Diabetes, Hypertension Linked to Cognitive Decline

N E W   Y O R K, Jan. 9, 2001 -- A decline in cognitive skills are not normally associated with diabetes and high blood pressure, but a new study shows people who suffer from the conditions could start losing mental abilities in middle age.

Led by Dr. David Knopman, the study conducted at the University of Minnesota tested the mental abilities of nearly 11,000 people between ages 47 to 70 at four sites around the country. Researchers then re-tested and compared participants’ scores six years later, finding that averages declined across the board, with a modest but statistically significant drop evident among diabetes and high blood pressure sufferers.

“This study showed that diabetes and hypertension were risk factors for losing cognitive function over the six years that we examined people,” Knopman said. He explained that volunteers took several mental function tests, one of memory and two tests of mental agility, doing things against a clock and solving a puzzle of sorts.

Those with either or both conditions were less able to think on their feet, Knopman said. “What we saw specifically was actually not that memory declines in people with diabetes and hypertension, but rather that their speed of doing things mentally declined.”

Though the cognitive decline over six years was so small that the patients themselves might not even notice it, the losses were strikingly consistent, Knopman said. The study was published in the current issue of the journal Neurology.

Link to Alzheimer’s

Knopman said the findings supported other work that associates mental declinewith diabetes. Smoking and having high cholesterol levels werenot linked with the mental declines, the researchers found.

There may be a link to Alzheimer’s, he added.

“We feel that the cognitive loss [seen in] diabetes andhypertension might make a person more susceptible to developingAlzheimer’s disease in the future,” Knopman said. “These thingsdon’t cause Alzheimer’s disease, but they might make it morelikely that a person would get it later in life.”

Knopman said it was not clear how the two conditions, whichaffect millions of Americans, might cause a loss of brainfunction. “Treatment of diabetes and hypertension is important even in middle age, not just in the elderly, for preventing cognitive decline in later life,” says Knopman, who is now at the MayoClinic in Rochester, Minn.

A survey of 1,000 Americans published on Monday found that 39percent considered themselves overweight, but only a thirdconsidered themselves at risk of developing diabetes. In fact,well over half of all Americans are overweight and beingoverweight greatly increases the risk of diabetes.

A companion survey of doctors found that 59 percent weremost worried about their patients being overweight because ofthe risk of diabetes.

“These survey results are alarming because they show thatAmericans are not making the connection between beingoverweight and developing Type-2 diabetes,” Dr. StevenHeymsfield, deputy director of the New York Obesity ResearchCenter at St. Lukes-Roosevelt Hospital, said in a statement. An estimated 14 million to 15 million Americans haveType-2 diabetes, which develops later in life, and as many as50 million Americans ages 6 and older have high bloodpressure.

The Associated Press contributed to this report.