It’s hard to know how to think about prediabetes, a condition in which a person’s blood sugar level is higher than normal but not high enough to qualify as full-blown diabetes. On the one hand, many people with prediabetes go on to develop diabetes, which is now the seventh-leading cause of death in the United States — but on the other hand, most don’t. Indeed, the condition is — paradoxically — both underdiagnosed and overdiagnosed, researchers say.
Confused? You’re not alone. A 2019 survey of primary care physicians showed they have limited knowledge about which patients should be screened for prediabetes, how to read lab tests to diagnose it and what to advise patients who are diagnosed.
One reason may be that five definitions — based on three types of blood-sugar tests — are in use in the United States, says Elizabeth Selvin, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health. In a recent article in the Annual Review of Public Health, Selvin and a colleague argued that the multiple definitions may explain why physicians might be uncertain about whether or how to act on screening results. The vast majority of people who have the condition are unaware of it, according to the US Centers for Disease Control and Prevention.
“When you don’t have consensus in the field of how to define something, how to diagnose it, and what to do, I think that creates a lot of confusion,” she says.
The picture isn’t getting any clearer, either. Emerging research suggests that high levels of blood glucose are not the whole story for prediabetes. An international research team recently identified six subtypes of prediabetes — three serious and three less so — that may provide new insight into why the condition affects individuals differently.