Pancreatic Insufficiency

Approximately 85–90 % of people with cystic fibrosis (CF) are exocrine pancreatic insufficient (PI). In CF associated with severe CFTR mutations, PI begins very early in life, usually within weeks of birth. Identification and management of PI is crucial to maintaining normal growth and weight in CF, and, thus, improving survival. In milder CF, PI may or may not develop with age. Approximately 30–40 % of individuals who are exocrine insufficient will develop CF-related diabetes. In this chapter we describe direct and indirect methods of assessment of exocrine PI, including cholecystokinin/secretin-stimulated pancreatic function testing, coefficient of fat absorption, and measurement of fecal elastase-1. The chapter also outlines the use of porcine-derived pancreatic enzyme replacement therapy (PERT). Management of PI in CF requires attention both to PERT and to non-PI complications of CF that may lead to malabsorption. Individuals with PS CF may be monitored yearly for possible development of PI.