The differences in clinical characteristics of hypertension in Asia, demands region-specific research and management approaches.
Hypertension, or high blood pressure, is a major public health concern worldwide. It is the single most important leading cause of cardiovascular disease mortality globally and in Southeast Asia.
Shockingly, one quarter (25%) of adults in Southeast Asia suffer from hypertension,putting the total number of affected individuals in the region higher than the global prevalence (22%).Only one in three adults with the condition are said to be on treatment, and only one in 10 have the condition under control.
Modern Lifestyle the Cause?
Malaysia’s most recent National Health and Morbidity Survey (NHMS) 2023 revealed that one in three (29.2%) adults are diagnosed with hypertension, while in Singapore, the total prevalence was 37% according to the National Population Health Survey 2022.
Some of the risk factors that contribute to the escalating rates of hypertension in the region include a diet that is high in salt and saturated fats – perpetuated by a culture where dining out is affordable and convenient – coupled with a sedentary lifestyle. As many as 65% of Malaysian adults are said to consume too much sodium, a known risk factor for hypertension, as a result of eating out frequently. Meanwhile, the average Singaporean consumes as much as 3,600mg of sodium daily - almost double the World Health Organisation’s (WHO) daily recommendation of 2,000mg of sodium.
According to Dr Navin Sukilan, Consultant Cardiologist from Subang Jaya Medical Centre (SJMC), Malaysia, “Rapid urbanisation and economic development have led to lifestyle changes that raise risks of hypertension, such as the increased consumption of processed foods and reduced physical activity."
"This has been further compounded by the recent shift to online or remote work post-pandemic, where many individuals have become less active as they spend longer hours seated, or confined to the same location, in the absence of commuting to the office or different physical locations for face-to-face meetings,” he adds.
The impact of hypertension on public health is profound, leading to a significant economic burden.
White-coat vs masked hypertension
Hypertension is increasingly prevalent in Asian populations, with a notable rise over the past 30 years, particularly in East and Southeast Asia. There are a number of Asia‐specific features of hypertension and hypertension‐related cardiovascular complications with unique aspects affecting Asians, such as a higher propensity for both white-coat and masked hypertension.
White coat hypertension (WCH), sometimes known as the white coat syndrome, refers to the phenomenon where a person's blood pressure readings are elevated in a medical setting, such as a doctor's office, compared to readings taken in other environments, like at home (normal ambulatory or home blood pressure). This increase in blood pressure can occur due to anxiety or stress-induced activation of the sympathetic nervous system during encounters with healthcare providers, and being at a healthcare facility.
WCH is generally more prevalent in urban areas and will become more of an issue over time as Asian populations age. Initially thought to not be a cause of concern, some healthcare professionals now think that white coat hypertension should be looked at more closely, as it might raise the risk of getting long-term high blood pressure. People with white coat hypertension also might have a higher risk of heart or blood vessel disease and organ damage, compared with people who have steady, ideal blood pressure.
On the other hand masked hypertension (MH) refers to a condition where a person's blood pressure readings are normal when measured in a clinical setting (typically less than 140/90 mmHg) but are elevated when measured outside the clinic, such as during daily activities or via home monitoring (elevated ambulatory or home blood pressure with a normal office blood pressure). This condition can lead to increased cardiovascular risk, as it might go undetected due to the normal readings observed in a medical office.
Masked hypertension tends to be more common in rural settings, and appears to be particularly more prevalent in Asian populations compared to Western populations, suggesting regional differences linked to demographics and healthcare settings.
Among the treated population, MH is proposed to represent inadequately treated hypertension, whereas patients with WCH are at risk for overtreatment because of persistently elevated office blood pressure. Both MH and WCH were shown to be associated with an increased long-term risk for cardiovascular events in multiple populations in Europe and Asia, further strengthening the argument regarding demographic influences in hypertension cases.
Differences in clinical characteristics of hypertension in Asia
According to a paper titled ‘Management of Hypertension in the Asia-Pacific Region: A Structured Review’, differences in hypertension and its outcomes have been observed between Asia-Pacific and Western populations. The molecular and biological characteristics unique to Asian populations are influenced by racial disparities, that are often intertwined with environmental, social, cultural, and economic influences. Furthermore, the variability in response to medication, medication adherence, and the fact that many risk assessment tools were originally designed for Caucasian populations create a complex interplay that affects both the prevalence and control of hypertension in Asians.
One of the authors, Dr Rohit Khurana, Senior Consultant Cardiologist at the Harley Street Heart & Vascular Centre, Singapore, says, “Asian individuals, particularly East Asians, show greater salt sensitivity and a higher risk of stroke and non-ischemic heart failure. South Asians have a high incidence of cardiovascular diseases (CVD) and metabolic disorders, such as type 2 diabetes, and face a higher risk of stroke and CVD due to elevated systolic and diastolic blood pressure”.
“In China, hypertension often goes underdiagnosed, despite higher average blood pressure levels, and additionally, circadian variations in blood pressure, such as morning and night-time hypertension, are more common in Asian populations compared to Europeans,” Dr Khurana adds.
The same paper says that variations of hypertension also exist within Asia-Pacific, with Japanese patients displaying higher morning blood pressure surges, while Thai patients show a higher prevalence of riser status (higher night-time blood pressure). These findings suggest a need for region-specific approaches in hypertension management.
Region-specific hypertension management
Despite being the most populous region globally, much of the data on hypertension management in the Asia-Pacific region are extrapolated from non-Asian populations, leaving significant knowledge gaps.
While many countries in Asia-Pacific have national hypertension guidelines, there is no regional consensus guideline, and the implementation of existing recommendations in clinical practice often faces barriers. These include the complexity of guidelines, language accessibility, trust in local versus international guidelines, affordability and availability of treatment, health literacy, and the lack of healthcare infrastructure and resources.
Says Dr Khurana, “Patients in Asia-Pacific differ demographically and clinically from those in the West – they have lower body mass index (BMI), higher smoking rates, lower alcohol consumption, and a higher incidence of prior strokes but lower rates of pre-existing cardiovascular disease. In resource-limited settings within the region, hypertension patients are more likely to experience end-organ damage, although data specific to Asia-Pacific remain sparse."
"Genetic variations in hypertension development and treatment response may also differ between Asian and Western populations, underscoring the need for more region-specific research. Thus, addressing these barriers is essential to improving hypertension management across the region,” he adds.
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