Study suggests diabetes screening should be guided by age, not weight

Millions of diabetes cases may be missed under the current U.S. screening guidelines, especially among Asian Americans, according to a new study. A better way to test for the condition would be to leave body weight out of it, the researchers suggest.

Current guidelines from the U.S. Preventive Services Task Force recommend screening adults ages 35-70 who are considered overweight or obese (having a body mass index over 25).

However, racial and ethnic minority groups, especially Asian people, tend to develop diabetes at lower BMIs, so to identify more people with the condition across groups, all adults ages 35-70 regardless of their weight should be screened, researchers said in a study Friday in the American Journal of Preventive Medicine.

“It’s a strategy that’s most likely to promote health equity,” said Matthew O’Brien, the lead author and an associate professor of medicine at Northwestern University Feinberg School of Medicine.

The researchers first looked at the amount of cases that would be detected under current guidelines, which were last updated in 2021, lowering the minimum age for screening to 35 from 40.

Looking at a national survey that recorded people’s blood sugar levels, the researchers found that the new guidelines do detect a greater share of people with people with prediabetes or diabetes. However, the percentage of cases identified among Asian people is significantly lower than for other racial and ethnic groups.

The researchers then looked at the amount of cases that would be identified if all adults ages 35-70, regardless of BMI, were screened. That criteria detects more cases within the broad population and more equal percentages of diabetes cases across racial groups.

The researchers also looked at lowering the minimum age to 18. While that also increases the amount of cases identified in the broad population, it results in large differences in diabetes detection across racial groups.

The trade-off of expanding the eligibility pool for screening is that there’s also a greater chance of testing people who don’t have prediabetes or diabetes.

Elizabeth Selvin, a professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health who was unaffiliated with the study, noted that the study doesn’t analyze the costs of expanded screening compared with the benefits.

“There is strong evidence that health care providers are already doing a good job with screening and diagnosis of diabetes in the U.S.,” she said. A study she worked on last year concluded that the proportion of undiagnosed cases has declined substantially over the last three decades and currently affects 1-2% of adults.

O’Brien, though, argued that the blood test to screen for these conditions is cheap and comes with few risks. To him, the goal should be to find as many cases as possible.

“I think the best approach is really just to maximize the detection of diabetes across the entire population and across all demographic groups that we care about,” he said. Given the serious harms linked to diabetes, including vision impairment, nerve damage, kidney disease, and heart disease, he added, “The earlier you treat diabetes, it has huge dividends in terms of getting diabetes under control more easily and then preventing downstream complications.”

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