Going Down

Good Question: Why Is Diabetes Incidence Going Down?

Diabetes Incidence TrendsThis is now unmistakeable. And it seems like a rare piece of good news. For the first time in decades, diabetes incidence is going down. The real question is, why?

And the honest answer is nobody knows.

A Trend That Started in 2008

Stephen Benoit and colleagues from CDC analyzed U.S. trends in the diabetes incidence and prevalence since 1980. For nearly 20 years, from 1990 to 2008, both incidence and prevalence grew. More new cases of diabetes and more people living with diabetes every year. But 2008 was the peak.

After that, new cases started declining. The number of people living with diabetes didn’t go down. More than 30 million Americans have it. That’s way too many, even though the total number has stopped growing.

But Why?

The short answer is that no one knows. Lots of things have changed, so we have many suspects. Diabetes prevention efforts might have played a role. More doctors are diagnosing prediabetes and attention to patients at risk might be helping. Another factor might be the dietary changes. Americans are eating less sugar and drinking less of it, too. That might be helping.

Overweight and Obesity?

Unfortunately, a key risk factor for diabetes – obesity – is still rising. The prevalence reached nearly 40 percent in 2016. Looking a bit closer though, you can see that we may be reaching a point where everyone who is susceptible to gaining weight already has overweight or obesity.

Prevalence of BMI Under 25

A BMI of 25 marks the dividing line between a healthy weight and overweight. This is useful for population studies, even though individual risks may vary. And what we’re seeing is that the population with a BMI less than 25 is no longer shrinking as fast as it did for the last three decades. In fact, for men, it looks like it’s been stable since about 2008.

Coincidentally, that’s also when new diabetes cases peaked.


A final and important note is that disparities in these trends are growing worse. The drop in new diabetes cases is mostly benefitting older, non-hispanic white adults. Diabetes prevalence is still growing for younger adults, blacks, and hispanics.

So we’ve hardly solved this problem. Rather, it seems that the dynamics are shifting. And much work lies ahead to reverse it.

Click here for the study and then here, here, and here for further perspective.

Going Down, photograph © CJS*64 / flickr

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2 Responses to “Good Question: Why Is Diabetes Incidence Going Down?”

  1. May 30, 2019 at 9:40 am, Mary-jo said:

    If prevalence growing in young adults, blacks, and Hispanics, it must have something to do with access to care and, as you mentioned, the attention and control for prediabetes, controlling it before it moves to diabetes. Compared to older, on-Hispanic, white adults, the first 3 groups typically don’t get routine medical attention, or even, when necessary, unless urgent care. I’m curious what the incidence and prevalence are in ages up to 20 y.o.

  2. May 30, 2019 at 8:27 pm, Michael said:

    The glass is still half empty. The authors say ‘we caution that trends are likely affected by changing awareness, detection, and diagnostic practices.’ These factors could explain an artificial increase in the rate of self-reported disease prior to 2008. The following decline would then simply be a consequence of that. Self-reporting is far from knowing what’s happening to survey sample’s HbA1C. Time will tell.