HYPERTENSION AND DIABETES: DOUBLE TROUBLE

2008-08-19 14:20:54
Source: Tribune Media
By: Harvard Health Letters

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Harvard Health Letters

HYPERTENSION AND DIABETES: DOUBLE TROUBLE

Do you have high blood pressure, also known as hypertension? If so, you should be tested for diabetes.

That recommendation comes from the U.S. Preventive Services Task Force, an independent panel of experts. It reviews the evidence for prevention strategies like testing for diabetes or taking aspirin. The task force's recommendations usually become guidelines for primary care doctors and some specialists.

High blood pressure and diabetes often travel together. Treating them simultaneously is a win-win approach. Among people with diabetes, controlling blood pressure cuts in half the chances of having a heart attack or stroke or dying of heart disease. Among people with high blood pressure, controlling blood sugar reduces the chances of losing vision, losing feeling in the fingers or feet, losing a limb, and suffering kidney damage.

Testing for diabetes

The diabetes test endorsed by the American Diabetes Association is the fasting blood sugar test. It involves having a small sample of blood drawn first thing in the morning before you have had anything to eat or drink. If your blood sugar is 126 milligrams per deciliter (mg/dL) or higher, and it's confirmed by a second test a few days later, you have diabetes. Some doctors check for diabetes by testing your blood sugar two hours after you drink a sugary beverage or by testing for the percentage of sugar-coated hemoglobin in the bloodstream (known as hemoglobin A1c).

Diabetes that appears in adulthood is usually type 2 diabetes. It begins years earlier as a slowly smoldering condition known as insulin resistance. Insulin is a hormone needed to move sugar from the bloodstream into muscle and other cells. Some people become progressively resistant to insulin's "open up for sugar" signal. The longer sugar lingers in the bloodstream, the more insulin the body makes. Over time, the insulin-making cells in the pancreas begin wearing out. This dual problem leads to higher and higher levels of blood sugar after meals and between them.

Too much sugar in the bloodstream affects tissues throughout the body. It damages the inner walls of small blood vessels, causing them to thicken and leak. The vessels may eventually clog, impeding blood flow to vital tissues. This insidious process can damage nerves, trigger heart attacks and strokes, harm the kidneys, and lead to vision loss. Keeping blood sugar levels as close to normal as possible can prevent these disabling or deadly complications.

Taking control

Diabetes and high blood pressure may be different diseases, but both respond to the same lifestyle changes. Daily exercise is an excellent way to lower blood pressure and keep blood sugar in check. For folks who are overweight, losing weight is good for both blood pressure and blood sugar. Stopping smoking works for both, as does adopting a healthier diet. Medications are usually needed to control blood pressure and blood sugar. Statins are helpful for both regardless of cholesterol level. But lifestyle changes should be the bedrock of treatment, not add-ons after medications. - Harvard Heart Letter

WARFARIN BOOKLET

The blood thinner warfarin (Coumadin) can be a tricky medication to take. A new 20-page booklet from the federal Agency for Healthcare Research and Quality offers tips on what to expect, what to watch out for, and ways to stay safe while taking warfarin. You can get a free copy of Your Guide to Coumadin/Warfarin Therapy at health.harvard.edu/127 or by calling 800-358-9295 (toll-free). - Harvard Heart Letter

AIR POLLUTION FAILS THE HEART; VITAMINS MAY HELP

Sitting in traffic puts a strain on the heart. Living near it is even worse. In a new study of people with heart failure, those whose homes were close to a major roadway were more likely to have died over a five-year period than those who lived away from traffic (Environmental Health Perspectives).

In studies like this, it's hard to point the finger at any single culprit. Exhaust spewing from the tailpipes of cars, trucks, and buses almost certainly plays an important role. It carries particles small enough to evade the lung's filters and get drawn deep into the lungs. Breathing in these particles can worsen heart failure or trigger heart attacks.

Getting enough vitamin B6, vitamin B12, and the amino acid methionine may somehow counteract the impact of these tiny particles. In a study of more than 500 elderly men, adequate intake of these nutrients offset air pollution's harmful effects on heart rate variability, a measure of heart health (Circulation).

Since this is the first study to suggest that vitamin B6, vitamin B12, and methionine offer some protection against exhaust-related heart disease, don't rush out and buy megadoses of these nutrients. Instead, add to your daily diet heart-healthy foods that are also rich in these nutrients. Good sources include many ready-to-eat cereals (pick whole-grain kinds for an extra boost for the heart), shellfish, salmon, sardines, broccoli, avocados, mushrooms, sunflower seeds, pumpkin seeds, sesame seeds, and lentils. - Harvard Heart Letter

TRANS FAT, AU NATUREL!

Trans fat is a certifiable nutritional bad guy. It lowers "good" HDL cholesterol and raises the "bad" LDL variety. Boston, Massachusetts, once infamous for banning books, has now joined New York City and other municipalities by banning trans fat from its restaurants. Many food makers have stopped using trans fat as an ingredient, for public health and PR reasons.

But there's some "natural" trans fat in meat and dairy products that these bans won't touch. Should we be worried about it? Probably not.

Artificial trans fat is made when a vegetable oil is converted into a solid through the process called partial hydrogenation, which sticks hydrogen atoms on oil molecules' fatty tails. But the addition of hydrogen, or hydrogenation, occurs in nature, too. Bacteria in animals' stomachs hydrogenate the fatty oils from animal feed, for example. Definite numbers are hard to come by, but a cup of whole milk may have about 0.24 grams of trans fat and a quarter pound of hamburger about 0.8 grams. That pales in comparison to the five or so grams contained in a single doughnut.

Two dairy industry-funded studies published in the March 2008 issue of The American Journal of Clinical Nutrition made some comparisons between the effects of artificial and natural trans fat. One involved putting healthy young people on a diet that provided 5 percent of their calories from either artificial or natural trans fat. That's a lot of trans fat -- about twice as much as the average American would consume even in trans fat's heyday. As expected, the HDL levels of the women in the study assigned to eat artificial trans fat went down, but notably, the HDL levels of the women assigned to eat natural trans fat actually went up. There was no difference in how the two different types of trans fat affected men.

The other study, conducted by Canadian researchers, compared people who consumed varying levels of trans fat. Large amounts (3.7 percent of calories) produced similarly bad effects on heart disease risk factors, regardless of whether the trans fat was artificial or natural. Relatively small amounts (1.5 percent or 0.8 percent of calories) from natural trans fat didn't affect heart disease risk factors. The dairy industry wants the natural trans fat in its products excluded from labeling rules that require the listing of trans fat, so these were perhaps just the kind of results it was looking for when it funded this research.

Study results that so neatly serve the interest of the sponsor merit some skepticism. Still, there is some reason to believe that artificial and natural trans fat might have different effects. One of the natural trans fats in dairy foods is vaccenic acid, which humans convert into conjugated linoleic acid, a substance with a variety of putative health benefits.

Besides, only a small percentage of the fat in any animal-based food, meat or dairy, is trans fat -- at the very most, 8 percent -- whereas a vegetable oil can become up to 65 percent trans fat after being hydrogenated. So you'd really need to butter up your morning toast to rival a large order of Burger King breakfast hash browns, which contain a whopping 13 grams of trans fat. - Harvard Health Letter

TREADMILL ALTERNATIVE

Doctors usually rely on a treadmill to gauge the severity of claudication -- leg pain brought on by exercise or activity. A French team devised a more pleasant approach -- a walk in a park with a global positioning system (GPS) attached to the belt or in a backpack. Data recorded by the GPS can show how far an individual walks without stopping, a key piece of information from treadmill tests. (Circulation). - Harvard Heart Letter

BRAVO FOR BYSTANDER

When a cardiac arrest strikes, survival depends on shocking the heart back to a normal rhythm. It doesn't take a professional to do this. Results from an 11-city study showed that when an untrained bystander uses an automated external defibrillator (AED) to shock the heart back to action, survival rates more than double. (American Heart Association)

New designs of AEDs may further improve survival for cardiac arrest victims. The PowerHeart AED uses voice prompts and a metronome to help a bystander correctly do chest compressions to keep blood circulating as well as administer a shock to the heart. Untrained volunteers who used the device on a manikin pressed the chest as fast and as hard as people trained to do cardiopulmonary resuscitation. (American Heart Association meeting). - Harvard Heart Letter

(C) 2008. PRESIDENT AND FELLOWS OF HARVARD COLLGE. ALL RIGHTS RESERVED DISTRIBUTED BY TRIBUNE MEDIA SERVICES, INC.

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