Diabetes a growing problem in United States

Janice Hopkins Tanne New York BMJ 2001;322:194 British Medical Journal 27jan01

The United States, like many other industrialised countries, faces a diabetes epidemic. "Sixteen million Americans—6% of the population—have diabetes, and one third of them don’t even realise it; 800 000 will be diagnosed this year. It is the leading cause of blindness, end stage renal disease, and leg amputations and the seventh leading cause of death," Dr Susan Hershberg Adelman told a seminar in New York last week.

Dr Adelman, a trustee of the American Medical Association, spoke at a meeting jointly sponsored by that association, the American Diabetes Association, and the pharmaceutical firm Aventis.

Worldwide, about 140 million people have diabetes, and the number will rise to 300 million by 2025, including 22 million in the United States. The incidence of type 2 diabetes, previously considered a disease of elderly people, is rising steeply among young adults and children. Asians, African-Americans, Latinos, and native Americans are at highest risk.

Type 1 diabetes, an autoimmune disease, "can be predicted in man and prevented in animal models," said Dr George Eisenbarth, a paediatric diabetes specialist at the University of Colorado Health Sciences Center in Denver. About 40% of the US population carry a gene predisposing to diabetes and other autoimmune diseases.

Family members of individuals with diabetes should be screened by measuring autoantibodies in the blood. Some prevention trials use insulin as a vaccine to "re-educate" the white blood cells that cause diabetes by attacking b cells in the pancreas. "If we had a safe and effective therapy to prevent diabetes, I think we would screen all children," Dr Eisenbarth said.

The major complications of diabetes are heart attack and stroke, not retinopathy, nephropathy, and neuropathy, said Dr Henry Ginsberg, professor of medicine at Columbia University College of Physicians and Surgeons in New York. "Eighty per cent of hospitalisations for patients with diabetes are for macrovascular disease, and 75% of deaths in patients with diabetes are cardiovascular deaths," he said, adding that these occur mostly in patients with type 2 disease.

A 50 year old patient with "average" blood pressure and cholesterol levels has a 7% chance of a heart attack within the next 10 years, but a similar patient with diabetes has a 40-50% risk, he said.

Dr Ginsberg urged doctors to treat diabetic patients with drugs if weight reduction and increased activity are not quickly successful. Insulin resistance is linked to risk factors for cardiovascular disease—high levels of triglycerides, low LDL (low density lipoprotein) cholesterol level, hypertension, increased hypercoagulability, and decreased ability to break down the clots. Treatment, he said, should include lowering blood pressure, treating lipids with a statin drug, and prophylactic aspirin.

· A study published in Circulation (2001;103:357-62) last week showed that pravastatin reduced the risk of type 2 diabetes. Patients with high cholesterol levels were given pravastatin in the west of Scotland coronary prevention study in an attempt to lower their risk of heart attacks. These patients turned out to have a 30% lower risk of developing diabetes.