Hypertension and diabetes make an unwelcome pair for any of us. We all know the importance of controlling high blood pressure and what will happen if we don’t, but to our surprise many people know little about this condition which may have no symptoms until it becomes severe. We at www.diabetic-lifestyle.com want you to be the expert about diabetes so that you live as long and as healthy a life as possible and so we are sharing with you, thanks to the American Heart Association, facts about high blood pressure.
Let’s start with some statistics about hypertension and then go on to explain the actual mechanism of the condition. In 1994, hypertension was listed as a contributing factor in 180,000 deaths in the US with stroke, heart attack and heart failure, and as the cause of death in 38,130 Americans. About 50 million Americans age 6 and older have hypertension, a statistic which means that one in four of all of us have high blood pressure. From 1984 to 1994 the death rate from high blood pressure declined 3.9 percent, but the actual number of deaths rose 21.7 percent. Men are at greater risk for developing hypertension than women until age 55. After that age the risk become equal, and after age 74 women have a higher risk. Blacks and whites in the Southeastern United States have a greater prevalence of hypertension and high death rate from stroke than those in other regions of the country As many as 30 percent of all deaths in hypertensive black men and 20 percent of all deaths in hypertensive black women may be attributable to high blood pressure. Compared to whites, blacks develop high blood pressure at an earlier age, and it is more severe at any decade of life. As a result blacks have a 1.3 times greater rate of non-fatal stroke, a 1.8 times greater rate fatal stroke, a 1.5 times greater rate of heart disease deaths, and a 5 times greater rate of end-stage renal disease when compared to whites as a result of high blood pressure.
For people age 60 and older, hypertension is present in about 60% of non-Hispanic whites, 71% of non-Hispanic blacks, and 61% of Mexican Americans. Surveys conducted in 1991-1992 showed that an estimated 2.2 million Americans age 15 and older had disabilities resulting from hypertension. All of this is the bad news. The good news is that hypertension is easy to diagnose and controllable so don’t stop reading yet.
What is blood pressure? It is a result of two forces: one created by the heart as it pumps blood into the arteries, the other created by the arterial blood vessels as they exert resistance to the blood flow from the heart. When the heart pumps, it causes the blood to flow through the large arteries into the smaller arteries, the arterioles. The walls of the arterioles can contract or expand, altering the resistance to blood flow and, thus the blood pressure. Contraction of the arterioles increases the resistance to blood flow and therefore reduces blood flow through arterioles while increasing blood pressure. Expansion of the arteries has the opposite effect on resistance, blood flow and pressure. Regulation of the inner diameter of the arterioles plays an important role in regulating blood flow and determining blood pressure. If the arterioles remain constricted, they can cause hypertension or high blood pressure.
We’ve all had our blood pressure measured with an instrument called a sphygmomanometer and a cuff which when inflated compresses a large artery in the arm, stopping the flow of blood. Next, the cuff is released, and the professional measuring your blood pressure listens with a stethoscope. When the blood starts to pulse through the artery, it makes a sound; this sound continues until pressure in the artery exceeds the pressure in the cuff. While the person listens, he or she records two measurements. The systolic pressure is the pressure of the blood flow when the heart beats ( the pressure just after the first sound is heard). The diastolic pressure is the pressure between heartbeats ( the pressure just after the last sound is heard). Blood pressure is measured in millimeters of mercury, which is abbreviated mm Hg. A typical reading might be 127/78 mm Hg for an adult, but this will vary due to age and other factors. The first number is the systolic pressure; the second is the diastolic pressure. The important thing to remember is the harder it is for the blood to flow, the higher the numbers will be. For most adults hypertension is diagnosed when the systolic reading greater than 140 mm Hg and/or the diastolic pressure is equal or greater then 90 mm Hg for extended periods of time.
High blood pressure means that the heart is working harder than normal, placing both the heart and the arteries under a great strain. This may contribute to heart attacks, strokes, kidney failure, and atherosclerosis. If this condition is not treated, the heart will have to work progressively harder to pump enough blood and oxygen to the organs and tissues to meet their needs. When this happens over time, the heart tends to enlarge. A slightly enlarged heart may function well, but one that is significantly enlarged has a hard time meeting the demands placed on it. Arteries and arterioles also suffer the effects of hypertension and over time will become scarred, hardened, less elastic. This occurs as people age, but with hypertension this process is accelerated probably because hypertension speeds atherosclerosis. This artery damage is important because hardened or narrowed arteries may not be able to supply the amount of blood needed to the body’s organs. If these organs don’t get the oxygen and nutriments they need, they can’t function properly. There’s also the risk that a blood clot may lodge in an artery narrowed by atherosclerosis, depriving part of the body of its blood supply. The heart, brain, and kidneys are especially prone to damage from hypertension.
There are two types of hypertension, essential and secondary. Essential hypertension , which makes up about 90% of cases, has no essential cause. There are some factors that have been identified that contribute to elevation of blood pressure, however, which include atherosclerosis, or hardening of the arteries, thickening or hypertrophy of the artery wall, and excess constriction of arterioles. In the remaining cases, the hypertension is secondary or a symptom of a recognizable problem such as kidney abnormality, tumor of the adrenal gland or congenital defect of the aorta. When the root cause is corrected, blood pressure usually returns to normal.
Now what can be done to treat hypertension? Many medications (antihypertensives) are available to lower blood pressure. Some called diuretics, rid the body of excess fluids and sodium. Others, called beta blockers, reduce the heart rate and the heart’s output of blood. Another class of antihypertensives is called sympathetic nerve inhibitors. Sympathetic nerves go from the brain to all parts of the body, including the arterioles. They can cause the arteries to constrict or narrow, thus increasing blood pressure. This class of drug reduces hypertension by inhibiting these nerves from constricting blood vessels. Another group of drugs is the vasodilators. These can cause the muscle in the walls of the blood vessels (especially the arterioles) to relax, allowing them to dilate. Two other classes of drugs used to treat hypertension are the angiotension converting enzyme (ACE) inhibitors and the calcium antagonists (calcium channel blocks). The ACE inhibitors interfere with the body’s production of angiotension, a chemical that causes the arterioles to constrict. The calcium antagonists can reduce the heart rate and relax blood vessels.
In most cases these drugs do lower blood pressure, but different people respond very differently to these medications. Most go through a trial period to find out which medication is most effective while causing the least side effects. Dietary and lifestyle changes also may help control hypertension. Some people with mild hypertension can lower their blood pressure by reducing salt intake. Excessive alcohol intake (more than an ounce per day) raises blood pressure in some people and may be restricted. The condition can resolve itself when obese people lose weight. Increased physical activity can also reduce blood pressure. These kinds of interventions are often tried with people with mild hypertension before medications are prescribed.
Finally let’s look at risk factors for developing hypertension. Being overweight or using excessive sodium is one risk factor. Age is a second; generally speaking the older people get the more likely they are to develop hypertension. Heredity is another risk factor. People whose parents have high blood pressure are more likely to get it. African-Americans are also more likely to have hypertension than whites. A woman is more likely to have hypertension if she is taking oral contraceptives and is over weight, had hypertension during a pregnancy, has a family history of the condition or has mild kidney disease.
Please take this one fact with you if you forget every thing else. Hypertension is called the "silent killer" for good reason. People can have it for years without knowing it, while it continues to do damage. For those of us with diabetes who have risk factors for long term complications which are the same as those for hypertension, it becomes mandatory that we keep our blood pressure at a normal level. We all know that just having diabetes makes us more prone to hypertension, so do make sure your physician watches you for any signs. Early detection makes all the difference. This is not a disease to take lightly.
