People in states that expanded Medicaid are more likely to be newly diagnosed with the disease. (Jorge Dan Lopez/Reuters)

People in the more than two dozen states that expanded Medicaid under the health-care law are far more likely to be newly diagnosed with diabetes than those in states that did not expand Medicaid, according to a study being published Monday.

The increased access to Medicaid, the state-federal program for the poor and disabled, resulted in more people getting tested for and diagnosed with one of the most prevalent and treatable chronic conditions in the United States, said the researchers from Quest Diagnostics, a private clinical laboratory.

For the study, researchers analyzed test results, stripped of identifying information, of Medicaid recipients diagnosed with diabetes in the first half of 2014. They found that diabetes cases jumped 23 percent from the year before in the 26 states and the District of Columbia, all of which expanded their Medicaid programs. In the nonexpansion states, the increase was less than 1 percent.

The analysis is being published online in Diabetes Care, the official publication of the American Diabetes Association.

Ann Albright, director of the Division of Diabetes Translation at the Centers for Disease Control and Prevention, and Judith Fradkin, director of the Division of Diabetes, Endocrinology, and Metabolic Diseases at the National Institutes of Health, talk about the need to identify those with pre-diabetes. (Meena Ganesan/Washington Post Live)

The study, which is being published five years to the day after President Obama signed the Affordable Care Act, is one of the first nationally representative analyses of the impact of the law on earlier diagnosis of diabetes, which is at epidemic levels in the United States and globally, researchers said.

“I cannot think of any other explanation except these people have now got health insurance” and are going to the doctor and getting tested, said study co-author Vivian Fonseca, a professor of medicine at Tulane University.

The earlier that patients have diabetes diagnosed, the more likely they are to be treated and to avoid other serious health risks. Patients with the illness have a higher risk of heart disease, stroke, kidney failure and blindness, and of losing toes, feet and legs to amputation. The risk of death for adults with diabetes is 50 percent higher than it is for adults without the disease, according to the Centers for Disease Control and Prevention.

Earlier research about Oregon’s 2008 experiment with Medicaid expansion also found that the health coverage significantly increased the probability of a diabetes diagnosis.

“What we’re seeing here is that this is playing out at a national level in much the same way,” said Ben Sommers, an assistant professor of health policy and economics at Harvard T.H. Chan School of Public Health, referring to the diabetes study.

An accompanying editorial in Diabetes Care said the “real-world benefits and costs of Medicaid expansion” should be used to guide health policy “to address the growing burden of chronic diseases.”

For the first few years after the ACA’s enactment, the debate over the law was largely hypothetical because its major provisions had not yet gone into effect, said Larry Levitt, senior vice president at the Kaiser Family Foundation. Now, “people can really start to assess what the law means in tangible terms, like how many people have gotten insurance and what that coverage means for their finances and their health,” he said.

Researchers are looking into the possibility of using a similar approach to analyze other chronic conditions, such as high cholesterol, high blood pressure and other preventive health screenings that consumers are more likely to get if they have health insurance, Fonseca said.

One of the main goals of the Affordable Care Act was to broaden Medicaid to cover a wider array of adults. Under the law, uninsured adults with incomes at or below 138 percent of the federal poverty level ($16,242 for an individual in 2015) would be eligible for Medicaid, increasing access to millions of people who were previously excluded from the public health insurance program.

The law, as enacted in 2010, required all 50 states to expand Medicaid, but the Supreme Court ruled in 2012 that states could not be compelled to expand their programs. At the time that Quest researchers were conducting their diabetes analysis, 26 states and the District had expanded their Medicaid programs, while 24 states had not. Medicaid continues to be at the front lines of the continuing political and ideological battle over the Affordable Care Act. Currently, 28 states and the District are expanding coverage.

In the analysis, Quest researchers said the division between the states over Medicaid expansion created an opportunity to look at the impact of that expansion on specific health metrics, such as disease detection. They chose diabetes as an indicator because more than 29 million Americans, or 9.3 percent of the U.S. population, have diabetes. About a quarter of them don’t yet realize it, according to the CDC. An additional 86 million Americans have pre-diabetes, which is marked by higher-than-normal blood sugar levels and puts them at an elevated risk of developing diabetes.

Researchers found that in the first six months of 2013 — before the Medicaid expansion took effect — there were 14, 625 patients who were newly diagnosed with diabetes in those states and the District of Columbia. By the first six months of 2014, however, there were 18,020 such patients in those same states, an increase of 23 percent.

By comparison, in the states that didn’t expand Medicaid, 11,612 patients were diagnosed with diabetes in the first six months of 2013. In 2014, there were 11,653 such patients, an increase of 0.4 percent.