MAY 2010 Bulletin

NATIONAL HYPERTENSION AWARENESS MONTH

As the country observes the month of May as “National Hypertension Awareness Month” under Proclamation No. 1761, let’s take a quick look on what Hypertension is all about, risk factors, and how Nutrition can affect the incidence of High blood pressure in one’s health.

What is Hypertension?

Hypertension is another name for high blood pressure. It is that condition when the pressure inside of your large arteries is too high. Because it does not usually produce any symptoms, the only way to detect hypertension is to have your blood pressure measured. Hypertension is a very common problem that affects about 8 million Filipinos. It is also the most common cardiovascular condition in the world. It is more common as people grow older and it occurs equally in men and women. Hypertension is not simply being tense or nervous.

What causes Hypertension?

More than 9 of every 10 people who have hypertension do not have a cause for it that can be identified.

We do know that you can inherit the tendency to hypertension from your parents. If your parents have hypertension (one or both), you are more likely to develop it than if your parents had normal blood pressure. Although less likely, you can still get hypertension even if your parents have normal blood pressure.

Your environment also plays a very important role. For example, you have a chance to avoid hypertension by keeping your weight, under control, keeping physically fit, eating a healthy diet, limiting your alcohol intake (no more than one mixed drink or one 12 oz. can of beer or one 6 oz. glass of wine daily), and avoiding smoking and medications that might increase your blood pressure. You cannot choose your own parents, but you can help reduce your chance of getting hypertension by leading a very healthy lifestyle.

There are other less common causes of hypertension. Most are due to disorders of the kidneys or endocrine glands. Your doctor can determine if the disorders are related to your hypertension by taking your history, performing a physical examination, and doing a few simple blood and urine tests. More sophisticated testing is not often required.

You may checkout the Philippine Society of Hypertension website for more info on Hypertension www.psh.org.ph/v2/

HYPERTENSION




Persistent high blood pressure (hypertension) often is called a “silent killer” because it usually has no specific symptoms or early warning signs. You can be hypertensive for years without realizing it. During those years, untreated hypertension may cause damage to vital organs, particularly the heart, the brain, the kidneys, and the eyes. It increases the risk of heart attack, congestive heart failure, stroke, and kidney failure. The good news is that hypertension can be treated and controlled. Hypertension affects nearly one-fourth of American adults and more than two-thirds of people older than 65. Most cases are essential hypertension, in which the cause is unknown.

Left untreated, the excessive pressure of blood on the arteries eventually scars and narrows them, reducing their elasticity. This increases the likelihood of atherosclerosis, because fatty plaque accumulates where arteries are damaged. The heart, forced to work much harder pumping blood through the narrowed arteries, becomes enlarged and inefficient. Eventually the heart is unable to supply enough nutrients and oxygen to organs and tissues. The kidneys, the brain, and the heart are especially vulnerable to the damaging effects of high blood pressure.




Blood clots also tend to form at sites of artery damage, further limiting blood flow. The clots can break loose and travel to the brain, causing a stroke, or to the heart, causing a heart attack.

Blood pressure is expressed as two numbers. The systolic is the higher number and represents pressure during the heart’s contraction. Diastolic is the lower number, measured during the heart’s rest phase. Normal blood pressure is generally defined as 120/80 mm Hg (millimeters of mercury) or lower. Persistent systolic pressure of 140 or higher or diastolic pressure of 90 or higher, or both, usually requires treatment.

Risk Factors for Hypertension

Even though the cause for most cases of hypertension is unknown, several factors clearly contribute to hypertension. As with heart disease risk, some hypertension risk factors are controllable and others are uncontrollable. Risk factors for hypertension under your control include the following:

• Obesity.


People with a BMI of 30 kg/m² or higher are more likely to develop high blood pressure.

• Eating too much salt.


High sodium intake increases blood pressure in some people.

• Lack of physical activity.


A sedentary lifestyle is associated with overweight and increased blood pressure.

• Drinking too much alcohol.


Heavy and regular use of alcohol increases blood pressure.


Risk factors for hypertension that are beyond your control include the following:

• Race. African Americans develop high blood pressure more often, at earlier ages, and with more severity than Caucasians.

• Age. Blood pressure risk rises with age; people with normal blood pressure at age 55 have a 90 percent lifetime risk of developing hypertension.

• Heredity. Family history of hypertension is strong predictive factor.

Some people clearly have a genetic predisposition to essential hypertension. But what role does diet play? Could changing our diets prevent or delay high blood pressure? And for people who have hypertension, can changing their diet help control their blood pressure?

Sodium and Hypertension




Excessive sodium can hold excessive fluid in the body, at least temporarily. These excesses can be burdensome on the kidneys, heart, and blood vessels. The consensus among heart disease experts is that too much sodium, ingested routinely over the years, plays a role in the underlying causes of hypertension in genetically predisposed or “salt-sensitive” people. The more salt they eat, the higher their blood pressure.

Population studies appear to bear this out. Rates of hypertension are greater in countries with high sodium intakes. On the other hand, primitive people, whose diets contain very little sodium, seldom have hypertension. Their blood pressure does not rise with age if they continue to eat their traditional diet. But if they adopt a “modern” (higher sodium) diet, blood pressure tends to rise, and they are more likely to become hypertensive.

The relation of dietary sodium to hypertension is one of the most heavily researched issues in nutrition. Unfortunately, study conclusions often differ. Among the most influential studies are the DASH (Dietary Approaches to stop Hypertension) studies, two large, carefully controlled trials sponsored by the National Heart, Lung and Blood Institute (NHLBI). The most recent study found that strictly reducing sodium for 4 weeks, along with eating generous amounts of fruits and vegetables, and low-fat dairy foods, lowered systolic blood pressure an average 7.1 mm Hg in nonhypertensive people and 11.5 mm Hg in hypertensive people. Limiting sodium, but not eating the extra fruits, vegetables, and dairy foods, lowered systolic blood pressure by an average 6.7 mm Hg.

Other Dietary Factors

Sodium is not the only dietary factor associated with hypertension. The carefully controlled DASH study also showed that foods low in fat and rich in calcium, magnesium, and potassium reduce blood pressure as well. Eating 10 servings of fruits and vegetables and 2-3 servings of low fat dairy products daily, while limiting fat and saturated fat, brought systolic blood pressure down by 5.9 mm Hg, even at the highest sodium intake of 3,450 mg. In an earlier 8-week study, a similar diet reduced systolic blood pressure by 3.5 mm Hg in nonhypertensive people and 11.3 mm Hg in people with hypertension.

The DASH studies show that limiting sodium, fat and cholesterol, as well as increasing fruits, vegetables and low-fat dairy foods, can lower blood pressure. The NHLBI recommends that all Americans follow the DASH combination diet. The Dietary Guidelines fro Americans echo the call to reduce sodium intake while consuming potassium-rich foods. Controlling weight, getting regular exercise, and reducing alcohol consumption also help reduce blood pressure.

Key Concepts:

Hypertension is a risk factor for atherosclerosis, kidney disease and stroke. Excess sodium intake raises blood pressure in those who are salt-sensitive. Inadequate levels of potassium, calcium, and possibly magnesium may also contribute to hypertension. Limiting sodium intake, along with eating lots of low-sodium vegetables, fruits, and low-fat dairy products, will probably help reduce hypertension and its side effects.

(Source: Discovering Nutrition, 2nd edition, American Dietetic Association)

Just to update, we got this reference guide from the 3rd report of the expert panel on detection, evaluation and treatment of high blood cholesterol in adults, National Cholesterol Education Program (NCEP).