The number of Americans with diabetes increased by more than 3 million in the past two years, according to new estimates released yesterday by the Centers for Disease Control and Prevention.

Diabetes now affects nearly 24 million people in the United States, or nearly 8 percent of the population, according to data for 2007. An additional 57 million are estimated to have "pre-diabetes," putting them at greater risk of the disease, the CDC said.

The state Department of Health estimates that 80,000 people in Hawai'i have diabetes, including 34,000 who are undiagnosed.

Although 2007 estimates for states and counties were not immediately available from the CDC, the latest results from the Department of Health survey upon which the data are based show the prevalence of diabetes is rising here.

The Behavioral Risk Factor Surveillance System survey for 2007 indicates that approximately 7.7 percent of Hawai'i's population has been diagnosed with diabetes, up from 7.1 percent in 2004, the most recent Hawai'i data from the CDC.

Five years ago, the prevalence of diabetes in Hawai'i was estimated at 6.4 percent, and 10 years ago at 5.3 percent, according to the CDC.

Retired endocrinologist and diabetes expert Dr. Wilfred Y. Fujimoto said the increase in diabetes cases probably is due both to increased awareness and diagnosis by healthcare providers and rising rates of risk factors for the disease, such as obesity and age.

Sandi Chang, supervisor of the Health Department's Chronic Disease Section, said climbing diabetes rates across the nation go hand-in-hand with the "obesity epidemic." Approximately 80 percent of people with diabetes in Hawai'i are overweight or obese.

She said losing up to 10 percent of body weight — 20 pounds for someone who weighs 200 pounds — can stave off the disease in those bordering on diabetes.

Diabetes occurs when the body does not produce or properly use insulin, a hormone made by the pancreas that allows glucose (sugar) from food to enter cells and be converted to energy.

When diabetes is not controlled, glucose and fats build up in the blood and, over time, damage vital organs and lead to potentially fatal complications such as heart attack, stroke, kidney failure, blindness and lower-limb amputation.

People with Type 1 diabetes produce no insulin. To survive, they must have insulin delivered by injection or a pump. Another type of diabetes is gestational diabetes, which occurs in about 4 percent of all pregnant women.

More prevalent is Type 2 diabetes, which can develop at any age, including childhood. Treatment includes making wise food choices, being physically active, losing excess weight and taking medication.

MAUI'S RATE HIGHEST

Medical and public health officials call diabetes a "silent disease" that can exist in a patient for years before it is diagnosed, usually when treatment is sought for one of its many complications.

"It's slow and gradual. It sneaks up on you, and you don't even realize you have it," Chang said.

Of particular concern to health officials in Hawai'i is the higher incidence of diabetes among Asians, Native Hawaiians and Pacific Islanders. Chang said it is not clear whether this is due to genetics, income levels, access to healthcare or a combination of factors.

The department's Behavioral Risk Factor Surveillance System survey for 2007 estimates a diabetes prevalence rate of 14 percent — highest in the state — in Nanakuli/Wai'anae, an area with a large population of Native Hawaiians and Pacific Islanders.

The survey said that 11.4 percent of Native Hawaiian respondents indicated they had been diagnosed with diabetes, compared with 9.1 percent Japanese, 7.8 percent Filipino and 4.7 percent white.

The 2007 survey, which asks participants if they have been told by a doctor that they have diabetes, also shows Maui County with the highest prevalence of the disease at 8 percent, followed by Honolulu at 7.8 percent, Hawai'i at 7 percent and Kaua'i at 6.9 percent.

Drawing any conclusions from the county data is difficult, because the estimates are based on phone surveys conducted on a random basis, so the numbers vary widely from year to year. State health officials say prevalence rates actually are similar across Hawai'i's counties.

Fujimoto, professor emeritus of medicine at University of Washington, said an increase in diagnosed cases could mean several things.

"Remember that the data are obtained by telephone survey and, therefore, depend upon people having phones, not cell phones, and that these are diagnosed cases of diabetes, which means that some populations, depending upon whether they see healthcare providers, may have disproportionately greater numbers of undiagnosed cases," he said.

"Conversely, some of the high rates may be due to greater access to healthcare providers."

GREATER AWARENESS

Chang said in either event, there is a continued need for public understanding of diabetes, which is perceived differently than acute illnesses.

"When you get cancer, people say, 'Poor thing. It's not his fault.' There is a lot of sympathy connected to it. And when you have a heart attack, you fix it or you die," she said.

"With diabetes there seems to be a sense of blame" because it involves lifestyle issues such as proper diet and exercise.

Much of the treatment takes place outside the doctor's office at home, she said.

"It's day to day, every single day, moving around, getting exercise, portion control and watching what you eat," Chang said. "It falls on the person and with their family. It's a entire lifestyle change."

Diabetes still disproportionately affects the elderly. Almost 17.5 percent of respondents 65 years and older said they had diabetes in 2007, according to DOH estimates.

The survey also showed a higher prevalence of diabetes among those with lower levels of education and income.