Spotlight on diabetes prevalence and control

Diabetes became significantly more common from 1999 to 2018, but control of associated risk factors did not, especially in rural areas of the U.S., according to data from the National Health and Nutrition Examination Survey.

Three recent studies used the National Health and Nutrition Examination Survey (NHANES) to analyze diabetes prevalence and control.

One study, published by JAMA on June 25, found that among 28,143 survey participants, the estimated age-standardized prevalence of diabetes increased significantly from 9.8% (95% CI, 8.6% to 11.1%) in 1999-2000 to 14.3% (95% CI, 12.9% to 15.8%) in 2017-2018. In that time, the estimated age-standardized proportions of adults with diagnosed diabetes who achieved a blood pressure less than 130/80 mm Hg and a low-density lipoprotein cholesterol level less than 100 mg/dL increased significantly, but achievement of individualized HbA1c targets did not. In 2015-2018, only 21.2% of the patients made all three targets, and this was less common among those who were ages 18 to 44 years, non-Hispanic Black, or Mexican-American. “The improvement in risk factor control reported before 2010 did not continue despite extensive public health investments, as well as advances in therapeutic management of diabetes in the past 2 decades,” the study authors wrote. “Reasons abound for poor risk factor control, but challenges lie in designing effective tailored approaches for improving adherence to medications and healthy lifestyle behaviors, as well as providing necessary health care access and resources, education, and self-management support for improving adherence and maintaining achieved adherence.”

Similarly, a study published by the New England Journal of Medicine on June 10 found that between 2007-2010 and 2015-2018, the percentage of adult NHANES participants with diabetes with an HbA1c level less than 7% declined from 57.4% (95% CI, 52.9% to 61.8%) to 50.5% (95% CI, 45.8% to 55.3%). The same time period saw minimal improvement in the percentage of patients with non–high-density lipoprotein (HDL) cholesterol less than 130 mg/dL. Between 2011-2014 and 2015-2018, the percentage of participants with a blood pressure less than 140/90 mm Hg decreased. The percentages of patients with diabetes who used medications for hyperglycemia or hypertension did not rise from 2010 to 2018, and the percentage using statins plateaued after 2014. “Evolving evidence about the risks and benefits of intensive treatment may have contributed to worsening glycemic and blood-pressure control,” the study authors noted. “Although treatment intensification requires a careful consideration of the risk–benefit trade-off, our results suggest that a considerable percentage of patients with uncontrolled risk factors may benefit from more aggressive treatment.”

Finally, a study published by Diabetes Care on June 14 used data from 6,372 NHANES participants with diabetes to compare the odds of having poor ABCS (HbA1c level >9%, blood pressure ≥140/90 mm Hg, non-HDL cholesterol level ≥160 mg/dL [≥4.1 mmol/L], and current smoking) by where patients lived. From 1999 to 2006, there were no statistically significant differences in poor ABCS by residence in a rural area (census tract population <2,500) versus a more urban one. However, between 1999-2006 and 2013-2018, urban adults with diabetes had greater improvements in blood pressure and cholesterol levels than those in rural areas, even after adjustment for race/ethnicity, education, income, and clinical characteristics. Over the 1999-2018 time period, minority race/ethnicity, lower education attainment, poverty, and lack of health insurance coverage were more strongly associated with worse ABCS in urban residents than rural. The study authors concluded that rural areas have seen less improvement in control of some risk factors and that rural-urban differences in control exist across sociodemographic groups. “Clinical and public health professionals need to incorporate evidence-based approaches in addressing sociodemographic barriers to achieve better ABCS measures across the nation but especially in disproportionately affected groups living in urban and rural areas,” they said.