Researchers call for improved diabetes screening for CF patients

CF Foundation recommends annual two-hour OGTT

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

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Rates of screening for diabetes among people with cystic fibrosis (CF) are not where they should be, a new study reports.

“Studies to improve our approach to [CF-related diabetes] screening are urgently needed,” the researchers wrote in “A provider survey of cystic fibrosis related diabetes screening and management practices at North American CF centers,” which was published in Frontiers in Endocrinology.

As many as half of people with CF will develop CF-related diabetes (CFRD). Since its onset is usually gradual and hard to notice, it’s recommended that regular screening be done to check for it so care can be initiated as soon as possible, if needed.

The CF Foundation (CFF) recommends that every year patients should have a two-hour oral glucose tolerance test (OGTT). In this procedure, a patient fasts overnight before having a blood sample drawn at the hospital. A second blood sample is taken two hours later after the patient drinks a sugary beverage. Comparing how blood sugar levels change helps clinicians identify signs of diabetes.

Yearly OGTT screening is recommended, but it might not actually be happening, which prompted researchers in the U.S. to survey 51 CF specialty centers and 25 endocrinologists (medical specialists in hormone-related conditions) to see if recommendations are being met and to identify strategies for improvement.

Just under half the centers reported an OGTT screen had been conducted for at least half their patients in the past year. Most pediatric centers (15 of 21) reported yearly diabetes screening for most of their patients, but this was rare for adult-only centers (4 of 19).

“It is unclear what is driving the higher OGTT completion rates in pediatric centers,” the researchers wrote. “It is possible that caregivers have a higher level of motivation to ensure their dependents with CF complete OGTT screening, although this was not specifically asked in our survey.”

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Improving diabetes screening for people with CF

Regardless of age served, the centers that reported sending regular reminders out to patients also generally reported better adherence to yearly screening. This might be a useful way to improve screening, the researchers said.

Among centers performing regular OGTT, there was some variability about how the test was administered. While many centers only performed blood draws twice, others included a third blood draw. Some centers and endocrinologists reported using other CFRD screening measures.

“Although OGTT is considered the gold standard screening method for CFRD, completion rates remain suboptimal, and many providers are utilizing alternate glycemia screening methods,” the researchers wrote.

The most common impediments to screening were facets of the OGTT itself that can be difficult for patients, such as its duration, the need to fast beforehand, and that the test must be scheduled in the morning.

“Although CF centers and endocrinologists had differences in reported barriers, both groups selected test duration as the most significant barrier to OGTT completion,” the researchers wrote.

In free-text part of the survey, some respondents said their centers have established protocols to help educate patients on the need for regular screenings and implement the screening. Responses often emphasized a need for flexibility and individualized solutions.

“Asking about individual patients’ barriers to OGTT screening may help with devising individualized solutions,” the researchers wrote, adding the survey’s findings suggest screening is often not being implemented according to CFF guidelines, underscoring the need for improvements. “Future studies are warranted to ascertain patient perceptions and barriers to diabetes screening and to determine what approaches align with management recommendations by experts but are also acceptable and feasible.”