The number of people with diabetes rose 17 percent in the U.S. between 1980 and 1987, an increase federal health researchers attribute to the aging of America.

The largest increase was among white males, though diabetes remains most prevalent among black females, according to the Centers for Disease Control.

In a related report by the CDC, a study of diabetes conducted between 1988 and 1989 found that it was most prevalent in the eastern states, with the highest rate in the District of Columbia.

The 38-state study of prevalence by race and sex found that during the seven-year period the number of white males with diabetes mellitus, the most common form of the condition, increased 33 percent -- from 2.1 million to 2.8 million.

The increase among black females was 24 percent, and among black males it was 16 percent; the incidence among white females remained unchanged.

Minorities continue to be more susceptible to diabetes, the CDC said. In 1987, for example, the prevalence among black females was more than twice that among white females -- 50.9 cases per 1,000 black females, compared with 23.4 per 1,000 white females.

Prevalence among black males was about one third higher than for white males, the CDC said.

For the nation as a whole, according to the CDC, cases of diabetes increased from 5.8 million 1980 to 6.8 million in 1987.

The CDC's estimates were based on self-reported cases, which health officials believe constitute only about half the total cases.

The report was based on a household survey of 120,000 U.S. residents who were asked if anyone in the family had had diabetes during the previous 12 months.

"Most of the increase is explained by the aging of the United States," said David Olson, a statistician with CDC's Center for Chronic Disease Prevention and Health Promotion, which prepared the report. "With increased age, there is a higher frequency of diabetes."

Olson said health officials are not sure why diabetes occurs more among minority groups, though some believe it is because blacks, Hispanics and Indians tend to have less access to preventive medicine.

Jeff Newman, an epidemiologist at the CDC's chronic disease branch, said the higher incidence of diabetes among minorities probably explained the regional differences in the state-by-state study. "The states that have large proportions of these groups do have a higher prevalence," he said.

Newman said the purpose of the state study was primarily to help plan local prevention programs, and he cautioned against drawing conclusions about anything in the states themselves that might be increasing the risk of diabetes.

The District of Columbia showed the highest prevalence, with 8.7 cases per 100 people. Other states with more than six cases per 100 included Michigan, with 7.1; Hawaii, 6.4; Alabama, 6.2; South Carolina, 6.1, and West Virginia, 6.1.

Montana had the lowest prevalence, with 2.8 cases per 100 people. Other states with fewer than four per 100 included Minnesota, with 3.2; Maryland, 3.6; Oklahoma, 3.6; South Dakota, 3.8; Utah, 3.8; Arizona, 3.9, and Nebraska, 3.9.

The CDC said that in 1987, costs associated with medical care and lost productivity due to diabetes amounted to $20.4 billion.

"Based on the increase in the number of people with (diabetes mellitus), the substantial economic and health care burden . . . is expected to increase," the report said.