One of the most common co-morbidities in people with cystic fibrosis is cystic fibrosis-related diabetes (CFRD). CFRD is present in 20% adolescents with CF and almost 50% of adults.

Cystic fibrosis (CF) is an autosomal recessively inherited condition. It results in thick viscous secretions that cause respiratory disease, chronic pancreatitis and reduction of total pancreatic islet cell mass by at least 50% due to fibrosis. Most people with CFRD have some residual endogenous insulin production. The prevalence of associated insulin resistance is debated.

With the improvement of life expectancy for people with CF, the median now being 43 years, the prevalence of CFRD has increased more than three-fold. CFRD needs optimal control to not only minimize microvascular complications related to diabetes but to avoid deterioration of lung function and nutritional status, and also frequency and severity of chest infections. There is more rapid loss of lung function in people with CFRD than those with CF but normal or impaired glucose tolerance.

Guidelines for an Australian approach to CFRD management have recently been developed as part of the Australian CF Standards of Care. ADS was involved in the consultative process.

All people with CF should be screened annually by 75g GTT from age 10 years. Women planning pregnancy need testing for pre-gestational CFRD ideally before, or otherwise early in pregnancy. Those women without CFRD need screening for gestational diabetes at both 12-16 weeks and 24-28 weeks.

People with CFRD should be managed by a multidisciplinary team with expertise in both CF and diabetes management. The higher energy requirements, delayed gastric emptying, need for pancreatic enzyme supplements, exercise and physiotherapy routines, pulmonary exacerbations, transplantation, steroid treatment will impact on management. Insulin therapy improves nutritional and respiratory status, not just glycaemic control. Diabetes complication screening is needed from 5 years after CFRD diagnosis.