Lower Your Blood Pressure With Exercise

• How Exercise Helps
  
• What's the Best Exercise?
  
• Exercise Precautions
  
• Exercise and Blood Pressure Medications
  

Regular exercise is a great way to prevent high blood pressure or hypertension. But did you know it's also one of the best means of lowering high blood pressure? It may even help you avoid having to take medication to bring your numbers into the normal ranges.

How Exercise Helps

Your blood pressure is determined by the force your heart produces in your arteries when it pumps blood through your body and by the tension of the artery walls. High blood pressure occurs when the blood pushes against artery walls with too much pressure.

Persistently high blood pressure puts a strain on the arteries, which can cause them to harden, become clogged or to weaken. This in turn increases the risk of heart disease and stroke.

Here's how exercise can help. The cells lining our artery walls contain chemicals that determine the degree of tension of the arteries. Exercise training keeps these cells — called vascular endothelial cells — healthy. Healthy endothelial cells release more chemical "relaxers" and inhibit the production of chemical "tighteners." With less resistance in the arteries, your heart can pump more efficiently and blood flows more easily.

What's The Best Exercise?

There is no "best" way to exercise to help lower blood pressure. The old "no-pain-no-gain" regimen of high-intensity activity aimed at pushing the heart and lungs to their limits is long gone. In 1995, experts unveiled a kinder, gentler approach: 30 minutes or more of moderate-intensity activity done on most — but preferably all — days of the week.

Brisk walking and leaf-raking joined jogging and swimming as acceptable activities. With this no-sweat version, you don't even have to be active for 30 minutes straight. Segments of 10 to 15 minutes are fine. The emphasis on moderate activity was aimed, in part, at getting people who wouldn't exercise to increase their daily physical activity.

Today, 30 minutes of moderate intensity exercise remains a good start. But the new goal, set by the Institute of Medicine is to perform 60 minutes of more vigorous exercise to raise your heart rate to a moderate intensity level.

In general, you should vary your daily workout with a combination of cardiovascular (aerobics) and resistance training. Also you want to stretch after each exercise session. To lower blood pressure, spend more time on aerobics. Some resistance training is fine but don't strain. Do more repetitions at lighter weights to prevent your blood pressure from temporarily spiking up.

Exercise Precautions

Since high blood pressure is a risk factor for heart disease and stroke, you should ask your doctor for advice about an exercise routine that is right for you. In general, if you don't have other risk factors for heart disease and you don't take blood pressure medication, no special precautions are necessary.

To insure that you stick with it, start slowly and gradually work up to longer and more intense exercise sessions. If you do experience chest pain, shortness of breath, dizziness or cold sweats, don't push through it. Contact your doctor; he or she may want to order a stress test before giving you the go-ahead to restart your program.

Exercise and Blood Pressure Medications

If you are taking one or more medications for high blood pressure, you can still exercise but you need to check with your doctor first. Depending upon the class of medication, you may need to take some extra precautions:

• Thiazide diuretics, such as hydrochlorothiazide and chlorthalidone, are first-line drugs to treat hypertension. But they can alter the levels of certain chemicals in your blood, especially potassium. Most diuretics cause the kidneys to eliminate potassium, which lowers the amount in the blood. Your doctor may want to check your potassium level if you plan to start a vigorous exercise program. Bananas, tomatoes and citrus fruits are good sources of potassium.
  

  Thiazide diuretics also lower blood volume slightly so you may be more prone dehydration with exercise. If you plan to do vigorous or prolonged exercise routines, talk with your doctor about lowering the dose of the thiazide diuretic and adding a blood pressure medicine with a different action. Some people, especially older women, are at risk of developing a very low blood sodium concentration. This situation will be made worse if you just re-hydrate with plain water rather than a sports drink.
  

• Beta blockers, such as atenolol, metoprolol and labetalol, and the calcium channel blockers verapamil and diltiazem slow the heart rate. When doing aerobic activity, don't be concerned if your heart rate (pulse) does not reach the recommended target heart range for moderate intensity exercise.You are still getting the benefits of exercise. Not reaching a target heart rate is not a reason to change the dose of beta blocker unless you are a competitive athlete.
  

Burn Those Calories

Any increase in the amount of physical activity you do is a step in the right direction. Burning more calories with shorts walks and climbing the stairs can help maintain a healthy body weight. And losing weight, even if you only increase your exercise a little, will help lower blood pressure.

If you're already somewhat active, try adding more exercise to your routine. Adding activities that burn an extra 100 calories per day can make a difference. Increase that to 300 calories per day and the weight-loss benefits really start to kick in.

Here are some examples of activities that will burn 300 calories per hour:

• Walking briskly (at a 4-mile per hour pace)
  
• Gardening
  
• Doubles tennis
  

Study: To Sleep Better, Perchance to Live Longer

Shakespeare once called sleep the "balm of hurt minds." Bodies, too, apparently. People with the severe form of apnea, which interferes with sleep, are several times more likely to die from any cause than are folks without the disorder, researchers report in Friday's edition of the journal Sleep. The findings in the 18-year study confirm smaller studies that have indicated an increased risk of death for people with apnea, also known as sleep-disordered breathing. "This is not a condition that kills you acutely. It is a condition that erodes your health over time," Dr. Michael J. Twery, director of the National Center on Sleep Disorders Research, said in a telephone interview. People with such disorders "have been sleep deprived for perhaps very long periods of time, they are struggling to sleep. If this is happening night after night, week after week, on top of all our other schedules, this is a dangerous recipe," said Twery, whose center is part of the National Heart, Lung and Blood Institute. The institute estimates that 12 million to 18 million people in the U.S. have moderate to severe apnea. The condition is not always detected because the sufferer is asleep when the problem occurs and it cannot be diagnosed during a routine office visit with a doctor. Researchers tested the patients for sleep-disordered breathing in the laboratory and then followed them over several years. For people with apnea, their upper airway becomes narrowed or blocked periodically during sleep. That keeps air from reaching the lungs. In some cases, breathing stops for seconds to a minute or so; the pauses in breathing disrupt sleep and prevent adequate amounts of oxygen from entering the bloodstream. "When you stop breathing in your sleep you don't know it, it doesn't typically wake you up," Twery said. Instead, it can move a person from deep sleep to light sleep, when breathing resumes. But the overall sleep pattern is disturbed, and it can happen hundreds of times a night. He said that a person typically will have four or five cycles per night of light sleep, deep sleep and REM (rapid eye movement) sleep, when most dreams occur. More deep sleep comes early in the night with more REM sleep closer to waking up. This pattern helps control hormones, metabolism and levels of stress. The institute, part of the National Institutes of Health, says apnea has been linked to a greater risk of heart disease, high blood pressure, stroke, diabetes and excessive daytime sleepiness. In the new report, the Wisconsin Sleep Cohort followed 1,522 men and women, ages 30 to 60. The annual death rate was 2.85 per 1,000 people per year for people without sleep apnea. People with mild and moderate apnea had death rates of 5.54 and 5.42 per 1,000, respectively, and people with severe apnea had a rate of 14.6, researchers said. Cardiovascular mortality accounted for 26 percent of all deaths among people without apnea and 42 percent of the deaths among people with severe apnea, according to the researchers led by Terry Young of the University of Wisconsin, Madison. In the same issue of the journal Sleep, a separate study of 380 adults between 40 and 65 in Australia came to a similar conclusion. This study found that after 14 years, about 33 percent of participants with moderate to severe sleep apnea had died, compared with 6.5 percent of people with mild apnea and 7.7 percent of people without apnea. "Our findings, along with those from the Wisconsin Cohort, remove any reasonable doubt that sleep apnea is a fatal disease," said lead author Dr. Nathaniel Marshall of the Woolcock Institute of Medical Research in Sydney, Australia. Apnea often is treated with a device that delivers continuous positive airway pressure through a mask over the nose and/or mouth. The U.S. study found that patients using this device had reduced death rates. There has been debate over whether to use airway pressure to treat patients who are not sleepy in the daytime, the report noted. The U.S. researchers noted that while theirs was a large study, 95 percent of the participants were white and most had adequate income and access to health care. "It is likely that our findings may underestimate the mortality risk of SDB in other ethnic groups or the lowest socio-economic strata where there is poor awareness and access to health care," they said. The U.S. research was supported by the National Institutes of Health. The Australian study was supported by the Australian National Health and Medical Research Council.

Burning Topics

• Genetic Testing Predicts Who Will Have Side Effects from Statin Drugs
  
• Low Levels of Good Cholesterol (HDL) Are Linked to Poor Memory
  
• Cipro and Similar Antibiotics Can Cause Tendon Pain or Rupture
  
• A Better Cholesterol Test
  
• Diabetes Rate Climbs to 8% of Americans
  

Genetic Testing Predicts Who Will Have Side Effects from Statin Drugs

Researchers have identified a gene that makes some people more likely than others to have side effects from cholesterol medicines called "statins." A study describing the findings was published online by the New England Journal of Medicine on July 23.

Statin cholesterol drugs occasionally cause muscle pain and weakness (myopathy), which can be severe. Commonly prescribed statins include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), simvastatin (Zocor), pravastatin (Pravachol) and rosuvastatin (Crestor). Approximately one out of every 10,000 patients who take a middle-range dose of a statin drug experience this side effect each year. It occurs much more frequently in people who take a high dose of a statin.

Researchers wanted to see if some people were genetically predisposed to this serious reaction. They compared the genes of 85 people who were taking a statin and developed myopathy with the genes of 90 people who did not experience myopathy while taking a statin. Both groups of patients were similar in terms of sex, age, estimated kidney function. The groups were also alike in terms of other medicines that they took regularly.

A gene on chromosome 12 appears to control how much statin enters the liver. Eighty-five percent of the general population have two normal copies of this gene, but 15% of people have a variation in one or both copies. Sixty-six or almost 80% of the people who had muscle symptoms had the variation for at least one of their genes. Because the gene is present in so many of the patients who have myopathy, it is very likely that this gene is predisposing people to have this painful drug reaction. The researchers calculated that if a person has one copy of the gene with the variation, then the risk for myopathy is roughly quadrupled compared with people who have two normal copies of the gene. If a person has two copies of the gene with the variation, then the risk is about 17 times normal.

Using genetic tests to predict a person's response to a medicine is called "pharmacogenomics." Genetic testing is likely to be requested in the future before a statin is started, or before the dose of a medicine is increased. In this way, people who have one or two copies of the gene variation can avoid statins (especially at a high dose).

Low Levels of HDL ("Good" Cholesterol Are Linked to Poor Memory

If your high-density lipoprotein (HDL) levels are low in middle age, your memory may be poorer than it normally would be. This is the finding of a study that was released online on June 30 by Arteriosclerosis, Thrombosis and Vascular Biology: Journal of the American Heart Association.

Researchers gave 3,673 middle-age people a short-term memory test when the study began. The average age of the participants at that time was 55. Participants listened to a list of 20 words, then were asked to write down as many as they could remember. The group was re-tested five years later. Cholesterol was measured at the time of each memory test.

Word-recall tests are not a perfect measure of memory, yet the study results are interesting. The initial memory test showed that people who had a low HDL (less than 40 milligrams per deciliter, mg/dL) scored 27% lower on their word-recall test compared with people who had HDL levels above 60 mg/dL. Most people in the study did not have significant changes in their HDL levels between the first and second tests. Five years after the first test, people with low HDL scored on average 53% lower on the memory test compared with people who had high HDL levels. In other words, the relationship between low HDL and poor memory was "magnified" as the group aged.

This study shows that there is a connection between HDL and memory, but not that low HDL causes poor memory. Statins can improve HDL, but aren't recommended if HDL is your only cholesterol abnormality. Boost your HDL level by making healthy changes in your lifestyle instead. Regular exercise helps your HDL level. The kinds of fats that you eat in your diet also matter: Reduce saturated fats and trans fats (which are found in hydrogenated and partially-hydrogenated vegetable oils) in your diet, and eat monounsaturated fats, such as olive oil, canola oil and peanut oils.

Cipro and Similar Antibiotics Can Cause Tendon Pain or Rupture

A group of antibiotics that are commonly prescribed for bacterial infections, such as urinary tract infections, pneumonia and skin infections, can cause curious but damaging side effects — tendonitis and tendon rupture. On July 8, the U.S. Food and Drug Administration (FDA) issued a new online alert to doctors and the public that went beyond an earlier notice about this concern. The new alert warned that these side effects may be more common than originally recognized.

The medicines in question are in the drug family known as fluoroquinolones. They include ciprofloxacin (Cipro, Proquin), levofloxacin (Levaquin), moxifloxacin (Avelox), gemifloxacin (Factive), norfloxacin (Noroxin) and ofloxacin (Floxin).

During treatment or within several months of their use, the drugs can trigger inflammation and, in some cases, rupture of a tendon. The most commonly affected tendon is the Achilles tendon, which is located at the back of the ankle. A ruptured Achilles tendon requires surgery to fix the damage. Other tendons that have been affected by these medications include the rotator cuff of the shoulder, the biceps tendon in the arm, and tendons in the hand and thumb. People are at greater risk of this side effect if they are over age 60, have had a heart, lung, or kidney transplant, or are taking corticosteroids, such as prednisone.

If you notice pain, swelling or redness in your ankle, shoulder or hand within three months after you have taken one of these antibiotics, stop using the medication, avoid exercising the painful area and contact your doctor.

A Better Cholesterol Test.

In the July 19 issue of Lancet, experts propose a new way for doctors to monitor your cholesterol levels and more accurately predict your heart-attack risk. They suggest measuring the concentration of protein particles in your blood called "apolipoprotein B100" (ApoB)and "apolipoprotein A1" (ApoA1). They may be more important to your heart risk than is cholesterol itself. To travel through your bloodstream, cholesterol combines with certain proteins to form particles called "lipoproteins." The two main types of lipoproteins are "low density" and "high density." They are also known as your "bad" cholesterol (LDL) and "good" cholesterol (HDL). Technically, LDL and HDL aren't themselves cholesterol. They are the small bundles that form and carry cholesterol through the body. ApoB is one of the proteins on LDL particles. HDL packages cholesterol with different proteins, including ApoA1.

The ratio of ApoB protein to ApoA1 protein is very closely linked to heart attack risk. In a study that measured LDL, HDL, ApoB and ApoA1 levels, researchers compared 9,345 people who had heart attacks with 12,120 individuals who were of similar age and gender, but who hadn't had heart attacks. The ratio of ApoB to ApoA1 predicted heart attack risk better than did the ratio of LDL to HDL, or total cholesterol to HDL.

Within the next few years, doctors may begin to report your cholesterol results differently, with a new focus on your ApoB to ApoA1 ratio. Medicines that lower LDL also reduce ApoB proteins, so treatments will not change. The other good news is that ApoB and ApoA1 can be measured with a random blood sample; they do not require a fasting test.

Diabetes Rate Climbs to 8% of Americans.

On June 24, statisticians from the U.S. Centers for Disease Control and Prevention(CDC) estimated that the total number of Americans with diabetes had climbed to 24 million in 2007, an increase of 3 million since 2005. The new number equals 8% of the U.S. population, including Americans of all ages. The rate of diabetes among mature adults is even more alarming. Almost 25% of Americans age 60 or older had diabetes in 2007. About 57 million people have pre-diabetes, a condition that makes you more likely to develop diabetes. People with pre-diabetes have mild elevations in blood sugar caused by resistance to the effects of insulin. Diabetes runs in families, but most experts agree that this increase in diabetes is due to poor weight control, poor diet and not enough exercise among Americans.