WEDNESDAY, Oct. 28, 2015 (HealthDay News) -- Medical science has made tremendous progress in prolonging the lives of people with type 2 diabetes. But, the prognosis still remains poor for patients who don't keep their blood sugar levels under control, according to results from a large-scale Swedish study.

People with type 2 diabetes carry a 15 percent increased risk of premature death compared to healthy people, the researchers reported in the Oct. 29 issue of the New England Journal of Medicine.

Those odds aren't great, but they're much better than they were as recently as 15 years ago, said senior author Dr. Marcus Lind, a physician at the University of Gothenburg in Sweden.

"Up to the year 2000, the excess risk of mortality in individuals with type 2 diabetes was generally considered to be doubled compared to the general population, implying a doubled risk to die during the following years," Lind said.

Now, the overall death rate for diabetics has "dropped to historical low levels," he added.

However, the risk of death is much higher in people younger than 65, those who poorly control their blood sugar levels, and those who've suffered kidney damage from type 2 diabetes, the researchers found.

The upshot is this -- type 2 diabetics have to do their part in managing their condition if they want the benefits that medical advances have wrought, said Dr. Robert Ratner, chief scientific and medical officer for the American Diabetes Association.

"If you develop diabetes, there is good evidence that attention to glucose [blood sugar] control and other cardiovascular risk factors from the onset can reduce any individual's risk of death," Ratner said.

The new study used data from the Swedish National Diabetes Register to compare the death rate among just over 435,000 people with type 2 diabetes with that of a healthy control group of 2.1 million people.

Type 2 diabetics younger than 65 have a death risk substantially greater than that of older diabetics, according to the study findings.

Excess risk of death was two to three times higher among those younger than 55, compared to between 30 percent and 40 percent higher for diabetics aged 65 to 75.

"What you begin to see is the increased risk of mortality in diabetes is highest the younger you are," Ratner said. "The significant impact is really in those individuals under the age of 75, and it gets progressively greater as you go younger."

The study authors speculated that the higher death rates seen among younger diabetics might owe, in part, to some gap in the care offered to these people.

Poor control of blood sugar levels can make that bad situation even worse for younger diabetics, the researchers found.

Anyone who didn't manage their diabetes through lifestyle changes, insulin or medication faced a greatly increased risk of death, said study co-author Dr. Mikhail Kosiborod. He is a cardiologist at Saint Luke's Mid America Heart Institute and a professor of medicine at the University of Missouri-Kansas City.

"If you look at the data, regardless of the age we look at, regardless of everything else, the worse the glycemic control the higher the mortality," Kosiborod said.

But diabetics under 55 with poorly controlled blood sugar had a more than fourfold increased risk of early death, compared to healthy people. That risk was 55 percent higher for diabetics 75 and older who didn't bother to manage their diabetes, the findings showed.

Finally, a patient's death risk skyrockets if poorly controlled diabetes results in damage to their kidneys, the researchers said.

Diabetics younger than 55 who've entered end-stage kidney disease are 14 times more likely to die than a healthy person, according to the study.

End-stage kidney disease also multiplies the death risk sevenfold for diabetics 55 to 64, and sixfold for diabetics 65 to 74, the investigators found.

"Renal [kidney] disease and worsened kidney function are huge risk factors for overall mortality, regardless of age group," Kosiborod said.

Kosiborod concluded that "the strong message from our data is that if you are a young patient, there's a lot you can do to protect your health."

These steps include eating right, quitting smoking, and controlling blood pressure and cholesterol levels, he said.

But the best thing a person can do is try to avoid getting type 2 diabetes in the first place, Kosiborod added.

Type 2 diabetes prevention is possible, he said. "Clinical trials have shown that aggressive and intensive lifestyle interventions can prevent diabetes. You should do everything you possibly can to prevent this condition from occurring," Kosiborod said.