Maintenance of nutritional status in patients with cystic fibrosis: new and emerging therapies

Abstract

Poor clinical outcomes in cystic fibrosis are often associated with undernutrition. Normal growth and development should be achieved in cystic fibrosis, and nutritional counseling is paramount at all ages. Prevention and early detection of growth failure is the key to successful nutritional intervention. The advance in nutritional management is certainly one factor that has contributed to the improved survival in recent decades. This review outlines the major nutritional parameters in the management of the patient with cystic fibrosis, including recent advances in pancreatic enzyme replacement therapy and fat-soluble vitamin therapy. There are sections on complicated clinical situations which directly affect nutrition, for example, before and after lung transplantation, cystic fibrosis-related diabetes, and bone health.

Keywords: cystic fibrosis; fat-soluble vitamins; nutrition; pancreatic enzymes.

Figure 1

Improving bone health in cystic fibrosis. Notes: Patients that have had a previous fragility fracture, a documented significant reduction in BMD (defined as >3% in the lumbar spine or >5%–6% in the proximal femur), or awaiting solid organ transplantation in which a significant reduction in BMD has been documented, should undergo a treatment plan equivalent to a T/Z score less than or equal to −2.0. ^¶Use Z scores for children <18. T and Z scores are nearly equivalent over the ages 18–30. Use T scores for ages 30 and higher. Some experts and guidelines (WHO) would not initiate bisphosphonate treatment without additional risk factors until the T score is less than or equal to −2.5. ^‡IV bisphosphonates have been associated with severe bone pain and should be used with caution. Evidence grades: I: Evidence obtained from at least one properly randomized controlled trial. II-1: Evidence obtained from well-designed controlled trials without randomization. II-2: Evidence obtained from well-designed cohort or case-control analytic studies, preferably from more than one center or research group. III: Opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees. “T/Z” indicates the scan results. Abbreviations: ADEKS, vitamins A, D, E, and K; BMD, bone mineral density; DXA, dual energy X-ray absorptiometry; FEV₁, forced expiratory volume in 1 second.