DEAR DR. DONOHUE: I am 82. Enclosed are copies of the tests done on my carotid arteries. I would appreciate your opinion on the test results. – M.P.

ANSWER: The tests are sound-wave tests of your carotid arteries. The carotid arteries divide into the internal and external carotids. The internal carotids supply the brain with blood. Blocked internal carotid arteries are a cause of strokes.

There’s a 60 percent to 79 percent narrowing of your right internal carotid artery and a 40 percent to 59 percent narrowing of your left internal carotid. The 19 percent range of narrowing on the report is very large. It would be helpful if the radiologist could narrow that range.

The general advice given for carotid narrowing goes roughly like this: If people have a 70 percent to 99 percent narrowing and if those people have symptoms or have had a previous stroke or TIA (ministroke), surgically removing the artery buildup reduces the risk of having a first or repeat stroke.

If I understand your situation correctly, you have had no symptoms from the narrowing. You are over 75. Most doctors would tell you to pay attention to those things that contribute to stroke prevention – maintaining normal blood pressure, lowering cholesterol, strictly controlling diabetes, exercising, not smoking. Surgery might be advised only for those your age with special circumstances.

The stroke booklet explains the different kinds of stroke, their treatment and their prevention. Readers can order a copy by writing: Dr. Donohue – No. 902, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.00 Can. with the recipient’s printed name and address.

DEAR DR. DONOHUE: I weigh 165 pounds, and my waist is 44 inches. I know a large waist puts me at a high risk for a heart attack. Please explain why. – M.P.

ANSWER: The two main areas for fat deposits are under the skin – subcutaneous fat – and deep in the abdomen, surrounding organs like the liver and small intestine – visceral fat. I always thought that fat was fat. It turns out that isn’t true. Visceral fat is criminal fat. It has direct access to the liver, which turns it into cholesterol. Visceral fat is also an active organ. It releases chemical substances that incite inflammation, including artery inflammation. Inflamed arteries become clogged arteries, and that’s another reason why this kind of fat increases the risk for heart attack and stroke. It also releases substances that make body cells less responsive to insulin, so blood sugar rises, with all the complications that such a rise generates.

A man’s waist should measure 40 inches (102 cm) or less, and a woman’s 35 inches (89 cm) or less.

Exercise – walking, jogging, biking and swimming – reduces visceral fat.

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 www.rbmamall.com