The prevalence of youth-onset diabetes in the United States rose significantly from 2001 to 2017, with rates of type 2 diabetes climbing disproportionately among racial/ethnic minorities, according to investigators.
In individuals aged 19 years or younger, prevalence rates of type 1 and type 2 diabetes increased 45.1% and 95.3%, respectively, reported lead author Jean M. Lawrence, ScD, MPH, MSSA, program director of the division of diabetes, endocrinology, and metabolic diseases at the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Md., and colleagues.
“Elucidating differences in diabetes prevalence trends by diabetes type and demographic characteristics is essential to describe the burden of disease and to estimate current and future resource needs,” Dr. Lawrence and colleagues wrote in JAMA.
The retrospective analysis was a part of the ongoing SEARCH study, which includes data from individuals in six areas across the United States: Colorado, California, Ohio, South Carolina, Washington state, and Arizona/New Mexico (Indian Health Services). In the present report, three prevalence years were evaluated: 2001, 2009, and 2017. For each year, approximately 3.5 million youths were included. Findings were reported in terms of diabetes type, race/ethnicity, age at diagnosis, and sex.
Absolute prevalence of type 1 diabetes per 1,000 youths increased from 1.48 in 2001, to 1.93 in 2009, and finally 2.15 in 2017. Across the 16-year period, this represents an absolute increase of 0.67 (95% confidence interval, 0.64-0.70), and a relative increase of 45.1% (95% CI, 40.0%-50.4%). In absolute terms, prevalence increased most among non-Hispanic White (0.93 per 1,000) and non-Hispanic Black (0.89 per 1,000) youths.
While type 2 diabetes was comparatively less common than type 1 diabetes, absolute prevalence per 1,000 youths increased to a greater degree, rising from 0.34 in 2001 to 0.46 in 2009 and to 0.67 in 2017. This amounts to relative increase across the period of 95.3% (95% CI, 77.0%-115.4%). Absolute increases were disproportionate among racial/ethnic minorities, particularly Black and Hispanic youths, who had absolute increases per 1,000 youths of 0.85 (95% CI, 0.74-0.97) and 0.57 (95% CI, 0.51-0.64), respectively, compared with 0.05 (95% CI, 0.03-0.07) for White youths.
“Increases [among Black and Hispanic youths] were not linear,” the investigators noted. “Hispanic youths had a significantly greater increase in the first interval compared with the second interval, while Black youths had no significant increase in the first interval and a significant increase in the second interval.”
Dr. Lawrence and colleagues offered several possible factors driving these trends in type 2 diabetes.
“Changes in anthropometric risk factors appear to play a significant role,” they wrote, noting that “Black and Mexican American teenagers experienced the greatest increase in prevalence of obesity/severe obesity from 1999 to 2018, which may contribute to race and ethnicity differences. Other contributing factors may include increases in exposure to maternal obesity and diabetes (gestational and type 2 diabetes) and exposure to environmental chemicals.”
Dr. Megan Kelsey
According to Megan Kelsey, MD, associate professor of pediatric endocrinology, director of lifestyle medicine endocrinology, and medical director of the bariatric surgery center at Children’s Hospital Colorado, Aurora, the increased rates of type 2 diabetes reported by the study are alarming, yet they pale in comparison with what’s been happening since the pandemic began.
“Individual institutions have reported anywhere between a 50% – which is basically what we’re seeing at our hospital – to a 300% increase in new diagnoses [of type 2 diabetes] in a single-year time period,” Dr. Kelsey said in an interview. “So what is reported [in the present study] doesn’t even get at what’s been going on over the past year and a half.”
Dr. Kelsey offered some speculative drivers of this recent surge in cases, including stress, weight gain caused by sedentary behavior and more access to food, and the possibility that SARS-CoV-2 may infect pancreatic islet beta cells, thereby interfering with insulin production.
Type 2 diabetes is particularly concerning among young people, Dr. Kelsey noted, as it is more challenging to manage than adult-onset disease.
Young patients “also develop complications much sooner than you’d expect,” she added. “So we really need to understand why these rates are increasing, how we can identify kids at risk, and how we can better prevent it, so we aren’t stuck with a disease that’s really difficult to treat.”
To this end, the NIH recently opened applications for investigators to participate in a prospective longitudinal study of youth-onset type 2 diabetes. Young people at risk of diabetes will be followed through puberty, a period of increased risk, according to Dr. Kelsey.
“The goal will be to take kids who don’t yet have [type 2] diabetes, but are at risk, and try to better understand, as some of them progress to developing diabetes, what is going on,” Dr. Kelsey said. “What are other factors that we can use to better predict who’s going to develop diabetes? And can we use the information from this [upcoming] study to understand how to better prevent it? Because nothing that has been tried so far has worked.”
The study was supported by the Centers for Disease Control and Prevention, NIDDK, and others. The investigators and Dr. Kelsey reported no conflicts of interest.