The number of adults in California diagnosed with diabetes rose from 1.5 million in 2001 to 1.8 million in 2005, with Native Americans, Latinos and Asians showing the biggest increases.
Overall, a report released Wednesday found that 7% of California adults were diagnosed in 2005 with the chronic disease that, if not managed, can lead to blindness, kidney failure, heart attack and leg or foot amputations.
Experts estimate that the actual numbers are higher by as much as one-third because Type 2 diabetes, the most common type of the disease, can go undiagnosed for years.
“This is the tip of the iceberg,” said Dr. Allison L. Diamant, an associate professor at UCLA’s David Geffen School of Medicine and the report’s lead author.
The survey, released by the UCLA Center for Health Policy Research, was unusual in that it looked at diabetes prevalence not just among ethnic groups but within them.
In Latinos, for example, the prevalence of diabetes in Californians of Mexican descent increased from 7.2% in 2001 to 8.2% in 2005. Diabetes in those of Central American heritage rose even more dramatically, from 5.2% in 2001 to 8.7% in 2005.
But the most surprising findings were for Californian Asians. Native Americans, Latinos and African Americans have long had high rates of diabetes compared with whites.
However, the UCLA report found that while the prevalence of diabetes in whites rose from 5.6% in 2001 to 6% in 2005, in Californians of Asian heritage it swelled from 5% to 6.5%. California has the largest population of Asians in the United States.
Californians of Japanese heritage had the highest prevalence of diabetes at 10.2%, followed by Filipinos (8.6%), Koreans (7.4%) and Vietnamese (7%). Those of Chinese descent had a prevalence rate of just 4.4%.
One reason for the increase in diagnoses might be linked to when groups of immigrants arrived. Previous studies have found that immigrants often arrive in good health but in subsequent years adopt American fast-food and sedentary habits that future generations continue.
“Living in the U.S. is not necessarily good for your health, especially if you’re low-income,” Diamant said.
In poorer neighborhoods, nutritious food and safe places to exercise can be scarce.
Obesity is strongly linked to Type 2 diabetes. Genes also play a role, influencing, among other things, how and where a person stores fat. Native Americans have a strong genetic predisposition to diabetes, and many Latinos share some of that genetic heritage, said Dr. Mayer B. Davidson, an endocrinology professor at Charles R. Drew University of Medicine and Science and at UCLA’s School of Medicine, who was not associated with the study.
Another surprising finding in the study was that the already high prevalence of diabetes in African Americans remained flat at 10.1%, which could mean that education and awareness campaigns in that community are paying off, Diamant said. Or it could mean that many African Americans are going without medical care, which means they aren’t being diagnosed, she said.
Davidson believes it must be the latter.
“I am surprised that it’s not going up,” Davidson said. “African Americans in general are more obese as a group than other populations.”
Diabetes prevalence in the state was found to be at a low of 2.5% in Nevada County, which is nestled against the Sierra Nevada northeast of Sacramento, and at a high of 11.2% in Imperial County, which borders Arizona and Mexico.
In Los Angeles County, the rate of diabetes was 7.2% of the adult population. But because of its overall population size, it has the greatest number of people with diabetes in the state: 520,000. The same can be said for California overall. Its prevalence rate is no higher than the national average, but it is the most populous state.
The survey was based on data from the California Health Interview Survey, which is conducted every two years in English, Spanish, Mandarin, Cantonese, Vietnamese and Korean with 43,000 adults from every county in the state.