Diabetes and Insulin Treatment Adds to CF Burden and Ways Are Needed to Ease It, Study Says

Having to take insulin to treat cystic fibrosis-related diabetes (CFRD) adds to patient distress and sense of a poorer quality of life, a study says, alerting experts to a need to find approaches that might ease this burden.

The findings were described in the study “The impact of cystic fibrosis-related diabetes on health-related quality of life,” published in the Journal of Cystic Fibrosis.

Diabetes is a common complication of CF, affecting 40% to 50% of adult patients, and one impacting lung function, weight, and survival. CFRD is caused by the accumulation of sticky, thick mucus, which is characteristic of CF, scarring and injuring the pancreas — the organ where insulin, a hormone key to controlling blood sugar (glucose) levels, is produced.

As a result of pancreas damage, these patients cannot produce enough insulin, similar to those with type 1 diabetes.

Some may also develop partial insulin resistance, meaning their bodies stop responding to the hormone as they should, as is seen in type 2 diabetics.

Treating CFRD requires frequent under-the-skin insulin injections, repeated monitoring of blood sugar levels, and managing treatment-related low blood sugar, all of which amounts to an additional burden on patients.

Prior studies have examined the impact of CFRD on quality of life, but none have used recent CF-specific assessments or analyzed if perceived burden levels change with the degree of a patient’s glucose intolerance.

Recognizing this, a team of researchers surveyed 151 adults with CF being treated at the CF Clinic at St. Paul’s Hospital, in Canada, and compared health-related quality of life between those with CFRD and those with pre-diabetes, or impaired glucose tolerance (IGT).

Pre-diabetic people have blood glucose raised beyond normal levels, but not high enough to be considered diabetes. Those with IGT also face a much higher risk of becoming diabetic. 

Participants were asked to completed the CFQ-R 14+, a questionnaire designed to assess the health-related quality of life of adolescents and adults with CF ages 14 years and older.

Results were compared between those with CFRD on insulin, with CFRD but not on insulin, those with impaired glucose tolerance, and those with normal blood glucose tolerance.

Researchers saw that CFRD patients who had to take regular injections of insulin felt a significantly worse burden in what concerns treatment — treatment burden domain of CFQ-R 14+ of 44.4, compared to a median score of 66.7 in all the other three groups.

Similar results were obtained after adjusting the analysis for group differences in disease severity and the burden of other CF treatments.

No significant differences were reported for other quality of life domains — physical functioning, vitality, emotion, eating, health perceptions, social relations, body image, role functioning, weight, respiratory symptoms, digestion.

“In conclusion, the additional requirement for insulin significantly contributes to treatment burden in adults with CFRD, and therefore novel strategies to reduce treatment burden for this group are urgently needed” researchers wrote.

But, they added, “we had too few patients in the CFRD on insulin group to determine if a specific insulin regimen (e.g. pump vs. bolus vs. basal vs. bolus/basal) contributed most to the increased treatment burden.” Specific factors that diminish life quality in insulin-dependent CF patients — like the frequency of glucometer testing and type of insulin administration — need further study.