9%; inpatient mortality, 1.68%. In-hospital complications were not common Results indicate that HF is significantly linked with inpatient mortality. In multivariate logistic regression, DM, heart rate, hyperlipidaemia and age were associated with higher in-hospital HF



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TABLE 2 continued

Study

Year

Study design

Study population

Key findings

Almahmeed et al.21

2012

Literature review

Patients with CHD

Hajat et al.22

2012

Abu Dhabi, UAE; 138 adults aged ≥18 years

Jamil et al.23

2013

Population-wide cardiovascular screening programme using self-reported indicators, blood tests and anthropometric measures Case–control study

Beta-blockers are effective, as are numerous other therapies; issues related to the use of beta-blockers in CVD and hypertension are overstated ‘The mean age of the participants was 36.82 years (SD=14.3); 43% were men. Risk factor prevalence rates were: obesity, 35%; overweight, 32%; central obesity, 55%; DM, 18%; preDM, 27%; dyslipidaemia, 44%; and hypertension, 23.1%. In addition, 26% of men were smokers, compared with 0.8% of women.’

Shehab et al.24

2013

GRACE

18 UAE hospitals; patients with ACS

Sulaiman et al.25

2014

Prospective multinational multicentre registry, GRACE

Kumar et al.26

2014

Cross-sectional multicentre study

Saheb et al.27

2014

Prospective analysis

Yusufali et al.28

2015

Ong et al.29

2015

Shah et al.30

2015

Voluntary point-of-care CVDRF screening was conducted in follow-up for newly diagnosed DM, hypertension and dyslipidaemia Prospective international multicentre cohort study of out-of-hospital cardiac arrests Cross-sectional

47 hospitals in seven Gulf countries (Saudi Arabia, Oman, UAE, Yemen, Kuwait, Qatar and Bahrain) (14 February 2012 to 13 November 2012); 5005 patients >18 years of age admitted with acute HF 64 centres in the UAE, Kuwait and Qatar (October 2008 – December 2010); patients with asymptomatic peripheral arterial disease with prior cerebrovascular or coronary event Two UAE government hospitals (1 December 2011 to 30 November 2012); patients with decompensated HF Nine health care facilities, four shopping malls and three labour camps in five cities of the UAE

UAE government hospital (2011–2012); patients with MI

January 2009 – December 2012

Random sampling from health screening centre, Abu Dhabi

‘The relationship among variables were examined followed by recommendation, discussion, and analysis for the treatment and prevention of CAD in UAE. The findings demonstrated higher incidence of Type A personality in the MI group. Additionally, these individuals were much more likely to suffer from hypertension and a history smoking, when compared to controls.’ Women were significantly older, suffered more often from cardiac risk factors and were treated with reperfusion and beta-blockers significantly less often. Prevalence of HF was higher in women than in men (24.6% vs. 12.5%; P