Archive for February, 2008

Hypertension: Your life could be at risk!

Written by Tyrone M. Reyes, M.D.

If you’re over 60, there’s a good chance that you have hypertension. High blood pressure, which affects millions of Filipinos, rarely presents any symptoms (“silent epidemic”) and, if left untreated, can have fatal consequences. Research from the US National Health and Nutrition Examination Survey, conducted by the Centers for Disease Control and Prevention, and published in a recent issue of the American Heart Association’s (AHA) journal Hypertension, revealed that in 2003-2004, only 37 percent of people with hypertension were successfully keeping their blood pressure under control. It was reported as the primary or contributing cause of death of more than a quarter-million Americans in 2002. “We now have plenty of good scientific evidence that elevated blood pressure is a major risk factor for heart attack and stroke,” comments cardiologist Erica C. Jones, MD of the Weill Medical College of Cornell University in New York. “The biggest danger from uncontrolled hypertension is, of course, the risk of a brain hemorrhage (hemorrhagic stroke and lacunar stroke),” adds Arum Karlamangla, MD, assistant professor of medicine at UCLA. “And blood pressure does not have to be high for long periods of time for these events to happen,” he stresses. Other risk factors are blood clots forming in the coronary arteries (a heart attack) or arteries to the brain (ischemic stroke). If blood pressure is high for years, it can also lead to atherosclerotic plaques in these same arteries and the arteries of the legs, which then become substrates for clot formation. According to the AHA, even a small reduction in high blood pressure can help decrease the incidence of strokes and heart attacks.

Prevention

To avoid the potentially life-threatening consequences of uncontrolled hypertension, the most important thing you can do is to have your blood pressure checked regularly and work with your doctor to keep it under control.

“While genetic factors may account for as much as 30 percent of the blood pressure increase seen in the population, a number of environmental factors have a definite role in causing high blood pressure,” says James Davis, MD, a professor of medicine at UCLA. “Increased salt intake, excessive alcohol drinking, and obesity are modifiable risk factors for the development of high blood pressure. Reducing salt and alcoholic intake, and reducing weight through a combination of dietary modification and exercise can both prevent hypertension and reduce blood pressure in those already afflicted. Atherosclerosis is also linked to hypertension, and aggressive identification and treatment of patients at risk will reduce hypertension as well.”

Treatment

For some patients, it may be difficult to keep blood pressure at a safe level without the help of medications. There are many different kinds of medications to treat high blood pressure; your doctor can customize a treatment regimen that works best for you.

Some of the most commonly used drugs to treat high blood pressure are:

• Diuretics. Sometimes called “water pills,” these drugs flush excess water and sodium from the body by increasing urination. This reduces the amount of fluid in the blood and flushes sodium from the blood vessels so that they can open wider, increasing blood flow and thus reducing the blood’s pressure against the vessels. Often, diuretics are used in combination with other high blood pressure drugs. Types of diuretics include thiazides, such as chlorothiazide and hydroclorothiazide; potassium-sparing diuretics, such as spirinolactone (Aldactone); and loop diuretics, such as furosemide (Lasix, others).

• Beta blockers. These drugs slow the heartbeat by blocking the effect of nerve impulses to the heart and blood vessels, thereby lessening the burden on the heart. Beta blockers include propanolol (Inderal), metoprolol (Betaloc, others), and atenolol (Tenormin).

• ACE inhibitors. ACE (angiotensin-converting enzyme) inhibitors inhibit formation of the hormonal angiotensin II, which causes blood vessels to narrow, thus increasing blood pressure. ACE inhibitors include ramipril (Tritace), captopril (Capoten), and lisinopril (Zestril).

• Calcium channel blockers. These prevent calcium from entering the muscle cells of the heart and blood vessels, thus relaxing blood vessels and decreasing blood pressure. Some calcium-channel blockers are nifedipine (Adalat, Calcibloc, others), verapamil (Isoptin), and diltiazem (Dilzem).

• Alpha-beta blockers. These combine the actions of alpha blockers, which relax blood vessels, and beta blockers, which slow the heartbeat. The dual effect reduces the amount — and thus pressure — of blood through blood vessels.

Often, combinations of two drugs from different classes are used to improve the drug’s effectiveness. Many doctors begin newly diagnosed hypertensive patients with diuretics or beta blockers. The Joint National Committee (JNC) on Prevention, Detection, Evaluation and Treatment of High Blood Pressure recommends diuretics or beta blockers as the first line of treatment. However, based on a patient’s situation — for example, use of other medicines — doctors may choose to start treatment with another antihypertensive drug.

“While most patients will benefit from the use of a low-dose diuretic such as hydrochlorothiazide, the choice of medications needs to be tailored to the individual, and often depends on whether or not the person has co-morbid conditions,” says Dr. Davis. “People who have diabetes or heart disease, in addition to high blood pressure, will benefit from certain types of medications than from others. Patients can optimize blood pressure control by working closely with their physician and other caregivers.”

Prehypertension

Even if your blood pressure is just slightly elevated, your risk of cardiovascular death may be greatly increased. A new study found postmenopausal women with prehypertension — systolic pressures of 120-129 mmHg and diastolic pressures of 80-99 mmHg — have a 58 percent higher risk of cardiovascular death, compared to those with normal blood pressure (120/80 mmHg or below). Researchers from George Washington University studied data from 60,785 postmenopausal women in the Women’s Health Initiative (WHI) and found almost 40 percent had prehypertension. Over a 10-year period, women with prehypertension had a 76 percent greater risk of heart attack, a 93 percent higher risk of stroke, and a 36 percent increased chance of being hospitalized with heart failure. The risks held up even after adjusting for age, body mass index, and type 2 diabetes, leading the researchers to argue that prehypertension should be considered an independent risk factor for cardiovascular disease just as smoking and type 2 diabetes are.

“The increased cardiovascular risk with prehypertension is certainly smaller than the risk associated with having diabetes (158 percent higher risk), but is greater than that associated with smoking (34 percent higher),” the researchers write in the February 20, 2007 issue of the AHA journal Circulation. “Since smoking is pretty much unchallenged as a cardiovascular risk factor, perhaps prehypertension should be afforded the same acceptance,” they appealed.

Lifestyle Changes

“For many patients, lifestyle changes will be enough to get their pressure down to the normal range,” says Dr. Jones. The AHA’s 2007 prevention guidelines recommend lifestyle changes such as an increased intake of fruits and vegetables, and low-fat dairy products, along with exercise, weight loss, and reduced sodium intake. The guidelines recommend that people over age 50 cut sodium intake to 1,500 mg a day.

The DASH (Dietary Approaches to Stop Hypertension) diet can lower systolic pressure by more than five points and diastolic pressure by at least three points. For information on the DASH diet, look up: http://www.nhlbi.nih.gov/health/public/heart/hbp/dash/new dash.pdf.

“Regular exercise has been shown to reduce blood pressure by as much as 10 points,” says Dr. Jones. “I recommend older people to walk at a moderate pace, or whatever pace they feel comfortable with, every day if possible.”

Even without any symptoms, you could be at serious risk for some very dangerous complications. High blood pressure is asymptomatic, which is why screening for hypertension is so important. Those who have relatives or family members with hypertension or have a family history of stroke or heart disease should be especially concerned about having their blood pressure checked. It’s a matter of life and death!

Source: Philippine Star
http://philstar.com/index.php?Health%20And%20Family&p=49&type=2&sec=41

Retina specialists cite benefits of pegaptanib therapy

When you’re looking at a grid of straight lines and actually seeing it as wavy, “listen” to your eyes. They are sending you an urgent message.

If your vision is getting blurred or distorted and most especially if you’re past 50, Dr. Amadeo Veloso, a retina specialist and assistant medical director of the Asian Eye Institute (AEI) at Rockwell Center, Makati City, recommends that you see an eye doctor fast.

“Chances are that the person bothered by such an eye difficulty is on the way to or already suffering from age-related macular degeneration (AMD),” said Veloso, who did postgraduate studies at the Schepens Eye Institute of the Harvard Medical School in Boston for two and a half years following his graduation from the UP College of Medicine and residency training at the St. Luke’s Medical Center as an eye doctor specializing in retina and vitreous (eye fluid) diseases.

If untreated, a person with AMD, he said, won’t go totally blind but will suffer the terrible consequence of losing his central vision.

“He can still move around because his peripheral sight stays, but not his central vision which equips him with the capability to take in the fine details of what’s before him,” he said.

Macular degeneration is the leading cause of blindness in persons aged 55 and older in the US. It is a medical condition in which the light sensing cells in the macula, the central area of the retina, malfunction and, over time, cease to work.

AMD begins with characteristic yellow deposits in the macula called drusen. People with drusen can go on to develop advanced AMD, which has two forms, dry and wet.

The dry form causes vision loss when the photoreceptors and cells supporting them in the central part of the eye die. At best, treatment for dry AMD can only control the condition.

The wet form of advanced AMD, on the other hand, causes vision loss due to the abnormal growth of the blood vessels under the macula. Bleeding, leaking and scarring from these blood vessels eventually cause irreversible damage to the photoreceptors and supporting cells, if left untreated.

Presently, there are a lot of treatments available for wet AMD. Of these, Veloso and another Harvard-trained retina specialist at the AEI, Dr. Harvey Uy, have extensive experience using the drug pegaptanib. Injected directly into the eye, the drug, according to the two doctors, works fast and has no known serious adverse effects.

Since its approval in the country by the Bureau of Food and Drugs on Oct. 14, 2005, Veloso has treated about 25 to 30 patients who have had at least more than one injection of pegaptanib each.

“After four or six injections, all of them have responded very well to the drug,” said Veloso. “The AMD was controlled, meaning the abnormal growth of the blood vessels under the macula was prevented and so were the bleeding, leakage and swelling.”

Being the first doctor to have used pegaptanib in Asia, Uy, a retina specialist who trained at UP College of Medicine-Philippine General Hospital, St. Luke’s Medical Center, and Massachusetts Eye and Ear Infirmary of the Harvard Medical School, reported similarly positive experiences with the drug.

He said he has had about eight patients so far on pegaptanib therapy. “My patients’ vision usually quickly stabilized as a result of pegaptanib therapy, meaning their vision stopped getting worse,” he said.

Uy and Veloso both maintained that the best way to lessen the chances of developing AMD is to keep the macula healthy by having a healthy lifestyle, and avoiding smoking, too much sun exposure and fatty food, keeping blood pressure and cholesterol count at normal levels, eating vegetables and other foods rich in vitamin A, and undergoing regular retinal examination.

Genes also play a crucial factor in the development of AMD. “If you come from a family with a history of eye problems, you must see your eye doctor regularly,” they advised.

Source: Philippine Star
http://www.philstar.com/index.php?Science%20and%20Technology&p=49&type=2&sec=36&aid=2007071847

}