The Pediatric Endocrine Society has backed a position
statement from the American Diabetes Association and clinical practice
guidelines produced by the Cystic Fibrosis Foundation that tackle the problem
of cystic fibrosis-related diabetes.
The statement, which appeared in Diabetes
Care, represents the first time that experts from three major
organizations came together to create guidelines, according to Antoinette
Moran, MD, member of the Cystic Fibrosis-Related Diabetes Committee.
“There is still great heterogeneity in the United
States and around the world in how [cystic fibrosis-related diabetes] is
defined, diagnosed and managed,” Moran, also of the division of pediatric
endocrinology at the University of Minnesota in Minneapolis, told Endocrine
Today. “The endocrine community has been less familiar with the management
of these patients than the [cystic fibrosis] community. The goal of the
statement is to guide consistent and appropriate clinical practice based on the
most current knowledge.”
The statement is the third of its kind, Moran explained,
and was born from a desire to update previous recommendations.
“The last position statement was written about 10
years ago at a time when there were not much data available to guide
decisions,” she said. “New data over the last decade have resulted in
increased understanding of how best to diagnose and treat [cystic
fibrosis-related diabetes].”
Moran also noted that the guidelines will be reviewed
every 3 years and will undergo updates if a sufficient amount of new research
is available.
Special screening considerations
“In [cystic fibrosis], the nutritional and
pulmonary consequences of diabetes are of greater concern,” the guidelines
committee wrote. “[Cystic fibrosis-related diabetes] is associated with
weight loss, protein catabolism, lung function decline, and increased
mortality, and thus regular screening is warranted.”
Such screening should occur annually, with the initial
visit occurring at age 10 years. In this population, HbA1c is not an adequate
indicator of diabetes, according to the guidelines committee, and the oral
glucose tolerance test should be used instead.
Self-monitoring of blood glucose levels is insufficient
to diagnose cystic fibrosis-related diabetes. Nevertheless, it may be
beneficial for cystic fibrosis patients with acute pulmonary exacerbation and
during continuous drip enteral feedings, the committee wrote. In both
situations, however, hyperglycemia indicated by SMBG must be confirmed by
laboratory testing.
According to the committee, cystic fibrosis-related
diabetes can be diagnosed in patients with acute illness if FPG levels of at
least 126 mg/dL or 2-hour postprandial plasma glucose levels of at least 200
mg/dL persist for more than 48 hours. Similarly, mid- or postfeeding plasma
glucose levels exceeding 200 mg/dL on 2 separate days indicate a diagnosis of
cystic fibrosis-related diabetes in patients on enteral continuous drip
feedings.
Additionally, pregnant women should be screened before
and after delivery, and those undergoing transplantation should also be tested
before and after the procedure.
Management issues
Patients with the disease should receive insulin
therapy, but oral diabetes agents prove less effective for treatment, the
committee wrote. SMBG should be performed at least three times daily, and
patients should follow the ADA recommendations for glucose goals.
Likewise, guidelines for blood pressure measurement and
monitoring for microvascular complications should be in line with ADA
recommendations, according to the committee. Patients with hypertension or
microvascular complications, however, do not require sodium or protein
restrictions. Annual lipid profiles are also recommended for patients with
pancreatic exocrine sufficiency or with certain other risk factors, such as
obesity or family history of coronary artery disease.
Physicians should also consider the emotional toll that
the additional diagnosis places on patients with cystic fibrosis, and a
multidisciplinary team and ongoing diabetes education should be provided, the
committee wrote.
“[Cystic fibrosis-related diabetes] is very
different from either type 1 or type 2 diabetes and requires a unique approach
specifically tailored to this population,” Moran said. “In
particular, the association of insulin insufficiency and hyperglycemia with
early death from inflammatory pulmonary disease is a unique and significant
aspect of [cystic fibrosis-related diabetes].”
For more information:
Disclosure: Dr. Moran has no direct financial interest in any of the products
mentioned in this article nor is she a paid consultant for any companies
mentioned.
As improved care of pulmonary disease in cystic fibrosis has allowed
survival into and beyond middle age, endocrinologists are becoming aware that
cystic fibrosis-related diabetes is a common problem. The new clinical care
guidelines published in December 2010’s Diabetes Care
represent good practical support for clinicians, patients, and their families.
Most, but not all, of the recommendations reflect consensus opinion from an
expert panel, due to the paucity of clinical trials in cystic fibrosis-related
diabetes. Highlights from these guidelines that strike me as most important
include 1) recommendation to screen patients with cystic fibrosis annually
beginning at age 10, using standard 2-hour oral glucose tolerance testing as
the “gold standard” for diagnosis (and using existing cut-offs of 126
mg/dl fasting and > 200 mg/dl at the 2-hour time point), and 2) treating
patients with at least mealtime bolus insulin therapy, to promote adequate
nutrition and prevent excessive weight loss, and premature decline in pulmonary
function. Oral antihyperglycemic therapy for cystic fibrosis-related diabetes
is strongly discouraged in the guidelines. Using postprandial glycemic values
on the OGTT as the basis for diagnosis and treatment recognizes unique
pathophysiology of cystic fibrosis-related diabetes, in that insulin reserve,
while depleted and inadequate to normalize postprandial blood glucose, is often
adequate to prevent fasting hyperglycemia. The relevant caveat regarding
treatment is that patients with normal fasting glucose may not require basal
insulin therapy.
– Stephen A. Brietzke, MD
Endocrine
Today Editorial Board Member
Disclosure: Dr. Brietzke has no direct financial interest in any
products mentioned in this article nor is he a paid consultant for any
companies mentioned.