The Effect of Age and Gender on Human Blood Pressure
Researched by Kendra C. 2001-02	PURPOSE  HYPOTHESIS  EXPERIMENT DESIGN  MATERIALS  PROCEDURES  RESULTS  CONCLUSION  RESEARCH REPORT  BIBLIOGRAPHY  ACKNOWLEDGMENTS  ABOUT THE RESEARCHER

The purpose of this experiment is to determine if people that are younger, middle aged, or older has the highest blood pressure, and which gender has the highest blood pressure. To determine which age group has the highest blood pressure, I will test people ages 12-13, around 32, and around 52. To determine which gender has the highest blood pressure, I will test girls and boys. 

I became interested in this idea when I did a research report in 5th grade on Diabetes. I found out that weight and obesity is a main factor in blood pressure, so I wanted to know if age and gender affected blood pressure too. 

The information gained from this experiment could help people that fit into the age group I am testing to know whether they are more likely to have high, low, or normal blood pressure.

My first hypothesis was that people ages 52-53 would have the highest blood pressure. I base this on an article called "Hypertension" that says over half of the people ages 65 and older have hypertension. This would most likely mean that the older you are, the higher your blood pressure will probably be. 

My second hypothesis was that females will have higher blood pressure than males. I based this on an article called "High Blood Pressure" that stated that older women usually have hypertension. 

The constants in this study were:
* The blood pressure monitor
* The amount of time it takes to take the blood pressure
* The number of subjects in each group
* The number of males and females in each age group

The manipulated variable was the age of the subjects or the gender of the subjects. 

The responding variable was the blood pressure.

To measure the responding variable I took two blood pressure measurements for each subject, and then average them. 

Quantity	Item Description
5	Girls ages 12-13
5	Boys ages 12-13
5	Women ages 29-35
5	Men ages 29-35
5	Women ages 49-55
5	Men ages 49-55
1	Chart to hold and collect data in
1	Pencil or pen
1	Blood Pressure Monitor
1	Desk
1	Chair

Set up Materials
1 Gather materials
2 Set up table with two chairs facing each other by a table 
3 Have blood pressure device and chart with a pencil or pen by a table
Conduct Experiment 
4 Call first subject that is age 12-13 into testing room
5 Have subject sit down at table and relax three minutes
6 Record subject’s age and gender, but no name
7 Take subject’s blood pressure 
8 Record subject’s blood pressure in their chart area
9 Thank subject and lead back to classroom
10 Repeat steps 4-9 with other subjects aged 12-13
11 Repeat steps 4-10 testing subjects aged 32-33
12 Repeat steps 4-10 testing subjects aged 52-53

The results of the experiment were that in the age groups of 12-13, boys had a higher blood pressure in both the systolic and diastolic readings. In the age group of around 32-33, women had a higher blood pressure in both the systolic and diastolic readings. 

For 12-13 year old boys, the total average blood pressure reading was 94.4 for the systolic  reading, and 58.5 for the diastolic reading. For 12-13 year old girls, the average systolic reading was 90.1, and the average diastolic reading was 51.9. For 32-33 year old men, the average systolic reading was 98.5, and the average diastolic reading was 61.7. For 32-33 year old women, the average systolic reading was 104.5 and the average diastolic reading was 62.7. For 52-53 year old men, the average systolic reading was 128.1, and the average diastolic reading was 72.9. For women ages 52-53, the average systolic reading was 124.4, and the average diastolic reading was 71.3. 

For 12-13 year old boys and girls, the total average systolic reading was 92.3, and the average diastolic reading was 55.2. For women and men in the 32-33 age group, the average systolic reading was 101.5, and the average diastolic reading was 64.5. For the age group of 52-53, the total average reading for men and women was 126.3 for systolic, and 72.1 for the diastolic. 

View My Data and Graphs

My first hypothesis was that people ages 52-53 would have the highest blood pressure. My second hypothesis was that girls would have higher blood pressure than boys will. 

The results indicate that my first hypothesis should be accepted, because people in the highest age group had a higher average blood pressure than the other two age groups. My second hypothesis overall should be rejected, because males did not always have the higher average blood pressure. However, it did appear that males had a higher blood pressure than females in the youngest and oldest age groups.

Because of the results of this experiment, I wonder if there would be a difference in the blood pressures of people under stress and people under normal conditions. I also wonder if athletic kids would have a higher or lower blood pressure than non athletic kids, and if athletic adults would have a higher or lower blood pressure than non athletic adults.

If I were to conduct this project again I would test a bigger subject group so that I would have a more accurate average blood pressure reading for each age group, and use a better blood pressure monitor. I would also do all of the subject trials on the same day so that there would be more of a constant in the surroundings, temperature, etc. 
 

RESEARCH REPORT INTRODUCTION Human health is very important to this world. Without it, our species could easily become extinct. Blood pressure has been proven to be a main factor in human health. If the blood pressure gets too high or too low, very serious diseases can develop in the body, sometimes bringing fatal happenings. But high and low blood pressure can be prevented, if you know if you are at risk.   BLOOD PRESSURE   Blood pressure is the force of the blood upon the arteries. The pressure maintained in the arteries is started in the heart. High and low blood pressure occur when the body is pumping blood at too fast of a rate, or too slow of a rate. High Blood Pressure is called Hypertension, and Low Blood Pressure is called Hypotension.  When your blood pressure is taken, there will be two readings- one on the top and one on the bottom. The reading on top is called the "systolic" blood pressure. The one on the bottom is called the diastolic blood pressure. Systolic blood pressure records the pressure during the contracting phase of the heart. Diastolic blood pressure records the pressure during the resting phase of the heart (the pressure between each heartbeat). For example, if your blood pressure reading was 120/56, the 120 would be the systolic reading, and the 56 would be the diastolic reading.   Blood pressure is determined by the amount of blood your heart pumps and the resistance to blood flow in the arteries (this is also known as peripheral vascular resistance).    Hypertension (High Blood Pressure) A normal adult's systolic blood pressure is under 130, and the diastolic blood pressure is under 85. Any higher than this is considered Hypertension, one of the highest causes of death in the United States. Over 50 million Americans have it, but about a third of them don’t know it. Plus, only 27% of the people with Hypertension are being treated adequately; whether they know they have it or not.  The reason why Hypertension is so serious is not Hypertension itself, but the risks that it causes. If you have Hypertension, the risk of stroke goes up with your blood pressure. Hypertension also increases the risk for heart failure, heart attack, congestive heart failure, kidney failure, and brain damage.  There are different types of Hypertension.  Isolated Systolic Hypertension is when your systolic blood pressure is too high, but your diastolic blood pressure is normal. Isolated Systolic Hypertension (ISH) is in over two thirds of elder people with Hypertension. Research has proved, however, that when it is treated prevents over 24,000 strokes and over 50,000 incidents of severe cardiovascular problems each year. It also saves $500,000,000 each year.  Most people with Hypertension have no symptoms. That is why it is so hard to tell if you have Hypertension or not- because unless you take your blood pressure often and know how high and low it should be, you don’t know that you are even at risk. If you do have symptoms, they are not drastic. These symptoms can include headaches, nosebleeds, and dizziness. Your blood pressure reacts to many things. If you have small arteries or if your arteries are clogged, your blood pressure reacts by going up, making your heart work harder (in this case pumping faster and harder) to get the blood to the rest of the body. Another thing that makes your blood pressure react is personal salt intake. Salt intake has a major impact on your blood pressure. More salt in your body means that more water is being retained in your circulation, so it will probably cause your blood pressure to go up. Also, as your salt intake becomes greater, your arteries get more clogged up, and your blood vessels become more narrow.  The reason that you get Hypertension isn’t always identifiable. Only about 1 out of 20 times will the cause be identified. When the cause can be identified, it is called Secondary Hypertension because the Hypertension is caused from something else, so it is the second disease. The causes that usually cause Secondary Hypertension are renal failure, Glomerulonephritis, kidney disorders, and adrenal gland problems.    Hypotension (Low Blood Pressure) Hypotension is when the systolic blood pressure is too far below 130, and the diastolic blood pressure is too far below 85. Hypotension is not very common, but can still be very harmful.  If Hypotension gets too far out of hand, it can cause a shock. This shock can last for a very short time, or it can be fatal.  You can get Hypotension by losing too much blood or bodily fluids. Sometimes you can also get Hypotension from other diseases, but that is very uncommon.  Chronic Low Blood Pressure is when you have a mild form of Hypotension. It is not hazardous to your health. This is not uncommon as it can result from medications given for Hypertension, pregnancy, or Arteriosclerosis.    THE HUMAN HEART "From the moment it begins beating until the moment it stops, the human heart works tirelessly. In an average lifetime, the heart beats more than two and a half billion times, without ever pausing to rest. Like a pumping machine, the heart provides the power needed for life."   The Structure of the Human Heart The heart is placed between the lungs, and is a little lager than your personal fist (your heart is a little larger than your fist). The heart has two linings, the first of a membrane called epicardium, and the second of pericardium.  The heart is divided into four chambers, and two sides. A  "wall" called the septum divides the left and right side of the heart. Valves divide the two sides into four chambers that are placed one on top of another (there are two total sides, and four total chambers. There are two chambers to a side, therefore making it so that there is a top right and left chamber called the right and left atrium, and a bottom right and left chamber called right and left ventricles).    How the Human Heart Works Veins take the red blood (blood without oxygen) through the right side of the heart, so that it can be sent to the lungs to get oxygen. This blood is now delivered to the left side of the heart, where it can be pumped through the arteries to the rest of the body. The left and right sides of the heart are designed to pump in a rhythmical pattern.  When you exercise, the pace of this pattern goes up in such a way to keep the oxygen flowing steadily. Obviously, the more you exercise, the more oxygen you use, so the faster your heart is pumping blood.  Each time that the heart contracts, a flap on each valve directs the blood in the right direction, then shuts quickly to prevent blood from flowing in the wrong direction.   Diseases Related to the Human Heart  Diseases related to the heart are the leading cause of death in the United States. Knowing what these diseases are, how they are caused, and how the can be prevented, has proven to be a very successful prevention in itself. The diseases below are only some of the horrible death causing diseases related to the human heart. Heart Disease-Heart Disease is a very serious condition. Risks of getting it can be Hypertension, smoking, and High Blood Cholesterol. Heart Disease results from the conditions that cause pain and swelling in the heart. One of these conditions is called Pericarditis, which is when the pericardium (the first protective membrane surrounding the heart) swells to an extremely painful size. When Pericarditis happens, the pericardium may swell up to a size so big that it begins to compress the heart to a point where it cannot pump enough blood to the body. This condition may cause death unless a doctor can operate and drain the pericardium back to its’ normal size.  Heart Attack-Heart Attack is a condition in which a blood clot suddenly and completely blocks a coronary artery. Unless blood flow returns within minutes, heart cells begin to die, and muscle damage occurs, then increases. This damage may affect the heart’s ability to pump blood, and may result in death. There are usually no symptoms before a person has a heart attack, but if there is they may include dizziness, indigestion, and severe pain. When the attack actually occurs, there may be chest pain and/or neck, jaw, and arm, and back pain. This pain can last for minutes or for hours.   Arrhythmia- Arrhythmia is a disease in which the heart is beating in an abnormal rhythm. This can mean either the heart is beating slower than usual, or faster than usual. If the heart is beating below 60 beats per minute it is called Bradycardia, and when the heart is beating above 100 beats per minute, it is called Tachycardia. Bradycardia may occur from a separate disease or medicine. Tachycardia may occur if the atria or ventricles send signals for the heart to beat too rapidly. If the heart beats too rapidly, death may occur.   Heart Failure-Heart Failure is a disorder in which the heart isn’t pumping enough blood. When it starts, the body will automatically narrow the arteries that lead to the arms, legs, and other less important organs and body parts so that more blood will be pumped to the brain and the other vital organs. Drugs and operations are the only known cures for heart attack, except for a heart transplant.    History and Technology of Heart Research The heart has always been known to be an important organ, although those before us didn’t know just how important it is.  The Ancient Greeks were the first to find out that the heart was a beating organ. They found this out by observing and treating battlefield injuries and through animal sacrifices.  The Ancient Egyptians believed that the heart was the center of all emotions and thoughts. This is still believed in some places, but it is not a very common belief.   OBESITY Obesity is a main factor in blood pressure. If you have too much body fat, your blood pressure can skyrocket. There is several ways to determine if you have too much body fat. Many scales now have the body fat measurement programmed into them, so when you enter your height and gender, it weighs you, then tell you if you have too much body fat.  Also, doctors can tell how much body fat you have by knowing your age, gender, and weight. No matter how you have your body fat measurement taken, the measurement is always based on your height, gender, and weight. The basic terms used to verify which how healthy your body is are underweight, healthy, overweight, and obese. According to a study made by the National Heart, lung, and Blood Institute, between 1960 and 1994, 55% of the population was overweight or obese.

BIBLIOGRAPHY  "Blood Pressure." November 30, 2001 <http://www.infoplease.com/ce6/sci/A087944.html Crawford, Michael H. "Heart" 1/17/02 <http://aolsvc.worldbook.aol.com/wbol/wbPage/na/ar/co/249920 Cooper, Kenneth H., M.D. Overcoming Hypertension. New York: Bantam Books, 1990. pp. 769-770 Frazier, O.H., M.S. "Human Heart." The World Book Encyclopedia. 1998.  "Healthy Heart I.Q. Questions and Answers." December 5, 2001 <http://www.infoplease.com/ina/A0762301.html "Healthy Weight, Overweight, and Obesity in the United States" 1/1/02 <http://aolsvc.aol.infoplease.com/ipa/A0883555.html "High Blood Pressure." Mayo Clinic Family Health Book. 1996. pp. 647-653. "Hypertension." November 9, 2001 <http://www.highbp.com/ "Interesting Facts About the Heart" 1/17/02 <http://aolsvc.wordlbook.aol.com/wbol/wbAuth/na/ta/co/ta24920 "Measuring Body Mass" 1/1/02 >http://aolsvc.infoplease.com/ipa/A0762241.html Pierce, William S., M.D. "Artificial Heart," 1/17/02 <http://aolsvc.worldbook.aol.com/wbol/wbPage/na/ar/co/032430 Simone, Joseph V. "Artery" <http://aolsvc.worldbook.aol.com/wbol/wbPage/na/ar/co/032140

ACKNOWLEDGEMENTS

I would like to thank the following people for their help in my project:
 

• Mrs. Ranger, my science teacher, for allowing students to come out of the classroom to be subjects in my project. 
• My parents, for driving me around to find subjects, and for helping me through my project. 
• Mrs. Helms, the teachers assistant, for helping me cut the pages for my display board.
• Mr. Newkirk, the science teacher, for walking me through the steps of a great project. 

Menu of 2001-2002 Science Projects

Back to the Selah Home page