By Suzanne Leigh, Medical Tribune News Service
Light drinking has long been associated with protection against
heart disease. Now new research indicates that moderate alcohol
intake may benefit patients with type 2 diabetes, also known as
adult-onset diabetes.
In a study published Wednesday in the Journal of the American
Medical Association, researchers found that the risk of fatal heart
disease among people with diabetes who consumed one or more
alcoholic beverages a day fell to one-fifth of the risk faced by
lifetime teetotalers with diabetes.
In the study, Dr. Charles Valmadrid and colleagues at the
department of ophthalmology and visual sciences at the University
of Wisconsin-Madison Medical School identified 983 people with
diabetes, average age 68, and questioned them about their present
and former drinking habits.
Study participants were tracked for 12 years.
The researchers used lifetime abstainers as a baseline of 1.00
by which to compare the relative risk of death due to heart
disease. They also adjusted for factors such as age, gender,
smoking, insulin use and conditions related to heart disease.
They found that those who consumed less than one drink per week
had a relative risk of dying from heart disease of 0.54. For those
who consumed one or more alcoholic beverage per day, the risk was
0.21.
Commenting on this risk disparity, the authors said that the
benefit of alcohol ``seems greatest in individuals at higher risk
of cardiovascular mortality.''
Heart disease is the leading cause of death in the general
population but among type 2 diabetics the incidence is two to four
times higher, according to the Bethesda, Md.-based National
Diabetes Information Clearinghouse.
The elevated blood-glucose levels that result from the body's
failure to either make sufficient insulin or utilize adequately
that which it does make can alter the structure of blood vessels.
Over time, fatty substances accumulate on the walls of the blood
vessels, stunting circulation and damaging the heart and other
organs.
In an accompanying editorial, Drs. Michael Criqui and Beatrice
Golomb of the department of medicine at the University of
California at San Diego, said the Valmadrid study confirmed that
moderate alcohol consumption ``likely provides benefit.'' However,
it is possible that this benefit has been inflated by comparing the
death rates of lifetime alcohol abstainers with moderate drinkers.
``Clearly those who avoid alcohol consumption include an
overrepresentation of persons destined for a less favorable
risk-benefit ratio were they to drink,'' the authors noted.
More seriously, alcohol can exacerbate diabetic nerve damage and
worsen insulin resistance, they said. It can also induce low
blood-glucose levels. Typically when glucose levels drop, the liver
converts stored carbohydrate into glucose. But when alcohol is
consumed, the liver acts to clear it from the blood instead. The
onset of hypoglycemia, or low blood-glucose levels, can occur very
quickly and in severe cases can result in coma and brain damage.
The Alexandria, Va.-based American Diabetes Association (ADA)
cautions patients with uncontrolled diabetes from consuming
alcohol. In addition to the risks of hypoglycemia, nerve damage and
diabetic eye disease, alcohol is high in calories and low in
nutrition, factors that are contrary to dietary recommendations.
Poor diet and obesity are associated with diabetes and diabetic
complications, according to the ADA.
