1. AIM 1. Characterization of glucose tolerance, nutritional and clinical status, socioeconomic status, family history of diabetes and genotype in Hispanic CF children compared to Caucasian CF children. Each child will undergo a two-hour oral glucose tolerance test and will be categorized by glucose tolerance according to standards set forth by the 1998 CF Consensus Conference on Diabetes. Nutritional status will be determined by three-day food journals and intake will be compared to energy needs measured by indirect calorimetry. Socio-economic status will be calculated from reported family income and medical insurance coverage. Genotyping will be done at the laboratory of Dr. Arthur Beaudet at Baylor College of Medicine. Clinical status will be measured using modified NIH scores. Family history for both type 1 and type 2 diabetes will be obtained in Spanish by Dr.Vanderwel. This specific aim tests the hypothesis that glucose intolerance /frank CF related diabetes occurs at a younger age in Hispanics than in Caucasians with CF, and is correlated to family history of diabetes and clinical status.