Treating high blood pressure, high cholesterol, diabetes and other vascular risk factors may help lower the risk of Alzheimer's disease in people who already show signs of declining thinking skills or memory problems. The research is published in the April 13, 2011, online issue of Neurology, the medical journal of the American Academy of Neurology.
Researchers followed 837 people with mild cognitive impairment, the stage of memory loss that often leads to Alzheimer's disease. Of the group, 414 had at least one vascular risk factor. Participants were given blood tests and a medical history questionnaire and also underwent other tests that measured blood pressure, body mass, memory and thinking skills.
Participants who had vascular risk factors were placed into three groups: those with no risk factors treated, those with some risk factors treated and those with all risk factors treated. Treatment of risk factors included using high blood pressure medicines, insulin, cholesterol-lowering drugs and diet control. Smoking and drinking were considered treated if the person stopped smoking or drinking at the start of the study.
After five years, 298 people developed Alzheimer's disease. The others still had mild cognitive impairment. People with risk factors such as high blood pressure, diabetes, cerebrovascular disease and high cholesterol were two times more likely to develop Alzheimer's disease than those without vascular risk factors. A total of 52 percent of those with risk factors developed Alzheimer's disease, compared to 36 percent of those with no risk factors.
Of those with vascular risk factors, people who were receiving full treatment were 39 percent less likely to develop Alzheimer's disease than those receiving no treatment. Those receiving some treatments were 26 percent less likely to develop the disease compared to people who did not receive any treatment.
"Although this was not a controlled trial, patients who were treated for their high blood pressure, high cholesterol, heart disease and diabetes had less progression of their memory or thinking impairment and were less likely to develop dementia," said study author Yan-Jiang Wang, MD, PhD, with the Third Military Medical University in Chongqing, China.