A new national study in Iran on the effects of implementing of new definition of blood pressure based on the 2017 American Heart Association/AHA and the American College of Cardiology / ACC guidelines, shows that about 11 million Iranians have high blood pressure and with considering the doubling of the number of cardiovascular deaths due to high blood pressure during the last three decades in Iran, the implementation of new guideline will reduce the heavy burden of blood pressure on the health system.
Writer : Fereshteh Hashemi
May 20, 2022
Lowering the threshold of high blood pressur concurrent with growing global concerns about the upward trend of premature deaths
11 million Iranians have high blood pressure /Reducing the heavy burden of high blood pressure in Iran with the implementation of a new hypertension guideline
According to the Iran Science Watch (ISW) the prevalence of hypertension is declining especially in high-income countries and emerging economies, but based on The Study of Hypertension in Adults aged 30 to 79 in 185 countries (2019), statistics show a doubling of the number of people with high blood pressure in low-income countries over the past three decades.
1.3 billion people with high blood pressure
1.3 billion people with high blood pressure, 8.5 million deaths and 200 million DALYs (Disability-adjusted life years) due to high blood pressure in the world, the important role of this disease in the incidence of cardiovascular disease, heart attack and stroke and chronic kidney disease as well as the inclusion of this risk factor among the three leading causes of cardiovascular death, are very alarming.
Also despite easy access to antihypertensive drugs, only 50% of women and less than 40% of men in the world are treated, and blood pressure of 24% of women and 19% of men under treatment are controlled.
Perhaps it is because of growing concern about this statistic that the definition of hypertension recommended in The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure / (JNC7) which is widely used among general practitioners and specialists, has been changed in The 2017 American Heart Association (AHA) and American College of Cardiology (ACC) guidelines and decreased normal level of hypertension from >=140/90 mmHg to >=130/80 mmHg , and prehypertension which was previously between 120 and 139, and diastolic blood pressure which was between 80 and 89 are considered as levated blood pressure.
What will be the effects of implementing the “New guideline defining blood pressure” in Iran ?
Iranian medical sciences researchers in a new national study entitled Prevalence, awareness, treatment, and control of hypertension based on ACC/AHA versus JNC7 guidelines in the PERSIAN cohort study  that its results published in the International Journal of Scientific Reports from Nature Publications, examined the effects of implementing the 2017 American Heart Association / AHA and the American Heart College / ACC guidelines and redistribution of patients at risk of this disease in Iran.
In the present study which was conducted based on the baseline data of the Prospective Epidemiologic Research Studies in Iran (PERSIAN) In the years 2014 to 2020 with the participation of 164000 adults aged 35 to 70 years of different ethnicities living in 16 provinces Iran, 55% of participants were female, 71% lived in urban areas , 21% illiterate.
Professor Reza Malekzade
11 million Iranians have high blood pressure
Professor Reza Malekzadeh, Distinguished Professor of Tehran University of Medical Sciences, main PI of the Persian Cohort Study and Senior Researcher of this study said: ”Based on the JNC7 guideline (>=140/90 mmHg ), 6.5 million adults aged 35 to 70 years in the Iran have the hypertension disease , but based on the 2017 ACC/AHA hypertension guideline (>=130/80 mmHg) the number of adults diagnosed with hypertension is estimated at 11 million. ”
37% prevalence of hypertension among Iranian adults
According to the senior author of this study ,based on the JNC7 guideline (more than 140/90 mm Hg) ,a total of 14% (more than 24,000 people) were added to the group of hypertensive patients. Also the sex-age standardized prevalence of hypertension among adults was 22.3% based on the JNC7 guideline and 37% based on the 2017 ACC/AHA guidelines.
Lack of gender differences in high blood pressure
He added : ”based on the JNC7 guideline, the prevalence of hypertension among women is significantly higher than men in the study population but based on the 2017 ACC/AHA guidelines, there is no difference in the prevalence of hypertension between the sexes. The prevalence of hypertension was greater with age regardless of both guidelines. ”
The importance of identifying people at risk
Professor Malekzadeh said: ” Out of a total of 14% of participants who have been diagnosed with high blood pressure according to the new guideline, most of them are young men under the age of 55. The important point is that these people were less likely to have metabolic risk factors, common diseases associated with hypertension, and a 10-year risk of major disease events. however, 31% of these individuals (4% of the total study participants) required pharmacological intervention. These findings could indicate the importance of identifying high-risk individuals who are prone to high blood pressure later in life and should be identified and managed in the early stages of the disease. ”
Half of patients are unaware of high blood pressure
Dr. Farid Najafi, Professor of Epidemiology of Kermanshah University of Medical Sciences and the first author of this study , referred to the
findings of this study on the level of awareness of people with high blood pressure and said: ” Our findings showed the ratio of awareness about high blood pressure among affected adults, it is 77% based on the JNC7 guideline and 49% based on the ACC / AHA guideline. Among participants who were recently classified as hypertensive, only 3% were aware of their disease. Also, based on the new guideline for determining blood pressure, awareness of the disease is higher among women as well as the elderly. ”
Only half of those with high blood pressure are treated
He added: ” The results of the study showed that based on the new guideline, only half (50%) of patients with high blood pressure in the study population were treated , while this ratio is 82% according to the old guideline. In addition, none of the participants who were recently diagnosed with high blood pressure were treated. In comparison, the rate of treatment of hypertension according to the new guideline increases with age. Women are also more likely to be treated based on both old and new blood pressure guideline. ”
Hypertension is not controlled in 46% of patien*
The first author of the present study said: ”The findings indicate that the rate of control of hypertension among” all affected adults “, based on the previous guideline, is 63% and based on the new guideline, 23%. In “treated people”, the rate of control of high blood pressure is 76% based on the previous guideline and 46% based on the new guideline . Findings related to the implementation of the new guideline for determining blood pressure also show that the rate of control of hypertension is higher among women than men; However, the control of hypertension decreases with age in both sexes. ”
Doubling the number of untreated hypertensive patient who require medical intervention
Dr. Najafi also added : ”Based on the previous guideline for hypertension, among the untreated hypertensive adults, more than 7000 participants are eligible for drug treatment, but according to the new guideline, this number has doubled and more than 15000 participants need medication intervention. Also, out of the total number of people (24 312) who were reclassified as hypertension, 7 671 people needed medical therapy. ”
Accordin to the first author of this study ”In general, the implementation of the new guideline for hypertension leads to an increase in the prevalence of the disease (63%), reduced awareness of patients (37%), reduced treatment of the disease (38%), reduced control of hypertension in adults (63%) and reduced control in adults treated for hypertension (39%) compared to the previous guideline. ”
Will the new guideline drastically increase the level of clinical interactions and drug interventions and impose an additional burden on Iran’s health care system?
Professor Malekzadeh said: ”Clinical trial studies have shown the benefits of lowering the hypertensive threshold from >=140/90 mmHg to >=130/80 mmHg and its effect in significantly reducing major cardiovascular events, especially myocardial infarction. Accordingly, it can be said with confidence that the new guideline do not increase the use of blood pressure medications among most of the people studied, and incidentally, compared to previous guideline , the main responsibilities are to prevent hypertension with non-pharmacological interventions and by educating people, lifestyle modification and especially reducing salt intake in the diet. In fact, the similarities between the old and new guideline are much greater than the differences.
The new guideline is an important step to preventing high blood pressure
Professor Malekzadeh reminded: ”The new guideline Increases people’s level of awarness about this diseases and is definitely an important step to controlling blood pressure and will reduce the burden of this disease as a risk factor for cardiovascular disease, heart attacks and strokes and chronic kidney disease. ”
Distinguished Professor of Tehran University of Medical Sciences ,also about the requirements of implementing the new guideline for determining blood pressure said: ”Controlling high blood pressure and preventing its increase in the country by implementing the new guideline , requires the knowledge of specialists, health care providers and the general public about the new guideline and as well as cooperation of helth policymakers in correct implementation of new definitions. ”
He said : ”Previous hypertension guideline (JNC7) is still a widely used guide for measuring, controlling and treating hypertension in Iran, especially among general practitioners in remote areas; but studies have shown that over the past few years, the trend of using the new guideline in Iran is increasing and it is expected that the new global guideline will be gradually accepted among Iranian physicians; because early prevention is an important need to maintain optimal blood pressure levels even in adults without the common risk factors for cardiovascular disease. ”
Iran is one of the countries with the high prevalence of hypertension
Distinguished Professor of Tehran University of Medical Sciences , noted that ”Iran is one of the countries with the high prevalence of hypertension. Cardiovascular deaths due to high blood pressure” have doubled in Iran over the past three decades. On the other hand, high blood pressure is one of the most important risk factors for chronic kidney disease. The importance of controlling high blood pressure in preventing cardiovascular deaths and myocardial infarction is of great importance and it can be acknowledged that if its prevalence in the country is controlled, we will see a 25% reduction in myocardial infarction and cardiovascular death. Accordingly, we believe that early prevention is essential to maintain optimal blood pressure levels even in adults free of traditional risk factors for cardiovascular diseases. ”
Senior Researcher of this study, described high blood pressure as a silent , asymptomatic disease which is dangerous and sometimes deadly, and said: ” Being over 55 years of age, genetic background, high salt intake, overeating, Insufficient physical activity ,overweight and obesity, high blood fats, alcohol consumption, unhealthy diet, area of residence , lifestyle and air polution are the most important risk factors for high blood pressure. ”
He emphasized : ”Reducing salt intake in the daily diet is one of the most effective measures to prevent an increase in the number of people with high blood pressure. This is while the average daily consumption of salt in Iran (11 grams) is twice the allowable limit (5 grams). ”
Distinguished Professor of Tehran University of Medical Sciences said: ”Everyone should measure their blood pressure from the age of 35. Blood pressure should be measured every month or at least every two to three months, and in the meantime, people with suspected high blood pressure should see a doctor as soon as possible and be treated. ”
Complete treatment of high blood pressure is as important as the onset and control of the disease
He pointed that complete cure of high blood pressure is as important as starting treatment and controlling it , emphasized : ” High quality blood pressure medications are produced and available in the Iran; In particular, combined blood pressure medications that contain two types of medications in different doses are also produced in the country and are covered by insurance, which, if used properly, can easily control blood pressure and prevent heart attacks and strokes.