CFRD (CF-related diabetes)

Question

When do we speak of CF-related diabetes? When should be started with insulin according to the guidelines? Can a tablet also reduce the glucose?

Answer

CF - related diabetes is a type of diabetes that can arise in the context of cystic fibrosis. When the pancreas fails to secrete enough insulin or the insulin secretion is delayed, this type of diabetes can develop.
Diabetes is diagnosed in a CF patient when the blood sugar levels exceed certain limits in a test called "oral glucose tolerance test “(sugar load test ). In this test, the patient must drink a standardized amount of sugar or glucose solution on an empty stomach. The blood sugar is measured just before and 2 hours after taking the sugar drink. If after 2 hours, the blood glucose level is higher or equal to 200 mg/dl, we can speak of CF related diabetes. If the value is less than 140 mg/dl, the test is considered as normal. Values between 140 and 200 mg/dl are considered as a disturbed glucose metabolism, a pre-stage of diabetes.
Most guidelines recommend insulin treatment in case the sugar load test is compatible with diabetes. The presence or absence of symptoms such as fatigue, poor weight evolution, general decline or increased respiratory complaints are not taken into account in the decision to start insuline treatment .
Besides this sugar load test we can also look at the evolution of the blood sugar values after standard meals. This is very important in order to decide on the dose and to set up the appropriate insulin scheme.
Clinical data suggest that also the pre-stage of diabetes is harmful to the health of CF patients. Whether this pre-stage also should be treated or not is still questioned and no consensus exists.
Besides a reduced and delayed insulin secretion, CF patients may develop decreased insulin sensitivity. The latter is most common in case of repeated severe infections, or when the patient is treated with steroids. Tablets for diabetes assess mainly the reduced the insulin sensitivity. However, because insulin deficiency is the main problem with CF related diabetes, a treatment with tablets only will not be sufficient for most patients with CF related diabetes.

22.10.2013