About 5 in 1,000 U.S. adults have type 1 diabetes, 4 in 1,000 kids
In addition to a U.S. study assessing rates of type 1 diabetes in different age groups, a Swedish study looked at differences by age in whether patients' relatives also had the disease, finding that it was likely more tied to genetics in childhood-onset cases.
Two recent studies looked at type 1 diabetes rates in adults and children.
The first study, published by JAMA on April 4, used the 2019 to 2022 cycles of the National Health Interview Survey to assess the prevalence of type 1 diabetes among 110,283 adults and 30,708 youths. The rate in adults was 5.3 per 1,000 (95% CI, 4.8 to 5.8 per 1,000), highest among those ages 45 to 64 years (6.1 per 1,000) and 65 years or older (5.3 per 1,000). The prevalence of type 1 diabetes in survey participants under age 18 years was 3.5 per 1,000 (95% CI, 2.8 to 4.4 per 1,000), with increased rates among those ages 10 to 17 years (5.0 per 1,000) and boys (4.0 per 1,000).
"These results are consistent with the CDC's estimates for 2021. This study adds to existing research by providing more precise up-to-date national estimates and by characterizing differences across subgroups," said the study authors. They called for more research on care for older patients with type 1 diabetes and on achieving health equity in diabetes care.
The other study, published by The Lancet Diabetes & Endocrinology on March 29, looked at more than 2.8 million Swedish people, identifying 3,240 cases of adult-onset type 1 diabetes (median onset age, 23.4 years) and 17,914 cases of childhood-onset type 1 diabetes (median onset age, 9.8 years). Having a first-degree relative with type 1 diabetes was significantly tied to development of diabetes at either point, but more strongly in childhood than adulthood (hazard ratios [HRs], 9.92 [95% CI, 9.38 to 10.50] and 7.21 [95% CI, 6.28 to 8.28], respectively). The risk of developing type 1 diabetes before the age 30 years was also smaller if a first-degree relative developed it during adulthood rather than childhood (HRs, 6.68 [95% CI, 6.04 to 7.39] and 10.54 [95% CI, 9.92 to 11.19], respectively).
In the studied population, adult-onset type 1 diabetes seems to have weaker familial aggregation and lower heritability than childhood-onset type 1 diabetes, the study authors concluded. They noted that the results were limited by inclusion of only Swedish patients (who have among the highest incidence of type 1 diabetes in the world) and only following patients up to age 30 years. Still, the findings "suggest that the influence of environmental factors is more prominent for adult-onset type 1 diabetes than childhood-onset type 1 diabetes, emphasising the potential for preventive interventions targeting these factors," the authors said.