KEYSTONE, COLO. — Treatment of cystic fibrosis-related diabetes is essentially insulin adjusted to a largely unrestricted diet, Dr. Robert H. Slover said at a conference on the management of diabetes in youth.
“Never calorie-restrict these patients. High energy intake is necessary for their survival,” he stressed. “These kids can eat 10,000 calories per day and still lose weight.”
The oral medications used to treat type 2 diabetes can't be used in cystic fibrosis-related diabetes (CFRD). They carry unacceptable risks of liver damage in this population. Plus, the sulfonylureas interfere with the chloride transporter, added Dr. Slover of the Barbara Davis Center for Childhood Diabetes at the University of Colorado, Denver.
Basal/bolus insulin regimens can be used, although some patients are able to maintain excellent glycemic control with mealtime injections only.
It's important to bear in mind, however, that glycosylated hemoglobin measurements may underestimate the degree of abnormal glucose metabolism in patients with CFRD. That's because they have increased red blood cell turnover, which dilutes the HbA1c, he explained at the conference sponsored by the university and the Children's Diabetes Foundation at Denver.
Intermittent insulin is used during episodes of infection or corticosteroid administration. Insulin infusion may be necessary when enteral feeding is used.
The dietary management principles operative in CFRD are markedly different than are those in type 1 diabetes. The recommended caloric energy intake in type 1 diabetes is 100% of the recommended daily allowance—and less if the patient is overweight. Patients with CFRD are encouraged to consume 120%–150% of the caloric RDA. They don't fuss over the glycemic index of foods, either.
Type 1 diabetic patients are encouraged to restrict intake of refined carbohydrates to less than 25 g/day while consuming a high-fiber, low-salt diet. In contrast, patients with CFRD are allowed to take in refined carbohydrates liberally throughout the day, although between-meal sugary drinks are discouraged. They are also advised to eat a high-salt diet and minimize intake of soluble and insoluble fiber because fiber promotes satiety, which has the unwanted effect of limiting energy intake.
The more than 22,000 Americans with CF receive much of their health care in the nation's 117 CF centers. Dr. Slover urged physicians with expertise in diabetes management to make themselves available at their nearby CF center. The centers traditionally have been staffed mainly by pulmonologists, who at times feel a bit overwhelmed the increase in the number of CFRD patients as a result of the marked life span gains in the CF population.
'Never calorie-restrict these patients. High energy intake is necessary fortheir survival.' DR. SLOVER