Analysis of Diabetes Trends Shows Decline in Rates of Glycemic Control for American Adults

The rate at which adults with diabetes are achieving glycemic control has shown a recent decline following more than a decade of progress seen between 1999 and 2010, as reported in the New England Journal of Medicine.

Researchers sampled data from the National Health and Nutrition Examination Survey (NHANES) to analyze trends in diabetes treatment and risk-factor control between 1999 and 2018. The sample included 6653 participants who were at least 20 years old, were not pregnant, and were diagnosed with diabetes by a doctor.

The data showed that although the percentage of NHANES participants who achieved glycemic control increased from 44% during 1999-2002 to 57.4% in 2007-2010, the percentage drastically declined to 50.5% in 2015-2018. Researchers considered a participant to have achieved glycemic control if they had maintained glycated hemoglobin (A1C) levels below 7%.

A decline in the percentage of participants who had achieved blood pressure control happened concurrently with the decline in glycemic control, as data showed that the proportion increased from 64% in 1999-2002 to 74.2% in 2011-2013, then declined to 70.4% in 2015-2018. Researchers considered a participant to have achieved blood pressure control if they had maintained systolic and diastolic blood pressures of less than 140/90 mm Hg.

Despite significant improvement in rates of lipid control in the early 2000s, control rates essentially leveled off in the 2010s. Little improvement was seen between 2007-2010 as the percentage of participants achieving lipid control rose from 52.3% to 55.3% and from 55.7% to 60.5% between 2015-2018. Researchers considered a participant to have achieved lipid control if they had maintained non–high-density lipoprotein cholesterol levels of less than 130 mg/dL.

The proportion of participants who maintained glycemic control, blood pressure control, and lipid control simultaneously was 24.9% during 2007-2010 but declined to 22.2% in 2015-2018. Adults with diabetes who fail to control each target are at higher risk for serious health complications and deaths.

These findings suggest a shift has occurred over the past decade that has interfered with diabetes control measures. The authors explain that a possible attribution for this shift could be 2 major trials published in 2008, whose results suggested that the extreme lowering of A1C levels could provide cardiovascular benefits to a diabetic patient.

Some patients who had their blood sugar lowered in accordance with the trials’ suggestion showed increased risks of low blood sugar, or hypoglycemia, which can have adverse effects on one’s health. As a result, diabetic treatment became more conservative in the period following the trials.

A third trial regarding blood pressure had similar results in the way it increased adverse cardiovascular health effects and led to less intensive treatment. Experts believe that the easing up of treatment after these trials may have been cause for the national decline in blood pressure control and glycemic control that led to diabetic health implications after 2010.

The use of glucose-lowering, blood pressure–lowering, and statin medication stalled after 2010 following large increases earlier in the decade. Similarly, the rate at which diabetic participants with uncontrolled blood pressure used combination therapy as a treatment method declined and then stalled after 2010 among participants with poor glycemic control.

Other elements that may have influenced the sphere of diabetic care and population-level risk-factor control include the growing availability of various drug classes and agents, increased use of combination therapy, and ever-changing clinical guidance.

“These trends are a wake-up call, since they mean that millions of Americans with diabetes are at higher risk for major complications” said Michael Fang, PhD, a postdoctoral fellow at the Johns Hopkins University Bloomberg School of Public Health and lead author of the study, in a statement. “Our study suggests that worsening control over diabetes may already be having a detrimental effect at the national level.”

Reference

Fang M, Wang D, Coresh J, Selvin E. Trends in diabetes treatment and control in US adults, 1999-2018. N Engl J Med. 2021;384(23):2219-2228. doi:10.1056/NEJMsa2032271