DEAR DR. DONOHUE: I had a triple coronary artery bypass in April 1998. The vessel used for the grafts was taken from my leg.

A cardiologist tells me that the leg vessel graft needs replacement in eight years. It is not as good as grafts taken from arteries in the arm or the chest wall. I feel fine. It has been 10 years since my operation. Am I living on borrowed time? Why isn’t the leg vessel as good as the others? – W.P.

Hold on a minute. Predictions about the longevity of grafts for clogged arteries are hazardous. The source of the graft is not the sole factor in its life span. The general health of the person getting the graft is most important. Diabetes, for example, has a negative effect on all blood vessels, including grafts. If graft recipients make major changes in how they live – watch their weight, keep their cholesterol low, get exercise, pay attention to blood pressure and don’t smoke – then their grafts are bound to stay healthy for a long time.

The leg vessel you speak of is a long and large leg vein. Veins are not the same as arteries. Arteries have to stand up to pressure that is much higher than it is in veins, so arteries are tougher. At five years, 75 percent of vein grafts are functioning well, and at 15 years, 50 percent are still in good shape. Some last much longer.

The “chest wall” graft isn’t from the chest wall. These grafts come from arteries within in the chest. They are directly hooked up to heart arteries, so they have long lives – as long as arteries have. Most of these grafts stay open for 20 or more years.

Many heart surgeons use an arm artery as the source of their grafts. The arm does quite well with only one major artery. These grafts are better than vein grafts. They’re arteries. They have a life span between that of a vein graft and that of the inner chest artery graft.

The booklet on coronary artery disease discusses this common problem in depth. Readers can order a copy by writing: Dr. Donohue – No. 101, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: My doctor told me I should start taking medication for diabetes because my last reading was 108 (5.9), and the time before 110 (6.1). I informed the doctor that I would like to try to reduce the count myself without medicine. This did not please the doctor. I would appreciate your thoughts. – Anon.

You don’t have diabetes. You have prediabetes. After an eight-hour fast, a plasma glucose (blood sugar) of 126 mg/dL (7.0 mmol/L) or higher is diabetes, and the test should be repeated. A normal blood sugar is one less than 100 (5.6). The in-between numbers are prediabetes. People with prediabetes have to be watched more closely so they don’t become diabetics.

A modest weight loss – 5 percent to 10 percent of body weight, can often take a person out of the prediabetes category. Add some daily exercise – a weekly total of 150 minutes – and the chances of having a normal blood sugar increase. Brisk walking is a suitable exercise.

Having a go at lowering blood sugar without medicine shouldn’t rile the doctor.

DEAR DR. DONOHUE: My husband is on blood pressure and cholesterol-lowering medicine. He is now trying herbal medicines ordered from a catalog. I understood that when you are on medicines, you should consult your doctor before making changes or discontinuing them.

My husband says that he is going to stop all medicines. He is 57. I always thought blood pressure medicine was for life. What is the truth? – P.

The truth is that stopping medicines without consulting the doctor is foolhardy. Some people can get off blood pressure medicine by adhering to a strict, low-salt diet, losing weight and exercising. And some people can get off cholesterol medicine by adopting a low-fat – especially low-saturated-fat – diet. Giving up medicines blindly is asking for trouble, as is substituting unproven remedies.

DEAR DR. DONOHUE: My dad lived with us for five years. He was in his late 80s. All during those years, the only medical problem he talked about was constipation. About a month ago, he said he had a stomachache, and he thought it was due to constipation. This was on a Friday night, and I let things pass until Monday, when the pain got worse. I took him to the emergency room, and my dad was admitted to the hospital. For a full week he underwent testing. Then they diagnosed him with diverticulitis. That same night, he died. His death certificate said he died of peritonitis from diverticulitis. Would he still be alive if I had acted more quickly? – J.O.

You’re torturing yourself about something that doesn’t deserve the slightest bit of guilt. Your dad was in a hospital with doctors all over the place and with testing facilities that you certainly don’t have at your home. It took a full week for his physicians to diagnose his trouble. There is no way you could have made the diagnosis.

One of your father’s diverticula burst, and colon bacteria flooded his abdominal cavity causing the infection of peritonitis. That’s a very difficult infection to cure, even in an otherwise healthy, younger person. You did everything appropriately.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from

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