BP

National diabetes screening recommendations based solely on a blood pressure cutoff miss more than half of patients who have undiagnosed diabetes, researchers found.

In an analysis of NHANES data, U.S. Preventive Services Task Force (USPSTF) criteria for diabetes screening based on a cut point of 135 mmHg/80 mmHg had a sensitivity of only 44.4% in detecting patients with undiagnosed disease, Judith Fradkin, MD, of the National Institute of Diabetes and Digestive and Kidney Diseases in Bethesda, Md., and colleagues reported online in the American Journal of Preventive Medicine.

"The Task Force diabetes screening criteria did not adequately distinguish people with and without undiagnosed diabetes and missed more than half of those who had undiagnosed diabetes," they wrote.

The single-criterion USPSTF screening recommendations are in contrast to screening based on a combination of several risk factors -- the approach supported by a host of other medical organizations. These risk factors include age, overweight, family history, hypertension, hyperlipidemia, and others.

To determine the effectiveness of the national screening criteria, Fradkin and colleagues looked at data on 7,189 adults in the 2003-2010 National Health and Nutrition Examination Survey (NHANES).

Among patients who hadn't received an official diagnosis of diabetes, 4% were found to have undiagnosed diabetes as determined by fasting plasma glucose or HbA1c criteria; this separated into 2.2% with undiagnosed diabetes who had a blood pressure reading below the cutoff and 1.8% with a reading above that threshold.

In terms of specificity, 74.8% of the patients were correctly determined to not have undiagnosed diabetes, which means that about a quarter (25.2%) of patients were needlessly referred for screening.

HbA1c levels among patients with undiagnosed diabetes were generally similar regardless of the blood pressure cutoff. About 10.6% of those with a blood pressure reading below the cutoff and 14.3% of those with a reading above it had an HbA1c between 7% and 7.9%, while 12.8% and 9.4%, respectively, had an HbA1c of 8% or higher.

The prevalence of multiple risk factors for cardiovascular disease was also similar regardless of blood pressure cutoff. Almost all patients had at least one heart disease risk factor, and about half had three or more, they reported.

Also, the prevalence of having a history of cardiovascular disease was similar regardless of the cutoff (13% and 17%), as was prevalence of stroke (3% and 4%).

Only prevalence of kidney disease was higher among those with blood pressure readings beyond 135/80 mm Hg (32.2% versus 22.9%).

"Other than for blood pressure itself, the cardiovascular disease risk factor profile for people with undiagnosed diabetes was similar regardless of the USPSTF blood pressure screening cutpoint," they wrote. "Further, a large proportion of people with undiagnosed diabetes, but with blood pressure below the screening cut-point, have levels of glycemia and lipid levels that may warrant treatment, or intensified treatment, to prevent the complications of diabetes by current [American Diabetes Association] treatment guidelines."

They concluded that risk-score calculators are more useful for identifying people who should be screened for diabetes, as screening based on blood pressure alone "results in poor identification of those with undiagnosed diabetes and increases the probability of morbidity in people who are left undiagnosed and thus untreated."

In an accompanying editorial, Vanita Aroda, MD, of Georgetown University, and Vivian Fonseca, MD, of Tulane University, wrote that there's an "overwhelming body of evidence of the benefits of early identification, prevention, and treatment of diabetes."

"It is clearly time to reevaluate the current USPSTF criteria for diabetes screening," they wrote, "in order to evaluate and make recommendations that can stem the tide of the diabetes epidemic and reduce the risk of complications in those diagnosed with the disease."

The study was supported by the NIDDK.

The researchers reported no conflicts of interest.

The editorialists reported relationships with Novo Nordisk, Sanofi, Eli Lilly, Abbott, Pamlab, and Reata Pharmaceuticals.

Title : BP
Published on : Friday, July 19, 2013
Category : Diabetes
Post URL : http://internal-med.blogspot.com/2013/07/bp.html