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BLOOD PRESSURE, CHOLESTEROL, AND ALZHEIMER’S:

THEY COULD BE CONNECTED

(April 2002)

Several studies have suggested that a high blood pressure is associated with an increased risk of Alzheimer’s disease years later. Others have found that a high cholesterol is a risk factor for subsequent development of Alzheimer’s disease. Healthful Life is intrigued with and has reported on two studies indicating those being treated with powerful cholesterol-lowering drugs called statins have a reduced risk of developing Alzheimer’s (see Archives article on Alzheimer’s).

All this is preliminary, but it is gathering support. A study from Finland published in the British Medical Journal June 16, 2001 examined the occurrence of Alzheimer’s in 1,449 men and women ages 40 to 64 years who were followed for an average of 21 years. At enrollment, blood pressure and total blood cholesterol levels were measured.

If the systolic blood pressure at enrollment was a little elevated (140 to 159 millimeters of mercury), there was almost a twofold greater risk of subsequently developing Alzheimer’s. This risk increased to between two and threefold if the systolic blood pressure was more elevated (over 160 millimeters). If the total blood cholesterol was quite high (over 250 milligrams, normal 200 milligrams or less), the risk of subsequent Alzheimer’s was 2.2 to 2.9 fold increased. If both systolic blood pressure and cholesterol were elevated, there was about a three-fold greater risk.

Interestingly, at the end of the long follow-up period, when the tests for Alzheimer’s were done, the cholesterol levels and blood pressure did not differ between those who developed Alzheimer’s and those who did not.

Commentary: The results reported here give some additional support to the argument that elevated blood pressure and elevated cholesterol level are possible risk factors for Alzheimer’s. Although the diastolic pressure at enrollment was not felt to be a risk factor, there was a trend to increased risk for those with a diastolic pressure over 95 millimeters of mercury (normal less than 90 millimeters of mercury, ideal 80 millimeters or less). In two other studies, the diastolic blood pressure elevation was more of a risk factor for Alzheimer’s than the systolic pressure.

It is a bit confusing that cholesterol levels and blood pressure at enrollment differed between those who subsequently would get Alzheimer's and those who did not, but not at the time of diagnosis of Alzheimer's, an average of 21 years later; possibly it was due to the effects of treatment for the high cholesterol or high blood pressure.

Another problem in applying these findings to other populations is that the average cholesterol levels in those who did and those who did not get Alzheimer’s were much higher on average than that found in, for example, the United States.

This is all very preliminary. We need a lot more evidence before we can tell whether a high blood cholesterol level or a high blood pressure promote Alzheimer’s disease. If they do, we need to understand the mechanisms. If treating a high cholesterol level with powerful statin drugs also reduces the risk of Alzheimer’s, is it due to the cholesterol lowering? Some experts think it is not and that it relates to some other action of the statin drugs, such as reducing evidence of inflammation.

Still, even if we do not have answers yet, it is another reason to get your cholesterol level and blood pressure checked regularly (Healthful Life recommends doing cholesterol at a biennial (every other year) prevention examination and blood pressure annually - and, if needed, take actions to keep both cholesterol and blood pressure in the normal range.

Kiuipetto, M., et al. Midlife vascular risk factors and Alzheimer’s disease in late life. British Medical Journal. Vol 322. (June 16) Pgs 1147-1151. 2001.