Heart And Brain Health Linked

January 2008 - Two recent studies have thrown new light on links between cardiovascular and brain health.

Research led by the Johns Hopkins University School of Medicine published in Neurology showed that Alzheimer's disease (AD) may progress more rapidly in people with hypertension (high blood pressure) or atrial fibrillation (irregular heartbeat). The study concluded that treating these conditions may slow memory loss in patients able to tolerate current medication.

Lead researcher Michelle M. Mielke of the department of psychiatry and behavioral sciences said:

"The possibility that specific vascular conditions may affect how fast a person with AD declines provides new opportunities for slowing the rate of AD progression. Treatments for atrial fibrillation and high blood pressure are relatively inexpensive and safe and may reduce memory decline in AD patients with these conditions."

The study examined 135 men and women newly diagnosed with AD enrolled in the Cache County (Utah) Study on Memory Health and Aging, which has been monitoring 5092 people 65 or older since 1995. All had undergone annual memory tests for an average of three years.

Researchers found that ten participants with high blood pressure (systolic pressure over 160) when diagnosed with AD showed a rate of memory loss approximately 100 per cent faster than those with normal blood pressure. Ten with atrial fibrillation at the time of diagnosis showed a 75 per cent faster rate of memory decline than those without.

Michelle Mielke explained:

"What makes this group and study unique is that we have been following these participants in the community for over a decade, even before they were first diagnosed with AD, so we know a good deal about their medical history. Studies that enrol AD patients only from clinics may miss key factors, such as date of onset and history of cardiovascular disease and treatment."

Similar studies are in progress using larger sample sizes to increase understanding of the potential role played by vascular factors before AD diagnosis and during disease progression. Research led by Johns Hopkins psychiatrist Paul Rosenberg examining the effects of high blood pressure and high cholesterol treatments such as beta-blockers, diuretics, calcium-channel blockers and statins on cognitive and functional decline is due for publication.

In a separate study from the University of Pittsburgh presented at the annual meeting of the Radiological Society of North America researchers found reduced blood flow in the brains of adults with Alzheimer's disease and hypertension.

Co-author Cyrus Raji said:

"While hypertension is not a cause of Alzheimer's disease, our study shows that it is another hit on the brain that increases its vulnerability to the effects of the disease."

Researchers explain that according to the National Heart, Lung and Blood Institute, approximately 50 million Americans have hypertension and are at increased risk of heart attack, stroke and aneurysm. There is increasing evidence linking cardiovascular health to brain health.

Researchers used the non-invasive technique of arterial spin-labeled magnetic resonance imaging (MRI) to measure blood flow in the brain in a group of older adults including 48 normal individuals (of whom 38 had hypertension), 20 Alzheimer's patients (50 per cent with hypertension) and 20 with mild cognitive impairment (50 per cent with hypertension). Researchers explain that mild cognitive impairment (affecting brain functions such as language, attention and reasoning) is a transition stage between normal aging deficits and greater levels of dementia.

The study found that blood flow in the brain was substantially decreased in all patients with hypertension compared to those without. Cerebral blood flow was lowest among Alzheimer's patients, but was also significantly lower in those with hypertension in the normal group.

Co-author Oscar Lopez, professor of neurology and psychiatry added:

"This study demonstrates that good vascular health is also good for the brain. Even in people with Alzheimer's disease, it is important to detect and aggressively treat hypertension and also to focus on disease prevention."

Related Articles

• Mediterranean Diet May Help Alzheimer's
  A Mediterranean diet may help people with Alzheimer's disease live longer than those relying on a more traditional Western diet.
• Health Benefits of Olive Oil
  New research suggests that significant differences in cancer rates between northern and southern Europeans may be explained by the anti-cancer effects of olive oil in the diet.
• Loneliness Affects Health
  Pointing out that loneliness is not the same as solitude which can be highly valued they nevertheless conclude that social isolation and physical aging may have a deleterious effect on health.
• Fruity Vegetables Reduce Childhood Asthma
  A diet rich in fish and "fruity vegetables" such as tomatoes, aubergines, cucumber, green beans and courgettes can reduce childhood asthma and allergies.