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A STUDY OF STUDENTS ACQUAINTANCE WITH OBESITY AS A RISK FACTOR FOR HYPERTENSION
1PhD Kristina Zaharieva 2MD, PhD Teodora Nedeva 3MD, PhD Ognyan Sherbanov
1 Chief Assistant, Biologist, Ruse University "Angel Kanchev", Faculty of Public Health and Health Care, Department of "Health Care" 2Associate Professor, Ruse University "Angel Kanchev", Faculty of Public Health and Health Care, Department of "Health Care" 3Cardiologist, Multiprofile Hospital of Active Treatment "Medika",
Department of Cardiology
Abstract: Obesity and hypertension as important public health challenges are increasing worldwide. The number of people with hypertension is growing up every year. The growing prevalence of obesity is increasingly recognized as one of the most important risk factors for the development of hypertension. Preventing and managing obesity-related hypertension requires multiple, parallel efforts with involvement of government, industry, health professionals and individual self-care. In the article below we present a study conducted among 140 students at the age of 21 to 26 who have hypertension and obesity. The analyses of our inquiry is similar with the results of other investigators of obesity- related hypertension. Our team confirms the already well known fact that high blood pressure and overweight are very closely connected clinical conditions and patients often underestimate their impact on health. These diseases have many risk factors most of which are preventable if one is well informed and cares about his health. Out students do not have the necessary knowledge about the etiology of obesity and hypertension, neither about the risks and therapeutic strategies. Many of the interviewed confess that they need additional information and further education about prevention and different treatment techniques of this disease. As a teaching staff we have the competence and responsibility to provide them the necessary current data of these problems.
Key words: body mass index, education, hypertension, obesity, risk factors, students
I. Introduction
Obesity is a medical condition in which excess body fat accumulates to the extent that it may have an adverse effect on health. It is defined by body mass index (BMI). BMI is closely related to both total body fat and percentage body fat. For the first time it was described in 1896 by Ouetelet. In children and adolescents obesity is defined not as an absolute number but in relation to a historical normal group, such that obesity is a BMI greater than the 95th percentile. BMI is a simple calculation-subject's weight is divided by the square of their height. It is calculated as follows: BMI= m/h2, where m is subject's weight, usually expressed in kilograms and h is person's height, in meters.
World Health Organization (WHO), in 1997 established the most commonly used definitions. Published in 2000, they provide the values, shown in table 1.
Table 1. WHO definition of BMI
BMI (KG/M2) CLASSIFICATION
From Up to
18.5 Underweight
18.5 25.0 Normal weight
25.0 30.0 Overweight
30.0 35.0 Class I obesity
35.0 40.0 Class II obesity
40.0 Class III obesity
Some modifications are made by different authors and Class III obesity is divided in two categories: 1. Any BMI > 35 or 40 kg/m2 is severe obesity
2. A BMI > 35 kg/m2 and experiencing obesity- related health conditions or > 40- 44,9 kg/m2 is morbid
obesity
3. A BMI > 45 or 50 kg/m2 is super obesity
Obesity is one of the major epidemiological problems in most of the countries and also one of the main risk factors for hypertension. The relevance of both obesity and hypertension, as important public health challenges, is increasing worldwide [6]. Many cases of high arterial blood pressure are related to an increase in patient's body mass [10]. Obesity is set as the main preventable cause of illness and premature death. This topic is a subject of several recent investigations. In current cardiology literature, many facets of the obesity/hypertension nexus are discussed. The most widely emphasized are:
1. Potential mechanisms by which overweight can lead to elevated arterial pressure
2. Interaction of obesity with the sequel of hypertension
3. Therapeutic regimens that are believed to optimally treat this particular kind of high blood pressure.
All these issues are still a subject of ongoing research and debates. Authors cannot give definite answers to many of the related questions [6,10].
Researchers, from University of Sheffield UK and Harvard School of Public Health USA, have identified six distinct clusters of obese individuals, defined as:
1. Heavy-drinking males
2. Younger healthy females
3. Physically sick but happy elderly
4. Affluent healthy elderly
5. Unhappy anxious middle-aged
6. Poorest health (published in peer- reviewed Journal of Public Health, on April 20, 2015)
Hypertension is defined as blood pressure higher than 140 over 90 mm Hg (millimeters of mercury). A diagnosis of hypertension may be made when one or both- systolic or diastolic pressure are high. There are two types of high blood pressure: 1. Primary (essential) hypertension- there is no identifiable cause of high blood pressure, it tends to develop gradually over many years 2. Secondary hypertension- there are underlying conditions for high blood pressure. Appears suddenly and causes higher blood pressure than does the primary hypertension. Various medications and conditions lead to it: obstructive sleep apnea, kidney diseases, adrenal gland tumors, thyroid problems congenital blood vessels defects, medications such as birth control pills, cold remedies, decongestants, over-the- counter pain relievers, illegal drugs- amphetamines and cocaine, chronic alcohol use or alcohol abuse. Uncontrolled high blood pressure may lead to: stroke and heart attacks, heart failure, aneurysm, narrowed and weakened kidney or eye vessels, metabolic syndrome, problems with understanding and memory [1].
According to 2013 ESH/ESC Guidelines for the management of arterial hypertension, table 2, the hypertension is defined and classified as follow [3]:
Table 2: Definition and classification of office blood pressure levels (mm Hg) [3]
Category Systolic Diastolic
Optimal <120 And <80
Normal 120-129 And/or 80-84
High normal 130-139 And/or 85-89
Grade 1 hypertension 140-159 And/or 90-99
Grade 2 hypertension 160-169 And/or 100-109
Grade 3 hypertension >180 And/or >110
Isolated systolic hypertension >140 and <90
High blood pressure has many risk factors including: age (risk increases with aging. To age 45, high blood pressure is more common in men, and women are more likely to develop hypertension after age 65); race (high arterial pressure is particularly common among blacks and develops at an earlier age than it does in whites. Serious cardiac complications also are more common in this population); family history (tends to run in families); being overweight or obese (the need of oxygen and nutrients supply is higher, also the blood volume and the pressure on artery walls is grater); not being physically active (lack of physical activity increases the risk of overweight, the heart rate is
higher, the heart works harder with each contraction and the force in the arteries is stronger); smoking (smoking itself or chewing tobacco raises blood pressure and damage artery walls); much salt in the diet (eating too much sodium causes fluid retention and rise of arterial pressure); little intake of potassium and vitamin D (potassium helps balance the amount of sodium in the cells; vitamin D affects enzyme production in kidneys and this increases the blood pressure); too much alcohol drinking (heavy drinking damages heart); stress and anxiety (high levels of stress lead to temporary increase in arterial pressure); certain chronic conditions ( kidney disease, diabetes, sleep apnea increase the risk of hypertension); pregnancy. Hypertension is more common in adults, but children may be at risk too. For some children, high blood pressure is caused by kidney or heart problems, but for a growing number of kids, poor lifestyle habits, unhealthy diet, lack of exercises and obesity, contribute to high blood pressure [11].
It is well- known that hypertension is associated with sequelae including atherosclerosis, renal insufficiency, cerebrovascular disease, coronary artery disease, left ventricular hypertrophy- powerful risk factor for cardiovascular death (Framingham Heart Study), atrial fibrillation, congestive heart failure. Obesity- related hypertension predisposes to these conditions as well, but there is a difference in the sequelae observed in obese vs lean individuals with hypertension. Recently, a phenomenon called "obesity paradox" was described - obese individuals are more likely to develop cardiovascular structural abnormalities but they have better survival than lean individuals with hypertension [4,8,14].
Obesity- associated arterial hypertension is a multifactorial disorder, including genetic and environmental factors. It is not possible to identify one single mechanism as a dominant aetiological factor. Hypertension in obese people is characterized by: activation of the renin- angiotensin and sympathetic nervous systems; sodium retention; hyperinsulinemia; structural changes in kidneys, glomerular hyperfiltration, increased urinary albumin loss; elaboration of adipokines (leptin- a hormone produced in the fat), promoting insulin and leptin resistence; endocannabinoid system; increased procoagulatory activity; endothelial dysfunction and other abnormalities. Guyton hypothesis is that sustained hypertension can occur only when there is an abnormal relationship between natriuresis and arterial pressure [7]. All hypertension results from disease in the kidney. Various factors can alter the pressure- natriuresis relationship in normal kidneys- for example aldosterone increases renal tubular sodium reabsorption and the production of hypertension even in people who have normal renal function. The question is how does obesity affect the pressure- natriuresis relationship? High body mass is associated with increased blood flow, hypertension, vasodilatation, cardiac output, glomerular filtration rate and renal sodium retention [2,5,12,13]. Lifestyle in the prevention and management of obesity and hypertension is of great importance. Adoption of healthy lifestyle facilitates weight loss, increases responsiveness to antihypertensive medications and produces independent benefits on cardiac risk factors. Reccommended are: loss of weight; dietary approaches to stop hypertension diet; salt restriction; increased physical activity and exercises; alcohol moderation and behavioral modification [9].
II. Research
Aim of study: High blood pressure and overweight are very significant socio- medical problems nowadays. Both conditions are closely connected and associated with many co- morbidities. The situation in our country Bulgaria, is extremely serious. Statistical data shows that 63% of men and 46% of women in active age, suffer from overweight and respectively 17% and 19% of them are obese.(/:http://www.bb-team.org/articles/3477_zatlastyavane-epidemiyata-na-hhi-vek#ixzz49 ViEPTT3/) This is a good enough reason, although these clinical conditions are widely discussed in current literature, to conduct a study concerning the problems. Taking these notes into consideration, the aims of our investigation were:
- To establish the students acquaintance with obesity as a risk factor for hypertension
- When finding deficit in students awareness of the importance of obesity for the development of hypertension, to propose some alternatives to overcome the disease
Subject of research. Students from Ruse University "Angel Kanchev", at the age of 21 to 26 years.
Research tools: Inquiry- questionary about the relationship between obesity and hypertension and interview
Materials and methods: The research was conducted during the period October 2015 - March 2016. Investigated were 140 students who had hypertension and different types of obesity. The survey was discussed and the results interpreted with the assistance of medical specialists- cardiologist and GP.
All answers of the questions from the research are analyzed and the results are illustrated through tables and figures as follows:
In table 3, the results from the answers of the first two questions:
1. "From what period of time are you overweight?"
2. "What types ofproblems may obesity cause?" are presented:
Table 3: Answers of the first two questions from the inquiry
l.From what period of time are you overweight? For more than 10 years -42% of students From 7 to 8 years -31% of students From 5 years -16% of students from 3 years -11% of students
2. What types of problems may obesity cause? Only aesthetic problems -46% of students Problems with health -27% of students Problems with health and aesthetic -14% of students It does not cause any problems at all -13% of students
The answer results show that some of our students are overweight or obese from childhood and adolescence. That was the period when their parents and they themselves should had controlled their weight and BMI respectively, the food intake, the type of daily diet and exercise activities. It is well known fact that all these factors are modifiable. Although the age of 21 to 26 is not an old age, the risk factors such as overweight, eating drinking habits, smoking and physical activity are already difficult to be changed or at least desire great efforts, especially when someone have already existing disease like hypertension and obesity. Unfortunately for a serious part- 46% of our students, obesity is only an aesthetic problem and only 27% of interviewed students really realize that overweight can cause very serious health problems, diseases and co- morbidities.
On figure 1, we present the answers of the third question: 3. "Did you have any information that obesity is a very significant factor for developing hypertension?
Fig. 1 Percentage and type of the answers of questions 3
As it is obvious from the diagram, 53% of the students were well informed that overweight and hypertension are closely connected conditions and that obesity has a very important risky role for high blood pressure. 28% of them do not have the necessary information concerning the relationship among overweight and high blood pressure, and 19% have never heard about these conditions and the possibility they to be connected somehow. Our opinion is that we received such a result, because some of the participants in the inquiry are not medical students but from other faculties of our university.
On figure 2 we illustrate the results from the next question: 4. "When your high blood pressure was first established, what was your weight- normal or overweight?"
Fig. 2 Relationship among weight and debut of hypertension
The results we received correlate with the data published from other researchers- 77% of the observed are overweight and only 23% have normal body mass index. The predisposition and connection between overweight/obesity and high blood pressure/hypertension is obvious and undoubted.
The results from the answers of the following questions: 5. "Did you adjust your overweight after your disease - hypertension was diagnosed?", 6. "Did the adjustment of your weight influence the values of your blood pressure?" are presented on fig. 3:
Fig. 3 The impact of weight adjustment on the values of blood pressure and grade of hypertension
The diagram shows that in 29% of the respondents the weight was normalized, in 37%-corrected and 34% of the students did not make any efforts and remained overweight. Returning body weight to normal in 71% of the students led to minimization of the elevated levels of blood pressure but in the other 29% weight reduction had no influence on high blood pressure. Those students shared the fact that they treat obesity and hypertension with combined pharmacological and non-pharmacological therapy (they had prescribed some medications and at the same time most of them made efforts on changing life habits- performed different diets, increased daily physical activities, etc.)
On fig. 4, we show the results from the answers on question: 7. "Do you need any additional information about the relationship between overweight and hypertension?"
Fig. 4 Students need of some additional knowledge about hypertension and obesity
Unfortunately many of the students- 72%, need additional information or further education about the relationship among obesity and hypertension and its impact on their health and the possible co- existing problems. Alarming fact is that 19% of young people cannot assess the great seriousness of the fact to have overweight and high blood pressure and lack of knowledge about the connection among both clinical conditions and the possibility of developing other co- morbidities and complications also. Only 9% of the investigated do not need any additional information about obesity as an important health problem.
Conclusions:
1. Based on the answers received and their analysis, we can conclude that our results are similar with the inference of the other investigators - the values of high arterial blood pressure are affected by the body weight and by the degree of obesity. Obesity is the leading etiological factor in the pathogenesis of many diseases that affect the active population and lead to disability and inability to work.
2. Our students are not well informed about the connection of both medical conditions and need additional scientific information concerning this problem. As a teaching staff we have to make efforts to implement the necessary knowledge. It is well known fact that some risk factors, like age,
race, gender, are not modifiable at all, but others, such as overweight, obesity, low physical activity, smoking, drinking and stress can be changed after some personal efforts and self care. Students must be well informed and motivated to make the necessary changes. We can offer help, give information and knowledge in the university consulting office "Health Education" and in the eligible subjects in the students programme- "School Health",and "Health Education" as well.
3. A visit to the medical specialist- either general practitioner, cardiologist or endocrinologist is useful especially when a general check- up and initial pharmacological therapy are indicated.
4. Obesity and hypertension are among of the major epidemiological problems in most of the countries and also the main risk factors for conditions leading to disability or sudden death. Fortunately hypertension and obesity are preventable with pharmacological and non- pharmacological strategies.
REFERENCES
1. About high blood pressure, Dallas, TX: American Heart Association, information published online, accessed 22 June 2015.
2. Engeli S. Dysregulation of the endocannabinoid system in obesity. J Neuroendocrinol. 2008;20(suppl 1):110-115.
3. 2013 ESH/ESC Guidelines for the management of arterial hypertension
4. Frohlich E. D. Clinical management of the obese hypertensive patient. Cardiol Rev. 2002;10(3):127-138.
5. Grassi G., Quarti-Trevano F., Seravalle G., Arenare F., Brambilla G., Mancia G. Blood pressure lowering effects of rimonabant in obesity-related hypertension. J Neuroendocrinol. 2008;20(suppl 1):63-68
6. Krzystof Narkiewicz, obesity and hypertension- the issue is more complex than we thought, Oxford Journals, Medicine and Health, nephrology Dialysis Transplantation, Vol. 21, Issue 2, Pp.264-267
7. Laragh J. H. Presentation of the Harvey Award to Arthur C. Guyton. Am J Hypertens. 1989;2(7):573-574
8. Lavie C. J., Milani R. V., Ventura H. O., Cardenas G. A., Mehra M. R., Messerli F. H. Disparate effects of left ventricular geometry and obesity on mortality in patients with preserved left ventricular ejection fraction. Am J Cardiol. 2007;100(9):1460-1464
9. Lewis Landsberg, Louis J. aronne, Lawrence J. Beilin, Valerie Burke, Leon I. Igel et all., Obesity- Related Hypertension: Pathogenesis, Cardiovascular Risk, and Treatment, The Journal of Clinical Hypertension, Vol. 15, Issue 1, pages 14-33, January 2013
10. Maniecka Bryla, Szymocha M., Bryla M., Overweight and obesity as risk factors in hypertension - study of the working population, Mad Lav., 2011 Nov- Dec;102(6):523-38
11. Mayo Clinic Staff, Diseases and Conditions, High Blood Pressure, November 2015. www. mayoclinic. org
12. Richard N. Re., Obesity- Related Hypertension, Ochsner J. 2009 Fall: 9(3): 133-136
13. Sarzani R. Endocannabinoids, blood pressure and the human heart. J Neuroendocrinol. 2008;20(suppl 1):58-62
14. Wofford M. R., Hall J. E. Pathophysiology and treatment of obesity hypertension. Curr Pharm Des. 2004;10(29):3621-3637
