Arterial hypertension (AH) is a medical condition in which blood pressure (BP) is elevated above 139/89 mmHg. The upper value represents systolic pressure, i.e. pressure on the walls of blood vessels occurring due to systole (contraction) of the left ventricle (1). Persons with AH experience accelerated development of atherosclerosis and changes in blood vessels and other organs in the body. Therefore, BP >140/90 mmHg must be treated to avoid the development of atherosclerosis and consequent damage to target organs (2).
Epidemiology and the development of arterial hypertension
Epidemiological studies have demonstrated an important and independent association between high BP and various diseases, especially coronary heart disease, cerebrovascular stroke, congestive heart failure, and altered renal function. Many studies conducted on members of both sexes in different populations have found that there is a strong association between BP and cardiovascular (CV) diseases. Risk progressively increases with increased BP. The overall incidence of AH is between 1% and 2% in the second and third decade of life and 4% to 8% in the sixth and seventh decade of life. The prevalence of AH in persons above the age of 35 is 27.8% in the USA and 44.2% in Europe (49% in Finland 47% in Spain, 38% in Sweden, and 38% in Italy). The prevalence of AH in Croatia is 39% in men and 37% in women. The incidence of AH in Bosnia and Herzegovina is above 30%, which is approximately 200,000 persons with hypertension according to statistical estimates (3).
Clogged arteries provide reduced blood supply to tissues and organs, damaging them and deteriorating their function over time. Due to tissue and organ ischemia, the minute volume of the heart increases in order to secure sufficient oxygen supply, further increasing BP (4). The atherosclerotic plaque that has formed in blood vessel walls breaks apart due to insufficient elasticity, causing the formation of a thrombus that closes the blood vessel (5). BP often increases gradually, and the patient may not notice any symptoms until one of the complications of AH arises, such as myocardial infarction and stroke (6).
Cardiovascular risk factors
There are many risk factors that have been shown to contribute to the development of AH, such as stress, genetics, smoking, and alcohol, but it is clear that overweight has a leading role in the development of AH in most study participants. Obesity, a sedentary lifestyle, stress, excessive consumption of alcohol, or excessive consumption of salty and fatty food can play a significant role in the development of AH (7). These causes can also be classified as modifiable causes of AH, since they can be influenced. Changing any of these habits listed above can avoid AH development if there is no hereditary, non-modifiable cause. Some studies have shown that stress can lead to occasional BP increases. Namely, stress activates biochemical mechanisms in the body that lead to vasoconstriction of blood vessels due to the secretion of certain hormones, thus partially explaining the mechanism of AH development. Many studies have demonstrated an association between AH and risk factors that have a large influence on the development and progression of AH (8,9).
The goals of this study were: a) determine the deviation in BP values in newly-diagnosed, untreated, and inadequately treated patients with hypertension in comparison with normal values; b) emphasize the importance of screening for AH in emergency medicine in order to facilitate identification of newly-diagnosed cases and treating a larger number of patients.
Patients and Methods
The study was conducted at the Emergency Medical Clinic of the JZU Health Center Živinice between January 1 and April 30, 2022, and examined the prevalence of patients presenting with AH as well as cardiovascular risk factors important to the development of AH. Four groups were formed as a consecutive sample of a total of 160 participants of both sexes, older than 18 years of age.
The first group comprised 40 participants who were admitted to the Emergency Medicine Service (EMS) due to AH. The second group comprised 40 participants with hypertension who were receiving no treatment. The third group comprised 40 participants in whom incidental measurements determined high BP values. The fourth group were the controls, comprising 40 participants who presented at the clinic due to issues possibly related to high BP, but whose BP was within reference ranges during their examination at the EMS (normotensive participants).
All data were analyzed using descriptive statistical methods, with numerical data presented as measures of mean tendency and variance and clearly shown in the appropriate tables and figures. Statistical significance was calculated using non-parametric methods and tests: the χ2 test was used to calculate differences within groups, and the Kruskal-Wallis test was used to calculate differences between groups along with the χ2 test, and additional testing was performed with the Mann-Whitney U test if there was a statistically significant difference between the groups. For parametric data, difference between groups were calculated using single factor analysis of variance (ANOVA), with subsequent calculation with Tukey’s HD test if there were differences between groups, and the Student t test was used for dependent samples. Statistical hypotheses were tested at the α=0.05 level, i.e. the difference between groups was considered significant if p<0.05. Statistical analysis was performed with the support of biomedical application software under the name “MedCalc for Windows version 12.4.0”, Copyright © 1993-2013, and mostly using the a “SPSS Statistics 17.0”, Copyright © 1993-2007 software.
Results
The study included a total of 160 participants, of whom there were 59 men (36.9%) and 101 women (63.1%). This difference in the prevalence of male and female participants was also statistically significant (χ2=11.025; df=1; p=0.001).
Calculating the differences between groups found a statistically significant difference between the observed groups, with the highest range and the highest median in the group of untreated patients, indicating that the differences were the largest in this group (χ2=13.11; df=3; p=0.004) (Figure 1).
However, the Kruskal-Wallis for other analyzed patient groups also found a statistically significant difference between groups (χ2=30.446; df=2; p<0.001). The group of inadequately treated participants had the highest median range and highest median, indicating that this difference was mostly caused by BP values in this group (Table 1).
Median values of systolic and diastolic pressure at admission in the study groups, as well as their highest and lowest values, are shown inTable 2. Correlation testing between body mass index (BMI) and systolic pressure values found that there was a unidirectional correlation (Pearson’s r=0.136; p=0.043
There was no correlation (Figure 2) between BMI values and participant age (Pearson’s r=-0.98; p=0.1).
Discussion
According to the results of the present study, average participant age was 49.7 years. The study had more women with AH (63.1%) and statistically significantly less men (36.9%). In the present study study, the ratio of women and men with regard to AH incidence was not in agreement with a study conducted in France and Geneva, but is in agreement to a study conducted in India, where men are more likely to have AH (10). The study conducted in France reported that AH was more common in ages between 55 and 74. Incidence in men (47%) was somewhat higher than in women (37%). AH is the most common cardiovascular disorder in European high-income countries, where AH is observed in 20% to 50% of the adult population (11).
Oras et al. emphasized that BP is measured in almost all patients presenting to emergency medical care, regardless of the issue that the patient was admitted for, and that up to one third of these patients have elevated BP values (140/90 mmHg or more). However, it has been established that trips to the emergency room are common in stressful situations, which represent conditions in which elevated BP is often registered. Consequently, the authors determined that incidence of CV diseases is increased in these conditions, especially for myocardial infarction. They concluded that stress was one of the main risk factors for development of AH and further development of CV diseases (12).
A study conducted by Shao et al. estimated risk factors in patients with AH. The most important risk factors were smoking and insufficient levels of physical activity. The clinical picture of AH was dominated by headaches and nausea, with changes in mental status in more than half the patients. Generalized weakness was present in 80% of AH cases. Such risk factors were associated with poorer socioeconomic conditions and high levels of illiteracy in the population (13).
Arterial hypertension, together with smoking and high lipid levels, is the main cause of myocardial infarction and stroke. A study conducted in England showed that incidence of AH was approximately 37%. Smoking, male sex, hypercholesterolemia, and age were closely associated with AH. It was established that half of the participants knew they had AH but did not use antihypertensive therapy (14).
Stress and smoking were leading risk factors in all observed groups of participants with AH and were present (individually or in combination) in 37.4% participants. A significant association between risk factors and AP was observed in newly-diagnosed patients with hypertension. None of the studied risk factors were present in the (normotensive) control group of 18 (45.0%) participants.
This study showed that average BMI in the group of newly-diagnosed patients with hypertension was 28.3, 27.1 in the group of inadequately treated patients, and 28.1 in untreated patients, for a mean BMI of 27.0 in the study groups. A significant difference was observed in BMI values between the study groups and normotensive participants. BMI values in the study groups were somewhat higher in comparison with the control group of normotensive participants, who had a BMI of 24.4, which is in agreement with the study conducted by Wang in the USA (15).
In the present study, positive family history (hereditary predisposition to AH) was present in more than half of newly-diagnosed, inadequately treated, and untreated patients with hypertension. At the same time, only 7% of the control group (normotensive) participants had a positive family history. Muiesan et al. conducted a study with by far the largest number of participants, almost 702 million, and their study included 15 large studies in the USA, Canada, Australia, Israel, Sweden, Iran, and the Congo. It was established that positive family history for AH was present in 7% of patients with AH, which is similar to the results of this study (16).
In Great Britain, a study conducted by Reynard et al. comprising 45.2% men and 48.2% women found high levels of cholesterol in the blood. A third of the participants were using hypolipidemic. Studies have shown that more than two thirds of 4 million adults had high levels of cholesterol and AH (17).
In this study, measured BP values (before treatment) in the group of newly-diagnosed and untreated patients with hypertension were within ranges for moderate AH (160-179 / 100-109 mmHg), while BP values were higher in the group of inadequately treated patients with hypertension (≥180 / 110 mmHg). Highest median systolic and diastolic pressure values were observed in the group of inadequately treated patients with hypertension (193.88 / 107 mmHg). This agrees with a study conducted in Great Britain, were BP values in inadequately treated patients with hypertension were 175 / 107 mmHg on average (18).
Conclusion
Analysis of four groups of participants was used to examine the prevalence of AH in emergency medical care as well as risk factors for developing AH. The following conclusions were reached: a) patient age indicated that AH most commonly develops between 40 and 60 years of age; b) 47.8% patients with hypertension have a positive family history (hereditary predisposition for development of hypertension); c) the most common risk factors that affect the development and progression of AH are smoking and stress.