Hypertension and its consequent end-organ damage including Hypertensive Heart Disease (HHD) are a major concern that impact health, resulting into impairment and reduced quality of life (QOL). The purpose of this study was to describe the burden of HHD in Iran and comparing it with the World Bank upper middle-income countries (UMICs) in terms of disability-adjusted life years (DALY), mortality and prevalence.
Using data from the Global Burden of Disease study 2017, we compared the number of DALYs, deaths and prevalence trends for HHD from 1990 to 2017 in all age groups for both sex in Iran, and compared the epidemiology and trends with UMICs and globally.
The age-standardized DALY rate for HHD increased by 51.6% for men (95% uncertainty interval [UI] 305.8 to 436.7 per 100,000) and 4.4% for women (95% UI 429.4 to 448.7 per 100,000) in Iran. The age-standardized prevalence of HHD in Iran was almost twice times higher than globally and 1.5-times more than the World Bank UMICs. The age-standardized death rate for HDD increased by 60.1% (95% UI 17.3 to 27.7% per 100,000) for men and by 21.7% (95% UI 25.85 to 31.48 per 100,000) for women from 1990 to 2017. Age-standardized death rate in Iran was 2.4 and 1.9 times higher than globally and UMICs, respectively.
Citation: Omidi N, Arabloo J, Rezapour A, Alaeddini F, Bragazzi NL, Pourasghari H, et al. (2021) Burden of Hypertensive Heart Disease in Iran during 1990–2017: Findings from the Global Burden of Disease study 2017. PLoS ONE 16(9): e0257617. https://doi.org/10.1371/journal.pone.0257617
Editor: Amir Radfar, University of Central Florida, UNITED STATES
Received: April 7, 2021; Accepted: September 6, 2021; Published: September 22, 2021
Copyright: © 2021 Omidi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The datasets used and/or analysed during the current study are available in the article itself and can be found freely at http://ghdx.healthdata.org/gbd-results-tool.
Funding: The authors received no specific funding for this work.
Competing interests: The authors have declared that no competing interests exist.
Abbreviations: HHD, Hypertensive Heart Disease; QOL, Quality of Life; UMICs, Upper middle-income countries; DALY, disability-adjusted life years; GBD, The Global Burden of Diseases; UI, Uncertainty interval; SBP, systolic Blood Pressure; YLLs, Years of life lost; YLDs, Years lived with disability; ICD, International Classification of Diseases; GNI, Gross national income
Hypertension and its consequent end-organ damage including Hypertensive Heart Disease (HHD) are a major concern that impact health, generating impairment and reducing quality of life (QOL) [1, 2]. Current 2017 American Cardiology Association/American Heart Association as well as other international organizations (such as the World Health Organization, WHO) guidelines define hypertension as a systolic blood pressure(SBP) higher than 120 mm hg or a diastolic pressure more than 80mm Hg [3, 4]. HHD with either left or right side heart involvement is associated with increased risk of cardiovascular events , systemic vascular resistance, intra-cardiac pressure overload, interstitial fibrosis, concentric left ventricular hypertrophy, diastolic dysfunction, and left atrial enlargement . The spectrum of HHD is highly heterogeneous, spanning from uncontrolled hypertension to either diastolic or systolic heart failure, which has significant mortality and morbidity rates .
Recent estimates show that 874 million adults worldwide have a SBP of 140 mm Hg or higher . Prevalence of hypertension tends to increase with aging (79% of men and 85% of women >75 years old have hypertension) [3, 4]. The global burden of hypertension in 2010 was estimated at approximately 1.4 billion and is likely to surpass 1.6 billion by 2025 . In 2016 non-communicable diseases accounted for up to 40.5 million (71%) of global deaths and 17.9 million (44%) of non-communicable deaths were due to cardiovascular disease. Hypertension is the leading risk factor for mortality and disability [9, 10]. In 2010, more than one billion hypertensive adults were living in low- and middle-income countries where the rate of achieving blood pressure goals was 7.7% [8, 10].
The fibrotic remodeling and left ventricular hypertrophy contribute to renin angiotensin aldosterone system activation . According to some global estimates ), annual death rate per 100,000 people for SBP of at least 110 to 115 mm Hg increased from 135.6 to145.2 and for SBP of 140 mm Hg or higher increased from 97.9 to 106.3 from 1990 to 2015. Disability-adjusted life-years (DALYs) associated with SBP of at least 110 to 115 mm Hg increased from 148 million to 211 million and for SBP of 140 mm Hg or higher increased from 95.9 million to 143.0 million . To the best of our knowledge, no study has ever been done to comprehensively compare the burden of HHD in Iran and the World Bank Upper Middle-Income Countries (UMICs), stratifying by age and sex incidence and prevalence trends, mortality rates, and compare the overall burden of HHD by country, from 1990 to 2017.
The present study aims at filling in this gap in knowledge. It can provide detailed information to policy- and decision-makers in making informed, evidence-based decisions to prioritize and allocate resources to counteract and mitigate against the burden of HHD. More specifically, these data can be utilized to inform different interventions, from intensive screening aimed at identifying early stages of hypertension-related cardiac damage (HHD), to taking into account trade-offs and opportunities that characterize every screening program. More specifically, the aim of this study is to present a detailed, comprehensive overview of DALY, death and prevalence trends from 1990 to 2017 in all age groups for both men and women in Iran. Moreover, we compare the epidemiology and trends in HHD from 1990 to 2017 in Iran, UMICs and globally.
The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) estimates incidence, prevalence and mortality rates, years of life lost (YLLs), years lived with disability (YLDs) and disability-adjusted life years (DALYs), for 354 causes by sex, age, and location for 195 countries and territories for 21 regions and 7 super-regions for the years 1990–2017. Detailed description of the GBD 2017 methodology has been provided in previous publications [13–17].
In the current study, we reported numbers and rates of prevalence, death and DALYs of HHD in 2017 and its temporal changes from 1990 to 2017, according to the GBD 2017 data and methodology. These estimates were disaggregated by age group, sex and geographical regions (Iran and the World Bank UMICs group).
The GBD study methods are compliant with the Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) recommendations . All estimations used in our study are extracted from the GBD 2017 study, the data of which are publicly available online at: http://ghdx.healthdata.org.
GBD measures and age-standardized estimates
The GBD 2017 study uses the International Classification of Diseases (ICD)-9 and ICD-10 codes for HHD with sequelae (severity levels) where each sequela has a specific disability weight ranging from 0.041 to 0.049. DisMod-MR 2.1, a Bayesian meta-regression tool, was used to estimate non-fatal health losses. This method uses heterogeneous epidemiological data from different data sources to produce internally consistent estimates of incidence and prevalence of HHD . HHD DALYs are the sum of YLDs and YLLs for each location, year, sex and age group. All age-standardized rates were calculated using the GBD world population age standard .
Comparisons with the World Bank UMICs group
The World Bank UMICs were selected for comparison with Iran: they include 56 countries, such as Brazil, the Russian Federation, Indonesia, Iraq and China. UMICs have a Gross national income (GNI) per capita between $4,046 and $12,535 . We compared Iran and the above-mentioned group by age-standardized rates of death, and DALYs in 1990 and 2017.
All data in this study are computed with their 95% uncertainty intervals (UIs) [13–17]. Each parameter was calculated 1,000 times and a distribution with 1,000 samples was produced. The 95% UIs were used to better capture the degree of uncertainty due to the lack of data for some geographic locations (countries/territories) and time periods, and heterogeneity of sources combined together. UIs were derived from the 2.5th and 97.5th values of the 1,000 draws to determine the upper and lower intervals of the 95% UI for each parameter.
Table 1 shows that there were 276,641(95% UI 235,496–321,324) cases of HHD in 2017 in Iran. Crude prevalence numbers for men and women for all ages increased by 197% and 214.9%, respectively and the age-standardized prevalence rate for HHD increased by 6.2% (95% UI 291.6 to 309.9 per 100,000) for men and 7.2% (95% UI 494.4 to 530.3 per 100,000) for women from 1990 to 2017.
Table 2 shows that crude death number for men and women for all ages increased by 398.6% and 284.4%, respectively. The most increasing death numbers for men and women are in the octogenarians, respectively (1142% and 553.2%). The age-standardized death rate for HDD increased by 60.1% (95% UI 17.3 to 27.7% per 100,000) for men and by 21.7% (95% UI 25.85 to 31.48 per 100,000) for women.
Tables 3 and 4 shows that the crude number of DALYs for men and women for all ages increased by 272% and 189.9% respectively. Similar to the death numbers, this increase was severe in the octogenarians. Between 1990 and 2017, the age-standardized DALY rate for HHD increased by 51.6% for men (95% UI 305.8 to 436.7 per 100,000 and 4.4% for women (95% UI 429.4 to 448.7 per 100,000).
Table 5 compares the indices between Iran, the UMICs and globally. Data shows that the age-standardized prevalence rate (per 100,000) of HHD in Iran has been about two times higher than this rate in the world [420.3 (95% UI 356–489) versus 217.8 (95% UI 184–254)] in 2017. However, the percentage change in this rate in Iran and the world was similar since 1990. Further, the age-standardized death rate (per 100,000) for Iran were 2.5 times higher than the global rate in 2017 [29.53 (95% UI 23.71–31.28) vs 12.28 (95% UI 8.98–13.20)]. The percentage of changes in the age-standardized death rate increased in Iran (34%), while it decreased in the world (-19%). The pattern of the change in DALYs rate is similar to the death rate mentioned above. The age-standardized DALY rate was two times higher in Iran than in the world. Also, between 1990 to 2017, DALYs rate increased in Iran, but it decreased in the world.
Table 6 demonstrated death and DALYs percentages of HHD in all age groups in 1990 and 2017 in Iran, UMICs and globally for all causes. According to the table, the proportion of HHD attributable death to all causes deaths increased four-fold since 1990 accounting for 4.5% of all causes deaths in 2017 in Iran.
This is the first report evaluating the epidemiology and trends of HHD in Iran and UMICs over the past 27 years.
One of the key findings of the present study is that the number of DALYs has increased from 1990 to 2017 in all age groups for both men and women in Iran. Age-standardized DALY increased in both sexes, more in males than female (51.6% vs. 4. 4%) in Iran. Age-standardized DALY rate was higher in females compared with males (448.7 vs. 436.7) in 2017. The percentage of changes for DALY rate was lower in females during the 27-year period and this could be due to higher baseline DALY rates in 1990. The increase in DALY in both sexes could be attributed to aging, prevalence of hypertension and higher life expectancy [12, 20]. According to the World Bank United Nations Population division data, total life expectancy in Iran increased from 63.8 in 1990 to 75.7 years in 2017. Due to population growth in Iran, 24 million additional people were exposed to HHD in 2017 .
The other main finding of the present report was that age-standardized death rate in both sexes increased from 1990 to 2017 in Iran and the increase had a steeper slope in males. The potential cause for higher death rates in females could be explained taking into account the higher prevalence of hypertension and obesity [12, 21]. The increases in death attributed to HHD could be explained by the increase in prevalence of hypertension and improvement in detection of hypertension induced end-organ damage.
The prevalence of HHD increased from 1990 to 2017 in all age groups despite the availability of preventive interventions and potent versatile antihypertensive medications. The higher prevalence in women could be explained by aging (63.8–77) and obesity. These findings support the observation that dietary salt intake, fruit and vegetable consumption, overweight and obesity, and physical activity have also changed substantially over the same time period . Among major cardiovascular risk factors at the global scale, the prevalence of obesity and overweight increased substantially over the last two decades . Overall, about 13% of the world’s adult population (11% of men and 15% of women) and 19.5% of adults in Organization for Economic Cooperation and Development (OECD) countries was obese in 2016, whereas the national prevalence rates of obesity in Iran are 22.7% (15.3% of men and 29.8% of women). Also, there was a significant difference between the prevalence of obesity among males and females in Iran [21–23].
The proportion of HHD attributed mortality to all-cause mortality has increased in Iran from 1990 to 2017. Compared with the UMICs and globally, the proportion of attributed death in Iran was 1.89 and 2.73 times respectively. DALY proportion of HHD to all-cause increased in Iran, UMICs and globally during the aforementioned period, however the proportion of HHD induced disability in Iran in 2017 was 1.38 and 2.16 times higher than UMICs and globally, respectively.
The age-standardized rates demonstrated that the indices in Iran were higher than those of UMICs and globally in 2017. Age-standardized prevalence rate of HHD increased by 15.1% in UMICs. The higher rate of prevalence in Iran compared with UMICs and globally could be explained by higher prevalence of obesity in Iran. The age-standardized prevalence of HHD in Iran was almost twice times higher than globally and 1.5-times more than World Bank UMICs. Age-standardized death rate in Iran was 2.4 and 1.9 times higher than globally and UMICs respectively. Also, age-standardized DALY rate in Iran was 2.11 and 1.8 times higher than globally and UMICs respectively. Comparing results globally and with UMICs during the aforementioned period demonstrated that the age-standardized death and DALY rate per 100,000 decreased from 1990 to 2017 globally and in UMICs, while these trends increased in Iran. This should encourage public health policy-providers to develop and implement robust screening and follow-up program among the general population.
This study and GBD studies used vital registration and administrative hospital data as well as data from representative cross-sectional surveys to inform disease trends across geography and time; these data were adjusted to account for differences in reporting of disease across health systems. Varying practices, resources, patient populations, and quality of data recording, however, likely cause differences in the quality and uniformity of data.
Age standardized DALY and death rate increased in both sexes from 1990 to 2017 in Iran and this increase was steeper in males. The age-standardized prevalence and death rate of HHD in Iran were almost twice times higher than globally. The higher prevalence and death rates in Iran in comparison with UMICs and globally should encourage public health decision-makers to perform intensive screening activities in at risk population to prevent HHD and mitigate its mortality, specifically, adopting an age and a gender-specific perspective.
Permission for publishing these data was granted by Professor Christopher J.L. Murray, the Director of the Institute for Health Metrics and Evaluation (IHME) to Health Management and Economics Research Center, Iran University of Medical Sciences, Tehran, Iran.
- 1. Drazner MH. The progression of hypertensive heart disease. Circulation. 2011;123(3):327–34. pmid:21263005
- 2. Krepp JM, Lin F, Min JK, Devereux RB, Okin PM. Relationship of electrocardiographic left ventricular hypertrophy to the presence of diastolic dysfunction. Annals of Noninvasive Electrocardiology. 2014;19(6):552–60. pmid:24750238
- 3. Carey RM, Whelton PK. Prevention, detection, evaluation, and management of high blood pressure in adults: synopsis of the 2017 American College of Cardiology/American Heart Association Hypertension Guideline. Annals of internal medicine. 2018;168(5):351–8. pmid:29357392
- 4. Whelton PK, Carey RM, Aronow WS. Acc/aha/aapa/abc/acpm/ags/APhA/ASH/ASPC/nma/pcna guideline for the prevention, Detection, evaluation, and management of high blood pressure in adults: a Report of the American College of Cardiology/American heart Association. Task force on clinical practice guidelines//J. Am. Coll. Cardiol.-2017.-Nov 13. Почки. 2018;7(1).
- 5. Vakili BA, Okin PM, Devereux RB. Prognostic implications of left ventricular hypertrophy. American heart journal. 2001;141(3):334–41. pmid:11231428
- 6. Cuspidi C, Giudici V, Negri F, Sala C, Mancia G. Left ventricular geometry, ambulatory blood pressure and extra-cardiac organ damage in untreated essential hypertension. Blood pressure monitoring. 2010;15(3):124–31. pmid:20305545
- 7. Slivnick J, Lampert BC. Hypertension and heart failure. Heart failure clinics. 2019;15(4):531–41. pmid:31472888
- 8. Mills KT, Bundy JD, Kelly TN, Reed JE, Kearney PM, Reynolds K, et al. Global disparities of hypertension prevalence and control: a systematic analysis of population-based studies from 90 countries. Circulation. 2016;134(6):441–50. pmid:27502908
- 9. Danaei G, Ding EL, Mozaffarian D, Taylor B, Rehm J, Murray CJ, et al. The preventable causes of death in the United States: comparative risk assessment of dietary, lifestyle, and metabolic risk factors. PLoS Med. 2009;6(4):e1000058. pmid:19399161
- 10. Egan BM, Kjeldsen SE, Grassi G, Esler M, Mancia G. The global burden of hypertension exceeds 1.4 billion people: should a systolic blood pressure target below 130 become the universal standard? Journal of hypertension. 2019;37(6):1148–53. pmid:30624370
- 11. Qin W, Rudolph AE, Bond BR, Rocha R, Blomme EA, Goellner JJ, et al. Transgenic model of aldosterone-driven cardiac hypertrophy and heart failure. Circulation research. 2003;93(1):69–76. pmid:12791709
- 12. Forouzanfar MH, Liu P, Roth GA, Ng M, Biryukov S, Marczak L, et al. Global burden of hypertension and systolic blood pressure of at least 110 to 115 mm Hg, 1990–2015. Jama. 2017;317(2):165–82. pmid:28097354
- 13. GBD 2017 Causes of Death Collaborators. Global, regional, and national age-sex-specific mortality for 282 causes of death in 195 countries and territories, 1980–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. 2018;392(10159):1736–88.
- 14. GBD 2017 DALYs and HALE Collaborators. Global, regional, and national disability-adjusted life-years (DALYs) for 359 diseases and injuries and healthy life expectancy (HALE) for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. 2018;392(10159):1859–922.
- 15. GBD 2017 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017. The Lancet. 2018;392(10159):1789–858.
- 16. GBD 2017 Mortality Collaborators. Global, regional, and national age-sex-specific mortality and life expectancy, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017. The lancet. 2018;392(10159):1684–735.
- 17. GBD 2017 Risk Factor Collaborators. Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. The Lancet. 2017;390(10100):1345–422. pmid:28919119
- 18. Stevens GA, Alkema L, Black RE, Boerma JT, Collins GS, Ezzati M, et al. Guidelines for Accurate and Transparent Health Estimates Reporting: the GATHER statement. The Lancet 2016;388(10062):e19–e23.
- 19. Bank W. World Bank Country and Lending Groups 2020 [Available from: https://datahelpdesk.worldbank.org/knowledgebase/articles/906519.
- 20. Bank TW. Life expectancy at birth, total (years)—Iran, Islamic Rep 2019 [Available from: https://data.worldbank.org/indicator/SP.DYN.LE00.IN?locations=IR.
- 21. Blüher MJNRE. Obesity: global epidemiology and pathogenesis. 2019;15(5):288–98.
- 22. Djalalinia S, Saeedi Moghaddam S, Sheidaei A, Rezaei N, Naghibi Iravani SS, Modirian M, et al. Patterns of Obesity and Overweight in the Iranian Population: Findings of STEPs 2016. 2020;11:42.
- 23. Organization(WHO) WH. Obesity and overweight 2017 [Available from: https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight.