Study of Hepatic Glucose Production and De Novo Lipogenesis in Patients With Cystic Fibrosis

PROTOCOL ENTRY CRITERIA: --Disease Characteristics-- Diagnosis of cystic fibrosis OR Normal healthy volunteer; not an endurance-trained athlete No colonization with Burkholderia cepacia --Prior/Concurrent Therapy-- Endocrine therapy: At least 2 months since prior oral or IV corticosteroids; low-dose inhaled corticosteroids allowed Other: Short-acting insulin therapy allowed; at least 24 hours since prior long-acting insulin (i.e., neutral protamine Hagedorn, or ultalente); at least 4 weeks since prior oral or IV antibiotics; no hospital admissions within the past 6 weeks --Patient Characteristics-- Hepatic: No elevation of SGOT or SGPT within the past 3 months Other: Must be medically stable; diabetes mellitus allowed; weight stable within the past 3 months; not pregnant; no prisoners