More than one out of every three individuals in the United States have diabetes and another 26 percent have impaired fasting glucose, which increases the risk of developing diabetes, new study findings suggest.

The prevalence of diagnosed diabetes has increased in recent years, while undiagnosed diabetes and impaired fasting glucose has remained constant over the past decade.

“Despite public health messages, we’re not finding a counterbalance of fewer people with undiagnosed diabetes,” study co-author Dr. Catherine C. Cowie, of the National Institute of Diabetes and Digestive and Kidney Diseases, in Bethesda, told Reuters Health.

The findings are based on an analysis of four years of data from the National Health and Nutrition Examination Survey (NHANES). The study included information on 4,761 adults, age 20 years or older, who were classified according to their glycemic status. Cowie and her team compared data from the 1999-2002 with data from 1988-1994.

Over 35 percent of study participants, representing 73.3 million individuals had diabetes or impaired fasting glucose in 2002, the researchers report in the journal Diabetes Care. A total 9.3 percent had diabetes in 1988-2002 and the prevalence of undiagnosed remained stable at 2.8 percent during this period.

However, the prevalence of diagnosed diabetes rose from 5.1 percent in 1988-1994 to 6.5 percent in 1999-2002. They also estimate that about one third of diabetics are undiagnosed.

“We were surprised by the fact that diagnosed diabetes is increasing,” Cowie said. “We need to do a better job of diagnosing those one in three who don’t know they have it (diabetes) and finding those with impaired fasting glucose.”

SOURCE: Diabetes Care, June 2006.