About one in 20 adults ages 65 or older with prediabetes will progress to clinical diabetes within the following year, data from the showed.
Of more than 50,152 seniors in the study with a confirmed prediabetes diagnosis by HbA1c testing, 14.3% progressed to diabetes over a median follow-up period of 2.3 years, according to Alain K. Koyama, ScD, of the CDC in Atlanta, and colleagues.
This resulted in an estimated annual progression rate (APR) of 5.3% (95% CI 5.1-5.4), they wrote in a research letter.
Several clinical factors were predictive of which patients would progress from prediabetes (HbA1c within a range from 5.7% to 6.4%) to diabetes (HbA1c of 6.5% or higher), with the strongest predictors being body mass index (BMI) and initial HbA1c level.
Looking first at BMI, the rate of individuals that progressed to diabetes increased in conjunction with a higher BMI. The rate of incident diabetes was the highest for those with severe obesity (BMI of 40 or higher):
- BMI <18.5: 3.9% APR
- 18.5-24.9: 3.5%
- 25-29.9: 4.9%
- 30-34.9: 6.4%
- 35-39.9: 7.3%
- ≥40: 7.6%
As for HbA1c levels, there was a stark difference in the rate of people who progressed to diabetes if they were on the lower end of the "prediabetes" range versus the higher end. For example, patients with HbA1c levels of 5.7% to 5.9% had an APR of 2.8% (95% CI 2.7-2.9) versus 8.2% (95% CI 7.9-8.4) for those with HbA1c levels of 6.0% to 6.4%.
As expected, those with a family history of diabetes progressed at a higher rate from prediabetes to diabetes, as did those with a hypertension diagnosis versus normotensive individuals.
But there wasn't much difference between age groups when it came to diabetes progression, with similar rates seen among people in groups ages 65 to 69, 70 to 74, 75 to 79, and 80 or older. Likewise, there were generally similar APRs seen among the difference races and ethnicities, including for Black, Hispanic, Asian/Pacific Islander, and white patients.
"Our findings may provide important information to evaluate the cost-effectiveness of lifestyle interventions in older adults with prediabetes identified by HbA1c testing in clinical settings," Koyama's group wrote, although they cautioned that "their [electronic health records]-based sample was representative of patients comprising the health care organizations contributing data and may not be representative of the general U.S. population."
A 2021 study found that, in a community-based cohort of older adults, the prevalence of prediabetes was high, but that during the study period, regression to normoglycemia or death happened more often than progression to diabetes, so the "findings suggest that prediabetes may not be a robust diagnostic entity in older age," those authors stated.
Still, there is now a greater emphasis on diabetes prevention, especially in a prediabetes population. In a 2021 statement, the U.S Preventive Services Task Force gave screening for prediabetes and type 2 diabetes in adults (age 35-70) who have overweight or obesity a grade "B" recommendation. The Task Force advised healthcare providers to offer or refer patients with prediabetes to "effective preventive interventions."
Disclosures
The study was supported by the CDC/Westat.
Koyama disclosed no relationships with industry. A co-authors disclosed funding from Westat.
Primary Source
JAMA Network Open
Koyama AK, et al "Progression to diabetes among older adults with hemoglobin A1c–defined prediabetes in the US" JAMA Netw Open 2022; DOI: 10.1001/jamanetworkopen.2022.8158.