Introduction
HHD is a medical condition that is characterized by a range of pathological alterations in the heart, primarily affecting the left ventricle. It develops as a consequence of prolonged high blood pressure and is associated with several manifestations such as myocardial hypertrophy, arteriosclerosis, and cardiac arrhythmias [
1,
2]. The clinical presentation of HHD varies, ranging from no symptoms or mild chest discomfort and palpitations to breathlessness, heart failure, and potentially even sudden cardiac death [
3]. HHD is a disease caused by high blood pressure, and is a key underlying mechanism for the incidence and mortality of cardiovascular diseases [
4]. As the fourth most common cause of cardiovascular and cerebrovascular fatalities, hypertensive heart disease ranks just below ischemic heart disease, stroke, and cardiomyopathy [
5].
In this study, our analysis was based on the comprehensive dataset of GBD 2019. The primary objectives were as follows: (1) to evaluate the disparities in health outcomes associated with hypertensive heart disease, taking into account the Socio-demographic Index (SDI); (2) to examine the temporal patterns of health inequalities related to hypertensive heart disease between 1990 and 2019. The overall goal of this study is to provide comprehensive insights and help prioritize and allocate healthcare resources to alleviate the health inequalities and disease burden of HHD globally across countries.
Discussion
The secondary analysis of the GBD 2019 research data offers a comprehensive global overview of the health burden attributed to HHD. It specifically sheds light on the cross-national health disparities resulting from socioeconomic inequalities. Our findings demonstrate that the burden of DALYs associated with HHD is primarily concentrated in economically disadvantaged and underdeveloped regions, affecting predominantly male populations, as well as middle-aged and elderly individuals. In addition, although there has been a decrease in the global age-standardized burden of HHD, the overall burden continues to rise, highlighting persistent health inequalities associated with HHD. Research indicates that the increase in the number of DALYs associated with HHD globally can be attributed to both population growth and aging [
12,
13]. According to estimates, the global population has grown from 5.35 billion (95% UI 5.24 to 5.46 billion) in 1990 to 7.74 billion (95% UI 7.48 to 7.99 billion) in 2019 [
10]. In England and Wales, the elderly population accounted for 18.6% of the total population in 2021. It is estimated that by 2030, the elderly population will surpass 1 billion people [
14,
15]. The age-standardized DALY rates reflect the trends in the global burden of hypertensive heart disease (HHD) from 1990 to 2019, indicating a consistent decline in HHD burden (age-standardized) over the past 28 years. HHD is considered an age-related disease, and both individual and global disease burdens have increased with the aging of patients and populations.
It is estimated that globally, approximately 1.39 billion adults (aged ≥ 20) are living with hypertension, with 694 million men and 694 million women affected, in 2010 [
16]. The number of individuals with hypertension in low-income and middle-income countries is nearly triple that of high-income countries. In terms of healthcare expenditure on hypertension, the global burden was estimated to be 1.44 billion US dollars in 2010, and it is projected to exceed 1.6 billion US dollars by 2025 [
16]. Hypertension is a major risk factor for cardiovascular disease [
17,
18]. In 2019, the number of deaths among young people globally due to cardiovascular diseases related to hypertension was 640,239, representing a 43.0% increase compared to 1990 [
19]. These results align with our findings.
Health inequality monitoring utilizes data on health inequalities, which refer to significant differences in health outcomes among different population subgroups. It provides information for policies and programs aimed at addressing health inequalities, including unfair, avoidable, or remediable health disparities [
20,
21].
In terms of age distribution, the age-standardized burden of HHD is closely associated with increasing age, consistent with previous reports. As HHD has been identified as an age-related disease, its global disease burden increases with both the aging of patients and the population as a whole [
1,
22].
In terms of inter-country inequality, the disease distribution map and cross-regional comparisons reveal that the burden of HHD is closely associated with the socio-economic index, consistent with previous reports [
23]. Regarding the SDI index, the DALYs for HHD are highest in regions with moderate SDI and lowest in regions with high SDI. The age-standardized DALYs rates are highest in low SDI regions and lowest in high SDI regions.
Although the aforementioned results are precise, they do not provide the optimal comparability for measuring and monitoring inequalities. To address this, we calculated the Slope Index of Inequality (SII) and Concentration Index based on the SDI index. We found that in 2019, the burden of HHD showed a negative correlation with the socio-economic level. Over the past 30 years, this inequality has consistently decreased in terms of the Slope Index of Inequality (SII), but has remained at a moderately high level in relative measures (Concentration Index).
This study has several limitations. Firstly, the limited data collection in economically underdeveloped regions may result in an underestimation of the true burden of HHD. Secondly, the lack of clinical information on HHD in the GBD 2019 study and reliance on secondary analysis of available data are noteworthy. Thirdly, the use of aggregated national-level data instead of regional-level data may introduce potential bias in estimating DALYs and can lead to geographical variations. Furthermore, the GBD study has taken several steps to improve the reliability and comparability of data, but in some parts of the world, health data on cardiovascular diseases remains extremely limited. The lack of data is a significant reason why no significant change in the prevalence or mortality of hypertensive heart disease could be detected in many regions. In countries with overestimated cardiovascular disease mortality, only limited data is available. Additionally, the GBD study includes an estimate of measurement error for each result, reported in the form of a 95% uncertainty interval (UI). In regions with wide UIs, the ability to detect time trends is also limited. Other sources of error in the GBD study may include regional patterns of clinical diagnosis of HHD, death code redistribution, selection of data sources, and the measurement of the Socio-Demographic Index. Furthermore, similar results (such as data related to the burden of HHD and its spatial distribution [
24]) have already been published using data from the GBD 2019 database. While this study offers a global perspective on the socio-economic inequality of HHD burden, the conclusions may not be directly applicable to specific regions.
In summary, this study reveals that despite societal advancements, the burden of hypertensive heart disease (HHD) continues to be concentrated in countries with moderate SDI indices. To mitigate global inequalities arising from socio-economic disparities, it is crucial to ensure a more equitable utilization and allocation of healthcare resources. This entails prioritizing the needs of vulnerable populations, including the poor, elderly, and male individuals. By doing so, we can work towards reducing the disparities and promoting better health outcomes for all.
Publisher’s Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.